I am a member of the Stanford Blood and Marrow Transplantation (BMT) faculty, the Stanford Immunology Program and the Institute of Stem Cell Biology and Regenerative Medicine. I have attended on the BMT clinical service since 1997, and I oversee a research laboratory. My current clinical efforts and basic research focus on improving the safety and efficacy of hematopoietic cell transplantation (HCT) which is the most widely practiced and powerful form of cellular therapy. To achieve this goal we address two fundamental issues of HCT – the preparation of the recipient to accept a transplanted hematopoietic graft, and the impact of the graft cellular content on the success of the therapy. We have applied our expertise to develop novel ways to achieve engraftment of blood forming stem cells with the goal to replace chemotherapy and radiation. We have also developed the tools and methods that will allow us to transplant grafts of pure blood forming stem cells with the goal to eliminate potentially harmful passenger cells contained in a blood stem cell graft.
- Cancer > Blood and Marrow Transplant
- Blood and Marrow Transplantation
Member, Stanford Diabetes Research Center (2018 - Present)
Honors & Awards
Postdoctoral Fellowship, Juvenile Diabetes Foundation (1986-1988)
Postdoctoral Fellowship, Juvenile Diabetes Foundation (1989-1991)
Postdoctoral Fellowship, Juvenile Diabetes Foundation (1991-1993)
Excellence in Research in the Field of Hematopoiesis, Cheryl Whitlock Award (1996)
Career Award in the Biomedical Sciences, Burroughs Wellcome Fund (1996-2000)
Junior Faculty Scholars Award, Howard Hughes Medical Institute (1996-2000)
Scholar Award, Amy Strelzer Manasevit (2001)
Fellowship:Stanford University Medical Center (1997) CA
Residency:UCSF Medical Center (1994) CA
Internship:UCSF Medical Center (1993) CA
Medical Education:Stanford University School of Medicine (1992) CA
Current Research and Scholarly Interests
The research interests are to understand the cellular and molecular basis of resistance to engraftment of transplanted allogeneic bone marrow (BM) cells and to understand the way in which BM grafts modify immune responses. This research complements our interest in clinical BM transplantation and aspects of these studies are aimed at solving some of the major problems of BM transplantation which include graft-vs-host disease and BM engraftment failure. Conventional BM transplantation involves the transfer of heterogeneous populations of cells composed of rare hematopoietic stem cells (HSCs) and differentiated blood cell types. To study these issues our approach has been to transplant phenotypically purified cells under defined conditions. The specific projects in my laboratory include:
1) Identification of the cells and molecules responsible for resistance to engraftment of purified allogeneic HSCs. We and others have shown that cells with NK determinants constitute a significant barrier to allogeneic HSC engraftment, and that transplanted whole BM contains a population that facilitates engraftment. In these experiments our approach to identify the cell population(s) and mechanism by which HSC engraftment is resisted is to use recipient mice from strains that lack defined immune functions. We are studying the cells in BM and spleen that are bound and/or depleted by a-ASGMI, and in this way identify the candidate barrier populations.
2) Use of transplants of purified HSCs to induce tolerance to allo- and autoantigens, and study of the mechanisms by which such tolerance is induced. We continue to develop preclinical models for organ tolerance induction and treatment of autoimmune disease by using cell specific therapy. One goal is to decrease the morbidity of the recipient preparative regimen and to determine the lowest level of chimerism needed to induce immune tolerance. We propose to test donor/host strain combinations most relevant to human disease, including minor mismatched and haploidentical grafts.
3) Identification of the cells and molecules that confer graft vs leukemia/lymphoma (GVL) effects. We have developed a model of B cell lymphoma relapse after HSC transplant. To date our studies show that while purified allogeneic HSCs have no GVL activity, a population of BM cells that express CD3 and CD8 have significant GVL activity, and do not cause GVHD at the cell doses administered.
Independent Studies (11)
- Directed Reading in Immunology
IMMUNOL 299 (Aut, Win, Spr, Sum)
- Directed Reading in Medicine
MED 299 (Aut, Win, Spr, Sum)
- Early Clinical Experience in Immunology
IMMUNOL 280 (Aut, Win, Spr, Sum)
- Early Clinical Experience in Medicine
MED 280 (Aut, Win, Spr, Sum)
- Graduate Research
IMMUNOL 399 (Aut, Win, Spr, Sum)
- Graduate Research
MED 399 (Aut, Win, Spr, Sum)
- Graduate Research
STEMREM 399 (Aut, Win, Spr)
- Medical Scholars Research
MED 370 (Aut, Win, Spr, Sum)
- Teaching in Immunology
IMMUNOL 290 (Aut, Win, Spr, Sum)
- Undergraduate Research
IMMUNOL 199 (Aut, Win, Spr, Sum)
- Undergraduate Research
MED 199 (Aut, Win, Spr, Sum)
- Directed Reading in Immunology
Graduate and Fellowship Programs
Allogeneic hematopoietic cell transplantation after failed autologous transplant for lymphoma using TLI and anti-thymocyte globulin conditioning
BONE MARROW TRANSPLANTATION
2015; 50 (10): 1286-1292
We describe 47 patients with lymphoma and failed prior autologous hematopoietic cell transplantation (HCT) who received TLI-ATG (anti-thymocyte globulin) conditioning followed by allogeneic HCT. Thirty-two patients had non-Hodgkin lymphoma (NHL; diffuse large B-cell lymphoma (n=19), T-cell NHL (n=6), mantle cell lymphoma (n=4) or other B-cell subtypes (n=3)), and 15 had Hodgkin lymphoma. The median follow-up was 4.9 (range, 2.1-11.9) years. The cumulative incidence of grade II-IV acute GvHD at day +100 was 12%, and the cumulative incidence of extensive chronic GvHD at 1 year was 36%. The 3-year cumulative incidences of overall survival (OS), PFS and non-relapse mortality (NRM) were 81%, 44% and 7%, respectively. Fifteen patients died (relapse, n=10; NRM, n=5). Among the 25 patients with relapse after allogeneic HCT, 11 (44%) achieved durable (>1 year) CRs following donor lymphocyte infusion or chemoradiotherapy. The majority of surviving patients (75%; n=24) were able to discontinue all immunosuppression. For patients with relapsed lymphoma after autologous HCT, allogeneic HCT using TLI-ATG conditioning is a well-tolerated, predominantly outpatient therapy with low NRM (7% at 3 years), a low incidence of GvHD, durable disease control and excellent OS (81% at 3 years).
View details for DOI 10.1038/bmt.2015.149
View details for PubMedID 26146806
Ablative Tumor Radiation Can Change the Tumor Immune Cell Microenvironment to Induce Durable Complete Remissions.
Clinical cancer research
2015; 21 (16): 3727-3739
The goals of the study were to elucidate the immune mechanisms that contribute to desirable complete remissions of murine colon tumors treated with single radiation dose of 30 Gy. This dose is at the upper end of the ablative range used clinically to treat advanced or metastatic colorectal, liver, and non-small cell lung tumors.Changes in the tumor immune microenvironment of single tumor nodules exposed to radiation were studied using 21-day (>1 cm in diameter) CT26 and MC38 colon tumors. These are well-characterized weakly immunogenic tumors.We found that the high-dose radiation transformed the immunosuppressive tumor microenvironment resulting in an intense CD8(+) T-cell tumor infiltrate, and a loss of myeloid-derived suppressor cells (MDSC). The change was dependent on antigen cross-presenting CD8(+) dendritic cells, secretion of IFNγ, and CD4(+)T cells expressing CD40L. Antitumor CD8(+) T cells entered tumors shortly after radiotherapy, reversed MDSC infiltration, and mediated durable remissions in an IFNγ-dependent manner. Interestingly, extended fractionated radiation regimen did not result in robust CD8(+) T-cell infiltration.For immunologically sensitive tumors, these results indicate that remissions induced by a short course of high-dose radiotherapy depend on the development of antitumor immunity that is reflected by the nature and kinetics of changes induced in the tumor cell microenvironment. These results suggest that systematic examination of the tumor immune microenvironment may help in optimizing the radiation regimen used to treat tumors by adding a robust immune response. Clin Cancer Res; 21(16); 3727-39. ©2015 AACR.
View details for DOI 10.1158/1078-0432.CCR-14-2824
View details for PubMedID 25869387
Chimerism, Graft Survival, and Withdrawal of Immunosuppressive Drugs in HLA Matched and Mismatched Patients After Living Donor Kidney and Hematopoietic Cell Transplantation.
American journal of transplantation
2015; 15 (3): 695-704
Thirty-eight HLA matched and mismatched patients given combined living donor kidney and enriched CD34(+) hematopoietic cell transplants were enrolled in tolerance protocols using posttransplant conditioning with total lymphoid irradiation and anti-thymocyte globulin. Persistent chimerism for at least 6 months was associated with successful complete withdrawal of immunosuppressive drugs in 16 of 22 matched patients without rejection episodes or kidney disease recurrence with up to 5 years follow up thereafter. One patient is in the midst of withdrawal and five are on maintenance drugs. Persistent mixed chimerism was achieved in some haplotype matched patients for at least 12 months by increasing the dose of T cells and CD34(+) cells infused as compared to matched recipients in a dose escalation study. Success of drug withdrawal in chimeric mismatched patients remains to be determined. None of the 38 patients had kidney graft loss or graft versus host disease with up to 14 years of observation. In conclusion, complete immunosuppressive drug withdrawal could be achieved thus far with the tolerance induction regimen in HLA matched patients with uniform long-term graft survival in all patients.
View details for DOI 10.1111/ajt.13091
View details for PubMedID 25693475
A trial of plerixafor adjunctive therapy in allogeneic hematopoietic cell transplantation with minimal conditioning for severe combined immunodeficiency
2014; 18 (6): 602-608
For infants with SCID, the ideal conditioning regimen before allogeneic HCT would omit cytotoxic chemotherapy to minimize short- and long-term complications. We performed a prospective pilot trial with G-CSF plus plerixafor given to the host to mobilize HSC from their niches. We enrolled six patients who received CD34-selected haploidentical cells and one who received T-replete matched unrelated BM. All patients receiving G-CSF and plerixafor had generally poor CD34(+) cell and Lin(-) CD34(+) CD38(-) CD90(+) CD45RA(-) HSC mobilization, and developed donor T cells, but no donor myeloid or B-cell engraftment. Although well tolerated, G-CSF plus plerixafor alone failed to overcome physical barriers to donor engraftment.
View details for DOI 10.1111/petr.12309
View details for Web of Science ID 000340530800017
View details for PubMedCentralID PMC5413354
Treatment of 4T1 Metastatic Breast Cancer with Combined Hypofractionated Irradiation and Autologous T-Cell Infusion.
2014; 182 (2): 163-169
The goal of this study was to determine whether a combination of local tumor irradiation and autologous T-cell transplantation can effectively treat metastatic 4T1 breast cancer in mice. BALB/c mice were injected subcutaneously with luciferase-labeled 4T1 breast tumor cells and allowed to grow for 21 days, at which time metastases appeared in the lungs. Primary tumors were treated at that time with 3 daily fractions of 20 Gy of radiation each. Although this approach could eradicate primary tumors, tumors in the lungs grew progressively. We attempted to improve efficacy of the radiation by adding autologous T-cell infusions. Accordingly, T cells were purified from the spleens of tumor-bearing mice after completion of irradiation and cryopreserved. Cyclophosphamide was administered thereafter to induce lymphodepletion, followed by T-cell infusion. Although the addition of cyclophosphamide to irradiation did not improve survival or reduce tumor progression, the combination of radiation, cyclophosphamide and autologous T-cell infusion induced durable remissions and markedly improved survival. We conclude that the combination of radiation and autologous T-cell infusion is an effective treatment for metastatic 4T1 breast cancer.
View details for DOI 10.1667/RR13471.1
View details for PubMedID 24992165
Total lymphoid irradiation-antithymocyte globulin conditioning and allogeneic transplantation for patients with myelodysplastic syndromes and myeloproliferative neoplasms.
Biology of blood and marrow transplantation
2014; 20 (6): 837-843
Allogeneic hematopoietic cell transplantation (allo HCT) is the only curative therapy for the myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN), but treatment toxicity has been a barrier to its more widespread use. The nonmyeloablative regimen of total lymphoid irradiation (TLI) and antithymocyte globulin (ATG) permits the establishment of donor hematopoiesis necessary for the graft-versus-malignancy effect and is protective against acute graft-versus-host disease (aGVHD), but it has minimal direct cytotoxicity against myeloid diseases. We explored the use of TLI-ATG conditioning to treat 61 patients with allo HCT for MDS (n = 32), therapy-related myeloid neoplasms (n = 15), MPN (n = 9), and chronic myelomonocytic leukemia (n = 5). The median age of all patients was 63 years (range, 50 to 73). The cumulative incidence of aGVHD grades II to IV was 14% (95% confidence interval [CI], 4% to 23%) and for grades III to IV, 4% (95% CI, 0 to 9%), and it did not differ between patients who received allografts from related or unrelated donors. The cumulative incidence of nonrelapse mortality (NRM) at 100 days, 12 months, and 36 months was 0%, 7%, and 11%. Overall survival and progression-free survival were 41% (95% CI, 29% to 53%) and 35% (95% CI, 23% to 48%), respectively. The safety and tolerability of TLI-ATG, as exemplified by its low NRM, provides a foundation for further risk-adapted or prophylactic interventions to prevent disease progression.
View details for DOI 10.1016/j.bbmt.2014.02.023
View details for PubMedID 24607552
Donor hematopoiesis in mice following total lymphoid irradiation requires host T-regulatory cells for durable engraftment.
2014; 123 (18): 2882-2892
Total lymphoid irradiation (TLI) with antithymocyte globulin (ATG) is a unique regimen that prepares recipients for allogeneic hematopoietic cell transplantation by targeting lymph nodes, while sparing large areas of the bone marrow. TLI is reported to increase the frequency of CD4(+)CD25(+)FoxP3(+) T-regulatory cells (Treg) relative to conventional T cells. In this study, barriers to hematopoietic stem cell (HSC) engraftment following this nonmyeloablative conditioning were evaluated. TLI/ATG resulted in profound lymphoablation but endogenous host HSC remained. Initial donor HSC engraftment occurred only in radiation exposed marrow sites, but gradually distributed to bone marrow outside the radiation field. Sustained donor engraftment required host lymphoid cells insofar as lymphocyte deficient Rag2γc(-/-) recipients had unstable engraftment compared with wild-type. TLI/ATG treated wild-type recipients had increased proportions of Treg that were associated with increased HSC frequency and proliferation. In contrast, Rag2γc(-/-) recipients who lacked Treg did not. Adoptive transfer of Treg into Rag2γc(-/-) recipients resulted in increased cell cycling of endogenous HSC. Thus, we hypothesize that Treg influence donor engraftment post-TLI/ATG by increasing HSC cell cycling, thereby promoting the exit of host HSC from the marrow niche. Our study highlights the unique dynamics of donor hematopoiesis following TLI/ATG, and the effect of Treg on HSC activity.
View details for DOI 10.1182/blood-2013-10-530212
View details for PubMedID 24591203
- European LeukemiaNet classification intermediate risk-1 cohort is associated with poor outcomes in adults with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplantation BLOOD CANCER JOURNAL 2014; 4
B6.g7 mice reconstituted with BDC2·5 non-obese diabetic (BDC2·5NOD) stem cells do not develop autoimmune diabetes.
Clinical and experimental immunology
2013; 174 (1): 27-37
In BDC2.5NOD mice, a spontaneous model of Type 1 diabetes, CD4(+) T cells express a transgene-encoded T-cell receptor (TCR) with reactivity against a pancreatic antigen, chromogranin. This leads to massive infiltration and destruction of the pancreatic islets and subsequent diabetes. When we reconstituted lethally irradiated, lymphocyte-deficient B6.g7 (I-A(g7+) ) Rag(-/-) mice with BDC2.5NOD (ckit(+) Lin(-) Sca-1(hi) ) hematopoietic stem and progenitor cells (HSPC), the recipients exhibited hyperglycemia and succumbed to diabetes. Surprisingly, lymphocyte-sufficient B6.g7 mice reconstituted with BDC2.5NOD HSPCs were protected from diabetes. In this study, we investigated the factors responsible for attenuation of diabetes in the B6.g7 recipients. Analysis of chimerism in the B6.g7 recipients showed that, although B cells and myeloid cells were 98% donor-derived, the CD4(+) T cell compartment contained ∼50% host-derived cells. These host-derived CD4(+) T cells were enriched for conventional Tregs (CD25(+) Foxp3(+) ) and also for host-derived CD25(-) Foxp3(-) CD4(+) T cells that express markers of suppressive function, CD73, FR4 and CD39. Though negative selection did not eliminate donor-derived CD4(+) T cells in the B6.g7 recipients, these cells were functionally suppressed. Thus, host-derived CD4(+) T cells that emerge in mice following myeloablation exhibit a regulatory phenoytpe and likely attenuate autoimmune diabetes. These cells may provide new therapeutic strategies to suppress autoimmunity.
View details for DOI 10.1111/cei.12163
View details for PubMedID 23795893
Fine mapping of the Bmgr5 quantitative trait locus for allogeneic bone marrow engraftment in mice
2013; 65 (8): 585-596
To identify novel mechanisms regulating allogeneic hematopoietic cell engraftment, we used forward genetics and previously described identification, in mice, of a bone marrow (BM) engraftment quantitative trait locus (QTL), termed Bmgr5. This QTL confers dominant and large allele effects for engraftment susceptibility. It was localized to chromosome 16 by quantitative genetic techniques in a segregating backcross bred from susceptible BALB.K and resistant B10.BR mice. We now report verification of the Bmgr5 QTL using reciprocal chromosome 16 consomic strains. The BM engraftment phenotype in these consomic mice shows that Bmgr5 susceptibility alleles are not only sufficient but also indispensable for conferring permissiveness for allogeneic BM engraftment. Using panels of congenic mice, we resolved the Bmgr5 QTL into two separate subloci, termed Bmgr5a (Chr16:14.6-15.8 Mb) and Bmgr5b (Chr16:15.8-17.6 Mb), each conferring permissiveness for the engraftment phenotype and both fine mapped to an interval amenable to positional cloning. Candidate Bmgr5 genes were then prioritized using whole exome DNA sequencing and microarray gene expression data. Further studies are warranted to elucidate the genetic interaction between the Bmgr5a and Bmgr5b QTL and identify causative genes and underlying gene variants. This may lead to new approaches for overcoming the problem of graft rejection in clinical hematopoietic cell transplantation.
View details for DOI 10.1007/s00251-013-0709-6
View details for Web of Science ID 000321779300003
View details for PubMedID 23666360
Pathways analysis of differential gene expression induced by engrafting doses of total body irradiation for allogeneic bone marrow transplantation in mice
2013; 65 (8): 597-607
A major challenge in allogeneic bone marrow (BM) transplantation is overcoming engraftment resistance to avoid the clinical problem of graft rejection. Identifying gene pathways that regulate BM engraftment may reveal molecular targets for overcoming engraftment barriers. Previously, we developed a mouse model of BM transplantation that utilizes recipient conditioning with non-myeloablative total body irradiation (TBI). We defined TBI doses that lead to graft rejection, that conversely are permissive for engraftment, and mouse strain variation with regards to the permissive TBI dose. We now report gene expression analysis, using Agilent Mouse 8x60K microarrays, in spleens of mice conditioned with varied TBI doses for correlation to the expected engraftment phenotype. The spleens of mice given engrafting doses of TBI, compared with non-engrafting TBI doses, demonstrated substantially broader gene expression changes, significant at the multiple testing-corrected P <0.05 level and with fold change ≥2. Functional analysis revealed significant enrichment for a down-regulated canonical pathway involving B-cell development. Genes enriched in this pathway suggest that suppressing donor antigen processing and presentation may be pivotal effects conferred by TBI to enable engraftment. Regardless of TBI dose and recipient mouse strain, pervasive genomic changes related to inflammation was observed and reflected by significant enrichment for canonical pathways and association with upstream regulators. These gene expression changes suggest that macrophage and complement pathways may be targeted to overcome engraftment barriers. These exploratory results highlight gene pathways that may be important in mediating BM engraftment resistance.
View details for DOI 10.1007/s00251-013-0710-0
View details for Web of Science ID 000321779300004
View details for PubMedID 23703256
Host-derived CD4+T cells attenuate stem cellmediated transfer of autoimmune arthritis in lethally irradiated C57BL/6.g7 mice
ARTHRITIS AND RHEUMATISM
2013; 65 (3): 681-692
In the K/BxN mouse model of inflammatory arthritis, T cells carrying a transgenic T cell receptor initiate disease by helping B cells to produce arthritogenic anti-glucose-6-phosphate isomerase (anti-GPI) autoantibodies. We found that lethally- irradiated lymphocyte-deficient C57BL/6 (B6).g7 (I-A(g7) +) recombinase-activating gene-deficient (Rag(-/-)) mice reconstituted with K/BxN hematopoietic stem and progenitor cells exhibit arthritis by week 4. In contrast, healthy B6.g7 recipients of K/BxN hematopoietic stem and progenitor cells show only mild arthritis, with limited extent and duration. The objective of this study was to investigate the factors responsible for the attenuation of arthritis in B6.g7 recipients.Antibody responses were measured by enzyme-linked immunosorbent assay. Fluorescence-activated cell sorting analyses were performed for testing chimerism, expression of markers of activation and suppression, tetramer binding, and intracellular cytokines in CD4+ T cells. Suppressive activity of CD4+ T cells was studied by adoptive transfer.Titers of anti-GPI antibodies in reconstituted B6.g7 mice were ∼60-fold lower than in reconstituted B6.g7 Rag(-/-) mice. Examination of chimerism in the reconstituted B6.g7 mice showed that B cells and myeloid cells in these mice were donor derived, but CD4+ T cells were primarily host derived and enriched for cells expressing the conventional regulatory markers CD25 and FoxP3. Notably, CD4+CD25-FoxP3- T cells expressed markers of suppressive function (CD73 and folate receptor 4), and delayed disease after adoptive transfer. Activation of donor-derived CD4+ T cells was reduced, and thymic deletion of these cells appeared increased.Despite myeloablation, host CD4+ T cells having a regulatory phenotype emerge in these mice and attenuate autoimmunity.
