- Pediatric Hematology-Oncology
Instructor in Pediatrics, Harvard Medical School (1973 - 1974)
Assistant Professor of Pediatrics, Harvard Medical School (1974 - 1977)
Associate Professor of Pediatrics, Stanford University (1977 - 1987)
Professor of Pediatrics, Stanford University (1987 - Present)
Internship: Stanford Health Care at Lucile Packard Children's Hospital (1969) CA
Fellowship: Boston Childrens Hospital Pediatric Hematology and Oncology Fellowship (1974) MA
Residency: Children's Hospital Boston Medical Center Pediatric Residency (1973) MA
Medical Education: Northwestern University Feinberg School of Medicine (1968) IL
Board Certification: American Board of Pediatrics, Pediatrics (1982)
Board Certification: American Board of Pediatrics, Pediatric Hematology-Oncology (1982)
Board Certification: American Board of Pathology, Hematology (1983)
BA, Northwestern University, Philosophy (1961)
PhD, University of Illinois, Physiology (1967)
MD, Northwestern University, Medicine (1968)
Current Research and Scholarly Interests
Hematology/Oncology, biology, and treatment of bone marrow failure disorders, hereditary coagulation disorders-clinical trials.
A Study of AG-348 in Adult Participants With Pyruvate Kinase (PK) Deficiency
Study AG348-C-003 is a multicenter study designed to evaluate the safety and efficacy of different dose levels of AG-348 (mitapivat) in participants with PK deficiency.
Pyruvate Kinase Deficiency Natural History Study
The purpose of this study is to describe the range and incidence of symptoms, treatments, and complications related to pyruvate kinase deficiency (PKD). Eligible patients are those of all ages with known PKD or with a hemolytic anemia and a family member with PKD. The study will collect retrospective medical history, routine clinical care data, and quality of life measures at baseline and annually for patients with PKD.
Stanford is currently not accepting patients for this trial. For more information, please contact Heather Hilmoe, CRA, 650-725-1662.
- Independent Studies (5)
- Prior Year Courses
BASELINE CHARACTERISTICS BY AGE OF A GLOBAL COHORT OF PATIENTS DIAGNOSED WITH PYRUVATE KINASE DEFICIENCY - A DESCRIPTIVE ANALYSIS FROM THE PEAK REGISTRY
FERRATA STORTI FOUNDATION. 2021: 107-108
View details for Web of Science ID 000719458000188
SLC25A38 Congenital Sideroblastic Anemia: Phenotypes and genotypes of 31 individuals from 24 families, including 11 novel mutations, and a review of the literature.
The congenital sideroblastic anemias (CSAs) are a heterogeneous group of inherited disorders of erythropoiesis characterized by pathologic deposits of iron in the mitochondria of developing erythroblasts. Mutations in the mitochondrial glycine carrier SLC25A38 cause the most common recessive form of CSA. Nonetheless, the disease is still rare, there being fewer than 70 reported families. Here we describe the clinical phenotype and genotypes of 31 individuals from 24 families, including 11 novel mutations. We also review the spectrum of reported mutations and genotypes associated with the disease, describe the unique localization of missense mutations in transmembrane domains and account for the presence of several alleles in different populations. This article is protected by copyright. All rights reserved.
View details for DOI 10.1002/humu.24267
View details for PubMedID 34298585
The active component of Ginseng, Ginsenoside Rb1, improves erythropoiesis in models of Diamond Blackfan Anemia by targeting Nemo-like Kinase.
The Journal of biological chemistry
Nemo-like kinase (NLK) is a member of the MAPK family of kinases and shares a highly conserved kinase domain with other MAPK family members. The activation of NLK contributes to the pathogenesis of Diamond Blackfan Anemia (DBA), reducing c-myb expression and mTOR activity, and is therefore a potential therapeutic target. Unlike other anemia's, the hematopoietic effects of DBA are largely restricted to the erythroid lineage. Mutations in ribosomal genes induces ribosomal insufficiency and reduced protein translation, dramatically impacting early erythropoiesis in the bone marrow of DBA patients. We sought to identify compounds that suppress NLK and increases erythropoiesis in ribosomal insufficiency. We report that the active component of ginseng, ginsenoside Rb1, suppresses NLK expression and improves erythropoiesis in in vitro models of Diamond Blackfan Anemia. Ginsenoside Rb1-mediated suppression of NLK occurs through the upregulation of miR-208, which binds to the 3'-UTR of NLK mRNA and targets it for degradation. We also compare ginsenoside Rb1-mediated upregulation of miR-208 with metformin-mediated upregulation of miR-26. We conclude that targeting NLK expression through miRNA binding of the unique 3'-UTR is a viable alternative to the challenges of developing small molecule inhibitors to target the highly conserved kinase domain of this specific kinase.
View details for DOI 10.1016/j.jbc.2021.100988
View details for PubMedID 34298020
Pyruvate kinase deficiency in children.
Pediatric blood & cancer
BACKGROUND: Pyruvate kinase deficiency (PKD) is a rare, autosomal recessive red blood cell enzyme disorder, which leads to lifelong hemolytic anemia and associated complications from the disease and its management.METHODS: An international, multicenter registry enrolled 124 individuals younger than 18years old with molecularly confirmed PKD from 29 centers. Retrospective and prospective clinical data were collected.RESULTS: There was a wide range in the age at diagnosis from 0 to 16years. Presentation in the newborn period ranged from asymptomatic to neonatal jaundice to fulminant presentations of fetal distress, myocardial depression, and/or liver failure. Children <5years old were significantly more likely to be transfused than children >12 to <18years (53% vs. 14%, p=.0006), which correlated with the timing of splenectomy. Regular transfusions were most common in children with two severe PKLR variants. In regularly transfused children, the nadir hemoglobin goal varied considerably. Impact on quality of life was a common reason for treatment with regular blood transfusions and splenectomy. Splenectomy increased the hemoglobin and decreased transfusion burden in most children but was associated with infection or sepsis (12%) and thrombosis (1.3%) even during childhood. Complication rates were high, including iron overload (48%), perinatal complications (31%), and gallstones (20%).CONCLUSIONS: There is a high burden of disease in children with PKD, with wide practice variation in monitoring and treatment. Clinicians must recognize the spectrum of the manifestations of PKD for early diagnostic testing, close monitoring, and management to avoid serious complications in childhood.
View details for DOI 10.1002/pbc.29148
View details for PubMedID 34125488
Lentiviral Mediated Gene Therapy for Pyruvate Kinase Deficiency: Updated Results of a Global Phase 1 Study for Adult and Pediatric Patients
CELL PRESS. 2021: 42-43
View details for Web of Science ID 000645188700083
Metformin-induced suppression of NLK improves erythropoiesis in pre-clinical models of Diamond Blackfan Anemia through induction of miR-26a.
Diamond Blackfan Anemia (DBA) results from haploinsufficiency of ribosomal protein subunits in hematopoietic progenitors in the earliest stages of committed erythropoiesis. Nemo-like kinase (NLK) is chronically hyperactivated in committed erythroid progenitors and precursors in multiple human and murine models of DBA. Inhibition of NLK activity, or suppression of NLK expression, both improve erythroid expansion in these models. Metformin is a well-tolerated drug for type 2 diabetes mellitus with multiple cellular targets. Here we demonstrate that metformin improves erythropoiesis in human and zebrafish models of DBA. Our data shows that the effects of metformin on erythroid proliferation and differentiation is mediated by suppression of NLK expression through induction of miR-26a, which recognizes a binding site within the NLK 3'UTR to facilitate transcript degradation. We propose that induction of miR-26a is a potentially novel approach to treat DBA and could improve anemia in DBA patients without the potentially adverse side effects of metformin in a DBA patient population.
View details for DOI 10.1016/j.exphem.2020.09.187
View details for PubMedID 32926965
Diamond Blackfan anemia is mediated by hyperactive Nemo-like kinase.
2020; 11 (1): 3344
Diamond Blackfan Anemia (DBA) is a congenital bone marrow failure syndrome associated with ribosomal gene mutations that lead to ribosomal insufficiency. DBA is characterized by anemia, congenital anomalies, and cancer predisposition. Treatment for DBA is associated with significant morbidity. Here, we report the identification of Nemo-like kinase (NLK) as a potential target for DBA therapy. To identify new DBA targets, we screen for small molecules that increase erythroid expansion in mouse models of DBA. This screen identified a compound that inhibits NLK. Chemical and genetic inhibition of NLK increases erythroid expansion in mouse and human progenitors, including bone marrow cells from DBA patients. In DBA models and patient samples, aberrant NLK activation is initiated at the Megakaryocyte/Erythroid Progenitor (MEP) stage of differentiation and is not observed in non-erythroid hematopoietic lineages or healthy erythroblasts. We propose that NLK mediates aberrant erythropoiesis in DBA and is a potential target for therapy.
View details for DOI 10.1038/s41467-020-17100-z
View details for PubMedID 32620751
The variable manifestations of disease in pyruvate kinase deficiency and their management.
Pyruvate kinase deficiency (PKD) is the most common cause of chronic hereditary nonspherocytic hemolytic anemia and results in a broad spectrum of disease. Diagnosis of PKD requires a high index of suspicion and judicious use of laboratory tests that may not always be informative, including PK enzyme assay and genetic analysis of the PKLR gene. A significant minority of patients with PKD have occult mutations in non-coding regions of PKLR that are missed on standard genetic tests. The biochemical consequences of PKD result in hemolytic anemia due to red cell pyruvate and ATP deficiency while simultaneously causing increased red cell 2,3-diphosphoglycerate, which facilitates oxygen unloading. This phenomenon, in addition to numerous other factors such as genetic background and differences in splenic function result in a poor correlation between symptoms and degree of anemia from patient to patient. Therefore, red cell transfusions should be symptom-directed and not based on a hemoglobin threshold. Patients may experience specific complications, such as paravertebral extramedullary hematopoiesis and chronic debilitating icterus, that require personalized treatment. The decision to perform splenectomy or hematopoietic stem cell transplantation is nuanced and depends on disease burden and long-term outlook given that targeted therapeutics are in development. In recognition of the complicated nature of the disease and its management and the limitations of the PKD literature, an international working group of 10 PKD experts convened to better define the burden and manifestations of disease. This manuscript summarizes the conclusions of this working group and is a guide for clinicians and investigators caring for patients with PKD.
View details for DOI 10.3324/haematol.2019.240846
View details for PubMedID 32165483
Genotype-Phenotype Correlation and Molecular Heterogeneity in Pyruvate Kinase Deficiency.
American journal of hematology
Pyruvate kinase (PK) deficiency is a rare recessive congenital hemolytic anemia caused by mutations in the PKLR gene. This study reports the molecular features of 257 patients enrolled in the PKD Natural History Study. Of the 127 different pathogenic variants detected, 84 were missense and 43 non-missense, including 20 stop-gain codon, 11 affecting splicing, 5 large deletions, 4 in-frame indels, and 3 promoter variants. Within the 177 unrelated patients, 35 were homozygous and 142 compound heterozygous (77 for two missense, 48 for one missense and one non-missense, and 17 for two non-missense variants); the two most frequent mutations were p.R510Q in 23% and p.R486W in 9% of mutated alleles. Fify-five (21%) patients were found to have at least one previously unreported variant with 45 newly described mutations. Patients with two non-missense mutations had lower hemoglobin levels, higher numbers of lifetime transfusions, and higher rates of complications including iron overload, extramedullary hematopoiesis, and pulmonary hypertension. Rare severe complications, including lower extremity ulcerations and hepatic failure, were seen more frequently in patients with non-missense mutations or with missense mutations characterized by severe protein instability. PKLR genotype did not correlate with the frequency of complications in utero or in the newborn period. With ICCs ranging from 0.4-0.61, about the same degree of clinical similarity exists within siblings as it does between siblings, in terms of hemoglobin, total bilirubin, splenectomy status, and cholecystectomy status. Pregnancy outcomes were similar across genotypes in PK deficient women. This report confirms the wide genetic heterogeneity of PK deficiency. This article is protected by copyright. All rights reserved.
View details for DOI 10.1002/ajh.25753
View details for PubMedID 32043619
The pyruvate kinase (PK) to hexokinase enzyme activity ratio and erythrocyte PK protein level in the diagnosis and phenotype of PK deficiency.
British journal of haematology
Diagnosis of pyruvate kinase deficiency (PKD), the most common cause of hereditary non-spherocytic haemolytic anaemia, remains challenging in routine practice and no biomarkers for clinical severity have been characterised. This prospective study enrolled 41 patients with molecularly confirmed PKD from nine North American centres to evaluate the diagnostic sensitivity of pyruvate kinase (PK) enzyme activity and PK:hexokinase (HK) enzyme activity ratio, and evaluate the erythrocyte PK (PK-R) protein level and erythrocyte metabolites as biomarkers for clinical severity. In this population not transfused for ≥90 days before sampling, the diagnostic sensitivity of the PK enzyme assay was 90% [95% confidence interval (CI) 77-97%], whereas the PK:HK ratio sensitivity was 98% (95% CI 87-100%). There was no correlation between PK enzyme activity and clinical severity. Transfusion requirements correlated with normalised erythrocyte ATP levels (r = 0·527, P = 0·0016) and PK-R protein levels (r = -0·527, P = 0·0028). PK-R protein levels were significantly higher in the never transfused [median (range) 40·1 (9·8-73·9)%] versus ever transfused [median (range) 7·7 (0·4-15·1)%] patients (P = 0·0014). The PK:HK ratio had excellent sensitivity for PK diagnosis, superior to PKLR exon sequencing. Given that the number of PKLR variants and genotype combinations limits prognostication based on molecular findings, PK-R protein level may be a useful prognostic biomarker of disease severity and merits further study.
View details for DOI 10.1111/bjh.16724
View details for PubMedID 32463523
The variable manifestations of disease in pyruvate kinase deficiency and their management.
2020; 105 (9): 2229–39
Pyruvate kinase deficiency (PKD) is the most common cause of chronic hereditary non-spherocytic hemolytic anemia and results in a broad spectrum of disease. The diagnosis of PKD requires a high index of suspicion and judicious use of laboratory tests that may not always be informative, including pyruvate kinase enzyme assay and genetic analysis of the PKLR gene. A significant minority of patients with PKD have occult mutations in non-coding regions of PKLR which are missed on standard genetic tests. The biochemical consequences of PKD result in hemolytic anemia due to red cell pyruvate and ATP deficiency while simultaneously causing increased red cell 2,3-diphosphoglycerate, which facilitates oxygen unloading. This phenomenon, in addition to numerous other factors such as genetic background and differences in splenic function result in a poor correlation between symptoms and degree of anemia from patient to patient. Red cell transfusions should, therefore, be symptom-directed and not based on a hemoglobin threshold. Patients may experience specific complications, such as paravertebral extramedullary hematopoiesis and chronic debilitating icterus, which require personalized treatment. The decision to perform splenectomy or hematopoietic stem cell transplantation is nuanced and depends on disease burden and long-term outlook given that targeted therapeutics are in development. In recognition of the complicated nature of the disease and its management and the limitations of the PKD literature, an international working group of ten PKD experts convened to better define the disease burden and manifestations. This article summarizes the conclusions of this working group and is a guide for clinicians and investigators caring for patients with PKD.
View details for DOI 10.3324/haematol.2019.240846
View details for PubMedID 33054048
Comorbidities and complications in adults with pyruvate kinase deficiency.