View details for DOI 10.1002/art.37800
View details for Web of Science ID 000315452400017
View details for PubMedID 23233229
The road to purified hematopoietic stem cell transplants is paved with antibodies.
Current opinion in immunology
2012; 24 (5): 640-648
Hematopoietic progenitor cell replacement therapy remains a surprisingly unrefined process. In general, unmanipulated bone marrow or mobilized peripheral blood (MPB) grafts which carry potentially harmful passenger cells are administered after treating recipients with high-dose chemotherapy and/or radiotherapy to eradicate malignant disease, eliminate immunologic barriers to allogeneic cell engraftment, and to 'make space' for rare donor stem cells within the stem cell niche. The sequalae of such treatments are substantial, including direct organ toxicity and nonspecific inflammation that contribute to the development of graft-versus-host disease (GVHD) and poor immune reconstitution. Passenger tumor cells that contaminate autologous hematopoietic grafts may contribute to relapse post-transplant. Use of antibodies to rid grafts of unwanted cell populations, and to eliminate or minimize the need for nonspecifically cytotoxic therapies used to condition transplant recipients, will dramatically improve the safety profile of allogeneic and gene-modified autologous hematopoietic stem cell therapies.
View details for DOI 10.1016/j.coi.2012.08.002
View details for PubMedID 22939368
Prophylactic rituximab after allogeneic transplantation decreases B-cell alloimmunity with low chronic GVHD incidence
2012; 119 (25): 6145-6154
B cells are involved in the pathogenesis of chronic GVHD (cGVHD). We hypothesized that prophylactic anti-B-cell therapy delivered 2 months after transplantation would decrease allogeneic donor B-cell immunity and possibly the incidence of cGVHD. Therefore, in the present study, patients with high-risk chronic lymphocytic leukemia (n = 22) and mantle-cell lymphoma (n = 13) received a total lymphoid irradiation of 80 cGy for 10 days and antithymocyte globulin 1.5 mg/kg/d for 5 days. Rituximab (375 mg/m(2)) was infused weekly on days 56, 63, 70, and 77 after transplantation. The incidence of acute GVHD was 6%. The cumulative incidence of cGVHD was 20%. Nonrelapse mortality was 3%. Rituximab treatment after allogeneic transplantation significantly reduced B-cell allogeneic immunity, with complete prevention of alloreactive H-Y Ab development in male patients with female donors (P = .01). Overall survival and freedom from progression at 4 years for chronic lymphocytic leukemia patients were 73% and 47%, respectively; for mantle-cell lymphoma patients, they were 69% and 53%, respectively.
View details for DOI 10.1182/blood-2011-12-395970
View details for PubMedID 22563089
Tolerance and Withdrawal of Immunosuppressive Drugs in Patients Given Kidney and Hematopoietic Cell Transplants
AMERICAN JOURNAL OF TRANSPLANTATION
2012; 12 (5): 1133-1145
Sixteen patients conditioned with total lymphoid irradiation (TLI) and antithymocyte globulin (ATG) were given kidney transplants and an injection of CD34+ hematopoietic progenitor cells and T cells from HLA-matched donors in a tolerance induction protocol. Blood cell monitoring included changes in chimerism, balance of T-cell subsets and responses to donor alloantigens. Fifteen patients developed multilineage chimerism without graft-versus-host disease (GVHD), and eight with chimerism for at least 6 months were withdrawn from antirejection medications for 1-3 years (mean, 28 months) without subsequent rejection episodes. Four chimeric patients have just completed or are in the midst of drug withdrawal, and four patients were not withdrawn due to return of underlying disease or rejection episodes. Blood cells from all patients showed early high ratios of CD4+CD25+ regulatory T cells and NKT cells versus conventional naive CD4+ T cells, and those off drugs showed specific unresponsiveness to donor alloantigens. In conclusion, TLI and ATG promoted the development of persistent chimerism and tolerance in a cohort of patients given kidney transplants and hematopoietic donor cell infusions. All 16 patients had excellent graft function at the last observation point with or without maintenance drugs.
View details for DOI 10.1111/j.1600-6143.2012.03992.x
View details for Web of Science ID 000303235100012
View details for PubMedID 22405058
View details for PubMedCentralID PMC3338901
Co-transplantation of pure blood stem cells with antigen-specific but not bulk T cells augments functional immunity
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2012; 109 (15): 5820-5825
Impaired immunity is a fundamental obstacle to successful allogeneic hematopoietic cell transplantation. Mature graft T cells are thought to provide protection from infections early after transplantation, but can cause life-threatening graft-vs.-host disease. Human CMV is a major pathogen after transplantation. We studied reactivity against the mouse homologue, murine CMV (MCMV), in lethally irradiated mice given allogeneic purified hematopoietic stem cells (HSCs) or HSCs supplemented with T cells or T-cell subsets. Unexpectedly, recipients of purified HSCs mounted superior antiviral responses compared with recipients of HSC plus unselected bulk T cells. Furthermore, supplementation of purified HSC grafts with CD8(+) memory or MCMV-specific T cells resulted in enhanced antiviral reactivity. Posttransplantation lymphopenia promoted massive expansion of MCMV-specific T cells when no competing donor T cells were present. In recipients of pure HSCs, naive and memory T cells and innate lymphoid cell populations developed. In contrast, the lymphoid pool in recipients of bulk T cells was dominated by effector memory cells. These studies show that pure HSC transplantations allow superior protective immunity against a viral pathogen compared with unselected mature T cells. This reductionist transplant model reveals the impact of graft composition on regeneration of host, newly generated, and mature transferred T cells, and underscores the deleterious effects of bulk donor T cells. Our findings lead us to conclude that grafts composed of purified HSCs provide an optimal platform for in vivo expansion of selected antigen-specific cells while allowing the reconstitution of a naive T-cell pool.
View details for DOI 10.1073/pnas.1120237109
View details for PubMedID 22440752
Sirolimus and mycophenolate mofetil as GVHD prophylaxis in myeloablative, matched-related donor hematopoietic cell transplantation
BONE MARROW TRANSPLANTATION
2012; 47 (4): 581-588
We investigated sirolimus and mycophenolate mofetil (MMF) as GVHD prophylaxis in patients with advanced hematological malignancies receiving myeloablative hematopoietic cell transplantation (HCT) from HLA-identical sibling donors. On the basis of pre-study stopping rules, the trial was closed to accrual after enrollment of 11 adult patients. In all, 7 of the 11 patients received BU-containing preparative regimens. Sirolimus was discontinued in three patients because of the toxicity-related events of severe sinusoidal obstructive syndrome, portal vein thrombosis, altered mental status and in one patient because of the risk of poor wound healing. In all, 6 of the 11 patients developed grade II-IV acute GVHD (AGVHD) a median of 15.5 days post HCT. Two of three patients with grade IV AGVHD had sirolimus discontinued by 9 days post HCT. All patients responded to AGVHD therapy without GVHD-related deaths. There were two non-relapse- and two relapse-related deaths. At a median follow-up of 38 months (2-47 months), 7 of 11 patients were alive without disease. MMF and sirolimus GVHD prophylaxis did not reduce the risk of AGVHD, however, there were no GVHD-related deaths. The severe toxicities in the patients receiving the BU-containing preparative regimens limited the continued use of sirolimus and MMF for the prevention of AGVHD.
View details for DOI 10.1038/bmt.2011.104
View details for Web of Science ID 000302576700018
View details for PubMedID 21552302
View details for PubMedCentralID PMC3163055
Tandem chemo-mobilization followed by high-dose melphalan and carmustine with single autologous hematopoietic cell transplantation for multiple myeloma
BONE MARROW TRANSPLANTATION
2012; 47 (4): 516-521
Single autologous hematopoietic cell transplant (AHCT) with high-dose melphalan prolongs survival in patients with multiple myeloma but is not curative. We conducted a study of intensive single AHCT using tandem chemo-mobilization with CY and etoposide followed by high-dose conditioning with melphalan 200 mg/m(2) plus carmustine 15 mg/kg. One hundred and eighteen patients in first consolidation (CON1) and 58 patients in relapse (REL) were transplanted using this intensified approach. Disease response improved from 32% very good PR (VGPR)+CR pre-mobilization to 76% VGPR+CR post transplant in CON1. With a median follow-up of 4.7 years, the median EFS was 2.8 years, and the median OS was 5.1 years in CON1. OS from time of transplant was significantly shorter for REL (3.4 years) compared with CON1 (5.1 years; P=0.02). However, OS from time of diagnosis was similar in REL (6.1 years) and CON1 (6.0 years; P=0.80). The 100-day non-relapse mortality in the CON1 and REL groups was 0% and 7%, respectively. In summary, intensified single AHCT with tandem chemo-mobilization and augmented high-dose therapy is feasible in multiple myeloma and leads to high-quality response rates.
View details for DOI 10.1038/bmt.2011.106
View details for PubMedID 21602899
Long-Term Outcome of Patients with Metastatic Breast Cancer Treated with High-Dose Chemotherapy and Transplantation of Purified Autologous Hematopoietic Stem Cells
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2012; 18 (1): 125-133
Metastatic breast cancer remains a major treatment challenge. The use of high-dose chemotherapy (HDCT) with rescue by autologous mobilized peripheral blood (MPB) is controversial, in part because of contamination of MPB by circulating tumor cells. CD34(+)Thy-1(+) selected hematopoietic stem cells (HSC) represent a graft source with a greater than 250,000-fold reduction in cancer cells. Here, we present the long-term outcome of a pilot study to determine feasibility and engraftment using HDCT and purified HSC in patients with metastatic breast cancer. Twenty-two patients who had been treated with standard chemotherapy were enrolled into a phase I/II trial between December 1996 and February 1998, and underwent HDCT followed by rescue with CD34(+)Thy-1(+) HSC isolated from autologous MPB. More than 12 years after the end of the study, 23% (5 of 22) of HSC recipients are alive, and 18% (4 of 22) are free of recurrence with normal hematopoietic function. Median progression-free survival (PFS) was 16 months, and median overall survival (OS) was 60 months. Retrospective comparison with 74 patients transplanted between February 1995 and June 1999 with the identical HDCT regimen but rescue with unmanipulated MPB indicated that 9% of patients are alive, and 7% are without disease. Median PFS was 10 months, and median OS was 28 months. In conclusion, cancer-depleted HSC following HDCT resulted in better than expected 12- to 14-year PFS and OS in a cohort of metastatic breast cancer patients. These data prompt us to look once again at purified HSC transplantation in a protocol powered to test for efficacy in advanced-stage breast cancer patients.
View details for DOI 10.1016/j.bbmt.2011.07.009
View details for PubMedID 21767515
Adoptive Immunotherapy with Cytokine-Induced Killer Cells for Patients with Relapsed Hematologic Malignancies after Allogeneic Hematopoietic Cell Transplantation
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2011; 17 (11): 1679-1687
Donor leukocyte infusions induce remissions in some patients with hematologic malignancies who relapse after allogeneic hematopoietic cell transplantation (HCT); however, graft-versus-host disease (GVHD) remains the major complication of this strategy. Cytokine-induced killer (CIK) cells are a unique population of cytotoxic T lymphocytes that express the CD3(+)CD56(+) phenotype and show marked up-regulation of the natural killer cell receptor NKG2D (CD314). CIK cells are non-major histocompatibility complex-restricted and NKG2D-dependent in target recognition and cytotoxicity. We explored the feasibility of ex vivo expansion of allogeneic CIK cells in patients with relapsed hematologic malignancies after allogeneic HCT. Eighteen patients (median age, 53 years; range, 20-69 years) received CIK cell infusions at escalating doses of 1 × 10(7) CD3(+) cells/kg (n = 4), 5 × 10(7) CD3(+) cells/kg (n = 6), and 1 × 10(8) CD3(+) cells/kg (n = 8). The median expansion of CD3(+) cells was 12-fold (range, 4- to 91-fold). CD3(+)CD56(+) cells represented a median of 11% (range, 4%-44%) of the harvested cells, with a median 31-fold (range, 7- to 515-fold) expansion. Median CD3(+)CD314(+) cell expression was 53% (range, 32%-78%) of harvested cells. Significant cytotoxicity was demonstrated in vitro against a panel of human tumor cell lines. Acute GVHD grade I-II was seen in 2 patients, and 1 patient had limited chronic GVHD. After a median follow-up of 20 months (range, 1-69 months) from CIK infusion, the median overall survival was 28 months, and the median event-free survival was 4 months. All deaths were due to relapsed disease; however, 5 patients had longer remissions after infusion of CIK cells than from allogeneic HCT to relapse. Our findings indicate that this form of adoptive immunotherapy is well tolerated and induces a low incidence of GVHD, supporting further investigation as an upfront modality to enhance graft-versus-tumor responses in high-risk patient populations.
View details for DOI 10.1016/j.bbmt.2011.05.012
View details for PubMedID 21664472
A phase 1 study of imatinib for corticosteroid-dependent/refractory chronic graft-versus-host disease: response does not correlate with anti-PDGFRA antibodies
2011; 118 (15): 4070-4078
Stimulatory antiplatelet derived growth factor receptor α (PDGFRA) antibodies have been associated with extensive chronic graft-versus-host disease (cGVHD). We performed a phase 1 dose escalation trial of imatinib in corticosteroid-dependent/refractory cGVHD to assess the safety of imatinib and test the hypothesis that abrogation of PDGFRA signaling can ameliorate the manifestations of cGVHD. Fifteen patients were enrolled. Mean follow-up time was 56.6 weeks (range, 18-82.4 weeks). Imatinib 400 mg daily was associated with more frequent moderate to life-threatening adverse events than 200 mg daily. The main adverse events were nausea, edema, confusion, diarrhea, liver function test elevation, fatigue, and myalgia. The overall response rate was 40% (6 of 15). The treatment failure rate was 40% (6 of 15). Twenty percent (3 of 15) of subjects had stable disease. Of 4 subjects with phospho-PDGFRA and phospho-PDGFRB immunohistochemistry studies before and after treatment, inhibition of phosphorylation was observed in 3 but correlated with response in one. Anti-PDGFRA antibodies were observed in 7 of 11 evaluable subjects but correlated with clinical activity in 4. We conclude that cGVHD responds to imatinib through multiple pathways that may include PDGFRA signal transduction. This study is registered at www.clinicaltrials.gov as #NCT00760981.
View details for DOI 10.1182/blood-2011-03-341693
View details for Web of Science ID 000296282200013
View details for PubMedID 21828142
Rapid Reconstitution of Antibody Responses Following Transplantation of Purified Allogeneic Hematopoietic Stem Cells
JOURNAL OF IMMUNOLOGY
2011; 186 (7): 4191-4199
Allogeneic hematopoietic cell transplantation has broad clinical applications extending from the treatment of malignancies to induction of immunologic tolerance. However, adaptive cellular and humoral immunity frequently remain impaired posttransplantation. Here, recovery of T-dependent and T-independent Ab responses was evaluated in mice transplanted with purified hematopoietic stem cells (HSCs) devoid of the mature immune cells believed to hasten immune recovery. Mixed and full donor chimeras were created by conditioning recipients with sublethal or lethal irradiation, respectively, across different donor/host genetic disparities. By 6 wk posttransplantation, all animals demonstrated robust T-independent Ab responses, and all mixed chimeras and recipients of MHC-matched or haploidentical HSCs with a shared MHC haplotype had T-dependent Ab responses equivalent to those of untransplanted controls. Full chimeras that received fully MHC-disparate HSCs showed delayed T-dependent Ab responses that recovered by 12 wk. This delay occurred despite early reconstitution and proper migration to germinal centers of donor-derived T(follicular helper) (T(FH)) cells. Congenic transplants into T(FH)-deficient CD4(-/-) mice revealed restoration of T-dependent Ab responses by 6 wk, leading us to conclude that MHC disparity caused delay in humoral recovery. These findings, together with our previous studies, show that, contrary to the view that depletion of graft lymphocytes results in poor posttransplant immunity, elimination of immune-suppressing graft-versus-host reactions permits superior immune reconstitution. This study also provides insight into the regeneration of T(FH) cells and humoral immunity after allogeneic HSC transplantation.
View details for DOI 10.4049/jimmunol.1003674
View details for Web of Science ID 000288751200044
View details for PubMedID 21357265
Long-term outcomes in patients with high-risk myeloid malignancies following matched related donor hematopoietic cell transplantation with myeloablative conditioning of BU, etoposide and CY
BONE MARROW TRANSPLANTATION
2011; 46 (2): 192-199
Patients with high-risk or advanced myeloid malignancies have limited effective treatment options. These include high-dose therapy followed by allogeneic hematopoietic cell transplantation (HCT). We report a single-institution, long-term follow-up of 96 patients, median age 50 (range, 20-60) years, who received HLA-matched related HCT between 1992 and 2007. All patients were treated with a uniform preparatory regimen intended to enhance the widely used regimen of BU and CY that included: BU 16.0 mg/kg (days -8 to -5), etoposide 60 mg/kg (day -4), CY 60 mg/kg (day -2) with GVHD prophylaxis of CsA or FK506 and prednisone. Disease status at transplantation was high-risk AML (n=41), CML in second chronic phase or blast crisis (n=8), myelofibrosis and myeloproliferative disorders (n=8), and myelodysplasia (n=39). Thirty-six percent (n=35) of patients received BM whereas 64% (n=61) received G-CSF-mobilized PBPC. With a median follow-up of 5.6 years (range, 1.6-14.6 years) actuarial 5-year OS was 32% (95% CI 22-42) and 5-year EFS was 31% (95% CI 21-41). Relapse rate was 24% (95% CI 15-33) at 2 and 5 years. Nonrelapse mortality was 29% (95% CI 20-38) at day 100 and 38% (95% CI 29-47) at 1 year. Cumulative incidence of acute (grade II-IV) and extensive chronic GVHD was 27% (95% CI 18-36) and 29% (95% CI 18-40), respectively. There was no statistically significant difference in OS (31 vs 32%, P=0.89) or relapse rates (17 vs 28%, P=0.22) for recipients of BM vs PBPC, respectively. These results confirm that patients with high-risk or advanced myeloid malignancies can achieve long-term survival following myeloablative allogeneic HCT with aggressive conditioning.
View details for DOI 10.1038/bmt.2010.114
View details for PubMedID 20498648
Allogeneic T cells impair engraftment and hematopoiesis after stem cell transplantation.
Proceedings of the National Academy of Sciences of the United States of America
2010; 107 (33): 14721-14726
Because of the perception that depleting hematopoietic grafts of T cells will result in poorer immune recovery and in increased risk of graft rejection, pure hematopoietic stem cells (HSC), which avoid the potentially lethal complication of graft-versus-host disease (GVHD), have not been used for allogeneic hematopoietic cell transplantation (HCT) in humans. Ideal grafts should contain HSC plus mature cells that confer only the benefits of protection from pathogens and suppression of malignancies. This goal requires better understanding of the effects of each blood cell type and its interactions during engraftment and immune regeneration. Here, we studied hematopoietic reconstitution post-HCT, comparing grafts of purified HSC with grafts supplemented with T cells in a minor histocompatibility antigen (mHA)-mismatched mouse model. Cell counts, composition, and chimerism of blood and lymphoid organs were evaluated and followed intensively through the first month, and then subsequently for up to 1 yr. Throughout this period, recipients of pure HSC demonstrated superior total cell recovery and lymphoid reconstitution compared with recipients of T cell-containing grafts. In the latter, rapid expansion of T cells occurred, and suppression of hematopoiesis derived from donor HSC was observed. Our findings demonstrate that even early post-HCT, T cells retard donor HSC engraftment and immune recovery. These observations contradict the postulation that mature donor T cells provide important transient immunity and facilitate HSC engraftment.
View details for DOI 10.1073/pnas.1009220107
View details for PubMedID 20679222
View details for PubMedCentralID PMC2930440
Phase I/II Trial of GN-BVC, a Gemcitabine and Vinorelbine-Containing Conditioning Regimen for Autologous Hematopoietic Cell Transplantation in Recurrent and Refractory Hodgkin Lymphoma
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2010; 16 (8): 1145-1154
Autologous hematopoietic cell transplantation with augmented BCNU regimens is effective treatment for recurrent or refractory Hodgkin lymphoma (HL); however, BCNU-related toxicity and disease recurrence remain challenges. We designed a conditioning regimen with gemcitabine in combination with vinorelbine in an effort to reduce the BCNU dose and toxicity without compromising efficacy. In this phase I/II dose escalation study, the gemcitabine maximum tolerated dose (MTD) was determined at 1250 mg/m(2), and a total of 92 patients were treated at this dose to establish safety and efficacy. The primary endpoint was the incidence of BCNU-related toxicity. Secondary endpoints included 2-year freedom from progression (FFP), event-free survival (EFS), and overall survival (OS). Sixty-eight patients (74%) had 1 or more previously defined adverse risk factors for transplant (stage IV at relapse, B symptoms at relapse, greater than minimal disease pretransplant). The incidence of BCNU-related toxicity was 15% (95% confidence interval, 9%-24%). Only 2% of patients had a documented reduction in diffusing capacity of 20% or greater. With a median follow-up of 29 months, the FFP at 2 years was 71% and the OS at 2 years was 83%. Two-year FFP was 96%, 72%, 67%, and 14% for patients with 0 (n = 24), 1 (n = 37), 2 (n = 23), or 3 (n = 8) risk factors, respectively. Regression analysis identified PET status pretransplant and B symptoms at relapse as significant prognostic factors for FFP. This new transplant regimen for HL resulted in decreased BCNU toxicity with encouraging FFP and OS. A prospective, risk-modeled comparison of this new combination with other conditioning regimens is warranted.