European journal of haematology
Pyruvate kinase (PK) deficiency is caused by PKLR gene mutations, leading to defective red blood cell glycolysis and hemolytic anemia. Rates of comorbidities and complications by transfusion history and relative to the general population remain poorly quantified.Data for patients aged ≥18 years with two confirmed PKLR mutations were obtained from the PK Deficiency Natural History Study (NCT02053480). Frequencies of select conditions were compared with an age- and sex-matched cohort from a general insured US population without PK deficiency.Compared with the matched population (n=1220), patients with PK deficiency (n=122) had significantly higher lifetime rates of osteoporosis, liver cirrhosis, and pulmonary hypertension; splenectomy and cholecystectomy rates were also significantly higher in the 8 years before the index date. Sixty-five (53.3%) patients with PK deficiency were classified as Regularly Transfused, 30 (24.6%) as Occasionally Transfused, and 27 (22.1%) as Never Transfused. Regularly Transfused patients were significantly more likely than Never Transfused patients to have had splenectomy, cholecystectomy, and/or thrombosis. Liver iron overload was reported in 62% of patients and occurred regardless of transfusion cohort.Even Never Transfused patients with PK deficiency had higher rates of select comorbidities and complications than individuals without PK deficiency.
View details for DOI 10.1111/ejh.13572
View details for PubMedID 33370479
- Characterization of the Severe Phenotype of Pyruvate Kinase Deficiency. American journal of hematology 2020
L-leucine improves anemia and growth in patients with transfusion-dependent Diamond-Blackfan anemia: Results from a multicenter pilot phase I/II study from the Diamond-Blackfan Anemia Registry.
Pediatric blood & cancer
Diamond-Blackfan anemia (DBA) is an inherited bone marrow failure syndrome characterized by anemia, short stature, congenital anomalies, and cancer predisposition. Most cases are due to mutations in genes encoding ribosomal proteins (RP) leading to RP haploinsufficiency. Effective treatments for the anemia of DBA include chronic red cell transfusions, long-term corticosteroid therapy, or hematopoietic stem cell transplantation. In a small patient series and in animal models, there have been hematologic responses to L-leucine with amelioration of anemia. The study objectives of this clinical trial were to determine feasibility, safety, and efficacy of L-leucine in transfusion-dependent patients with DBA.Patients ≥2 years of age received L-leucine 700 mg/m2 orally three times daily for nine months to determine a hematologic response and any improvement in growth (NCT01362595).This multicenter, phase I/II study enrolled 55 subjects; 43 were evaluable. There were 21 males; the median age at enrollment was 10.4 years (range, 2.5-46.1 years). No significant adverse events were attributable to L-leucine. Two subjects had a complete erythroid response and five had a partial response. Nine of 25, and 11 of 25, subjects experienced a positive weight and height percentile change, respectively, at the end of therapy.L-leucine is safe, resulted in an erythroid response in 16% of subjects with DBA, and led to an increase in weight and linear growth velocity in 36% and 44% of evaluable subjects, respectively. Further studies will be critical to understand the role of L-leucine in the management of patients with DBA.
View details for DOI 10.1002/pbc.28748
View details for PubMedID 33025707
- Pharmacological Inhibition of Nemo-like Kinase Rescues mTOR-Mediated Translation and Primes Progenitors for Leucine-Stimulated Erythroid Expansion in Pre-Clinical Models of Diamond Blackfan Anemia AMER SOC HEMATOLOGY. 2019
- Long-Term Safety and Efficacy of Mitapivat (AG-348), a Pyruvate Kinase Activator, in Patients with Pyruvate Kinase Deficiency: The DRIVE PK Study AMER SOC HEMATOLOGY. 2019
- An Ongoing Global, Longitudinal, Observational Study of Patients with Pyruvate Kinase Deficiency: The PEAK Registry AMER SOC HEMATOLOGY. 2019
- Pyruvate Kinase (PK) Protein and Enzyme Levels in the Diagnosis and Clinical Phenotype of PK Deficiency AMER SOC HEMATOLOGY. 2019
- Comorbidities and Complications in Adults with Pyruvate Kinase Deficiency AMER SOC HEMATOLOGY. 2019
- Characterization of the Severe Phenotype of Pyruvate Kinase Deficiency AMER SOC HEMATOLOGY. 2019
- Immunosuppressive therapy for pediatric aplastic anemia: a North American Pediatric Aplastic Anemia Consortium study HAEMATOLOGICA 2019; 104 (10): 1974–83
MMP9 inhibition increases erythropoiesis in RPS14-deficient del(5q) MDS models through suppression of TGF-beta pathways.
2019; 3 (18): 2751–63
The del(5q) myelodysplastic syndrome (MDS) is a distinct subtype of MDS, associated with deletion of the ribosomal protein S14 (RPS14) gene that results in macrocytic anemia. This study sought to identify novel targets for the treatment of patients with del(5q) MDS by performing an in vivo drug screen using an rps14-deficient zebrafish model. From this, we identified the secreted gelatinase matrix metalloproteinase 9 (MMP9). MMP9 inhibitors significantly improved the erythroid defect in rps14-deficient zebrafish. Similarly, treatment with MMP9 inhibitors increased the number ofcolony forming unit-erythroid colonies and the CD71+erythroid population from RPS14 knockdown human BMCD34+cells. Importantly, we found that MMP9 expression is upregulated in RPS14-deficient cells by monocyte chemoattractant protein 1. Double knockdown of MMP9 and RPS14 increased the CD71+population compared with RPS14 single knockdown, suggesting that increased expression of MMP9 contributes to the erythroid defect observed in RPS14-deficient cells. In addition, transforming growth factorbeta(TGF-beta) signaling is activated in RPS14 knockdown cells, and treatment with SB431542, a TGF-betainhibitor, improved the defective erythroid development of RPS14-deficient models. We found that recombinant MMP9 treatment decreases the CD71+population through increased SMAD2/3 phosphorylation, suggesting that MMP9 directly activates TGF-betasignaling in RPS14-deficient cells. Finally, we confirmed that MMP9 inhibitors reduce SMAD2/3 phosphorylation in RPS14-deficient cells to rescue the erythroid defect. In summary, these study results support a novel role for MMP9 in the pathogenesis of del(5q) MDS and the potential for the clinical use of MMP9 inhibitors in the treatment of patients with del(5q) MDS.
View details for DOI 10.1182/bloodadvances.2019000537
View details for PubMedID 31540902
INHIBITION OF NEMO-LIKE KINASE IMPROVES ERYTHROPOIESIS IN MODELS OF DIAMOND BLACKFAN ANEMIA
View details for Web of Science ID 000490282100027
Immunosuppressive therapy for pediatric aplastic anemia: a North American Pediatric Aplastic Anemia Consortium study.
Quality of response to immunosuppressive therapy and long-term outcomes for pediatric severe aplastic anemia remain incompletely characterized. Contemporary evidence to inform treatment of relapsed or refractory severe aplastic anemia are also limited for pediatric patients. The clinical features and outcomes for 314 children treated from 2002-2014 with immunosuppressive therapy for acquired severe aplastic anemia were analyzed retrospectively from 25 institutions in the North American Pediatric Aplastic Anemia Consortium. The majority of subjects (n=264) received horse anti-thymocyte globulin plus cyclosporine with 61 months median follow up. Following horse anti-thymocyte globulin/cyclosporine, 71.2% (95% CI: 65.3,76.6) achieved an objective response. In contrast to adult studies, the quality of response attained in pediatric patients was high, with 59.8% (95% CI: 53.7,65.8) reaching a complete response and 68.2% (95% CI: 62.2,73.8) attaining at least a very good partial response with a platelet count ≥50,000/muL. At 5 years post-horse anti-thymocyte globulin/cyclosporine, overall survival was 93% (95% CI: 89,96), but event free survival without subsequent treatment was only 64% (95% CI: 57,69) without a plateau. Twelve of 171 evaluable patients (7%) acquired clonal abnormalities after diagnosis with a median time of 25.2 months (range 4.3-71 months) post-treatment. Myelodysplastic syndrome or leukemia developed in 6/314 (1.9%). For relapsed/refractory disease, treatment with a hematopoietic stem cell transplant had a superior event-free survival compared to second immunosuppressive therapy treatment in a multivariate analysis (HR=0.19, 95% CI:0.08, 0.47, p=0.0003). This study highlights the need for improved therapies leading to sustained high quality remission for children with severe aplastic anemia.
View details for PubMedID 30948484
Prevalence and management of iron overload in pyruvate kinase deficiency: report from the Pyruvate Kinase Deficiency Natural History Study
2019; 104 (2): E51–E53
View details for PubMedID 30213831
- Addressing the diagnostic gaps in pyruvate kinase deficiency: Consensus recommendations on the diagnosis of pyruvate kinase deficiency AMERICAN JOURNAL OF HEMATOLOGY 2019; 94 (1): 149–61
Safety and Efficacy of Mitapivat in Pyruvate Kinase Deficiency.
The New England journal of medicine
2019; 381 (10): 933–44
Pyruvate kinase deficiency is caused by mutations in PKLR and leads to congenital hemolytic anemia. Mitapivat is an oral, small-molecule allosteric activator of pyruvate kinase in red cells.In this uncontrolled, phase 2 study, we evaluated the safety and efficacy of mitapivat in 52 adults with pyruvate kinase deficiency who were not receiving red-cell transfusions. The patients were randomly assigned to receive either 50 mg or 300 mg of mitapivat twice daily for a 24-week core period; eligible patients could continue treatment in an ongoing extension phase.Common adverse events, including headache and insomnia, occurred at the time of drug initiation and were transient; 92% of the episodes of headache and 47% of the episodes of insomnia resolved within 7 days. The most common serious adverse events, hemolytic anemia and pharyngitis, each occurred in 2 patients (4%). A total of 26 patients (50%) had an increase of more than 1.0 g per deciliter in the hemoglobin level. Among these patients, the mean maximum increase was 3.4 g per deciliter (range, 1.1 to 5.8), and the median time until the first increase of more than 1.0 g per deciliter was 10 days (range, 7 to 187); 20 patients (77%) had an increase of more than 1.0 g per deciliter in the hemoglobin level at more than 50% of visits during the core study period, with improvement in markers of hemolysis. The response was sustained in all 19 patients remaining in the extension phase, with a median follow-up of 29 months (range, 22 to 35). Hemoglobin responses were observed only in patients who had at least one missense PKLR mutation and were associated with the red-cell pyruvate kinase protein level at baseline.The administration of mitapivat was associated with a rapid increase in the hemoglobin level in 50% of adults with pyruvate kinase deficiency, with a sustained response during a median follow-up of 29 months during the extension phase. Adverse effects were mainly low-grade and transient. (Funded by Agios Pharmaceuticals; ClinicalTrials.gov number, NCT02476916.).
View details for DOI 10.1056/NEJMoa1902678
View details for PubMedID 31483964
- Health Related Quality of Life and Fatigue in Patients with Pyruvate Kinase Deficiency AMER SOC HEMATOLOGY. 2018
- Leucine for the Treatment of Transfusion Dependence in Patients with Diamond Blackfan Anemia AMER SOC HEMATOLOGY. 2018
- Pharmacological Inhibition of Nlk (Nemo-like Kinase) Rescues Erythropoietic Defects in Pre-Clinical Models of Diamond Blackfan Anemia AMER SOC HEMATOLOGY. 2018
- Pklr Intron Splicing-Associated Mutations and Alternate Diagnoses Are Common in Pyruvate Kinase Deficient Patients with Single or No Pklr Coding Mutations AMER SOC HEMATOLOGY. 2018
- Genotype-Response Correlation in DRIVE PK, a Phase 2 Study of AG-348 in Patients with Pyruvate Kinase Deficiency AMER SOC HEMATOLOGY. 2018
The Genetic Landscape of Diamond-Blackfan Anemia.
American journal of human genetics
Diamond-Blackfan anemia (DBA) is a rare bone marrow failure disorder that affects 7 out of 1,000,000 live births and has been associated with mutations in components of the ribosome. In order to characterize the genetic landscape of this heterogeneous disorder, we recruited a cohort of 472 individuals with a clinical diagnosis of DBA and performed whole-exome sequencing (WES). We identified relevant rare and predicted damaging mutations for 78% of individuals. The majority of mutations were singletons, absent from population databases, predicted to cause loss of function, and located in 1 of 19 previously reported ribosomal protein (RP)-encoding genes. Using exon coverage estimates, we identified and validated 31 deletions in RP genes. We also observed an enrichment for extended splice site mutations and validated their diverse effects using RNA sequencing in cell lines obtained from individuals with DBA. Leveraging the size of our cohort, we observed robust genotype-phenotype associations with congenital abnormalities and treatment outcomes. We further identified rare mutations in seven previously unreported RP genes that may cause DBA, as well as several distinct disorders that appear to phenocopy DBA, including nine individuals with biallelic CECR1 mutations that result in deficiency of ADA2. However, no new genes were identified at exome-wide significance, suggesting that there are no unidentified genes containing mutations readily identified by WES that explain >5% of DBA-affected case subjects. Overall, this report should inform not only clinical practice for DBA-affected individuals, but also the design and analysis of rare variant studies for heterogeneous Mendelian disorders.
View details for PubMedID 30503522
Addressing the diagnostic gaps in pyruvate kinase (PK) deficiency: Consensus recommendations on the diagnosis of PK deficiency.
American journal of hematology
Pyruvate kinase deficiency is the most common enzyme defect of glycolysis and an important cause of hereditary, non-spherocytic hemolytic anemia. The disease has a worldwide geographical distribution but there are no verified data regarding its frequency. Difficulties in the diagnostic workflow and interpretation of PK enzyme assay likely play a role. By the creation of a global PKD International Working Group in 2016, involving 24 experts from 20 Centres of Expertise we studied the current gaps in the diagnosis of PKD in order to establish diagnostic guidelines. By means of a detailed survey and subsequent discussions, multiple aspects of the diagnosis of PKD were evaluated and discussed by members of Expert Centres from Europe, USA, and Asia directly involved in diagnosis. Broad consensus was reached among the Centres on many clinical and technical aspects of the diagnosis of PKD. The results of this study are here presented as recommendations for the diagnosis of PKD and used to prepare a diagnostic algorithm. This information might be helpful for other Centres to deliver timely and appropriate diagnosis and to increase awareness in pyruvate kinase deficiency. This article is protected by copyright. All rights reserved.
View details for PubMedID 30358897
Hb Adana (HBA2 or HBA1: c.179G > A) and alpha thalassemia: Genotype-phenotype correlation
PEDIATRIC BLOOD & CANCER
2018; 65 (9): e27220
Alpha thalassemia due to nondeletional mutations usually leads to more severe disease than that caused by deletional mutations. Devastating outcomes such as hydrops fetalis can occur with two nondeletional mutations, therefore warranting DNA-based workup for suspected carriers with subtle hematological abnormalities for family counseling purposes. We describe three cases with hemoglobin (Hb) Adana, a nondeletional alpha chain mutation, compounded with an alpha globin gene deletion resulting in thalassemia intermedia. We review the literature, draw genotype-phenotype correlations from published cases of Hb Adana, and propose that this correlation can be used by clinicians to help direct diagnostic studies and urge hematologists to thoroughly workup high-risk patients.
View details for PubMedID 29749692
Red Blood Cell Enzyme Disorders
PEDIATRIC CLINICS OF NORTH AMERICA
2018; 65 (3): 579-+
Mature red blood cells are reliant on the glycolytic pathway for energy production and the hexose monophosphate shunt for cell protection from oxidative insults. The most common red blood cell enzyme disorders are characterized by hemolysis but with wide clinical variability. Glucose-6-phosphate dehydrogenase deficiency is the most common red cell enzyme disorder worldwide. Frequent clinical presentations include neonatal jaundice and episodic hemolysis after exposure to oxidative stress. Symptoms of pyruvate kinase deficiency and other glycolytic enzyme disorders include neonatal jaundice, chronic hemolytic anemia, gallstones, and transfusion-related and transfusion-independent iron overload. Diagnosis is critical for appropriate supportive care, monitoring, and treatment.