View details for DOI 10.1016/j.bbmt.2010.02.022
View details for PubMedID 20197102
Allogeneic haematopoietic cell transplantation after nonmyeloablative conditioning in patients with T-cell and natural killer-cell lymphomas
BRITISH JOURNAL OF HAEMATOLOGY
2010; 150 (2): 170-178
Patients with T-cell and natural killer-cell lymphomas have poor outcomes. This study examined the role of allogeneic haematopoietic cell transplantation (allo-HCT) after nonmyeloablative conditioning in this setting. Seventeen patients with T-cell lymphoma or NK-cell lymphoma, including three patients in first complete remission, received allo-HCT after 2 Gy total-body irradiation and fludarabine. The median age was 57 (range, 18-73) years. The median number of prior therapies was 3 (range, 1-7), six patients (35%) had failed prior autologous HCT, and five patients (29%) had refractory disease at the time of allograft. Postgrafting immunosuppression was provided with mycophenolate mofetil with ciclosporin or tacrolimus. After a median follow-up of 3.3 (range, 0.3-8.0) years among surviving patients, the estimated probabilities of 3-year overall and progression-free survival were 59% and 53%, respectively, while the estimated probabilities of non-relapse mortality and relapse at 3 years were 19% and 26%, respectively. Sixty-five percent of patients developed grades 2-4 acute graft-versus-host disease and 53% of patients developed chronic graft-versus-host disease. Allo-HCT after nonmyeloablative conditioning is a promising salvage option for selected patients with T-cell and NK-cell lymphomas. These results suggest that graft-versus-T-cell lymphoma activity is responsible for long-term disease control.
View details for DOI 10.1111/j.1365-2141.2010.08210.x
View details for Web of Science ID 000279438600005
View details for PubMedID 20507311
Nonmyeloablative Allogeneic Hematopoietic Cell Transplantation in Patients With Acute Myeloid Leukemia
JOURNAL OF CLINICAL ONCOLOGY
2010; 28 (17): 2859-2867
Allogeneic hematopoietic cell transplantation (HCT) after high-dose conditioning regimens imposes prohibitively high risks of morbidity and mortality for patients with high-risk acute myeloid leukemia (AML) who are older or have comorbid conditions. Here, we examined outcomes after nonmyeloablative allogeneic HCT in such patients.Two hundred seventy-four patients (median age, 60 years) with de novo or secondary AML underwent allogeneic HCT from related (n = 118) or unrelated donors (n = 156) after conditioning with 2 Gy of total-body irradiation (TBI) with or without fludarabine. A calcineurin inhibitor and mycophenolate mofetil were used for postgrafting immunosuppression.With a median follow-up of 38 months in surviving patients, the estimated overall survival at 5 years was 33%. The estimated 5-year relapse/progression and nonrelapse mortality rates were 42% and 26%, respectively. The cumulative incidences of grades 2, 3, and 4 acute graft-versus-host disease (GVHD) were 38%, 9%, and 5%, respectively. The cumulative incidence of chronic GVHD at 5 years was 44%. Patients in first and second complete remission had better survival rates than patients with more advanced disease (37% and 34% v 18%, respectively). Patients with HLA-matched related or unrelated donors had similar survivals. Unfavorable cytogenetic risk status was associated with increased relapse and subsequent mortality. Chronic GVHD was associated with lower relapse risk.Allogeneic HCT from related or unrelated donors after conditioning with low-dose TBI and fludarabine, relying almost exclusively on graft-versus-leukemia effects, can result in long-term remissions in older or medically infirm patients with AML.
View details for DOI 10.1200/JCO.2009.27.1460
View details for Web of Science ID 000278548000009
View details for PubMedID 20439626
Long-term follow-up of patients with diffuse large B-cell non-Hodgkin's lymphoma receiving purged autografts after induction failure
BONE MARROW TRANSPLANTATION
2010; 45 (2): 303-309
Patients with diffuse large B-cell lymphoma (DLBCL) who do not achieve a complete response to front-line combination chemotherapy are often offered high-dose therapy and autologous hematopoietic cell transplantation (AHCT). However, the efficacy of this therapy in this patient population has been addressed in only a few published reports. We retrospectively analyzed the outcomes of patients with a diagnosis of de novo DLBCL who underwent AHCT at our center between 1988 and 2002, and identified 43 consecutive patients who had not achieved a CR before AHCT, although most showed at least a partial response (PR) to either induction or subsequent salvage chemotherapy. A total of 15 patients received a conditioning regimen that included high-dose chemotherapy with fractionated TBI (FTBI), whereas 28 patients received high-dose chemotherapy only. All autografts were treated ex vivo with MoAbs and complement in an effort to remove any residual malignant B cells. A total of 33 (77%) patients achieved a CR after AHCT. With a median follow-up of 7.3 years, the 5-year OS was 69% and EFS was 59%. Four patients died from non-relapse mortality. By univariate analyses, the following characteristics did not significantly impact OS: disease stage at diagnosis, age-adjusted IPI (International Prognostic Index) score, age > or =40 years, earlier radiotherapy and the use of FTBI in the conditioning regimen. These results confirm the long-term efficacy of AHCT for patients with DLBCL after induction failure.
View details for DOI 10.1038/bmt.2009.152
View details for Web of Science ID 000274397400013
View details for PubMedID 19597427
View details for PubMedCentralID PMC2886804
The biology of allogeneic hematopoietic cell resistance.
Biology of blood and marrow transplantation
2010; 16 (1): S2-7
At the most basic level, success of an allogeneic hematopoietic cell transplantation (HCT) procedure relies upon the engraftment of recipients with donor hematopoietic stem cells (HSCs) that will generate blood formation for the life of that individual. The formula to achieve durable HSC engraftment involves multiple factors including the recipient conditioning regimen, the nature of the genetic disparity between donor and recipient, and the content of the hematopoietic graft. Animal and clinical studies have shown that the biology of host resistance is complex, involving both immune and nonimmune elements. In this article, we review the factors that contribute to host resistance, describe emerging concepts on the basic biology of resistance, and discuss hematopoietic resistance as it relates specifically to patients with severe combined immunodeficiencies (SCID)- disorders that bring unique insights into the dynamics of cell replacement by allogeneic HSCs and progenitor cells.
View details for DOI 10.1016/j.bbmt.2009.11.005
View details for PubMedID 19913629
Ineffective Vaccination against Solid Tumors Can Be Enhanced by Hematopoietic Cell Transplantation
JOURNAL OF IMMUNOLOGY
2009; 183 (11): 7196-7203
Vaccination with tumor Ags has not been an effective treatment for solid tumors. The goal of the current study was to determine whether a combination of vaccination and hematopoietic cell transplantation (HCT) can effectively treat primary, disseminated, or metastatic CT26 and MC38 murine colon tumors. Vaccination of tumor-bearing mice with irradiated tumor cells and CpG adjuvant failed to alter progressive tumor growth. However, mice bearing primary, disseminated lung, or metastatic liver tumors were uniformly cured after administration of total body irradiation, followed by the transplantation of hematopoietic progenitor cells and T cells from syngeneic, but not allogeneic vaccinated donors. Requirements for effective treatment of tumors included irradiation of hosts, vaccination of donors with both tumor cells and CpG, transfer of both CD4(+) and CD8(+) T cells along with progenitor cells, and ability of donor cells to produce IFN-gamma. Irradiation markedly increased the infiltration of donor T cells into the tumors, and the combined irradiation and HCT altered the balance of tumor-infiltrating cells to favor CD8(+) effector memory T cells as compared with CD4(+)CD25(+)FoxP3(+) T regulatory cells. The combination of vaccination and autologous hematopoietic cell transplantation was also effective in treating tumors. In conclusion, these findings show that otherwise ineffective vaccination to solid nonhematologic tumors can be dramatically enhanced by HCT.
View details for DOI 10.4049/jimmunol.0900159
View details for Web of Science ID 000272478800039
View details for PubMedID 19890041
View details for PubMedCentralID PMC2783632
Salvage Allogeneic Hematopoietic Cell Transplantation with Fludarabine and Low-Dose Total Body Irradiation after Rejection of First Allografts
50th Annual Meeting of the American-Society-of-Hematology/ASH/ASCO Joint Symposium
ELSEVIER SCIENCE INC. 2009: 1314–22
We summarized results in 38 consecutive patients (median age=56 years) with hematologic malignancies (n=35), aplastic anemia (n=2), or renal cell carcinoma (n=1), who underwent salvage hematopoietic cell transplantation (HCT) for allograft rejection. In 14 patients, the original donors were used for salvage HCT, and, in 24 cases, different donors were used. Conditioning for salvage HCT consisted of fludarabine (Flu) and either 3 or 4 Gy total body irradiation (TBI). Sustained engraftment was achieved in 33 patients (87%). Grafts were rejected in 5 patients (13%), 4 of whom had myelofibrosis. With a median follow-up of 2 years (range: 0.3 to 7.8 years), the 2- and 4-year estimated survivals were 49% and 42%, respectively. The 2-year relapse rate and nonrelapse mortality (NRM) were 36% and 24%, respectively. The 2-year cumulative incidences of grades II-IV acute and moderate-severe chronic graft-versus-host disease (aGVHD, cGVHD) were 42% and 41%, respectively. In this cohort, TBI dose, grafts from original versus different donors, related versus unrelated donors, and HCT comorbidity scores did not have an impact on outcomes. We concluded that graft rejection after allogeneic HCT could be overcome by salvage transplantation using conditioning with Flu and low-dose TBI.
View details for DOI 10.1016/j.bbmt.2009.06.011
View details for Web of Science ID 000270257200012
View details for PubMedID 19747640
View details for PubMedCentralID PMC2757150
TLI and ATG conditioning with low risk of graft-versus-host disease retains antitumor reactions after allogeneic hematopoietic cell transplantation from related and unrelated donors
2009; 114 (5): 1099-1109
A hematopoietic cell transplantation regimen was adapted from a preclinical model that used reduced-intensity conditioning (RIC) and protected against graft-versus-host disease (GVHD) by skewing residual host T-cell subsets to favor regulatory natural killer T cells. One hundred eleven patients with lymphoid (64) and myeloid (47) malignancies received RIC using total lymphoid irradiation (TLI) and antithymocyte globulin (ATG) followed by the infusion of granulocyte colony-stimulating factor-mobilized grafts. Included were 34 patients at least 60 years of age, 32 patients at high risk of lymphoma relapse after disease recurrence following prior autologous transplantation, and 51 patients at high risk of developing GVHD due to lack of a fully human leukocyte antigen (HLA)-matched related donor. Durable chimerism was achieved in 97% of patients. Cumulative probabilities of acute GVHD (grades II-IV) were 2 and 10% of patients receiving related and unrelated donor grafts. Nonrelapse mortality (NRM) at 1 year was less than 4%. Cumulative incidence of chronic GVHD was 27%. The 36-month probability of overall and event-free survival was 60% and 40%, respectively. Disease status at start of conditioning and the level of chimerism achieved after transplantation significantly impacted clinical outcome. The high incidence of sustained remission among patients with active disease at time of transplantation suggests retained graft-versus-tumor reactions. Active trial registration currently at clinicaltrials.gov under IDs of NCT00185640 and NCT00186615.
View details for DOI 10.1182/blood-2009-03-211441
View details for PubMedID 19423725
A chromosome 16 quantitative trait locus regulates allogeneic bone marrow engraftment in nonmyeloablated mice
2009; 114 (1): 202-210
Identifying genes that regulate bone marrow (BM) engraftment may reveal molecular targets for overcoming engraftment barriers. To achieve this aim, we applied a forward genetic approach in a mouse model of nonmyeloablative BM transplantation. We evaluated engraftment of allogeneic and syngeneic BM in BALB.K and B10.BR recipients. This allowed us to partition engraftment resistance into its intermediate phenotypes, which are firstly the immune-mediated resistance and secondly the nonimmune rejection of donor BM cells. We observed that BALB.K and B10.BR mice differed with regard to each of these resistance mechanisms, thereby providing evidence that both are under genetic control. We then generated a segregating backcross (n = 200) between the BALB.K and B10.BR strains to analyze for genetic linkage to the allogeneic BM engraftment phenotype using a 127-marker genome scan. This analysis identified a novel quantitative trait locus (QTL) on chromosome 16, termed Bmgr5 (logarithm of odds 6.4, at 11.1 cM). The QTL encodes susceptibility alleles, from the BALB.K strain, that are permissive for allogeneic BM engraftment. Further identification of Bmgr5 genes by positional cloning may reveal new and effective approaches for overcoming BM engraftment obstacles.
View details for DOI 10.1182/blood-2009-03-208801
View details for Web of Science ID 000267789800031
View details for PubMedID 19417206
View details for PubMedCentralID PMC2710949
Identification of a Major Susceptibility Locus for Lethal Graft-versus-Host Disease in MHC-Matched Mice
JOURNAL OF IMMUNOLOGY
2009; 183 (1): 462-469
Graft-vs-host disease (GVHD) is the major cause of morbidity and mortality after allogeneic hemopoietic cell transplantation. From a genetic perspective, GVHD is a complex phenotypic trait. Although it is understood that susceptibility results from interacting polymorphisms of genes encoding histocompatibility Ags and immune regulatory molecules, a detailed and integrative understanding of the genetic background underlying GVHD remains lacking. To gain insight regarding these issues, we performed a forward genetic study. A MHC-matched mouse model was used in which irradiated recipient BALB.K and B10.BR mice demonstrate differential susceptibility to lethal GHVD when transplanted using AKR/J donors. Assessment of GVHD in (B10.BR x BALB.K)F(1) mice revealed that susceptibility is a dominant trait and conferred by deleterious alleles from the BALB.K strain. To identify the alleles responsible for GVHD susceptibility, a genome-scanning approach was taken using (B10.BR x BALB.K)F(1) x B10.BR backcross mice as recipients. A major susceptibility locus, termed the Gvh1 locus, was identified on chromosome 16 using linkage analysis (logarithm of the odds, 9.1). A second locus was found on chromosome 13, named Gvh2, which had additive but protective effects. Further identification of Gvh genes by positional cloning may yield new insight into genetic control mechanisms regulating GVHD and potentially reveal novel approaches for effective GVHD therapy.
View details for DOI 10.4049/jimmunol.0900454
View details for Web of Science ID 000275119400051
View details for PubMedID 19525392
View details for PubMedCentralID PMC2735236
Long-term outcome of patients with multiple myeloma after autologous hematopoietic cell transplantation and nonmyeloablative allografting
2009; 113 (14): 3383-3391
Autologous hematopoietic cell transplantation (HCT) followed by nonmyeloablative allogeneic HCT (auto/alloHCT) provides cytoreduction and graft-versus-myeloma effects. We report on long-term outcomes of 102 patients with multiple myeloma who received auto/alloHCT with a median follow-up of 6.3 years. Treatment consisted of high-dose melphalan and autograft followed by 2-Gy total body irradiation, with or without fludarabine, and alloHCT from human leukocyte antigen-identical siblings. Postgrafting immunosuppressive agent was cyclosporine or tacrolimus and mycophenolate mofetil. Forty-two percent of patients developed grade 2 to 4 acute graft-versus-host disease (GVHD) and 74% extensive chronic GVHD. Five-year nonrelapse mortality after allografting was 18%, 95% related to GVHD or infections. Among 95 patients with detectable disease, 59 achieved complete remissions. Median time to progression was 5 years. Median overall survival (OS) was not reached. Median progression-free survival (PFS) was 3 years. Five-year OS and PFS were 64% and 36%, respectively. Seventy-three patients receiving autoHCT within 10 months from treatment initiation had 5-year OS of 69% and PFS of 37%. In multivariate analysis, beta-2-microglobulin of more than 3.5 microg/mL at diagnosis and auto/alloHCT more than 10 months after treatment initiation correlated with shorter OS (P = .03 and P = .02) and PFS (P = .04 and P = .03), whereas Karnofsky scores less than 90% at allotransplantation correlated with shorter PFS only (P = .005). Long-term disease control and GVHD remain key issues.
View details for DOI 10.1182/blood-2008-07-170746
View details for Web of Science ID 000264848900034
View details for PubMedID 19015394
Purified hematopoietic stem cell allografts reconstitute immunity superior to bone marrow
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2009; 106 (9): 3288-3293
Antigen-specific immune responses are impaired after allogeneic hematopoietic cell transplantation (HCT). The events contributing to this impairment include host hematolymphoid ablation and donor cell regeneration, which is altered by pharmacologic immune suppression to prevent graft-versus-host disease (GVHD). A generally accepted concept is that graft T cell depletion performed to avoid GVHD yields poorer immune recovery because mature donor T cells are thought to be the major mediators of protective immunity early post-HCT. Our findings contradict the idea that removal of mature donor cells worsens immune recovery post-HCT. By transplantation of purified hematopoietic stem cells (HSC) compared with bone marrow (BM) across donor and recipient pairs of increasing genetic disparity, we show that grafts composed of the purified progenitor population give uniformly superior lymphoid reconstitution, both qualitatively and quantitatively. Subclinical GVHD by T cells in donor BM likely caused this lympho-depleting GVHD. We further determined in the major histocompatibility complex (MHC)-mismatched pairs, that T cell restricted proliferative responses were dictated by donor rather than host elements. We interpret these latter findings to show the importance of peripheral antigen presentation in the selection and maintenance of the T cell repertoire.
View details for DOI 10.1073/pnas.0813335106
View details for Web of Science ID 000263844100057
View details for PubMedID 19223585
View details for PubMedCentralID PMC2644259
The origins of the identification and isolation of hematopoietic stem cells, and their capability to induce donor-specific transplantation tolerance and treat autoimmune diseases
2008; 112 (9): 3543-3553
Advances in the understanding of the cells of the hematopoietic system have provided a rich basis for improving clinical hematopoietic cell transplants; finding and using proteins and molecules to amplify or suppress particular blood cell types; understanding the stepwise progression of preleukemic stages leading first to chronic myeloid disorders, then the emergence of acute blastic leukemias; and treating malignant and nonmalignant diseases with cell subsets. As a result of intense scientific investigation, hematopoietic stem cells (HSCs) have been isolated and their key functional characteristics revealed-self-renewal and multilineage differentiation. These characteristics are now found to be present in all tissue/organ stem cell studies, and even in the analysis of pluripotent embryonic, nuclear transfer, and induced pluripotent stem cells. Studies on HSC have identified hematopoiesis as one of the best systems for studying developmental cell lineages and as the best for understanding molecular changes in cell fate decision-making and for finding preclinical and clinical platforms for tissue and organ replacement, regeneration, and oncogenesis. Here we review the steps, from our viewpoint, that led to HSC isolation and its importance in self-nonself immune recognition.
View details for DOI 10.1182/blood-2008-08-078220
View details for Web of Science ID 000260301800011
View details for PubMedID 18948588
Non-myeloablative allogeneic haematopoietic cell transplantation for relapsed diffuse large B-cell lymphoma: a multicentre experience
7th International Meeting on AAA Proteins
WILEY-BLACKWELL PUBLISHING, INC. 2008: 395–403
Patients with relapsed diffuse large B-cell lymphoma (DLBCL) who have failed or are ineligible for autologous haematopoietic cell transplantation (HCT) have a poor prognosis. We examined the outcomes of non-myeloablative allogeneic HCT in this setting. Thirty-one patients with DLBCL and one patient with Burkitt lymphoma received allogeneic HCT following 2 Gy total body irradiation with or without fludarabine. Median age was 52 years. Twenty-four patients (75%) had undergone prior autologous HCT. Disease status at HCT was complete response (14/32, 44%), partial response (9/32, 28%), or refractory (9/32, 28%). Cumulative incidences of acute graft-versus-host disease (GVHD) grades II-IV, grades III-IV, and chronic GVHD were 53%, 19%, and 47% respectively. With a median follow-up of 45 months, 3-year estimated overall (OS) and progression-free survival (PFS) was 45% and 35% respectively. Three-year cumulative incidences of relapse and non-relapse mortality were 41% and 25% respectively. In multivariate models, chemosensitive disease and receipt of >or=4 lines of treatment before HCT were associated with better OS. Patients with chemosensitive disease had 3-year OS and PFS of 56% and 43% respectively. Non-myeloablative allogeneic HCT can produce long-term disease-free survival in patients with chemosensitive relapsed DLBCL who have failed or are ineligible for autologous HCT.