View details for PubMedID 29803284
CLINICAL OUTCOME OF HB KHARTOUM/beta THALASSEMIA COMPOUND HETEROZYGOSITY: A GLIMPSE INTO HOMOZYGOUS HB KHARTOUM
View details for Web of Science ID 000428851200076
Clinical spectrum of pyruvate kinase deficiency: data from the Pyruvate Kinase Deficiency Natural History Study
2018; 131 (20): 2183–92
An international, multicenter registry was established to collect retrospective and prospective clinical data on patients with pyruvate kinase (PK) deficiency, the most common glycolytic defect causing congenital nonspherocytic hemolytic anemia. Medical history and laboratory and radiologic data were retrospectively collected at enrollment for 254 patients with molecularly confirmed PK deficiency. Perinatal complications were common, including anemia that required transfusions, hyperbilirubinemia, hydrops, and prematurity. Nearly all newborns were treated with phototherapy (93%), and many were treated with exchange transfusions (46%). Children age 5 years and younger were often transfused until splenectomy. Splenectomy (150 [59%] of 254 patients) was associated with a median increase in hemoglobin of 1.6 g/dL and a decreased transfusion burden in 90% of patients. Predictors of a response to splenectomy included higher presplenectomy hemoglobin (P = .007), lower indirect bilirubin (P = .005), and missense PKLR mutations (P = .0017). Postsplenectomy thrombosis was reported in 11% of patients. The most frequent complications included iron overload (48%) and gallstones (45%), but other complications such as aplastic crises, osteopenia/bone fragility, extramedullary hematopoiesis, postsplenectomy sepsis, pulmonary hypertension, and leg ulcers were not uncommon. Overall, 87 (34%) of 254 patients had both a splenectomy and cholecystectomy. In those who had a splenectomy without simultaneous cholecystectomy, 48% later required a cholecystectomy. Although the risk of complications increases with severity of anemia and a genotype-phenotype relationship was observed, complications were common in all patients with PK deficiency. Diagnostic testing for PK deficiency should be considered in patients with apparent congenital hemolytic anemia and close monitoring for iron overload, gallstones, and other complications is needed regardless of baseline hemoglobin. This trial was registered at www.clinicaltrials.gov as #NCT02053480.
View details for PubMedID 29549173
- Increased Prevalence of Congenital Heart Disease in Children With Diamond Blackfan Anemia Suggests Unrecognized Diamond Blackfan Anemia as a Cause of Congenital Heart Disease in the General Population A Report of the Diamond Blackfan Anemia Registry CIRCULATION-GENOMIC AND PRECISION MEDICINE 2018; 11 (5): e002044
Anemia in Children
ANEMIA: PATHOPHYSIOLOGY, DIAGNOSIS, AND MANAGEMENT
View details for Web of Science ID 000588053200034
EFFECTS OF AG-348, A PYRUVATE KINASE ACTIVATOR, IN PATIENTS WITH PYRUVATE KINASE DEFICIENCY: UPDATED RESULTS FROM THE DRIVE PK STUDY
FERRATA STORTI FOUNDATION. 2017: 164
View details for Web of Science ID 000404127001345
Loss of FOXM1 promotes erythropoiesis through increased proliferation of erythroid progenitors.
Forkhead box M1 (FOXM1) belongs to the forkhead/winged-helix family of transcription factors and regulates a network of proliferation-associated genes. Its abnormal upregulation has been shown to be a key driver of cancer progression and an initiating factor in oncogenesis. FOXM1 is also highly expressed in stem/progenitor cells and inhibits their differentiation, suggesting that FOXM1 plays a role in the maintenance of multipotency. However, the exact molecular mechanisms by which FOXM1 regulates human stem/progenitor cells are still uncharacterized. To understand the role of FOXM1 in normal hematopoiesis, human cord blood CD34(+) cells were transduced with FOXM1 short hairpin ribonucleic acid (shRNA) lentivirus. Knockdown of FOXM1 resulted in a 2-fold increase in erythroid cells compared to myeloid cells. Additionally, knockdown of FOXM1 increased bromodeoxyuridine (BrdU) incorporation in erythroid cells, suggesting greater proliferation of erythroid progenitors. We also observed that the defective phosphorylation of FOXM1 by checkpoint kinase 2 (CHK2) or cyclin-dependent kinases 1/2 (CDK1/2) increased the erythroid population in a manner similar to knockdown of FOXM1. Finally, we found that an inhibitor of FOXM1, forkhead domain inhibitor-6 (FDI-6), increased red blood cell numbers through increased proliferation of erythroid precursors. Overall, our data suggest a novel function of FOXM1 in normal human hematopoiesis.
View details for DOI 10.3324/haematol.2016.156257
View details for PubMedID 28154085
Role of Mir-34 Upregulation in Disruption of c-Myc, c-Myb and NOTCH Signaling in Diamond-Blackfan Anemia
AMER SOC HEMATOLOGY. 2016
View details for Web of Science ID 000394452303022
Effects of AG-348, a Pyruvate Kinase Activator, on Anemia and Hemolysis in Patients with Pyruvate Kinase Deficiency: Data from the DRIVE PK Study
AMER SOC HEMATOLOGY. 2016
View details for Web of Science ID 000394446800011
Erythrocyte adenosine deaminase levels are elevated in Diamond Blackfan anemia but not in the 5q-syndrome
AMERICAN JOURNAL OF HEMATOLOGY
2016; 91 (12): E501–E502
View details for PubMedID 27556864
A novel pathogenic mutation in RPL11 identified in a patient diagnosed with diamond Blackfan anemia as a young adult
BLOOD CELLS MOLECULES AND DISEASES
2016; 61: 46–47
View details for PubMedID 27667165
- In memoriam: Bernard G. Forget AMERICAN JOURNAL OF HEMATOLOGY 2016; 91 (7): 653
EFFECTS OF AG-348, A PYRUVATE KINASE ACTIVATOR, ON ANEMIA AND HEMOLYSIS IN PATIENTS WITH PYRUVATE KINASE DEFICIENCY: EARLY DATA FROM THE DRIVE PK STUDY
FERRATA STORTI FOUNDATION. 2016: 169
View details for Web of Science ID 000379484600372
- Anti-Mur as the most likely cause of mild hemolytic disease of the newborn TRANSFUSION 2016; 56 (5): 1182-1184
- Diagnosis of Pyruvate Kinase Deficiency. Pediatric blood & cancer 2016; 63 (5): 771-772
Updated analysis: central venous access device infection rates in an expanded cohort of paediatric patients with severe haemophilia receiving prophylactic recombinant tissue plasminogen activator.
2016; 22 (1): 81-86
Central venous access devices (CVADs) are used in the care of paediatric haemophilic patients with difficult peripheral access, but their use is limited by complications such as infection. We previously published our experience with monthly recombinant tissue plasminogen activator (r-tPA) administration to CVADs of haemophilic patients as an intervention for infection prophylaxis, which suggested a 10-fold decrease in infection rate compared to published rates without r-tPA.This study was conducted to assess the CVAD infection rate in an expanded haemophilia cohort receiving r-tPA over an extended period.A retrospective review was performed on patients with haemophilia who received monthly r-tPA to CVADs, with data collected from January 1, 2008 to December 31, 2012. The data were merged with the previously reported data set (collected from June 1, 1998 to December 31, 2007).Over the entire observation period, there were 46 350 CVAD days among 32 patients [26 severe factor VIII (FVIII) deficiency, six severe FIX deficiency]. Eight patients received immune tolerance therapy for inhibitors and 24 patients received prophylactic factor administration. No patients were HIV positive. Three infections were observed, with an overall infection rate of 0.06 infections per 1000 CVAD days.A low CVAD infection rate, similar to that observed in our previous study (0.04 per 1000 CVAD days), was observed in this expanded haemophilia cohort treated with prophylactic r-tPA, supporting the use of monthly r-tPA as CVAD infection prophylaxis in haemophilia patients.
View details for DOI 10.1111/hae.12772
View details for PubMedID 26248602
Anti-Mur as the most likely cause of mild hemolytic disease of the newborn.
2016; 56 (5): 1182–84
Although rare in the United States, anti-Mur is relatively common in Southeast Asia and has been reported to have clinical significance in Chinese and Taiwanese populations.The infant was full term and the second child of a Chinese mother and Vietnamese father, presenting with jaundice. He was clinically diagnosed with immune-mediated hemolytic anemia.The direct antiglobulin test indicated that the infant's red blood cells were coated only with anti-IgG. Anti-Mur was identified in the maternal serum and the neonate's plasma. The father was found to be positive for the Mur antigen. The cause of the infant's hemolytic anemia was determined to be most likely anti-Mur.Since anti-Mur is implicated in causing hemolytic disease of the newborn, it is important to recognize this antibody more commonly found in Asian patients in the United States as the Mur+ phenotype has a higher prevalence in this population.
View details for PubMedID 26996653
Hematologic outcomes after total splenectomy and partial splenectomy for congenital hemolytic anemia.
Journal of pediatric surgery
2016; 51 (1): 122–27
The purpose of this study was to define the hematologic response to total splenectomy (TS) or partial splenectomy (PS) in children with hereditary spherocytosis (HS) or sickle cell disease (SCD).The Splenectomy in Congenital Hemolytic Anemia (SICHA) consortium registry collected hematologic outcomes of children with CHA undergoing TS or PS to 1 year after surgery. Using random effects mixed modeling, we evaluated the association of operative type with change in hemoglobin, reticulocyte counts, and bilirubin. We also compared laparoscopic to open splenectomy.The analysis included 130 children, with 62.3% (n=81) undergoing TS. For children with HS, all hematologic measures improved after TS, including a 4.1g/dl increase in hemoglobin. Hematologic parameters also improved after PS, although the response was less robust (hemoglobin increase 2.4 g/dl, p<0.001). For children with SCD, there was no change in hemoglobin. Laparoscopy was not associated with differences in hematologic outcomes compared to open. TS and laparoscopy were associated with shorter length of stay.Children with HS have an excellent hematologic response after TS or PS, although the hematologic response is more robust following TS. Children with SCD have smaller changes in their hematologic parameters. These data offer guidance to families and clinicians considering TS or PS.
View details for PubMedID 26613837
Hematologic outcomes after total splenectomy and partial splenectomy for congenital hemolytic anemia
JOURNAL OF PEDIATRIC SURGERY
2016; 51 (1): 122-127
View details for DOI 10.1016/j.jpedsurg.2015.10.028
View details for Web of Science ID 000367696600024
View details for PubMedCentralID PMC5083068
DRIVE PK: A Phase 2 Trial of AG-348 in Patients with Pyruvate Kinase Deficiency
AMER SOC HEMATOLOGY. 2015
View details for Web of Science ID 000368021802173
The Phenotypic Spectrum of Pyruvate Kinase Deficiency (PKD) from the PKD Natural History Study (NHS): Description of Four Severity Groups By Anemia Status
AMER SOC HEMATOLOGY. 2015
View details for Web of Science ID 000368020100301
Molecular Characterization of 140 Patients in the Pyruvate Kinase Deficiency (PKD) Natural History Study (NHS): Report of 20 New Variants
AMER SOC HEMATOLOGY. 2015
View details for Web of Science ID 000368020104219
Loss of FoxM1 Promotes Erythroid Differentiation through Increased Proliferation of Erythroid Progenitors
AMER SOC HEMATOLOGY. 2015
View details for Web of Science ID 000368019003057
Point-of-Care Quantitative Measure of Glucose-6-Phosphate Dehydrogenase Enzyme Deficiency
2015; 136 (5): E1268-E1275
Widespread newborn screening on a point-of-care basis could prevent bilirubin neurotoxicity in newborns with glucose-6-phosphate dehydrogenase (G6PD) deficiency. We evaluated a quantitative G6PD assay on a digital microfluidic platform by comparing its performance with standard clinical methods.G6PD activity was measured quantitatively by using digital microfluidic fluorescence and the gold standard fluorescence biochemical test on a convenience sample of 98 discarded blood samples. Twenty-four samples were designated as G6PD deficient.Mean ± SD G6PD activity for normal samples using the digital microfluidic method and the standard method, respectively, was 9.7 ± 2.8 and 11.1 ± 3.0 U/g hemoglobin (Hb), respectively; for G6PD-deficient samples, it was 0.8 ± 0.7 and 1.4 ± 0.9 U/g Hb. Bland-Altman analysis determined a mean difference of -0.96 ± 1.8 U/g Hb between the digital microfluidic fluorescence results and the standard biochemical test results. The lower and upper limits for the digital microfluidic platform were 4.5 to 19.5 U/g Hb for normal samples and 0.2 to 3.7 U/g Hb for G6PD-deficient samples. The lower and upper limits for the Stanford method were 5.5 to 20.7 U/g Hb for normal samples and 0.1 to 2.8 U/g Hb for G6PD-deficient samples. The measured activity discriminated between G6PD-deficient samples and normal samples with no overlap.Pending further validation, a digital microfluidics platform could be an accurate point-of-care screening tool for rapid newborn G6PD screening.
View details for DOI 10.1542/peds.2015-2122
View details for Web of Science ID 000363969600012
View details for PubMedID 26459646
View details for PubMedCentralID PMC4621802
Point-of-Care Quantitative Measure of Glucose-6-Phosphate Dehydrogenase Enzyme Deficiency.
2015; 136 (5): e1268-75
View details for DOI 10.1542/peds.2015-2122
View details for PubMedID 26459646
Erythrocyte pyruvate kinase deficiency: 2015 status report
AMERICAN JOURNAL OF HEMATOLOGY
2015; 90 (9): 825-830
Over the last several decades, our understanding of the genetic variation, pathophysiology, and complications of the hemolytic anemia associated with red cell pyruvate kinase deficiency (PKD) has expanded. Nonetheless, there remain significant gaps in our knowledge with regard to clinical care and monitoring. Treatment remains supportive with phototherapy and/or exchange transfusion in the newborn period, regular or intermittent red cell transfusions in children and adults, and splenectomy to decrease transfusion requirements and/or anemia related symptoms. In this article, we review the clinical diversity of PKD, the current standard of treatment and for supportive care, the complications observed, and future treatment directions.
View details for DOI 10.1002/ajh.24088
View details for Web of Science ID 000360218000027
View details for PubMedCentralID PMC5053227
THE CLINICAL FEATURES AND TREATMENT OF IRON OVERLOAD IN PYRUVATE KINASE DEFICIENCY (PKD): DATA FROM THE PKD NATURAL HISTORY STUDY (NHS)
FERRATA STORTI FOUNDATION. 2015: 588
View details for Web of Science ID 000361204904008
CATEGORIZATION OF CLINICAL SEVERITY IN PYRUVATE KINASE DEFICIENCY (PKD) IN AN INTERNATIONAL, OBSERVATIONAL COHORT
FERRATA STORTI FOUNDATION. 2015: 130–31
View details for Web of Science ID 000361204901281
Clinical outcomes of splenectomy in children: Report of the splenectomy in congenital hemolytic anemia registry.
American journal of hematology
2015; 90 (3): 187-192
The outcomes of children with congenital hemolytic anemia (CHA) undergoing total splenectomy (TS) or partial splenectomy (PS) remain unclear. In this study, we collected data from 100 children with CHA who underwent TS or PS from 2005 to 2013 at 16 sites in the Splenectomy in Congenital Hemolytic Anemia (SICHA) consortium using a patient registry. We analyzed demographics and baseline clinical status, operative details, and outcomes at 4, 24, and 52 weeks after surgery. Results were summarized as hematologic outcomes, short-term adverse events (AEs) (≤30 days after surgery), and long-term AEs (31-365 days after surgery). For children with hereditary spherocytosis, after surgery there was an increase in hemoglobin (baseline 10.1 ± 1.8 g/dl, 52 week 12.8 ± 1.6 g/dl; mean ± SD), decrease in reticulocyte and bilirubin as well as control of symptoms. Children with sickle cell disease had control of clinical symptoms after surgery, but had no change in hematologic parameters. There was an 11% rate of short-term AEs and 11% rate of long-term AEs. As we accumulate more subjects and longer follow-up, use of a patient registry should enhance our capacity for clinical trials and engage all stakeholders in the decision-making process. Am. J. Hematol. 90:187-192, 2015. © 2014 Wiley Periodicals, Inc.