View details for DOI 10.1111/j.1365-2141.2008.07365.x
View details for Web of Science ID 000260117300012
View details for PubMedID 18759762
View details for PubMedCentralID PMC2654416
Five-Year Follow-Up of Patients With Advanced Chronic Lymphocytic Leukemia Treated With Allogeneic Hematopoietic Cell Transplantation After Nonmyeloablative Conditioning
Tandem Bone Marrow Transplantation Meeting
AMER SOC CLINICAL ONCOLOGY. 2008: 4912–20
We reported encouraging early results of allogeneic hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning in 64 patients who had advanced chronic lymphocytic leukemia (CLL). Here, we have extended the follow-up to a median of 5 years and have included data on an additional 18 patients.Eighty-two patients, age 42 to 72 years, who had fludarabine-refractory CLL were conditioned with 2 Gy total-body irradiation alone or combined with fludarabine followed by HCT from related (n = 52) or unrelated (n = 30) donors.Complete remission (CR) and partial remission were achieved in 55% and 15% of patients, respectively. Higher CR rates were noted after unrelated HCT (67% v 48%). The 5-year incidences of nonrelapse mortality (NRM), progression/relapse, overall survival, and progression-free survival were 23%, 38%, 50%, and 39%, respectively. Among 25 patients initially reported in CR, 8% relapsed and 8% died as a result of NRM, whereas 84% have remained alive and in CR. Among 14 responding patients who were tested and who had molecular eradication of their disease, two died as a result of NRM, two relapsed, and 10 have remained negative. At 5 years, 76% of living patients were entirely well, whereas 24% continued to receive immunosuppression for chronic graft-versus-host disease; the median performance status in each group was 100% and 90%, respectively. Lymphadenopathy > or = 5 cm, but not cytogenetic abnormalities at HCT, predicted relapse. In a risk-stratification model, patients who had lymphadenopathy less than 5 cm and no comorbidities had a 5-year OS of 71%.Nonmyeloablative HCT resulted in a median survival of 5 years for patients who had fludarabine-refractory CLL with sustained remissions and in the continued resolution of chronic graft-versus-host disease in surviving patients.
View details for DOI 10.1200/JCO.2007.15.4757
View details for Web of Science ID 000260113600013
View details for PubMedID 18794548
Complementing mutations in core binding factor leukemias: from mouse models to clinical applications
2008; 27 (44): 5759-5773
A great proportion of acute myeloid leukemias (AMLs) display cytogenetic abnormalities including chromosomal aberrations and/or submicroscopic mutations. These abnormalities significantly influence the prognosis of the disease. Hence, a thorough genetic work-up is an essential constituent of standard diagnostic procedures. Core binding factor (CBF) leukemias denote AMLs with chromosomal aberrations disrupting one of the CBF transcription factor genes; the most common examples are translocation t(8;21) and inversion inv(16), which result in the generation of the AML1-ETO and CBFbeta-MYH11 fusion proteins, respectively. However, in murine models, these alterations alone do not suffice to generate full-blown leukemia, but rather, complementary events are required. In fact, a substantial proportion of primary CBF leukemias display additional activating mutations, mostly of the receptor tyrosine kinase (RTK) c-KIT. The awareness of the impact and prognostic relevance of these 'second hits' is increasing with a wider range of mutations tested in clinical trials. Furthermore, novel agents targeting RTKs are emanating rapidly and entering therapeutic regimens. Here, we present a concise review on complementing mutations in CBF leukemias including pathophysiology, mouse models, and clinical implications.
View details for DOI 10.1038/onc.2008.196
View details for Web of Science ID 000259722400001
View details for PubMedID 18604246
Hepatic parenchymal replacement in mice by transplanted allogeneic hepatocytes is facilitated by bone marrow transplantation and mediated by CD4 cells
2008; 47 (2): 706-718
The lack of adequate donor organs is a major limitation to the successful widespread use of liver transplantation for numerous human hepatic diseases. A desirable alternative therapeutic option is hepatocyte transplantation (HT), but this approach is similarly restricted by a shortage of donor cells and by immunological barriers. Therefore, in vivo expansion of tolerized transplanted cells is emerging as a novel and clinically relevant potential alternative cellular therapy. Toward this aim, in the present study we established a new mouse model that combines HT with prior bone marrow transplantation (BMT). Donor hepatocytes were derived from human alpha(1)-antitrypsin (hAAT) transgenic mice of the FVB strain. Serial serum enzyme-linked immunosorbent assays for hAAT protein were used to monitor hepatocyte engraftment and expansion. In control recipient mice lacking BMT, we observed long-term yet modest hepatocyte engraftment. In contrast, animals undergoing additional syngeneic BMT prior to HT showed a 3- to 5-fold increase in serum hAAT levels after 24 weeks. Moreover, complete liver repopulation was observed in hepatocyte-transplanted Balb/C mice that had been transplanted with allogeneic FVB-derived bone marrow. These findings were validated by a comparison of hAAT levels between donor and recipient mice and by hAAT-specific immunostaining. Taken together, these findings suggest a synergistic effect of BMT on transplanted hepatocytes for expansion and tolerance induction. Livers of repopulated animals displayed substantial mononuclear infiltrates, consisting predominantly of CD4(+) cells. Blocking the latter prior to HT abrogated proliferation of transplanted hepatocytes, and this implied an essential role played by CD4(+) cells for in vivo hepatocyte selection following allogeneic BMT.The present mouse model provides a versatile platform for investigation of the mechanisms governing HT with direct relevance to the development of clinical strategies for the treatment of human hepatic failure.
View details for DOI 10.1002/hep.22012
View details for Web of Science ID 000252939500040
View details for PubMedID 18220289
Tolerance and chimerism after renal and hematopoietic-cell transplantation.
New England journal of medicine
2008; 358 (4): 362-368
We describe a recipient of combined kidney and hematopoietic-cell transplants from an HLA-matched donor. A post-transplantation conditioning regimen of total lymphoid irradiation and antithymocyte globulin allowed engraftment of the donor's hematopoietic cells. The patient had persistent mixed chimerism, and the function of the kidney allograft has been normal for more than 28 months since discontinuation of all immunosuppressive drugs. Adverse events requiring hospitalization were limited to a 2-day episode of fever with neutropenia. The patient has had neither rejection episodes nor clinical manifestations of graft-versus-host disease.
View details for DOI 10.1056/NEJMoa074191
View details for PubMedID 18216356
Nonmyeloablative allogeneic hematopoietic cell transplantation in relapsed, refractory, and transformed indolent non-Hodgkin's lymphoma
48th Annual Meeting of the American-Society-of-Hematology
AMER SOC CLINICAL ONCOLOGY. 2008: 211–17
Few effective treatment options exist for chemotherapy-refractory indolent or transformed non-Hodgkin's lymphoma (NHL). We examined the outcome of nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) in this setting.Sixty-two patients with indolent or transformed NHL were treated with allogeneic HCT from related (n = 34) or unrelated (n = 28) donors after conditioning with 2 Gy of total-body irradiation with or without fludarabine. Nine unrelated donors were mismatched for >/= one HLA antigen. Sixteen patients had histologic transformation before HCT. Twenty patients (32%) had progressive disease after previous high-dose therapy with autologous HCT. Median age was 54 years, and patients had received a median of six lines of treatment before HCT. Median follow-up time after HCT was 36.6 months.At 3 years, the estimated overall survival (OS) and progression-free survival (PFS) rates were 52% and 43%, respectively, for patients with indolent disease, and 18% and 21%, respectively, for patients with transformed disease. Patients with indolent disease and related donors (n = 26) had 3-year estimated OS and PFS rates of 67% and 54%, respectively. The incidences of grade 2 to 4 acute graft-versus-host disease (GVHD), grade 3 and 4 acute GVHD, and extensive chronic GVHD were 63%, 18%, and 47%, respectively. Among survivors, the median Karnofsky performance status at last follow-up was 85%.Nonmyeloablative allogeneic HCT can produce durable disease-free survival in patients with relapsed or refractory indolent NHL, even in this relatively elderly and heavily pretreated cohort. Outcomes were particularly good in patients with untransformed disease and related donors, whereas patients with transformed disease did poorly. Long-term survivors reported good overall functional status.
View details for DOI 10.1200/JCO.2007.11.5477
View details for Web of Science ID 000254177100010
View details for PubMedID 18056679
Nonmyeloablative unrelated donor hematopoietic cell transplantation to treat patients with poor-risk, relapsed, or refractory multiple myeloma
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2007; 13 (4): 423-432
The purpose of this study was to determine long-term outcome of unrelated donor nonmyeloablative hematopoietic cell transplantation (HCT) in patients with poor-risk multiple myeloma. A total of 24 patients were enrolled; 17 patients (71%) had chemotherapy-refractory disease, and 14 (58%) experienced disease relapse or progression after previous autologous transplantation. Thirteen patients underwent planned autologous transplantation followed 43-135 days later with unrelated transplantation, whereas 11 proceeded directly to unrelated transplantation. All 24 patients were treated with fludarabine (90 mg/m(2)) and 2 Gy of total body irradiation before HLA-matched unrelated peripheral blood stem cell transplantation. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. The median follow-up was 3 years after allografting. One patient experienced nonfatal graft rejection. The incidences of acute grades II and III and chronic graft-versus-host disease were 54%, 13%, and 75%, respectively. The 3-year nonrelapse mortality (NRM) was 21%. Complete responses were observed in 10 patients (42%); partial responses, in 4 (17%). At 3 years, overall survival (OS) and progression-free survival (PFS) rates were 61% and 33%, respectively. Patients receiving tandem autologous-unrelated transplantation had superior OS and PFS (77% and 51%) compared with patients proceeding directly to unrelated donor transplantation (44% and 11%) (PFS P value = .03). In summary, for patients with poor-risk, relapsed, or refractory multiple myeloma, cytoreductive autologous HCT followed by nonmyeloablative conditioning and unrelated HCT is an effective treatment approach, with low NRM, high complete remission rates, and prolonged disease-free survival.
View details for DOI 10.1016/j.bbmt.2006.11.011
View details for Web of Science ID 000245540300005
View details for PubMedID 17287157
Factors associated with outcomes in allogeneic hematopoietic cell transplantation with nonmyeloablative conditioning after failed myeloablative hematopoietic cell transplantation
47th Annual Meeting of the American-Society-of-Hematology
AMER SOC CLINICAL ONCOLOGY. 2006: 4150–57
Several studies have investigated the feasibility of allogeneic hematopoietic cell transplantations (HCTs) after reduced-intensity conditioning in patients who experienced relapse after myeloablative HCT. Although most studies showed relatively low nonrelapse mortality (NRM) rates and encouraging short-term results, it has yet to be defined which patients would benefit most from these approaches.We analyzed data from 147 patients with hematologic malignancies who experienced treatment failure with conventional autologous (n = 135), allogeneic (n = 10), or syngeneic (n = 2) HCT and were treated with HLA-matched related (n = 62) or unrelated (n = 85) grafts after conditioning with 2 Gy of total-body irradiation with or without fludarabine.Three-year probabilities of NRM, relapse, and overall survival were 32%, 48%, and 27%, respectively, for related recipients, and 28%, 44%, and 44%, respectively, for unrelated recipients. The best outcomes were observed in patients with non-Hodgkin's lymphoma, whereas patients with multiple myeloma and Hodgkin's disease had worse outcomes as a result of high incidences of relapse and progression. Being in partial remission (PR) or complete remission (CR) at HCT (P = .002) and developing chronic graft-versus-host disease (GVHD; P = .03) resulted in lower risks of relapse and progression. Factors associated with better overall survival were PR or CR (P = .01) and lack of comorbidity (P = .03) at HCT and absence of acute GVHD after HCT (P = .06).Encouraging outcomes were seen with allogeneic HCT after nonmyeloablative conditioning in selected patients who had experienced relapse after a high-dose HCT, particularly in patients with non-Hodgkin's lymphoma. Results with unrelated grafts were comparable with results with related grafts.
View details for DOI 10.1200/JCO.2006.06.9914
View details for Web of Science ID 000240320000018
View details for PubMedID 16896000
Nonobese diabetic mice express aspects of both type 1 and type 2 diabetes
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2006; 103 (33): 12475-12480
Before the onset of autoimmune destruction, type 1 diabetic patients and an animal model, the nonobese diabetic (NOD) mouse, show morphological and functional abnormalities in target organs, which may act as inciting events for leukocyte infiltration. To better understand these abnormalities, but without the complications associated with lymphocytic infiltrates, we examined genes expressed in autoimmune target tissues of NOD/severe combined immunodeficient (scid) mice and of autoimmune-resistant C57BL/6/scid mice. Our results suggest that the NOD genetic background may predispose them to diabetic complications, including insulin resistance in the absence of high circulating glucose levels and without autoimmune destruction of their beta cells. Several of these genes lie within known type 1 and 2 diabetes loci. These data suggest that the NOD mouse may be a good candidate to study an interface between type 1 and type 2 diabetes.
View details for DOI 10.1073/pnas.0604317103
View details for Web of Science ID 000239867500050
View details for PubMedID 16895987
View details for PubMedCentralID PMC1832259
High-dose carmustine, etoposide, and cyclophosphamide followed by allogeneic hematopoietic cell transplantation for non-Hodgkin lymphoma
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2006; 12 (7): 703-711
Allogeneic hematopoietic cell transplantation (HCT) has been shown to be curative in a group of patients with aggressive non-Hodgkin lymphoma (NHL). A previous study has demonstrated equivalent outcomes with a conditioning regimen based on total body irradiation and another not based on total body irradiation with preparative therapy using cyclophosphamide, carmustine, and etoposide (CBV) in autologous HCT. We investigated the safety and efficacy of using CBV in an allogeneic setting. Patients were required to have relapsed or be at high risk for subsequent relapse of NHL. All patients had a fully HLA-matched sibling donor. Patients received carmustine (15 mg/kg), etoposide (60 mg/kg), and cyclophosphamide (100 mg/kg) on days -6, -4, and -2, respectively, followed by allogeneic HCT. All patients were treated with cyclosporine and methylprednisolone as prophylaxis for graft-versus-host disease (GVHD). Thirty-one patients (median age, 46 years) who were felt to be inappropriate candidates for autologous transplantation were enrolled. Each subject had a median of 3 previous chemotherapy regimens. All patients engrafted. Fifteen of 31 patients are alive. Median follow-up time was 11.5 months (range, .4-126). There were 8 deaths due to relapse. Nonrelapse mortality (n = 8) included infection (n = 3), GVHD (n = 2), diffuse alveolar hemorrhage (n = 1), veno-occlusive disease in the setting of concurrent acute GVHD of the liver (n = 1), and leukoencephalopathy (n = 1). Probabilities of event-free survival and overall survival were, respectively, 44% (95% confidence interval, 26%-62%) and 51% (33%-69%) at 1 year and 44% (26%-62%) and 47% (29%-65%) at 5 years. Probability of relapse was 33% (15%-51%) at 1 year and 5 years. Probability of nonrelapse mortality was 31% (13%-49%) at 1 year and 5 years. Incidences were 29% for acute GVHD and 39% for chronic GVHD. None of the 12 patients who developed chronic GVHD has disease recurrence. Patients who had required >3 previous chemotherapy regimens before HCT had an increased probability of relapse. CBV is an effective preparative regimen for patients with aggressive NHL who undergo allogeneic HCT.
View details for DOI 10.1016/j.bbmt.2006.02.009
View details for PubMedID 16785059
Of mice and men
2006; 107 (7): 2589-2590
View details for Web of Science ID 000236656900003
Unrelated donor granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cell transplantation after nonmyeloablative conditioning: The effect of postgrafting mycophenolate mofetil dosing
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2006; 12 (4): 454-465
We previously reported results in 71 patients with advanced hematologic malignancies given HLA-matched unrelated granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cell (G-PBMC) grafts after fludarabine 90 mg/m(2), 2 Gy of total body irradiation, and postgrafting mycophenolate mofetil (MMF) 15 mg/kg twice daily and cyclosporine 6.25 mg/kg twice daily orally. Graft rejection was 15%; the cumulative probability of acute graft-versus-host disease (GVHD) was 52%. According to MMF pharmacokinetic studies, which showed a short half-life of its active metabolite, mycophenolic acid, we increased MMF dosing from 15 mg/kg twice daily to 15 mg/kg 3 times daily to increase immunosuppression and reduce the incidence of both graft rejection and acute GVHD. Among 103 patients so treated, graft rejection occurred in 5%, whereas acute GVHD remained at 53%. Outcomes were compared with results of previous G-PBMC recipients given MMF twice daily. Infection rates were slightly higher with MMF 3 times daily than with MMF twice daily. Nevertheless, 2-year nonrelapse mortality and overall and progression-free survivals were similar for MMF 3-times-daily and twice-daily patients (19%, 58%, and 49% versus 20%, 48%, and 37%, respectively). Nonmyeloablative conditioning with postgrafting cyclosporine and MMF given 3 times daily allowed 95% durable engraftment of unrelated donor G-PBMC grafts.
View details for DOI 10.1016/j.bbmt.2005.12.030
View details for Web of Science ID 000236494600008
View details for PubMedID 16545729
Toward biomarkers for chronic graft-versus-host disease: National Institutes of Health Consensus Development Project on criteria for clinical trials in chronic graft-versus-host disease: III. Biomarker working group report
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2006; 12 (2): 126-137
Biology-based markers that can be used to confirm the diagnosis of chronic graft-versus-host disease (GVHD) or monitor progression of the disease could help in the evaluation of new therapies. Biomarkers have been defined as any characteristic that is objectively measured and evaluated as an indicator of a normal biologic or pathogenic process, a pharmacologic response to a therapeutic intervention, or a surrogate end point intended to substitute for a clinical end point. The following applications of biomarkers could be useful in chronic GVHD clinical trials or management: (1) predicting response to therapy; (2) measuring disease activity and distinguishing irreversible damage from continued disease activity; (3) predicting the risk of developing chronic GVHD; (4) diagnosing chronic GVHD: (5) predicting the prognosis of chronic GVHD; (6) evaluating the balance between GVHD and graft-versus-leukemia effects (graft-versus-leukemia or GVT); and (7) serving as a surrogate end point for therapeutic response. Such biomarkers can be identified by either hypothesis-driven testing or by high-throughput discovery-based methods. To date, no validated biomarkers have been established for chronic GVHD, although several candidate biomarkers have been identified from limited hypothesis-driven studies. Both approaches have merit and should be pursued. The consistent treatment and standardized documentation needed to support biomarker studies are most likely to be satisfied in prospective clinical trials.
View details for DOI 10.1016/j.bbmt.2005.11.010
View details for Web of Science ID 000235284900002
View details for PubMedID 16443511
Treatment for acute myelogenous leukemia by low-dose, total-body, irradiation-based conditioning and hematopoietic cell transplantation from related and unrelated donors
JOURNAL OF CLINICAL ONCOLOGY
2006; 24 (3): 444-453
The use of low-dose, irradiation-based preparative regimens have allowed the extension of allografting to older and medically infirm patients. The study reported here assessed outcomes for patients with acute myeloid leukemia (AML) in different stages of their disease, who were not considered candidates for conventional hematopoietic cell transplantation (HCT) because of age and/or other known risk factors and were given minimal conditioning followed by HCT from related or unrelated donors.The present study included 122 patients with AML, who were conditioned with 2 Gy total-body irradiation (TBI) on day 0 with or without preceding fludarabine (30 mg/m2/d from days -4 to -2), and given postgrafting cyclosporine at 6.25 mg/kg twice daily from day -3 and mycophenolate mofetil at 15 mg/kg twice daily from day 0.Durable engraftment was observed in 95% of the patients. Cumulative incidences of acute graft-versus-host disease grades 2 to 4 at 6 months were 35% after related and 42% after unrelated HCT, respectively. With a median follow-up of 44 months (range, 26 to 79 months), 51 patients were alive, of whom 48 were in complete remission (CR). Cumulative nonrelapse mortalities were 10% and 22%, and cumulative mortalities from disease progression were 47% and 33% at 2 years for related and unrelated recipients, respectively. Overall, 2-year survival was 48%, and disease-free survival was 44%. Patients receiving transplantation in CR1 had 2-year overall survivals of 44% after related and 63% after unrelated HCT, respectively.We conclude that HCT from related and unrelated donors after low-dose TBI is a promising treatment for elderly patients with AML.
View details for DOI 10.1200/JCO.2005.03.1765
View details for Web of Science ID 000234776300021
View details for PubMedID 16344316
Protective conditioning for acute graft-versus-host disease
NEW ENGLAND JOURNAL OF MEDICINE
2005; 353 (13): 1321-1331
Conditioning with total lymphoid irradiation plus antithymocyte serum protects mice against acute graft-versus-host disease (GVHD) after hematopoietic-cell transplantation. We tested this strategy in humans.Thirty-seven patients with lymphoid malignant diseases or acute leukemia underwent an experimental conditioning regimen with 10 doses of total lymphoid irradiation (80 cGy each) plus antithymocyte globulin, followed by an infusion of HLA-matched peripheral-blood mononuclear cells from related or unrelated donors who received granulocyte colony-stimulating factor.Of the 37 transplant recipients, only 2 had acute GVHD after hematopoietic-cell transplantation. Potent antitumor effects in patients with lymphoid malignant diseases were shown by the change from partial to complete remission. In the transplant recipients who underwent conditioning with total lymphoid irradiation and antithymocyte globulin, the fraction of donor CD4+ T cells that produced interleukin-4 after in vitro stimulation increased by a factor of five, and the proliferative response to alloantigens in vitro was reduced, as compared with normal control subjects and control subjects who underwent conditioning with a single dose of total-body irradiation (200 cGy).A regimen of total lymphoid irradiation plus antithymocyte globulin decreases the incidence of acute GVHD and allows graft antitumor activity in patients with lymphoid malignant diseases or acute leukemia treated with hematopoietic-cell transplantation.