View details for DOI 10.1002/ajh.23888
View details for PubMedID 25382665
View details for PubMedCentralID PMC4333061
Erythrocyte pyruvate kinase deficiency: 2015 status report.
American journal of hematology
2015; 90 (9): 825–30
View details for PubMedID 26087744
TNF-mediated inflammation represses GATA1 and activates p38 MAP kinase in RPS19-deficient hematopoietic progenitors.
2014; 124 (25): 3791-3798
Diamond-Blackfan anemia (DBA) is an inherited disorder characterized by defects in erythropoiesis, congenital abnormalities, and predisposition to cancer. Approximately 25% of DBA patients have a mutation in RPS19, which encodes a component of the 40S ribosomal subunit. Upregulation of p53 contributes to the pathogenesis of DBA, but the link between ribosomal protein mutations and erythropoietic defects is not well understood. We found that RPS19 deficiency in hematopoietic progenitor cells leads to decreased GATA1 expression in the erythroid progenitor population and p53-dependent upregulation of tumor necrosis factor-α (TNF-α) in nonerythroid cells. The decrease in GATA1 expression was mediated, at least in part, by activation of p38 MAPK in erythroid cells and rescued by inhibition of TNF-α or p53. The anemia phenotype in rps19-deficient zebrafish was reversed by treatment with the TNF-α inhibitor etanercept. Our data reveal that RPS19 deficiency leads to inflammation, p53-dependent increase in TNF-α, activation of p38 MAPK, and decreased GATA1 expression, suggesting a novel mechanism for the erythroid defects observed in DBA.
View details for DOI 10.1182/blood-2014-06-584656
View details for PubMedID 25270909
Understanding the Role of Erythrocyte Adenosine Deaminase in the Ribosomopathies
AMER SOC HEMATOLOGY. 2014
View details for Web of Science ID 000349233804095
RPS19 Deficiency Leads to GATA1 Downregulation through TNF-Mediated p38 MAPK Activation
AMER SOC HEMATOLOGY. 2014
View details for Web of Science ID 000349233801127
Novel protocol including liver biopsy to identify and treat CD8+ T-cell predominant acute hepatitis and liver failure.
2014; 18 (5): 503-509
In the majority of children with ALF, the etiology is unknown and liver transplantation is often needed for survival. A patient case prompted us to consider that immune dysregulation may be the cause of indeterminate acute hepatitis and liver failure in children. Our study includes nine pediatric patients treated under a multidisciplinary clinical protocol to identify and treat immune-mediated acute liver injury. Patients with evidence of inflammation and no active infection on biopsy received treatment with intravenous immune globulin and methylprednisolone. Seven patients had at least one positive immune marker before or after treatment. All patients had a CD8+ T-cell predominant liver injury that completely or partially responded to immune therapy. Five of the nine patients recovered liver function and did not require liver transplantation. Three of these patients subsequently developed bone marrow failure and were treated with either immunosuppression or stem cell transplant. This series highlights the importance of this tissue-based approach to diagnosis and treatment that may improve transplant-free survival. Further research is necessary to better characterize the immune injury and to predict the subset of patients at risk for bone marrow failure who may benefit from earlier and stronger immunosuppressive therapy.
View details for DOI 10.1111/petr.12296
View details for PubMedID 24930635
The role of the DNA damage response in zebrafish and cellular models of Diamond Blackfan anemia.
Disease models & mechanisms
2014; 7 (7): 895-905
Ribosomal biogenesis involves the processing of pre-ribosomal RNA. A deficiency of some ribosomal proteins (RPs) impairs processing and causes Diamond Blackfan anemia (DBA), which is associated with anemia, congenital malformations and cancer. p53 mediates many features of DBA, but the mechanism of p53 activation remains unclear. Another hallmark of DBA is the upregulation of adenosine deaminase (ADA), indicating changes in nucleotide metabolism. In RP-deficient zebrafish, we found activation of both nucleotide catabolism and biosynthesis, which is consistent with the need to break and replace the faulty ribosomal RNA. We also found upregulation of deoxynucleotide triphosphate (dNTP) synthesis - a typical response to replication stress and DNA damage. Both RP-deficient zebrafish and human hematopoietic cells showed activation of the ATR/ATM-CHK1/CHK2/p53 pathway. Other features of RP deficiency included an imbalanced dNTP pool, ATP depletion and AMPK activation. Replication stress and DNA damage in cultured cells in non-DBA models can be decreased by exogenous nucleosides. Therefore, we treated RP-deficient zebrafish embryos with exogenous nucleosides and observed decreased activation of p53 and AMPK, reduced apoptosis, and rescue of hematopoiesis. Our data suggest that the DNA damage response contributes to p53 activation in cellular and zebrafish models of DBA. Furthermore, the rescue of RP-deficient zebrafish with exogenous nucleosides suggests that nucleoside supplements could be beneficial in the treatment of DBA.
View details for DOI 10.1242/dmm.015495
View details for PubMedID 24812435
Novel deletion of RPL15 identified by array-comparative genomic hybridization in Diamond-Blackfan anemia
2013; 132 (11): 1265-1274
Diamond-Blackfan anemia (DBA) is an inherited red blood cell aplasia that usually presents during the first year of life. The main features of the disease are normochromic and macrocytic anemia, reticulocytopenia, and nearly absent erythroid progenitors in the bone marrow. The patients also present with growth retardation and craniofacial, upper limb, heart and urinary system congenital malformations in ~30-50 % of cases. The disease has been associated with point mutations and large deletions in ten ribosomal protein (RP) genes RPS19, RPS24, RPS17, RPL35A, RPL5, RPL11, RPS7, RPS10, RPS26, and RPL26 and GATA1 in about 60-65 % of patients. Here, we report a novel large deletion in RPL15, a gene not previously implicated to be causative in DBA. Like RPL26, RPL15 presents the distinctive feature of being required both for 60S subunit formation and for efficient cleavage of the internal transcribed spacer 1. In addition, we detected five deletions in RP genes in which mutations have been previously shown to cause DBA: one each in RPS19, RPS24, and RPS26, and two in RPS17. Pre-ribosomal RNA processing was affected in cells established from the patients bearing these deletions, suggesting a possible molecular basis for their pathological effect. These data identify RPL15 as a new gene involved in DBA and further support the presence of large deletions in RP genes in DBA patients.
View details for DOI 10.1007/s00439-013-1326-z
View details for Web of Science ID 000325706500007
View details for PubMedID 23812780
View details for PubMedCentralID PMC3797874
Immune Thrombocytopenia in Children Less Than 1 Year of Age: A Single-institution 10-year Experience.
Journal of pediatric hematology/oncology
2013; 35 (5): 406-408
Immune thrombocytopenia (ITP) in children less than one year of age is less well characterized compared to ITP in toddlers and school-age children. We performed a 10-year retrospective review of ITP patients in this age-cohort at our institution. Diagnosis and classification were made according to the 2009 International Working Group criteria. Fourteen infants were identified. Their bleeding scores were Grades 1 to 2 (79%), Grade 3 (22%), Grades 4 to 5 (0%). Eight patients received treatment with a 75% response rate. Three patients (21%) developed chronic ITP. These observations suggest that ITP in very young patients is similar to typical childhood ITP.