View details for PubMedID 16192477
Hematopoietic cell transplantation from HLA-identical sibling donors after low-dose radiation-based conditioning for treatment of CML
2005; 19 (6): 990-997
A total of 24 patients (median age 58; range, 27-71 years) with chronic myeloid leukemia (CML) in first chronic (CP1) (n=14), second chronic (n=4), or accelerated phase (n=6) who were not candidates for conventional hematopoietic cell transplantation (HCT), received nonmyeloablative HCT from HLA-matched siblings a median of 28.5 (range, 11-271) months after diagnosis. They were conditioned with 2 Gy total body irradiation (TBI) alone (n=8) or combined with fludarabine, 90 mg/m(2) (n=16). Postgrafting immunosuppression included cyclosporine and mycophenolate mofetil. All patients initially engrafted. However, 4 of 8 patients not given fludarabine experienced nonfatal rejection while all others had sustained engraftment. With a median follow-up of 36 (range, 4-49) months, 13 of 24 patients (54%) were alive and in complete remission. There were five (21%) deaths from nonrelapse mortality, one (4%) during the first 100 days after transplant. The proportions of grade II, III, and IV acute GVHD were 38, 4, and 8%, respectively. The 2-year estimate of chronic GVHD was 32%. The 2-year survival estimates for patients in CP1 (n=14) and beyond CP1 (n=10) were 70 and 56%, respectively. This study shows encouraging remission rates for patients with CML not eligible for conventional allografting.
View details for DOI 10.1038/sj.leu.2403730
View details for Web of Science ID 000229323900016
View details for PubMedID 15800667
Prevention of type 1 diabetes with major histocompatibility complex-compatible and nonmarrow ablative hematopoietic stem cell transplants
2005; 54 (6): 1770-1779
Progression to hyperglycemia in young nonobese diabetic (NOD) mice is blocked by the transplantation of hematopoietic cells mismatched at the major histocompatibility complex (MHC). Because the NOD MHC class II allele, I-A(g7), is the primary disease susceptibility gene, it is logical to conclude that MHC-mismatched hematopoietic grafts prevent diabetes by replacement of this susceptibility allele on critical hematolymphoid populations. In this report, transplantation of MHC-matched purified hematopoietic stem cells (HSCs) pre-vented diabetes development in NOD mice, demonstrating that alleles of non-MHC background genes expressed on hematopoietic cells are sufficient to disrupt the autoaggressive process. Nonmarrow ablative conditioning was 100% protective, further showing that elimination of NOD hematopoiesis, including T-cells, was not required for the graft to block diabetes pathogenesis. The current standard clinical practice of hematopoietic cell transplantation uses donor/recipient pairs that are matched at the MHC. In our view, the principles established here using an MHC-matched engineered hematopoietic graft in conjunction with nonmarrow ablative conditioning to successfully block autoimmune diabetes sufficiently reduces the morbidity of the allogeneic transplantation procedure such that a similar approach can be translated to the treatment of human autoimmune disorders.
View details for Web of Science ID 000229499600019
View details for PubMedID 15919799
Prognostic relevance of 'early-onset' graft-versus-host disease following non-myeloablative haematopoietic cell transplantation
BRITISH JOURNAL OF HAEMATOLOGY
2005; 129 (3): 381-391
We retrospectively analysed outcomes among 395 patients with haematologic malignancies who underwent non-myeloablative haematopoietic cell transplantation (HCT) from human leucocyte antigen (HLA)-matched related (n = 297) or unrelated donors (n = 98) in order to identify a possible correlation between the time of onset of graft-versus-host disease (GVHD) and survival. The non-myeloablative regimen consisted of 2 Gy total body irradiation with or without fludarabine, followed by postgrafting immunosuppression with mycophenolate mofetil and cyclosporine. The cumulative incidences of grades II-IV acute GVHD and extensive chronic GVHD were 45% and 47%, respectively, with related donors, and 68% and 68%, respectively, with unrelated donors. High-dose corticosteroid treatment for acute or chronic GVHD was started at a median of 79 (range, 8-799) days and 30 (range, 5-333) days after transplantation from related and unrelated donors respectively. With related donors, the cumulative incidence of non-relapse mortality among patients with GVHD was 55% at 4 years when prednisone was started before day 50 (n = 72), compared with 29% when treatment was started after day 50 (n = 115) (P < 0.001). With unrelated donors, time to onset of treatment for GVHD was not associated with survival. Patients with early-onset GVHD after non-myeloablative HCT from HLA-identical related donors might benefit from intensified primary immunosuppressive treatment.
View details for DOI 10.1111/j.1365-2141.2005.05458.x
View details for Web of Science ID 000228489700011
View details for PubMedID 15842663
HLA-matched unrelated donor hematopoietic cell transplantation after nonmyeloablative conditioning for patients with chronic myeloid leukemia
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2005; 11 (4): 272-279
We evaluated 10/10 HLA antigen-matched unrelated hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning with fludarabine 3 x 30 mg/m2 and 2 Gy of total body irradiation as treatment for patients with chronic myeloid leukemia who were ineligible for conventional HCT. Data from 21 consecutive patients in first chronic phase (CP1; n = 12), accelerated phase (AP; n = 5), second CP (CP2; n = 3), and blast crisis (n = 1) were analyzed. Stem cell sources were bone marrow (n = 4) or granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells (G-PBMCs; n = 17). The patient who underwent transplantation in blast crisis died on day 21 (too early to be evaluated for engraftment) from progressive disease. Sustained engraftment was achieved in 5 of 12 patients who underwent transplantation in CP1, 4 of 5 patients who underwent transplantation in AP, and 2 of 3 patients who underwent transplantation in CP2, whereas 9 patients rejected their grafts between 28 and 400 days after HCT. Specifically, 1 of 4 marrow recipients and 10 of 17 G-PBMC recipients achieved sustained engraftment. Graft rejections were nonfatal in all cases and were followed by autologous reconstitution with persistence or recurrence of chronic myeloid leukemia. Seven of 11 patients with sustained engraftment--including all 5 patients in CP1, 2 of 4 patients in AP, and neither of the 2 patients in CP2--were alive in complete cytogenetic remissions 118 to 1205 days (median, 867 days) after HCT. Two of the remaining 4 patients died of nonrelapse causes in complete (n = 1) or major (n = 1) cytogenetic remissions, and 2 died of progressive disease. Further efforts are directed at reducing the risk of graft rejection by exclusive use of G-PBMC and increasing the degree of pretransplantation immunosuppression.
View details for DOI 10.1016/j.bbmt.2004.12.326
View details for Web of Science ID 000228510800005
View details for PubMedID 15812392
Engraftment and survival following reduced-intensity allogeneic peripheral blood hematopoietic cell transplantation is affected by CD8(+) T-cell dose
2005; 105 (6): 2300-2306
The influence of graft composition on clinical outcomes after reduced-intensity conditioning is not well-characterized. In this report we prospectively enumerated CD34+, CD3+, CD4+, and CD8+ cell doses in granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cell (G-PBMC) allografts in 63 patients who received transplants following non-myeloablative conditioning with total body irradiation 200 cGy plus fludarabine as treatment for malignant diseases. Donors were HLA-identical siblings (n = 38) or HLA-matched unrelated individuals (n = 25). By univariate analyses G-PBMC CD8+ T-cell dose in at least the 50th percentile favorably correlated with full donor blood T-cell chimerism (P = .03), freedom from progression (P = .001), and overall survival (P = .01). No G-PBMC cell dose influenced grade II to IV acute or extensive chronic graft-versus-host disease. In multivariate analysis only G-PBMC CD8+ T-cell dose (P = .003; RR = 0.2, 95% CI = 0.1-0.6) was associated with improved freedom from progression. Infusion of low G-PBMC CD8+ T-cell dose for reduced-intensity allografting may adversely affect T-cell engraftment and survival outcome.
View details for DOI 10.1182/blood-2004-04-1473
View details for PubMedID 15572597
CD34, CD49 and CD8 cell doses do not influence engraftment, graft-versus-host disease, or survival following myeloablative human leukocyte antigen-identical peripheral blood allografting for hematologic malignancies
2005; 33 (3): 279-285
Optimal granulocyte colony-stimulating factor-mobilized peripheral blood progenitor cell (G-PBMC) graft compositions for myeloablative allogeneic hematopoietic cell transplantation (AHCT) have not been identified. G-PBMC cell contents were analyzed for influence on outcomes.Human leukocyte antigen(HLA)-identical related donor AHCT was used to treat 101 patients with hematologic malignancies at a single institution between 1995 and 2002. CD34+, CD3+, CD4+, and CD8+ cell doses were enumerated by flow cytometry and evaluated by univariate analysis.Categorized by the median of cell doses infused, no G-PBMC cell dose significantly correlated with neutrophil and platelet engraftment. Incidence of grade II to IV acute graft-versus-host disease (GVHD) was 24.6% (95% confidence interval [CI]: 15.9-33.3) and was not significantly influenced by evaluated G-PBMC cell doses. With a median follow-up time of 18 months for surviving patients, estimates for extensive chronic GVHD was 43.8% (95% CI: 31.4-56.2), for freedom from progression was 69.5% (95% CI: 58.1-80.9), and for overall survival was 46.9% (95% CI: 35.5-58.3). CD34+, CD3+, CD4+, and CD8+ cell doses were not significantly predictive of extensive chronic GVHD, freedom from progression or overall survival. Additionally, comparing patients receiving the upper versus lower 33rd percentiles of CD34+ cell dose, associations with extensive chronic GVHD remained insignificant (p=0.21; relative risk (RR)=1.7; 95% CI: 0.7-3.9).G-PBMC graft content does not influence outcomes after myeloablative AHCT. In particular, no significant association between extensive chronic GVHD was identified with any G-PBMC cell dose, including CD34.
View details for DOI 10.1016/j.exphem.2004.12.004
View details for PubMedID 15730851
Rapamycin (sirolimus) for treatment of chronic graft-versus-host disease
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2005; 11 (1): 47-55
We conducted a phase II trial in 19 chronic graft-versus-host disease (cGVHD) patients with rapamycin, calcineurin inhibitors, and prednisone with the goals of controlling cGVHD, reducing prednisone use, and defining the safety of this regimen. Rapamycin was begun as second-line (n = 9) or more than second-line (n = 10) therapy. With a median follow-up of 42 months, 16 patients were evaluable for response. Nine patients discontinued rapamycin because of poor compliance/patient request (n = 2) or an adverse event (n = 7), 3 of whom were not evaluable because of withdrawal at < or =1 month or noncompliance. The adverse events included serum creatinine > or =2.4 mg/dL (n = 4), hemolytic uremic syndrome (n = 2), and relapse of malignancy (n = 1). Fifteen of 16 evaluable patients had a clinical response. Five of the 16 discontinued the drug, and 1 died of relapsed leukemia. Of the 10 patients who continued rapamycin, 2 discontinued and 1 successfully tapered all systemic immunosuppression. Three of the 10 developed progressive cGVHD with tapering immunosuppression; all responded to resumption of prior medications. Four of the 10 patients required alternate therapy for persistent or progressive cGVHD while receiving rapamycin; prednisone was discontinued (n = 2) or tapered at the time of progressive disease (n = 2). Seventeen of 19 original patients were alive. One death was due to relapsed malignancy, and 1 was due to congestive heart failure. In this report of rapamycin as cGVHD therapy, there is evidence of rapamycin's efficacy. Given the significant toxicities described, investigation of altered administration of rapamycin and calcineurin inhibitors should be pursued in future cGVHD trials.
View details for DOI 10.1016/j.bbmt.2004.10.004
View details for PubMedID 15625544
Hematopoietic stem and progenitor cells: Clinical and preclinical regeneration of the hematolymphoid system
ANNUAL REVIEW OF MEDICINE
2005; 56: 509-538
A vast literature exists on the biology of blood formation and regeneration under experimental and clinical conditions. The field of hematopoiesis was recently advanced by the capacity to purify to homogeneity primitive hematopoietic stem and progenitor cells. Isolation of cells at defined maturational stages has enhanced the understanding of the fundamental nature of stem cells, including how cell fate decisions are made, and this understanding is relevant to the development of other normal as well as malignant tissues. This review updates the basic biology of hematopoietic stem cells (HSC) and progenitors, the evolving use of purified HSC as grafts for clinical hematopoietic cell transplantation (HCT) including immune tolerance induction, and the application of HSC biology to other stem cell fields.
View details for DOI 10.1146/annurev.med.54.101601.152334
View details for PubMedID 15660525
Cytokines and cytotoxic pathways in engraftment resistance to purified allogeneic hematopoietic stem cells
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2005; 11 (1): 1-12
The way that allogeneic hematopoietic cells are rejected is not completely understood. Regimen-resistant populations, including natural killer (NK) cells and lymphocytes, are thought to mediate the allograft barrier. In this report, the mechanism by which recipient cell populations resist engraftment of purified allogeneic hematopoietic stem cells (HSCs) was examined in mice. To define the immunoregulatory pathways involved in allogeneic hematopoietic cell resistance, HSC transplantations were performed in immune-defective recipients. Recipients were wild-type mice treated with alpha-NK cell antibodies or knockout strain mice lacking expression of CD8, perforin, Fas ligand, or 1 of the following cytokines: tumor necrosis factor alpha, transforming growth factor beta, interferon gamma, interleukin 4, or interleukin 10. Elimination of a single cytotoxic pathway was ineffective in reducing engraftment resistance, although mice treated with a polyclonal antibody that recognizes NK-cell determinants or CD8 expression showed a profound reduction in the engraftment barrier. Posttransplantation chimerism analysis revealed regeneration of host hematopoiesis in some experimental groups. These studies show, for the first time, that elimination of selected cytokines does not alter allogeneic hematopoietic resistance. Furthermore, the chimerism data reinforce the importance of competition for HSC niches in conjunction with immune mechanisms in resistance to long-term HSC engraftment.
View details for DOI 10.1016/j.bbmt.2004.10.002
View details for Web of Science ID 000226450300001
View details for PubMedID 15625539
Genetic susceptibility loci for lethal graft-versus-host disease in MHC-identical mice: Initial results from a genome-wide scan.
46th Annual Meeting of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2004: 328B–328B
View details for Web of Science ID 000225127701312
Approaches to transplantation tolerance in humans
2004; 77 (6): 932-936
Although transplantation tolerance to organ allografts has been achieved using a wide variety of immunologic interventions in laboratory animals, few tolerance induction protocols with complete immunosuppressive drug withdrawal have been tested in humans. Preclinical and clinical studies of the use of total lymphoid irradiation for the induction of chimeric and nonchimeric tolerance are summarized here.
View details for DOI 10.1097/01.TP.0000117782.93598.6E
View details for Web of Science ID 000220460500027
View details for PubMedID 15077041
Rituximab as adjuvant to high-dose therapy and autologous hematopoietic cell transplantation for aggressive non-Hodgkin lymphoma
43rd Annual Meeting of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2004: 777–83
Based on the favorable safety profile and the independent activity of rituximab in B-cell lymphoma, we evaluated its efficacy and toxicity after high-dose therapy (HDT) and autologous hematopoietic cell transplantation (HCT). Thirty-five patients with diffuse large cell (25 patients), mantle cell (3 patients), transformed (3 patients), or other (4 patients) subtypes of B-cell lymphoma received HDT followed by a purged autologous graft. The rituximab schedule was 4 weekly infusions (375 mg/m(2)) starting at day 42 after HCT and, for patients 5 to 35, a second 4-week course 6 months after HCT. All planned therapy was completed in 29 patients. With 30 months' median follow-up, the 2-year event-free survival (EFS) rate was 83% and the overall survival (OS) rate was 88%. For 21 patients with relapsed or refractory large cell lymphoma, the EFS rate was 81% and the OS rate was 85%. Grades 3 to 4 neutropenia occurred in 19 (54%) patients. A prospective study of immune reconstitution included measurements of lymphocyte subsets, immunoglobulins, and response to vaccination. Serious infections were not observed despite delayed B-cell recovery in all patients and suppressed immunoglobulin G (IgG) levels and low pneumococcus antibody titers in a subset. Rituximab after HDT and HCT is feasible, and these phase 2 data support the current US Intergroup phase 3 trial in recurrent/refractory diffuse large cell lymphoma.
View details for DOI 10.1182/blood-2003-04-1257
View details for PubMedID 12907446
Variable hematopoietic graft rejection and graft-versus-host disease in MHC-matched strains of mice
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2003; 100 (20): 11571-11576
MHC typing for human hematopoietic cell transplantation (HCT) from unrelated donors is currently performed by using a combination of serologic and molecular techniques. It has been determined that allelic differences in human MHC molecules, revealed by nucleotide sequencing but not by serologic typing, substantially influence graft rejection and graft-versus-host disease, two serious complications of clinical HCT. We studied transplantation of purified hematopoietic stem cells in a series of mouse strains that were matched at the MHC but had different background genes, and we observed striking differences in engraftment resistance and graft-versus-host disease severity, both factors depending on the donor-recipient strain combination. The individual mouse lines studied here were established nearly a century ago, and their MHC types were determined exclusively by serologic techniques. We considered the possibility that serologically silent MHC polymorphisms could account for our observations and, therefore, we performed DNA sequencing of the class I and II MHC alleles of our mouse strains. At each locus, exact homology was found between serologically MHC-matched strains. Our results likely extend to all serologically MHC-matched mouse strains used in modern research and highlight the profound and variable influence that non-MHC genetic determinants can have in dictating outcome after HCT.
View details for DOI 10.1073/pnas.2035077100
View details for Web of Science ID 000185685700072
View details for PubMedID 14504392
View details for PubMedCentralID PMC208799
Common lymphoid progenitors rapidly engraft and protect against lethal murine cytomegalovirus infection after hematopoietic stem cell transplantation
2003; 102 (2): 421-428
Lymphoid deficiency after allogeneic hematopoietic cell transplantation (HCT) results in increased susceptibility to infection; however, transplantation of mature lymphocytes frequently results in a serious complication known as graft-versus-host disease (GVHD). Here we demonstrate in mice that both congenic as well as allogeneic transplantation of low numbers of highly purified common lymphoid progenitors (CLPs)-a rare population of lymphoid-lineage-committed bone marrow cells-accelerates immune reconstitution after lethal irradiation and rescue with hematopoietic stem cells (HSCs). After congenic transplantation, 3 x 10(3) CLPs protected against murine cytomegalovirus (MCMV) infection at a level roughly equivalent to 107 unfractionated lymph node cells. In the allogeneic model of matched unrelated donor HSC transplantation, cotransplantation of 3 x 10(3) CLPs protected thymus-bearing as well as thymectomized hosts from MCMV infection and attenuated disease severity. Immunohistochemistry in combination with antibody depletion of T and natural killer (NK) cells confirmed that CLP-derived as well as residual host lymphocytes contribute to antiviral protection. Importantly, transplantation of allogeneic CLPs provided a durable antiviral immunity without inducing GVHD. These data support the potential for composing grafts with committed progenitors to reduce susceptibility to viral infection following HCT.
View details for DOI 10.1182/blood-2002-12-3834
View details for Web of Science ID 000184083500010
View details for PubMedID 12663447
Reconstitution of NK cell receptor repertoire following HLA-matched hematopoietic cell transplantation
2003; 101 (9): 3730-3740
Interactions between killer immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I ligands influence development of natural killer (NK) cell repertoire and response to infection, cancer, and allogeneic tissue. As KIRs and HLA class I molecules are highly polymorphic, clinical allogeneic hematopoietic cell transplantation is predicted to frequently involve KIR mismatch, and thus to provide a unique system for study of human NK cell receptor repertoire development. Eighteen leukemia patients undergoing HLA-matched transplantation and their donors were analyzed for KIR genotype. Ten of 13 HLA-identical donor-patient pairs were KIR mismatched and 3 were matched; all HLA-matched unrelated pairs were KIR mismatched. Reconstitution of recipient NK cell repertoire following transplantation was examined using flow cytometry and monoclonal antibodies specific for KIR and CD94:NKG2A. These data form 3 groups. Six to 9 months after transplantation, 8 patients (group 1) reconstituted an NK cell repertoire resembling that of their donor, and for KIR-mismatched transplants, distinct from the recipient before transplantation. In the first year after transplantation, 5 patients (group 2) exhibited a generally depressed frequency of KIR-expressing NK cells and concomitant high frequency of CD94:NKG2A expression. By 3 years after transplantation, the frequency of KIR-expressing NK cells had increased to donor values, in the 3 patients from group 2 analyzed for this period. The remaining 5 patients experienced severe clinical complications following transplantation and displayed unique features in their NK cell receptor reconstitution. These results demonstrate that a majority of HLA-matched hematopoietic cell transplantations involve KIR mismatch and reveal differences in NK cell repertoire having potential impact for immune responsiveness and transplantation outcome.
View details for PubMedID 12511415
Low-dose total body irradiation (TBI) and fludarabine followed by hematopoietic cell transplantation (HCT) from HLA-matched or mismatched unrelated donors and postgrafting immunosuppression with cyclosporine and mycophenolate mofetil (MNF) can induce durable complete chimerism and sustained remissions in patients with hematological diseases
2003; 101 (4): 1620-1629
Toxicities of high-dose conditioning regimens have limited the use of conventional unrelated donor hematopoietic cell transplantation (HCT) to younger, medically fit patients. Based on preclinical studies, an HCT approach has been developed for elderly or medically infirm patients with HLA-matched or mismatched unrelated donors. In this study, 52 patients with hematological diseases were included. Most (88%) had preceding unsuccessful conventional HCT or refractory/advanced disease. Patients were treated with fludarabine 30 mg/m(2)/d from days -4 to -2, 2 Gy total body irradiation on day 0, cyclosporine at 6.25 mg/kg twice daily from day -3, and mycophenolate mofetil at 15 mg/kg twice daily from day 0. Durable donor chimerism was attained in 88% of the patients. By day 28, a median of 100% of CD56(+) cells were of donor origin. Granulocyte and T-cell donor chimerism increased to medians of 100% on day 56 and day 180 (range, 55%-100%), respectively. Acute GVHD, grade II, was seen in 42% (CI, 29%-56%); grade III in 8% (CI, 0%-15%); and grade IV in 13% (CI, 4%-23%) of patients; it was fatal in 9%. The 100-day transplantation-related mortality was 11%. Complete remissions, including molecular remissions, were seen in 45% of patients with measurable disease before transplantation. Mortality from disease progression was 27% at one year. With a median follow-up of 19 months, 18 of the 52 patients (35%) were alive and 25% were in remission. HCT from HLA-matched or mismatched unrelated donors can be performed with a reduced intensity conditioning regimen in patients ineligible for conventional HCT.
View details for DOI 10.1182/blood-2002-05-1340
View details for Web of Science ID 000180846700061
View details for PubMedID 12393457
Biology of hematopoietic stem cells and progenitors: Implications for clinical application
ANNUAL REVIEW OF IMMUNOLOGY
2003; 21: 759-806
Stem cell biology is scientifically, clinically, and politically a current topic. The hematopoietic stem cell, the common ancestor of all types of blood cells, is one of the best-characterized stem cells in the body and the only stem cell that is clinically applied in the treatment of diseases such as breast cancer, leukemias, and congenital immunodeficiencies. Multicolor cell sorting enables the purification not only of hematopoietic stem cells, but also of their downstream progenitors such as common lymphoid progenitors and common myeloid progenitors. Recent genetic approaches including gene chip technology have been used to elucidate the gene expression profile of hematopoietic stem cells and other progenitors. Although the mechanisms that control self-renewal and lineage commitment of hematopoietic stem cells are still ambiguous, recent rapid advances in understanding the biological nature of hematopoietic stem and progenitor cells have broadened the potential application of these cells in the treatment of diseases.
View details for DOI 10.1146/annurev.immunol.21.120601.141007
View details for Web of Science ID 000182523500023
View details for PubMedID 12615892
Purified allogeneic hematopoietic stem cell transplantation blocks diabetes pathogenesis in NOD mice
2003; 52 (1): 59-68
Purified hematopoietic stem cells (HSCs) were transplanted into NOD mice to test whether development of hyperglycemia could be prevented. Engraftment of major histocompatibility complex-mismatched HSCs was compared with bone marrow (BM) grafts. HSCs differed from BM because HSCs were more strongly resisted and HSC recipients retained significant levels of NOD T-cells, whereas BM recipients were full donor chimeras. Despite persistent NOD T-cells, all HSC chimeras were protected from hyperglycemia, and attenuation of islet lesions was observed. T-cell selection was altered in allogeneic HSC recipients as demonstrated by deletion of both donor and host superantigen-specific T-cells. Syngeneic and congenic hematopoietic cell transplants were also performed to differentiate the influence of the preparative regimen(s) versus the allografts. Unlike the allogeneic HSC transplantations, syngeneic or congenic grafts did not retard diabetes development. In a pilot study, overtly diabetic NOD mice were cured by co-transplantation of allogeneic HSCs and donor-matched islets. We conclude that allogeneic HSC transplants block allo- and autoimmunity, despite residual host T-cell presence. These data demonstrate for the first time that purified HSC grafts block development of autoimmune diabetes and illuminate how HSC grafts alter thymic and peripheral T-cell responses against auto- and alloantigens.
View details for Web of Science ID 000180157300009
View details for PubMedID 12502494
Kinetics of mixed chimerism in peripheral blood hematopoietic subpopulations from 120 patients after nonmyeloablative hematopoietic stem cell transplant.
44th Annual Meeting of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2002: 39A–39A
View details for Web of Science ID 000179184700137
Immune tolerance to combined organ and bone marrow transplants after fractionated lymphoid irradiation involves regulatory NK T cells and clonal deletion
JOURNAL OF IMMUNOLOGY
2002; 169 (10): 5564-5570
Immune tolerance to organ transplants has been reported in laboratory animals and in humans after nonmyeloablative conditioning of the host and infusion of donor bone marrow cells. We examined the mechanisms of immune tolerance to mouse cardiac allografts in MHC-mismatched hosts that developed mixed chimerism after posttransplant conditioning with a 2-wk course of multiple doses of lymphoid tissue irradiation, depletive anti-T cell Abs, and an infusion of donor bone marrow cells. When CD1(-/-) or J(alpha)281(-/-) hosts with markedly reduced NK T cells were used instead of wild-type hosts, then the conditioning regimen failed to induce tolerance to the heart allografts despite the development of mixed chimerism. Tolerance could be restored to the CD1(-/-) hosts by infusing enriched T cells from the bone marrow of wild-type mice containing CD1-reactive T cells but not from CD1(-/-) host-type mice. Tolerance could not be induced in either IL-4(-/-) or IL-10(-/-) hosts given the regimen despite the development of chimerism and clonal deletion of host T cells to donor MHC-Ags in the IL-10(-/-) hosts. We conclude that immune tolerance to bone marrow transplants involves clonal deletion, and tolerance to heart allografts in this model also involves regulatory CD1-reactive NK T cells.
View details for Web of Science ID 000179170300026
View details for PubMedID 12421933
Related and unrelated nonmyeloablative hematopoietic stem cell transplantation for malignant diseases
29th World Congress of the International-Society-of-Hematology
SPRINGER JAPAN KK. 2002: 184–189
Patients with advanced hematological malignancies ineligible for conventional myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) due to advanced age or medical contraindications were enrolled in multi-center study to investigate the safety and efficacy of nonmyeloablative HSCT using a 2 Gy total body irradi ation (TBI)-based regimen. A total of 192 patients (median age 55) were treated with HLA-matched sibling peripheral blood stem cell (PBSC) grafts, and 63 patients (median age 53) received a 10 of 10 HLA-antigen matched unrelated donor (URD) HSCT (PBSC graft, n = 48; marrow graft, n = 15). Diagnoses included multiple myeloma (n = 61), myelodysplastic syndrome (n = 55), chronic myeloid leukemia (n = 31), non-Hodgkin lymphoma (n = 31), acute myeloid leukemia (n = 28), chronic lymphocytic leukemia (n = 24), Hodgkin Disease (n = 14). The conditioning regimen was fludarabine 30 mg/m2/d x 3 days and 2 Gy TBI. Ninety-five related HSCT patients received 2 Gy TBI without fludarabine. Postgrafting immunosuppression was combined mycophenolate mofetil an cyclosporine. Transplants were well tolerated with a median of 0 days of hospitalization in the first 60 days for eligible patients. For related HSCT recipients, median follow-up was 289 (100-1,188) days. Nonfatal graft rejection occurred in 6.8%. Of those with sustained engraftment, graft-versus-host disease (GVHD) occurred in 49% (33% grade II, 11% grade III, 5% grade IV). Day-100 non-relapse mortality was 6%. Overall, 59% (114/192) of patients were alive. The relapse/disease progression mortality was 18%, and non-relapse mortality was 22%. The projecte 2-year survival and progression-free survival were 50% and 40%. For the URD HSCT recipients, median follow-up was 190 (100-468) days. Graft rejection occurred in 27% (17/63) of patients, mostly in recipients of marrow grafts (9/15). Acute GVHD occurred in 63% (50% grade II, 13% grade III) of 46 engrafted patients. Chronic GVHD requiring therapy occurred in 50% of patients. Of the 63 URD HSCT patients, 54% were alive, 37% in CR, 3% PR, and 14% with disease progression or relapse. Related and unrelated nonmyeloablative HSCT is feasible and potentially curative in patients with advanced hematological malignancies who have no other treatment options.
View details for Web of Science ID 000179005800020
View details for PubMedID 12430851
Mixed chimerism and immunosuppressive drug withdrawal after HLA-mismatched kidney and hematopoietic progenitor transplantation
2002; 73 (9): 1386-1391
Rodents and dogs conditioned with total-lymphoid irradiation (TLI), with or without antithymocyte globulin (ATG), have been shown to develop mixed chimerism and immune tolerance without graft-versus-host disease (GVHD) after the infusion of major histocompatability complex (MHC)-mismatched donor bone marrow cells given alone or in combination with an organ allograft.Four human leukocyte antigen (HLA)-mismatched recipients of living donor kidney transplants were conditioned with TLI and ATG posttransplantation and infused with cyropreserved donor granulocyte colony-stimulating factor (G-CSF) "mobilized" hematopoietic progenitor (CD34+) cells (3-5x10(6) cells/kg) thereafter. Maintenance prednisone and cyclosporine dosages were tapered, and recipients were monitored for chimerism, GVHD, graft function, T-cell subsets in the blood, and antidonor reactivity in the mixed leukocyte reaction (MLR).Three of the four patients achieved multilineage macrochimerism, with up to 16% of donor-type cells among blood mononuclear cells without evidence of GVHD. Prolonged depletion of CD4+ T cells was observed in all four patients. Rejection episodes were not observed in the three macrochimeric recipients, and immunosuppressive drugs were withdrawn in the first patient by 12 months. Prednisone was withdrawn from a second patient at 9 months, and cyclosporine was tapered thereafter.Multilineage macrochimerism can be achieved without GVHD in HLA-mismatched recipients of combined kidney and hematopoietic progenitor transplants. Conditioning of the host with posttransplant TLI and ATG was nonmyeloablative and was not associated with severe infections. Recipients continue to be studied for the development of immune tolerance.
View details for Web of Science ID 000175933100002
View details for PubMedID 12023614
A non-myeloablative conditioning regimen followed by progenitor cell (CD34+) infusion after kidney transplantation can achieve mixed chimerism and immunosuppressive drug withdrawal
FEDERATION AMER SOC EXP BIOL. 2002: A1030–A1030
View details for Web of Science ID 000174593901680
Rapid establishment of dendritic cell chimerism in allogeneic hematopoietic cell transplant recipients
2002; 99 (4): 1442-1448
Regeneration of hematopoiesis after allogeneic hematopoietic cell transplantation (HCT) involves conversion of the recipient's immune system to donor type. It is likely that distinct cell lineages in the recipient reconstitute at different rates. Dendritic cells (DCs) are a subset of hematopoietic cells that function as a critical component of antigen-specific immune responses because they modulate T-cell activation, as well as induction of tolerance. Mature DCs are transferred with hematopoietic grafts and subsequently arise de novo. Little information exists about engraftment kinetics and turnover of this cell population in patients after allogeneic HCT. This study examined the kinetics of DC chimerism in patients who underwent matched sibling allogeneic HCT. T-cell, B-cell, and myelocytic and monocytic chimerism were also studied. Peripheral blood cells were analyzed at defined intervals after transplantation from 19 patients with various hematologic malignancies after treatment with myeloablative or nonmyeloablative preparatory regimens. Cell subsets were isolated before analysis of chimerism. Despite the heterogeneity of the patient population and preparatory regimens, all showed rapid and consistent development of DC chimerism. By day +14 after transplantation approximately 80% of DCs were of donor origin with steady increase to more than 95% by day +56. Earlier time points were examined in a subgroup of patients who had undergone nonmyeloablative conditioning and transplantation. These data suggest that a major proportion of blood DCs early after transplantation is donor-derived and that donor chimerism develops rapidly. This information has potential implications for manipulation of immune responses after allogeneic HCT.
View details for Web of Science ID 000173787600049
View details for PubMedID 11830498
Hematology / the Education Program of the American Society of Hematology. American Society of Hematology. Education Program
The concept of utilizing enhanced immunosuppression rather than myeloablative cytotoxic conditioning has allowed the engraftment of allogeneic stem cells from related and unrelated donors with lower early transplant-related mortality (TRM) and morbidity. This approach shifts tumor eradication to the graft-vs-host immune response directed against minor histocompatibility antigens expressed on tumor cells. This is not without risk, as the long-term effects of graft-versus-host disease (GVHD), it's treatment, or resulting complications and immunodeficiency may be life threatening. However, this approach does allow the application of a potentially curative procedure to elderly or medically infirm patients who would not tolerate high-dose conditioning regimens. Section I, by Dr. Sandmaier, describes the current use of nonmyeloablative regimens and matched related or unrelated donors for the treatment of patients with CLL, CML, acute leukemia, MDS, lymphoma, and myeloma. In Section II, Dr. Maloney discusses the use of cytoreductive autologous followed by planned non-myeloablative allografts as treatment for patients with myeloma or NHL. This tandem transplant approach has a lower TRM than conventional high dose allografting. The nonmyeloablative allograft may allow the graft-versus-tumor (GVT) immune response to eradicate the minimal residual disease that causes nearly all patients with low-grade NHL or myeloma to relapse following autologous transplantation. In Section III, Dr. Mackinnon discusses the risks and benefits of T cell depletion strategies to prevent acute GVHD, while retaining GVT activity by planned donor lymphocyte infusions. Finally, in Section IV, Dr. Shizuru discusses the relationship between GVHD and GVT activity. Future studies, employing a greater understanding of these issues and the separation of GVHD from GVT activity by immunization or T cell cloning, may allow nonmyeloablative allogeneic transplantation to be safer and more effective.
View details for PubMedID 12446434
Immunity to infections following hematopoietic cell transplantation
CURRENT OPINION IN IMMUNOLOGY
2001; 13 (4): 451-457
Hematopoietic cell transplantation has progressed from the use of unpurified bone marrow cells or mobilized peripheral blood cells to the use of purified stem cells and progenitor cells. These kinds of transplants can be designed to provide not only hematopoietic rescue but also augmented innate and acquired immunity.
View details for Web of Science ID 000169648600010
View details for PubMedID 11498301
Nonmyeloablative hematopoietic stem cell transplantation: Transplantation for the 21(st) century
FRONTIERS IN BIOSCIENCE-LANDMARK
2001; 6: G13-G16
Conventional approaches to allogeneic stem cell transplantation have used toxic high-dose conditioning therapy to achieve allogeneic engraftment and control of underlying disease. For engraftment purposes, preclinical studies and clinical observations have shown that conditioning regimens can be markedly reduced in intensity, resulting in reduced treatment toxicities. Preclinical canine studies demonstrated that the use of potent pre- and postgrafting immunosuppression allows for reduction in conditioning regimens while facilitating development of stable mixed chimerism. If attenuated conditioning regimens can be successfully translated to human stem cell transplantation, an improved safety profile will allow potentially curative treatment to a more representative patient profile not currently offered such therapy. Mixed chimerism could prove curative of disease phenotype of various nonmalignant disturbances of the hematopoietic and immune systems. For patients with hematopoietic malignancy, spontaneous conversion to full donor hematopoeisis after stem cell transplant may prove curative by virtue of graft versus host reactions directed against the malignancy, however infusion of additional donor lymphocytes may be needed to treat persistent disease.
View details for Web of Science ID 000170318400025
View details for PubMedID 11487474
Non-myeloablative hematopoietic stem cell transplantation
ISBT 7th European Congress
ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER. 2001: 231–34
Conventional approaches to allogeneic stem cell transplantation have used toxic high-dose conditioning therapy in attempts to eradicate underlying diseases and achieve allogeneic engraftment. Preclinical studies and clinical observations have shown that to achieve engraftment conditioning regimens could be markedly reduced in intensity with reduction in treatment toxicities. The use of potent pre- and postgrafting immunosuppression facilitated stable mixed hematopoietic chimerism in a preclinical canine model. The initial clinical experiences with attenuated conditioning regimens have shown promise as a modality to achieve human stem cell transplantation with an improved safety profile. This may allow offering potentially curative hematopoietic stem cell transplantation (HSCT) to a more representative patient population (older and sicker) who are currently not eligible for such therapy. Obtaining a state of mixed hematopoietic chimerism could prove curative of the disease phenotype of various nonmalignant disturbances of the hematopoietic and immune systems. On the other hand, patients with hematopoietic malignancy will likely require conversion to full donor hematopoeisis by virtue of graft-versus-host (GVH) reactions directed against both recipient hematopoiesis and underlying malignancy. The infusion of additional donor lymphocytes has been proposed by many groups to augment graft versus tumor responses, but most likely more specific strategies will need to be developed to improve efficacy and avoid nonspecific GVH reactions.
View details for Web of Science ID 000170142900014
View details for PubMedID 11499966
Hematopoietic cell transplantation in older patients with hematologic malignancies: replacing high-dose cytotoxic therapy with graft-versus-tumor effects
2001; 97 (11): 3390-3400
Toxicities have limited the use of allogeneic hematopoietic cell transplantation (HCT) to younger, medically fit patients. In a canine HCT model, a combination of postgrafting mycophenolate mofetil (MMF) and cyclosporine (CSP) allowed stable allogeneic engraftment after minimally toxic conditioning with low-dose (200 cGy) total-body irradiation (TBI). These findings, together with the known antitumor effects of donor leukocyte infusions (DLIs), led to the design of this trial. Forty-five patients (median age 56 years) with hematologic malignancies, HLA-identical sibling donors, and relative contraindications to conventional HCT were treated. Immunosuppression involved TBI of 200 cGy before and CSP/MMF after HCT. DLIs were given after HCT for persistent malignancy, mixed chimerism, or both. Regimen toxicities and myelosuppression were mild, allowing 53% of eligible patients to have entirely outpatient transplantations. Nonfatal graft rejection occurred in 20% of patients. Grades II to III acute graft-versus-host disease (GVHD) occurred in 47% of patients with sustained engraftment. With median follow-up of 417 days, survival was 66.7%, nonrelapse mortality 6.7%, and relapse mortality 26.7%. Fifty-three percent of patients with sustained engraftment were in complete remission, including 8 with molecular remissions. This novel allografting approach, based on the use of postgrafting immunosuppression to control graft rejection and GVHD, has dramatically reduced the acute toxicities of allografting. HCT with the induction of potent graft-versus-tumor effects can be performed in previously ineligible patients, largely in an outpatient setting. Future protocol modifications should reduce rejection and GVHD, thereby facilitating studies of allogeneic immunotherapy for a variety of malignancies. (Blood. 2001;97:3390-3400)
View details for Web of Science ID 000168927900011
View details for PubMedID 11369628
Expansion of cytolytic CD8(+) natural killer T cells with limited capacity for graft-versus-host disease induction due to interferon gamma production
2001; 97 (10): 2923-2931
T cells with natural killer cell phenotype and function (NKT cells) have been described in both human and murine tissues. In this study, culture conditions were developed that resulted in the expansion of CD8(+) NKT cells from bone marrow, thymus, and spleen by the timed addition of interferon-gamma (IFN-gamma), interleukin 2 (IL-2), and anti-CD3 monoclonal antibody. After 14 to 21 days in culture, dramatic expansion of CD3(+), CD8(+), alphabetaT-cell receptor(+) T cells resulted with approximately 20% to 50% of the cells also expressing the NK markers NK1.1 and DX5. The CD8(+) NKT cells demonstrated lytic activity against several tumor target cells with more than 90% lysis by day 14 to day 21 of culture. Cytotoxicity was observed against both syngeneic and allogeneic tumor cell targets with the greatest lytic activity by the cells expressing either NK1.1 or DX5. The expanded CD8(+) NKT cells produce T(H)1-type cytokines with high levels of IFN-gamma and tumor necrosis factor alpha. Expansion of the CD8(+) NKT cells was independent of CD1d. Ly49 molecules were expressed on only a minority of cells. A single injection of expanded CD8(+) NKT cells was capable of protecting syngeneic animals from an otherwise lethal dose of Bcl1 leukemia cells. Expanded CD8(+) NKT cells produced far less graft-versus-host disease (GVHD) than splenocytes across major histocompatibility barriers, even when 10 times the number of CD8(+) NKT cells as compared to splenocytes were injected. This reduction in GVHD was related to IFN-gamma production since cells expanded from IFN-gamma knock-out animals caused acute lethal GVHD, whereas cells expanded from animals defective in fas ligand, fas, IL-2, and perforin did not. These data indicate that CD8(+) NKT cells expanded in this fashion could be useful for preserving graft-versus-leukemia activity without causing GVHD.
View details for Web of Science ID 000170301300001
View details for PubMedID 11342413
- Toward regenerative medicine IMMUNITY 2001; 14 (4): 425-436
Engineering hematopoietic grafts: Purified allogeneic hematopoietic stem cells plus expanded CD8(+) NK-T cells in the treatment of lymphoma
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2001; 7 (10): 532-542
A major benefit of allogeneic hematopoietic cell transplantation (HCT) in the treatment of malignancies is the graft-versus-tumor (GVT) effect conferred by lymphocytes contained within the graft. However, lymphocytes can also induce the potentially lethal complication of graft-versus-host disease (GVHD). We have previously reported a method of generating large numbers of ex vivo activated and expanded T cells with antitumor activity after culture with interferon-y, cross-linking antibodies to CD3, and interleukin-2. Murine splenocytes expanded under these conditions are a heterogeneous population of which approximately 20% to 60% of cells express natural killer (NK)-cell markers (NK1.1 and DX5) and display major histocompatibility complex (MHC)-unrestricted antitumor activity. Here we demonstrate the in vivo antitumor activity of this population of expanded CD8+ NK-T cells when transplanted across MHC barriers into tumor-bearing hosts. In cotransfer studies with purified allogeneic hematopoietic stem cells, expanded CD8+ NK-T cells confer GVT activity with minimal to no GVHD. In vitro studies show that, although expanded NK-T cells lyse normal allogeneic bone marrow cells, they preferentially mediate cytolysis against tumor targets. These cells persist in the peripheral circulation of host animals for at least 3 weeks posttransfer. GVT activity is dependent on perforin, but not on Fas-ligand. We conclude that expanded CD8+ NK-T cells may serve as a valuable adjuvant population for allogeneic HCT because they mediate GVT effects with minimal GVHD.
View details for Web of Science ID 000172275500002
View details for PubMedID 11760085
Nonmyeloablative hematopoietic cell transplantation - Replacing high-dose cytotoxic therapy by the graft-versus-tumor effect
3rd International Conference on Hematopoietic Stem Cells: Genetics and Medicine
NEW YORK ACAD SCIENCES. 2001: 328–339
Conventional allografting produces considerable regimen-related toxicities that generally limit this treatment to patients younger than 55 years and in otherwise good medical condition. T cell-mediated graft-versus-tumor (GVT) effects are known to play an important role in the elimination of malignant disease after allotransplants. A minimally myelosuppressive regimen that relies on immunosuppression for allogeneic engraftment was developed to reduce toxicities while optimizing GVT effects. Pre-transplant total-body irradiation (200 cGy) followed by post-transplant immunosuppression with cyclosporine (CSP) and mycophenolate mofetil (MMF) permitted human leukocyte antigen (HLA)-matched sibling donor hematopoietic cell engraftment in 82% of patients (n = 55) without prior high-dose therapy. The addition of fludarabine (90 mg/m2) facilitated engraftment in all 28 subsequent patients. Overall, fatal progression of underlying disease occurred in 20% of patients after transplant. Non-relapse mortality occurred in 11% of patients. Toxicities were low. Grade 2-4 acute graft-versus-host disease (GVHD) associated with primary engraftment developed in 47% of patients, and was readily controlled in all but two patients. Donor lymphocyte infusions (DLI) were not very effective at converting a low degree of mixed donor/host chimerism to full donor chimerism; however, the addition of fludarabine reduced the need for DLI. With a median follow-up of 244 days, 68% of patients were alive, with 42% of patients in complete remission, including molecular remissions. Remissions occurred gradually over periods of weeks to a year. If long-term efficacy is demonstrated, such a strategy would expand treatment options for patients who would otherwise be excluded from conventional allografting.
View details for Web of Science ID 000172028500034
View details for PubMedID 11458521
Efficacy and toxicity of a CCNU-containing high-dose chemotherapy regimen followed by autologous hematopoietic cell transplantation in relapsed or refractory Hodgkin's disease
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2001; 7 (10): 552-560
High-dose CBV (cyclophosphamide, carmustine, and etoposide) in combination with autologous HCT achieves survival rates of approximately 50% at 5 years in recurrent or refractory Hodgkin's disease (HD). However, carmustine (BCNU) dose-dependent pulmonary toxicity occurs in 20% to 30% of patients. A decreased incidence of interstitial pneumonitis as well as a possible benefit in efficacy has been reported with lomustine (CCNU) compared to BCNU in the standard dose setting. In a dose-escalation study, we substituted CCNU for BCNU in the CBV regimen for 16 patients with HD (n = 12) or non-Hodgkin's lymphoma (n = 4). Based on the promising results, an additional 47 consecutive patients with HD were treated with the following regimen: CCNU (15 mg/kg) orally on day -6, etoposide (60 mg/kg) intravenously on day -4, and cyclophosphamide (100 mg/kg) intravenously on day -2. Peripheral blood progenitor cells and/or bone marrow were infused on day 0. With a median follow-up for the surviving patients of 3.2 years (range, 0.8-9.9 years), the 3-year overall survival rate was 57% (CI, +/-15%), event-free survival was 52% (CI, +/-14%), and freedom from progression was 68% (CI, +/-14%). There were 21 deaths, 10 due to HD. Six patients died due to respiratory failure. Interstitial pneumonitis occurred in 63% of patients and could not be correlated with prior chest radiotherapy. This regimen demonstrated survival rates similar to those of historical studies that used the CBV regimen. However, the incidence of interstitial pneumonitis was in excess of expected.
View details for Web of Science ID 000172275500004
View details for PubMedID 11760087
High-dose therapy and autologous hematopoietic-cell transplantation for follicular lymphoma beyond first remission: The Stanford University experience
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2001; 7 (5): 294-301
A retrospective analysis was performed to investigate the outcome of high-dose therapy (HDT) and autologous hematopoietic cell transplantation in patients with follicular lymphomas beyond first remission. Ninety-two patients with primary induction failure or relapsed follicular low-grade lymphoma (FLGL), follicular large cell lymphoma (FLCL), and transformed follicular lymphoma (TFL) were treated with myeloablative therapy consisting of etoposide (60 mg/kg), cyclophosphamide (100 mg/kg), and either carmustine (BCNU;15 mg/kg) or fractionated total body irradiation (FTBI; 1200 cGy) followed by transplantation of purged autologous bone marrow or peripheral blood hematopoietic cells. For the 49 patients with relapsed FLGL, the median age was 49 years and the median interval from diagnosis to HDT was 30 months. The 4-year estimate of overall survival (OS) was 60% (95% confidence interval [CI], 45%-75%) and of disease-free survival (DFS) was 44% (95% CI, 29%-59%). Treatment with the FTBI-containing HDT regimen was associated with significantly longer DFS (P = .04) and OS (P = .04) in our multivariate analysis. OS was also significantly longer among those treated with 3 or fewer chemotherapy regimens. For the 26 FLCL patients, the median age was 51 years and in 31% the indication for HDT was primary induction failure. For FLCL patients, the 4-year estimate of OS was 58% (95% CI, 37%-79%) and of DFS was 51% (95% CI, 30%-72%). Among the 17 patients with TFL, 13 (76%) transformed at first relapse, and only 6 patients (35%) achieved complete remission with salvage therapy prior to HDT. For TFL patients, the 4-year estimate of OS was 50% (95% CI, 24%-76%) and of DFS 49% (95% CI, 20%-78%). There were 3 occurrences of myelodysplasia (1 after treatment with TBI, 2 after BCNU treatment), yielding an estimated incidence of 7% (95% CI, 0%-16%) at 56 months. This analysis shows that relapsed FLGL patients treated with 3 or fewer different chemotherapy regimens show inferior survival. The HDT regimen containing FTBI appears to be superior to the BCNU-based regimen for relapsed FLGL, although longer follow-up is needed to evaluate late effects. Lastly, patients with TFL or induction failure and relapsed FLCL can achieve survival outcome comparable to those observed with the indolent follicular lymphomas.
View details for Web of Science ID 000169118600007
View details for PubMedID 11400952
- Allogeneic hematopoietic stem cell transplantation: From the nuclear age into the twenty-first century 6th Congress of the Asian-Society-of-Transplantation ELSEVIER SCIENCE INC. 2000: 2548–49
Purified hematopoietic stem cell grafts induce tolerance to alloantigens and can mediate positive and negative T cell selection
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2000; 97 (17): 9555-9560
Engraftment of allogeneic bone marrow (BM) has been shown to induce tolerance to organs genotypically matched with the BM donor. Immune reconstitution after BM transplantation therefore involves re-establishment of a T cell pool tolerant to antigens present on both donor and host tissues. However, how hematopoietic grafts exert their influence over the regenerating immune system is not completely understood. Prior studies suggest that education of the newly arising T cell pool involves distinct contributions from donor and host stromal elements. Specifically, negative selection is thought to be mediated primarily by donor BM-derived antigen-presenting cells, whereas positive selection is dictated by radio-resistant host-derived thymic stromal cells. In this report we studied the effect of highly purified allogeneic hematopoietic stem cells (HSCs) on organ transplantation tolerance induction and immune reconstitution. In contrast to engraftment of BM that results in near-complete donor T cell chimerism, HSC engraftment results in mixed T cell chimerism. Nonetheless we observed that HSC grafts induce tolerance to donor-matched neonatal heart grafts, and one way the HSC grafts alter host immune responses is via deletion of newly arising donor as well as radiation-resistant host T cells. Furthermore, using an in vivo assay of graft rejection to study positive selection we made the unexpected observation that T cells in chimeric mice rejected grafts only in the context of the donor MHC type. These latter findings conflict with the conventionally held view that radio-resistant host elements primarily dictate positive selection.
View details for Web of Science ID 000088840500041
View details for PubMedID 10920206
Effect of oral glutamine supplementation during bone marrow transplantation
JOURNAL OF PARENTERAL AND ENTERAL NUTRITION
2000; 24 (2): 61-66
Because all patients receiving bone marrow transplant (BMT) and peripheral blood progenitor cell transplant (PBPCT) experience gastrointestinal (GI) toxicity from the preparative regimen of chemotherapy, with or without radiation, oral glutamine was administered during the preparatory regimen and after transplant to maintain GI structure and function.To evaluate effects of oral glutamine on nutritional status and overall outcome, a prospective, randomized, double-blinded study was performed on 58 autologous and allogeneic BMT patients. Patients received 30 g of oral glutamine or placebo daily.The trends of decreased median length of stay and the median number of days of total parenteral nutrition (TPN) were seen in the group supplemented with the >0.285-g/kg (the recommended dosage) dose of glutamine; however, there was no statistically significant difference in the nutritional status and overall patient outcome as assessed by days receiving TPN, number of days required until oral intake resumed, length of hospitalization, number of days and highest grade of mucositis, and quantity and number of days of diarrhea.This study does not support the hypothesis that oral glutamine may offer benefit. Further investigation is required regarding clinical tools for determining effectiveness, administration for tolerance and compliance, dosage, and potential of oral glutamine usage.
View details for PubMedID 10772184
Four-cycle high-dose therapy with hematopoietic support for metastatic breast cancer: No improvement in outcomes compared with single-course high-dose therapy
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2000; 6 (1): 58-69
Multiple-cycle high-dose therapy with autologous hematopoietic progenitor cell (AHPC) support has been used to deliver dose-intensive therapy. We have used this approach as well as single-cycle high-dose therapy in treating patients with metastatic breast cancer. We present the outcomes of multiple-cycle high-dose therapies and compare them with those resulting from single-course high-dose therapies performed at a single institution. Fifty-five patients received 4 cycles of intensive chemotherapy with AHPC support. Three multicycle regimens were sequentially applied. Twenty patients were enrolled to receive 4 cycles of high-dose mitoxantrone, thiotepa, and cyclophosphamide. Nineteen subsequent patients received this regimen modified by the incorporation of paclitaxel. Sixteen patients received 2 cycles of high-dose melphalan, thiotepa, and paclitaxel and 2 cycles of mitoxantrone, thiotepa, and paclitaxel. The results of all 3 multiple-cycle therapies are compared with those of 55 contemporaneous patients with metastatic breast cancer who received a single course of high-dose cyclophosphamide and thiotepa or cyclophosphamide, cisplatin, and BCNU (carmustine) with hematopoietic cell rescue. Multiple-cycle therapy was associated with more infectious complications, increased transfusion requirements, and increased hospital admissions. However, there were no significant differences in outcomes between the groups. For 55 patients who received multiple-cycle therapy, the actuarial 3-year overall survival rate was 36% (95% confidence interval [CI] 23%-49%); freedom from progression and event-free survival were both 15% (CI 5%-25%). The median time to disease progression and median survival were 1.0 and 1.6 years, respectively. For the 55 patients who underwent a single course of high-dose therapy, the 3-year overall survival was also 36% (CI 18%-54%), whereas freedom from progression and event-free survival were both 19% (CI 7%-31%). The median time to progression and median survival were 0.8 and 2.2 years, respectively. Within the constraints of this patient population, the outcomes of 4 cycles of high-dose therapy with AHPC support were not superior to those resulting from single courses of high-dose therapy in the treatment of patients with metastatic breast cancer.
View details for Web of Science ID 000090022000007
View details for PubMedID 10708000
Non-myeloablative haematopoietic stem cell transplants
4th International Stem Cell Workshop on High-Dose Therapy and Transplantation of Haematopoietic Stem Cells
BLACKWELL WISSENSCHAFTS-VERLAGGMBH. 2000: 170–174
View details for Web of Science ID 000086780600026
Transplantation of highly purified CD34(+)Thy-I+ hematopoietic stem cells in patients with metastatic breast cancer
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2000; 6 (3): 262-271
We report here the transplantation of extensively purified "mobilized" peripheral blood CD34Thy-1 hematopoietic stem cells from 22 patients with recurrent or metastatic breast cancer. Patients were mobilized with either high-dose granulocyte colony-stimulating factor (G-CSF) alone or cyclophosphamide plus G-CSE Median purity of the stem cell product at cryopreservation was 95.3% (range, 91.1%-98.3%), and viability was 98.6% (range, 96.5%-100%). After high-dose chemotherapy with carmustine, cisplatin, and cyclophosphamide, CD34+Thy-1 cells at a median dose of 11.3 x 10(5) per kilogram (range, 4.7-163 x 10(5) per kilogram) were infused. No infusion-related toxicity was observed. Neutrophil recovery was prompt, with median absolute neutrophil count >500/microL by day 10 (range, 8-15 days) and >1000/microL by day 11 (range, 8-17 days). Median platelet recovery (>20,000/microL) was observed by day 14 (range, 9-42 days) and >50,000/microL by day 17 (range, 11-49 days). Tumor cell depletion below the limits of detection of a sensitive immunofluorescence-based assay was accomplished in all patients who had detectable tumor cells in apheresis products before processing. Although CD4+ T-cell reconstitution was slow, no unusual infections were observed. Neither early nor late graft failure was observed, and no patient required infusion of unmanipulated backup cells. At a median follow-up of approximately 1.4 years and a maximum follow-up of 2.5 years, 16 of the 22 patients remain alive, with 9 free of disease progression, and have stable blood counts. In summary, highly purified CD34+Thy-1+ cells used as the sole source of the hematopoietic graft result in rapid and sustained hematopoietic engraftment.
View details for Web of Science ID 000090022300006
View details for PubMedID 10871151
Pulmonary toxicity syndrome in breast cancer patients undergoing BCNU-containing high-dose chemotherapy and autologous hematopoietic cell transplantation
BIOLOGY OF BLOOD AND MARROW TRANSPLANTATION
2000; 6 (4): 387-394
We performed a retrospective review to investigate pulmonary toxicity syndrome (PTS) in a cohort of breast cancer patients undergoing BCNU-containing high-dose chemotherapy (HDC). Our aim was to characterize presentation, identify risk factors, determine outcome following therapy, and find any association with differences in survival. We reviewed the data of 152 patients with stage II or III or metastatic breast cancer treated with cyclophosphamide 5625 mg/m2, cisplatin 165 mg/m2, and BCNU 600 mg/m2 followed by autologous peripheral blood hematopoietic cell transplantation. During follow-up, PTS was diagnosed when the following criteria were met: (1) presentation with typical clinical symptoms of PTS, (2) an absolute carbon monoxide diffusion capacity (DLCO) decline of 10% compared with pre-HDC DLCO, and (3) no clinical evidence of active pulmonary infection. Patients were then treated with a course of corticosteroid therapy. The incidence of PTS for all 152 patients was 59%, with a median onset at 45 days (range, 21-149 days) post-HDC. The median absolute DLCO decrement was 26% (range, 10%-73%) at diagnosis of PTS. There was no significant correlation between patient age, stage of breast cancer, pre-HDC chemotherapy regimen, pre-HDC chest wall radiotherapy, tobacco use, prior lung disease, or baseline pulmonary function test results and the development of PTS. We did observe an interesting association between PTS and the development of a noncholestatic elevation of transaminases. Of PTS patients treated with prednisone therapy for a median of 105.5 days (range, 44-300 days), 91% achieved resolution of their PTS without pulmonary sequelae. At 3 years, the overall survival (OS) of stage II or III patients who developed PTS was 84% (95% confidence interval [CI], 73%-95%); of metastatic breast cancer patients with PTS, the OS was 58% (95% CI, 38%-78%). These values were not significantly different from those of patients who did not develop PTS (91% [95% confidence interval [CI], 81%-100%] and 53% [95% CI, 32%-74%], respectively). No significant differences in disease-free or event-free survival were observed between patients with and without PTS. The incidence of PTS in breast cancer patients treated with a BCNU-containing HDC regimen can be remarkably high. Treatment with a course of corticosteroid therapy is successful in the vast majority.
View details for Web of Science ID 000090022700005
View details for PubMedID 10917574
- Immune reconstitution NEW ENGLAND JOURNAL OF MEDICINE 1999; 341 (16): 1227-1229
- Lymphoid development from stem cells and the common lymphocyte progenitors 64th Symposia: Signaling and Gene Expression in the Immune System COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT. 1999: 1–12
Impact of admission body weight and chemotherapy dose adjustment on the outcome of autologous bone marrow transplantation.
Biology of blood and marrow transplantation
1999; 5 (5): 299-305
We performed a retrospective analysis of 473 consecutive adult patients undergoing autologous bone marrow transplantation for hematologic malignancies between 1988 and 1995. The analysis examined whether significant deviation from ideal body mass index is associated with a decrease in event-free survival (EFS), an increase in nonrelapse mortality (NRM) including late toxicities and second malignancies, or relapse. Chemotherapy dosing in underweight and overweight patients is administered based on the relationship of admission body weight (ABW) to ideal body weight (IBW). Doses were adjusted for obesity; however, the adjustment did not obviate increased risk for NRM. Patients were categorized into five groups according to the relationship of ABW to age-adjusted body mass index (aBMI) as a percent of actual BMI, as follows: group I, 70-79%; group II, 80-99%; group III, 100-119%; group IV, 120-139%; and group V, 140-199% aBMI. When body weight was expressed as percent BMI adjusted for age, there was a significantly increased risk for NRM in groups I and IV (p = 0.03 and 0.02, respectively). A trend toward greater NRM in group V (p = 0.10) was also noted. Multivariate analysis confirmed that the risk of NRM for extremely underweight and overweight patients is almost three times that of patients close to ideal body weight. Age-adjusted BMI was an independent predictive factor for NRM but not associated with increased relapse. We determined that dose adjustment could be safely used without significant increase of relapse. In patients with significant deviation of BMI from aBMI, dose adjustment and possible weight normalization should be considered.
View details for PubMedID 10534060
Graft-vs.-lymphoma effect in an allogeneic hematopoietic stem cell transplantation model.
Biology of blood and marrow transplantation
1999; 5 (6): 357-368
It is known that an important curative benefit of allogeneic bone marrow transplantation (BAMT) in the treatment of hematolymphoid malignancies is a graft-vs.-tumor (GVT) effect. GVT activity has been attributed to mature immune cells contained within the graft because T-cell depletion of bone marrow results in increased rates of disease relapse post-transplantation. We previously demonstrated successful engraftment of highly purified hematopoietic stem cells (HSCs) transplanted across major histocompatibility complex (MHC) barriers in mice. In the present study, we have developed a preclinical model of allogeneic HSC transplantation into lymphoma-inoculated mice, allowing us to directly test whether purified HSCs have measurable GVT activity. We then performed cotransfer studies of HSCs with purified immune cells to identify which population(s) confers tumor protection and the mechanism by which such cells suppress tumor growth. MHC-mismatched donor-recipient combinations were studied. All of the GVT activity was contained in the CD8+ cell fraction and, at the doses of CD8+ cells tested, tumor protection was separable from acute graft-vs.-host disease (aGVHD). Although there appears to be no functional difference between BM- and splenic-derived CDS8+ cells with regard to GVT activity without aGVHD, this was not the case for purified CD3+ cells. CD3+ cells derived from BM were tumor protective, whereas transplantation of equivalent doses of CD3+ cells purified from spleen resulted in lethal GVHD. The mechanism by which the GVT-conferring cells protect recipient mice from tumors was studied using immune defective mice as donors. We found that an intact pathway of perforin-dependent cytolysis, as well as an intact Fas-ligand pathway, is required in order to exert maximal anti-tumor activity.
View details for PubMedID 10595813
From stem cells to lymphocytes: Biology and transplantation
1997; 157: 13-40
We review the development of the hematopoietic system, focusing on the transition from hematopoietic stem cells (HSCs) to T cells. This includes the isolation of HSCs, and recent progress in understanding their ontogeny, homing properties, and differentiation. HSC transplantation is reviewed, including the kinetics of reconstitution, engraftment across histocompatibility barriers, the facilitation of allogeneic engraftment, and the mechanisms of graft rejection. We describe progress in understanding T-cell development in the bone marrow and thymus as well as the establishment of lymph nodes. Finally, the role of bcl-2 in regulating homeostasis in the hematopoietic system is discussed.
View details for Web of Science ID A1997XL05000002
View details for PubMedID 9255619
Transplantation of purified hematopoietic stem cells: requirements for overcoming the barriers of allogeneic engraftment.
Biology of blood and marrow transplantation
1996; 2 (1): 3-14
Allogeneic bone marrow transplantation currently plays a critical role in the treatment of leukemias and inherited disorders of hematopoiesis, and it shows great promise for the treatment of numerous other diseases. The problems of graft-vs-host disease (GVHD) and failure to engraft, however, remain formidable obstacles to the widespread use of this therapy. Successful transplantation of purified populations of hematopoietic stem cells (HSCs) can theoretically avoid the problem of GVHD, since purified HSCs lack the mature elements that allow the graft to mount a response against the host. In previous studies from our laboratory, a population of purified HSCs (Thy-1loLin-/loSca-1+) was isolated from mouse bone marrow (BM). These cells represent approximately 0.05% of BM cells and are capable of self-renewal and long-term reconstitution of all blood lineages. Here we report long-term engraftment of these purified HSCs transplanted in mice across successively more difficult allogeneic-histocompatibility barriers. Transplantation of purified HSCs were quantitatively compared with whole bone marrow (WBM) grafts containing equivalent numbers of stem cells. The mouse strain combinations tested were parent transplanted into F1 (Hh disparate), minor histocompatibility complex (mHC), and major histocompatibility complex (MHC) plus mHC disparities. One of the recipient strains studied for MHC-disparate transplantations was that of spontaneously autoimmune diabetic mice. Recipient mice were administered lethal doses of whole-body irradiation in the presence or absence of antibodies directed against natural killer (NK) cell-associated determinants and/or monoclonal antibodies against the CD4+ T cell subset. We find that as the barrier to transplantation increases, greater numbers of HSCs are required for radioprotection and engraftment. In all cases, stable hematopoietic chimeras were generated with HSCs alone, but 10-60 times the number of HSCs was required for radioprotection of mice transplanted across allogeneic or semiallogeneic disparities as compared to Ly-5 congenic differences. Furthermore, we demonstrate a clear advantage of WBM vs HSCs with regard to tha ability to engraft [corrected]. Chimeric mice showed no symptoms of GVHD, and their T cells were unable to induce GVHD in neonatal mice expressing H-2 antigens of donor and host. These data confirm that a cell population resident in WBM and distinct from purified stem cells is important in facilitating hematopoietic engraftment, in this case, of purified allogeneic HSCs. The differences in engraftment between WBM and HSCs could be reduced significantly by the addition of antibodies directed against NK determinants to the host preparative regimen. Similarly, since antibodies directed against host NK-associated antigens can reduce the barrier to allogeneic HSC engraftment, an interaction between the facilitating population within donated WBM and a resistant host population with NK determinants is implied.
View details for PubMedID 9078349
VASCULAR ADDRESSINS ARE INDUCED ON ISLET VESSELS DURING INSULITIS IN NONOBESE DIABETIC MICE AND ARE INVOLVED IN LYMPHOID-CELL BINDING TO ISLET ENDOTHELIUM
JOURNAL OF CLINICAL INVESTIGATION
1993; 92 (5): 2509-2515
In the nonobese diabetic (NOD) mouse, lymphocytic and monocytic infiltration of the pancreatic islets leads to beta cell destruction. To investigate the mechanisms by which lymphocytes enter the NOD pancreas, pancreata were immunostained using monoclonal antibodies to a variety of adhesion molecules known to be involved in lymphocyte binding to vascular endothelium, an initial step in the migration of lymphocytes from blood into organized lymphoid and inflamed tissues. These adhesion molecules include: lymphocyte homing receptors involved in tissue-selective binding of lymphocytes to peripheral lymph node (L-selectin) or mucosal lymphoid tissue (LPAM-1, alpha 4 beta 7-integrin) high-endothelial venules (HEV); and HEV ligands peripheral vascular addressin (PNAd) and mucosal vascular addressin (MAdCAM-1). In NOD pancreata, alpha 4 beta 7 is expressed on most infiltrating cells at all stages of insulitis, whereas L-selectin expression is more pronounced on cells in the islets at later stages. During the development of insulitis, MAdCAM-1 and to a lesser extent PNAd became detectable on vascular endothelium adjacent to and within the inflamed islets. The Stamper-Woodruff in vitro assay was used to examine lymphoid cell binding to such vessels. These functional assays show that both the mucosal (MAdCAM-1/alpha 4 beta 7) and the peripheral (PNAd/L-selectin) recognition systems are involved in this binding. Our findings demonstrate that expression of peripheral and mucosal vascular addressins is induced on endothelium in inflamed islets in NOD pancreas, and that these addressins participate in binding lymphoid cells via their homing receptors. This suggests that these adhesion molecules play a role in the pathogenesis of diabetes in these mice by being involved in the migration of lymphocytes from blood into the inflamed pancreas.
View details for Web of Science ID A1993MF29100054
View details for PubMedID 7693764
View details for PubMedCentralID PMC288436
Anti-CD4 antibodies in diabetes.
1993; 59: 237-252
View details for PubMedID 8096401
THE USE OF GRANZYME A AS A MARKER OF HEART-TRANSPLANT REJECTION IN CYCLOSPORINE OR ANTI-CD4 MONOCLONAL ANTIBODY-TREATED RATS
1993; 55 (1): 146-153
Granzyme A is a serine protease expressed by populations of human and mouse natural killer cells and activated CD4+ and CD8+ cytotoxic lymphocytes; its expression marks a subset of inflammatory cells in allografts, autoimmune diabetes, and a number of other inflammatory lesions. In order to describe more completely the correlation between granzyme A expression and the presence of in vivo cytolytic effects, we grafted allogeneic rat hearts with vascular anastomoses in a heterotopic location, and treated the hosts with either cyclosporine, anti-CD4 monoclonal antibody (MRC OX38), or no therapy. The grafts were evaluated by palpation for cardiac functions, by immunohistochemistry for CD4/CD8 expression, by hematoxylin-and-eosin staining for inflammatory infiltration, and by in situ hybridization for granzyme A expression. The appearance of granzyme A+ cells in untreated allografts preceded both functional and standard histopathological and immunohistochemical evidence of graft rejection by two days. In donor-recipient combinations where cyclosporine and anti-CD4 treatments allowed indefinite allograft survival, the allografts showed minimal numbers of granzyme A+ cells, whether cellular infiltrates developed or not. The number of granzyme A+ cells present in the cardiac allografts in treated and untreated animals correlated with either current or impending episodes of rejection. The early time course of granzyme A expression suggests that it can be used as an early and reliable marker of graft rejection.
View details for Web of Science ID A1993KH66000027
View details for PubMedID 8420039
GENETIC-CONTROL OF DIABETES-MELLITUS
3RD WORLD CONF ON DIABETES RESEARCH
SPRINGER VERLAG. 1992: S1–S7
Genetic inheritance predisposing individuals to diabetes mellitus was discussed in this work group. The two forms of the disease, Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent) were discussed separately since the pattern of inheritance and genes involved appear to be distinctly different. Within these subtypes there is considerable genetic heterogeneity, and superimposed environmental factors confound the analysis. New technologies that will allow finer molecular analysis, as well as new candidates genes, were presented.
View details for Web of Science ID A1992KA42900003
View details for PubMedID 1478375
- ANTI-CD4 MONOCLONAL-ANTIBODIES IN THERAPY - CREATION OF NONCLASSICAL TOLERANCE IN THE ADULT IMMUNOLOGICAL REVIEWS 1992; 129: 105-130
ANTI-CD8 ABROGATES EFFECT OF ANTI-CD4-MEDIATED ISLET ALLOGRAFT SURVIVAL IN RAT MODEL
1991; 40 (11): 1430-1434
We studied the effects of anti-CD4 treatment of diabetic ACI rats on the induction of tolerance to allogeneic (Lewis) islet allografts. When given as a 4-day treatment regimen, OX38, a mouse anti-rat CD4 antibody, caused depletion of greater than 80% of CD4+ cells from the peripheral blood of treated rats. After induction of diabetes (a single high-dose bolus of streptozocin) and 3 days after the initiation of anti-CD4 immunotherapy, recipient ACI rats were transplanted with fully allogeneic (Lewis) islets of Langerhans via the portal circulation. These transplanted islets were capable of returning the anti-CD4-treated ACI recipients to normoglycemia, which was maintained indefinitely in the absence of further immunosuppression. In contrast, treatment of recipient rats with OX8, an anti-CD8 monoclonal antibody (MoAb), induced only a slight prolongation of graft survival (less than or equal to 30 days). Further characterization of the cellular requirements for the induction of long-term transplantation survival revealed that successful pretransplantation anti-CD4 therapy could be ablated by the coincident treatment of recipient rats with depleting levels of anti-CD8 MoAb. These data point to the necessity of a regulator CD8+ cell in the induction of anti-CD4-mediated transplantation survival in this rat model of islet transplantation.
View details for Web of Science ID A1991GN93200010
View details for PubMedID 1834499
GENETIC DISSECTION OF T-CELL RECEPTOR-V-BETA GENE REQUIREMENTS FOR SPONTANEOUS MURINE DIABETES
JOURNAL OF EXPERIMENTAL MEDICINE
1991; 174 (3): 633-638
It has been demonstrated, in certain autoimmune disease models, that pathogenic T cells express antigen receptors of limited diversity. It has been suggested that the T cells responsible for the pathogenesis of type I diabetes mellitus might similarly demonstrate restricted T cell receptor (TCR) usage. Recently, attempts have been made to identify the V beta subset(s) that initiates and/or perpetuates the antiislet response in a mouse model of spontaneous autoimmune diabetes (non-obese diabetic [NOD] mice). In studies reported here, we have bred NOD mice to a mouse strain that congenitally lacks approximately one-half of the conventional TCR V beta alleles. Included in this deletion are TCR V beta gene products previously implicated as being involved in the pathogenesis of NOD disease. By studying second backcross-intercross animals, we were able to demonstrate that this deletion of TCR V beta gene segments did not prevent the development of insulitis or diabetes.
View details for Web of Science ID A1991GC96000014
View details for PubMedID 1831491
TRANSGENIC MICE FOR THE STUDY OF DIABETES-MELLITUS
TRENDS IN ENDOCRINOLOGY AND METABOLISM
1991; 2 (3): 97-104
Several recent studies have utilized transgenic technology to explore basic questions in the pathophysiology of diabetes mellitus. The ultimate expression of altered glucose homeostasis is a theme common to them. The experimental models have been diverse, however, and, in some instances, resulted in unexpected biologic effects. Many of the studies have examined the autoimmune etiology of insulin-dependent diabetes mellitus by expressing regulatory molecules of the immune system as transgenes in islet beta cells. The molecules have included products of the major histocompatibility complex (MHC), cytokines, and other cell surface antigens. Ectopic expression of these transgenes resulted in altered immune responses directed against islets, and these transgenic mice now serve as important models to study mechanisms of immunologic tolerance. Transgenic technology is also being used to explore basic aspects of islet beta-cell physiology and insulin metabolism. beta-cell function is disrupted by transgenic beta-cell expression of molecules such as calmodulin and H-ras. Hyperexpression of insulin as a transgene can result in a syndrome resembling features of non-insulin-dependent diabetes.
View details for Web of Science ID A1991FT22800004
View details for PubMedID 18411173
GENETIC-ANALYSIS OF DIABETES IN THE NONOBESE DIABETIC MOUSE .1. MHC AND T-CELL RECEPTOR BETA-GENE EXPRESSION
JOURNAL OF IMMUNOLOGY
1991; 146 (2): 529-534
Backcross nonobese diabetic (NOD) ((NOD x SWr)F1 x NOD) mice (108 females and 105 males) were typed for MHC, TCR V beta, and monitored for 350 days for the onset of diabetes. The presence of "antipolar" antibodies in the sera and the occurrence of insulitis was examined in a proportion of these backcross mice. There was no difference in the incidence of diabetes in mice heterozygous for TCR V beta b/a vs those homozygous for TCR V beta b/b. Among the 17 diabetics (all female) detected in this backcross, 14/17 were H-2nod/nod but 3/17 were H-2nod/q. This supports a previous observation suggesting that the MHC-linked diabetogenic gene originally thought to be recessive may rather be dominant but have a low penetrance in the heterozygous state. Antipolar autoantibodies were found in both female and male backcross mice, and were similarly distributed in diabetic and nondiabetic mice. There appeared to be no correlation between the level of these auto-antibodies and development of diabetes. The incidence and severity of insulitis was linked to MHC but no influence of TCR genes on insulitis nor an association between insulitis and antipolar antibodies could be demonstrated in this study. Further analyses of H-2nod/nod intercross mice homozygous for TCR V beta a or TCR V beta b are currently underway.
View details for Web of Science ID A1991EU50500019
View details for PubMedID 1824775
INDUCTION OF DONOR-SPECIFIC UNRESPONSIVENESS TO CARDIAC ALLOGRAFTS IN RATS BY PRETRANSPLANT ANTI-CD4 MONOCLONAL-ANTIBODY THERAPY
1990; 50 (3): 366-373
In the present report a monoclonal antibody designated OX-38 directed against the rat CD4 molecule was tested for its ability to prolong the survival of heterotopic vascularized rat heart allografts transplanted across major histocompatibility barriers. Fluorescence-activated cell-sorter analysis showed that administration of OX-38 selectively depleted 80-95% of CD4+ cells from peripheral blood of treated rats. The immunosuppressive effects of OX-38 in vivo were verified by suppression of an antibody response against OX-38 itself as a heterologous protein immunogen. Recipient rats received OX-38 antibody as a single agent given in pretransplant regimens. Nine of 12 treated rats have maintained heterotopic abdominal heart allografts for greater than 175 days. Control rats that did not receive antibody therapy rejected their grafts within 14 days. Rats that maintained heart allografts for greater than 100 days accepted second donor strain hearts but rejected third-party heart grafts transplanted into the femoral space. Anti-CD4-induced allograft unresponsiveness persisted for at least 90 days following surgical removal of donor tissue and retransplantation of a second donor-matched heart. These results indicated that transient, pretransplant therapy with monoclonal antibodies directed against the CD4+ lymphocyte induced specific, long-lasting unresponsiveness to fully MHC-mismatched cardiac allografts in rats without additional immunosuppression.
View details for Web of Science ID A1990DY85500002
View details for PubMedID 1976282
SELECTIVE T-CELL DEPLETION WITH OX-38 ANTI-CD4 MONOCLONAL-ANTIBODY PREVENTS CARDIAC ALLOGRAFT-REJECTION IN RATS
9TH ANNUAL MEETING AND SCIENTIFIC SESSIONS OF THE INTERNATIONAL SOC FOR HEART TRANSPLANTATION
MOSBY-YEAR BOOK INC. 1990: 482–88
New monoclonal antibodies directed to membrane molecules unique to lymphocyte subsets have provided the means to alter the immune response to alloantigens in a more selective fashion. This investigation demonstrates that monoclonal antibody-induced depletion of CD4 helper/inducer T lymphocytes before transplantation of a fully mismatched heart allograft allows permanent engraftment in rats without further immunosuppression. Five adult male ACI (RT1a) rats received cell-depleting doses of the mouse anti-rat CD4 monoclonal antibody, MRC Ox-38, for 1 month before undergoing heterotopic abdominal heart transplantation. No other immunosuppression was administered, and immunotherapy was discontinued the day of transplantation. After all five Lewis rat (RT1(1)) hearts were maintained free of rejection for more than 3 months, a second heterotopic transplant was performed, this time to the femoral vessels, using either fresh Lewis heart allografts (n = 3) or third-party, Brown-Norway (RT1n) hearts (n = 2). Histologic evaluation was performed 3 weeks later and revealed severe rejection of the femoral Brown-Norway grafts with no evidence of rejection in any of the femoral or original abdominal Lewis grafts. These results suggested that limited, pretransplant anti-CD4 immunotherapy allowed permanent engraftment of fully mismatched cardiac allografts in rats and conferred donor-specific unresponsiveness.
View details for Web of Science ID A1990EC26800005
View details for PubMedID 1977898
LOSS OF PANCREATIC-ISLET TOLERANCE INDUCED BY BETA-CELL EXPRESSION OF INTERFERON-GAMMA
1990; 346 (6287): 844-847
Interferon-gamma (IFN-gamma) is produced during the response to infection and participates in immunostimulatory events. We have previously reported the induction of diabetes in transgenic mice (ins-IFN-gamma) in which the expression of the lymphokine IFN-gamma is directed by the insulin promoter. This diabetes is a result of the progressive destruction of pancreatic islets that occurs with the influx of inflammatory cells. Here we demonstrate that this islet cell loss is mediated by lymphocytes, that engrafted histocompatible islets are destroyed, and that lymphocytes from the transgenic mice are cytotoxic to normal islets in vitro. These results indicate that the pancreatic expression of IFN-gamma can result in a loss of tolerance to normal islets, consistent with its role as an inducer of costimulatory activity, which is essential for lymphocyte activation during an immune response.
View details for Web of Science ID A1990DW48800055
View details for PubMedID 2118234
THE MOLECULAR-BASIS OF ANTIGEN-SPECIFIC RECOGNITION BY LYMPHOCYTES-T
COLLOQUIUM ON DEFENSE MOLECULES
WILEY-LISS, INC. 1990: 241–254
View details for Web of Science ID A1990BQ82X00020
CARDIAC ALLOGRAFT PROLONGATION IN MICE TREATED WITH COMBINED POSTTRANSPLANTATION TOTAL-LYMPHOID IRRADIATION AND ANTI-L3T4 ANTIBODY THERAPY
1989; 47 (4): 587-591
Neonatal cardiac allograft survival was examined in mice treated with anti-L3T4 antibody, posttransplantation total lymphoid irradiation (TLI) or a combination of both therapies. Independently, both posttransplantation TLI and short-course antibody treatment allowed minimal prolongation. However, synergistic prolongation in graft survival was observed with the combination (synergistic) therapy. Fluorescence-activated cell sorter analysis of peripheral blood lymphocytes from animals treated with combined anti-L3T4 and posttransplantation TLI additionally revealed "synergy" with respect to the degree of peripheral lymphocyte depletion.
View details for Web of Science ID A1989U208300004
View details for PubMedID 2523098
- INFLAMMATORY DESTRUCTION OF PANCREATIC BETA-CELLS IN GAMMA-INTERFERON TRANSGENIC MICE COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1989; 54: 837-842
USE OF ANTI-L3T4 AND ANTI-IA TREATMENTS FOR PROLONGATION OF XENOGENEIC ISLET TRANSPLANTS
1988; 46 (2): 210-215
The effects of T helper lymphocyte and Ia+ cell depletion were examined for their ability to independently and synergistically achieve prolongation of xenogeneic (rat-to-mouse) islet transplants. Recipient mice were depleted of T helper lymphocytes by short-term treatment with the anti-L3T4 monoclonal antibody GK1.5. Donor rat islets were treated prior to transplantation with a concentration of anti-Ia immunotoxin (13.4 x RT) that selectively depleted Ia+ cells within the islets while leaving functional insulin-secreting beta-cells unaffected. Anti-L3T4 treatment alone allowed transplants to be prolonged compared with untreated controls; however, all such treated mice rejected their xenogeneic transplant within 22 days. Although 13.4 x RT treatment of donor islets alone did not prolong engraftment, when donor rat islets were pretreated with the anti-Ia immunotoxin and grafted into L3T4-depleted mice, normoglycemia was maintained for greater than 50 days in 56% of transplants. These results suggest that neither L3T4 depletion nor anti-Ia immunotoxin treatment alone is enough to achieve indefinite survival of xenogeneic islets. However, decreasing the immunogenicity of the transplanted islets by anti-Ia immunotoxin treatment prior to transplantation into anti-L3T4 treated mice can allow greatly prolonged xenogeneic graft survival.
View details for Web of Science ID A1988P695400005
View details for PubMedID 2970132
IMMUNOTHERAPY OF THE NONOBESE DIABETIC MOUSE - TREATMENT WITH AN ANTIBODY TO T-HELPER LYMPHOCYTES
1988; 240 (4852): 659-662
Spontaneous diabetes mellitus was blocked in nonobese diabetic mice by treatment with a monoclonal antibody against the L3T4 determinant present on the surface of T-helper lymphocytes. Sustained treatment with the monoclonal antibody led to cessation of the lymphocytic infiltration associated with the destruction of the insulin-producing beta cells. Moreover, the mice remained normoglycemic after the antibody therapy was stopped. These studies indicate that immunotherapy with monoclonal antibodies to the lymphocyte subset may not only halt the progression of diabetes, but may lead to long-term reversal of the disease after therapy has ended.
View details for Web of Science ID A1988N126500035
View details for PubMedID 2966437
ISLET ALLOGRAFT SURVIVAL AFTER A SINGLE COURSE OF TREATMENT OF RECIPIENT WITH ANTIBODY TO L3T4
1987; 237 (4812): 278-280
Allografts of pancreatic islets of Langerhans were induced to survive for an indefinite period in diabetic mice if, at the time of engraftment, the mice received a single course of treatment with a monoclonal antibody directed against the L3T4 determinant, a nonpolymorphic cell surface glycoprotein present on the cell surface of the murine T helper-inducer lymphocyte subset. This treatment allowed the survival of islets of Langerhans transplanted across a major histocompatibility barrier without additional immunosuppression. The results demonstrate that the lymphocyte subset defined by the expression of the L3T4 molecules is central to the induction of allograft rejection and provides a model for tolerance induction for organ allograft transplantation.
View details for Web of Science ID A1987J154700019
View details for PubMedID 2955518
INHIBITION OF RAT MIXED LYMPHOCYTE PANCREATIC-ISLET CULTURES WITH ANTI-IA IMMUNOTOXIN
1986; 42 (6): 660-666
Studies reported here indicate that an anti-Ia immunotoxin can eliminate the allostimulatory subpopulation of cells present within the islets of Langerhans without damaging the hormone-secreting cells. Such studies made use of an in vitro correlate of transplantation rejection, the mixed lymphocyte islet cell (MLIC) reaction. Using the MLIC, it was demonstrated that an anti-Ia immunotoxin removed cells capable of stimulating the MLIC in a dose-dependent fashion without altering the hormone-secreting functions of the remaining cells when challenged with glucose and theophylline. These studies suggest the feasibility of using such anti-Ia immunotoxins in islet allograft transplantation models to circumvent problems inherent in complement-mediated cytotoxicity, a previously documented effective form of inducing islet allotransplantation tolerance.
View details for Web of Science ID A1986F366100016
View details for PubMedID 2947362
STRUCTURE, FUNCTION, AND IMMUNE PROPERTIES OF REASSOCIATED ISLET CELLS
1985; 34 (9): 898-903
Rat islets were mechanically dissociated to single cells and allowed to form aggregates by rotation-mediated cell-cell interaction. The aggregates, or neoislets, demonstrated insulin release in response to 20 mM glucose and 10 mM theophylline that was comparable to that of intact islets cultured for a similar time. However, basal insulin release was considerably greater than that from freshly isolated islets. The microscopic structure of the neoislets revealed sorting into a B-cell domain at the surface with A-cells interior to the aggregate. The neoislets generated no mitogenic response in allogeneic lymph node lymphocytes. Reassociation of single islet cells provides stable, functional endocrine units with substantial reduction of immunogenicity.
View details for Web of Science ID A1985AQC2600011
View details for PubMedID 3161769