View details for DOI 10.1097/MPH.0b013e3182580ab4
View details for PubMedID 22767132
MONTHLY RECOMBINANT TISSUE PLASMINOGEN ACTIVATOR ADMINISTRATION TO IMPLANTABLE CENTRAL VENOUS ACCESS DEVICES DECREASES INFECTIONS IN CHILDREN WITH HEMOPHILIA: UPDATED ANALYSIS FROM AN EXPANDED COHORT
WILEY-BLACKWELL. 2013: S17–S17
View details for Web of Science ID 000317984800057
Multiple clinical forms of dehydrated hereditary stomatocytosis arise from mutations in PIEZO1.
2013; 121 (19): 3925-?
Autosomal dominant dehydrated hereditary stomatocytosis (DHSt) usually presents as a compensated hemolytic anemia with macrocytosis and abnormally shaped red blood cells (RBCs). DHSt is part of a pleiotropic syndrome that may also exhibit pseudohyperkalemia and perinatal edema. We identified PIEZO1 as the disease gene for pleiotropic DHSt in a large kindred by exome sequencing analysis within the previously mapped 16q23-q24 interval. In 26 affected individuals among 7 multigenerational DHSt families with the pleiotropic syndrome, 11 heterozygous PIEZO1 missense mutations cosegregated with disease. PIEZO1 is expressed in the plasma membranes of RBCs and its messenger RNA, and protein levels increase during in vitro erythroid differentiation of CD34(+) cells. PIEZO1 is also expressed in liver and bone marrow during human and mouse development. We suggest for the first time a correlation between a PIEZO1 mutation and perinatal edema. DHSt patient red cells with the R2456H mutation exhibit increased ion-channel activity. Functional studies of PIEZO1 mutant R2488Q expressed in Xenopus oocytes demonstrated changes in ion-channel activity consistent with the altered cation content of DHSt patient red cells. Our findings provide direct evidence that R2456H and R2488Q mutations in PIEZO1 alter mechanosensitive channel regulation, leading to increased cation transport in erythroid cells.
View details for DOI 10.1182/blood-2013-02-482489
View details for PubMedID 23479567
Multiple clinical forms of dehydrated hereditary stomatocytosis arise from mutations in PIEZO1
2013; 121 (19): 3925-3935
View details for DOI 10.1182/blood-2013-02-482489
View details for Web of Science ID 000321870900023
View details for PubMedID 23479567
Erythrocyte adenosine deaminase: diagnostic value for Diamond-Blackfan anaemia
BRITISH JOURNAL OF HAEMATOLOGY
2013; 160 (4): 547-554
Diamond-Blackfan anaemia (DBA) is an inherited bone marrow failure syndrome (IBMFS) characterized by red cell aplasia. Mutations in ribosomal genes are found in more than 50% of cases. Elevated erythrocyte adenosine deaminase (eADA) was first noted in DBA in 1983. In this study we determined the value of eADA for the diagnosis of DBA compared with other IBMFS; the association of eADA in DBA with age, gender or other haematological parameters; and the association with known DBA-related gene mutations. For the diagnosis of DBA compared with non-DBA patients with other bone marrow failure syndromes, eADA had a sensitivity of 84%, specificity 95%, and positive and negative predictive values of 91%. In patients with DBA there was no association between eADA and gender, age, or other haematological parameters. Erythrocyte ADA segregated with, as well as independent of, known DBA gene mutations. While eADA was an excellent confirmatory test for DBA, 16% of patients with classical clinical DBA had a normal eADA.
View details for DOI 10.1111/bjh.12167
View details for Web of Science ID 000314068100015
View details for PubMedID 23252420
View details for PubMedCentralID PMC3609920
NEONATAL HEMATOLOGY: PATHOGENESIS, DIAGNOSIS, AND MANAGEMENT OF HEMATOLOGIC PROBLEMS, 2ND EDITION
View details for Web of Science ID 000325463000009
Stable Factor IX Activity Following AAV-Mediated Gene Transfer in Patients with Severe Hemophilia B
54th Annual Meeting and Exposition of the American-Society-of-Hematology (ASH)
AMER SOC HEMATOLOGY. 2012
View details for Web of Science ID 000313838900207
Frameshift mutation in p53 regulator RPL26 is associated with multiple physical abnormalities and a specific pre-ribosomal RNA processing defect in diamond-blackfan anemia
2012; 33 (7): 1037-1044
Diamond-Blackfan anemia (DBA) is an inherited form of pure red cell aplasia that usually presents in infancy or early childhood and is associated with congenital malformations in ∼30-50% of patients. DBA has been associated with mutations in nine ribosomal protein (RP) genes in about 53% of patients. We completed a large-scale screen of 79 RP genes by sequencing 16 RP genes (RPL3, RPL7, RPL8, RPL10, RPL14, RPL17, RPL19, RPL23A, RPL26, RPL27, RPL35, RPL36A, RPL39, RPS4X, RPS4Y1, and RPS21) in 96 DBA probands. We identified a de novo two-nucleotide deletion in RPL26 in one proband associated with multiple severe physical abnormalities. This mutation gives rise to a remarkable ribosome biogenesis defect that affects maturation of both the small and the large subunits. We also found a deletion in RPL19 and missense mutations in RPL3 and RPL23A, which may be variants of unknown significance. Together with RPL5, RPL11, and RPS7, RPL26 is the fourth RP regulating p53 activity that is linked to DBA.
View details for DOI 10.1002/humu.22081
View details for Web of Science ID 000304815100005
View details for PubMedID 22431104
View details for PubMedCentralID PMC3370062
Adenovirus-Associated Virus Vector-Mediated Gene Transfer in Hemophilia B
NEW ENGLAND JOURNAL OF MEDICINE
2011; 365 (25): 2357-2365
Hemophilia B, an X-linked disorder, is ideally suited for gene therapy. We investigated the use of a new gene therapy in patients with the disorder.We infused a single dose of a serotype-8-pseudotyped, self-complementary adenovirus-associated virus (AAV) vector expressing a codon-optimized human factor IX (FIX) transgene (scAAV2/8-LP1-hFIXco) in a peripheral vein in six patients with severe hemophilia B (FIX activity, <1% of normal values). Study participants were enrolled sequentially in one of three cohorts (given a high, intermediate, or low dose of vector), with two participants in each group. Vector was administered without immunosuppressive therapy, and participants were followed for 6 to 16 months.AAV-mediated expression of FIX at 2 to 11% of normal levels was observed in all participants. Four of the six discontinued FIX prophylaxis and remained free of spontaneous hemorrhage; in the other two, the interval between prophylactic injections was increased. Of the two participants who received the high dose of vector, one had a transient, asymptomatic elevation of serum aminotransferase levels, which was associated with the detection of AAV8-capsid-specific T cells in the peripheral blood; the other had a slight increase in liver-enzyme levels, the cause of which was less clear. Each of these two participants received a short course of glucocorticoid therapy, which rapidly normalized aminotransferase levels and maintained FIX levels in the range of 3 to 11% of normal values.Peripheral-vein infusion of scAAV2/8-LP1-hFIXco resulted in FIX transgene expression at levels sufficient to improve the bleeding phenotype, with few side effects. Although immune-mediated clearance of AAV-transduced hepatocytes remains a concern, this process may be controlled with a short course of glucocorticoids without loss of transgene expression. (Funded by the Medical Research Council and others; ClinicalTrials.gov number, NCT00979238.).
View details for DOI 10.1056/NEJMoa1108046
View details for Web of Science ID 000298320200002
View details for PubMedID 22149959
View details for PubMedCentralID PMC3265081
Adeno-Associated Viral Vector Mediated Gene Transfer for Hemophilia B
53rd Annual Meeting and Exposition of the American-Society-of-Hematology (ASH)
AMER SOC HEMATOLOGY. 2011: 4–5
View details for Web of Science ID 000299597100006
A Phase I/II clinical trial entailing peripheral vein administration of a novel self complementary adeno-associated viral vector encoding human FIX for Haemophilia B gene therapy
MARY ANN LIEBERT INC. 2011: A20
View details for Web of Science ID 000296707900069
Reduced ribosomal protein gene dosage and p53 activation in low-risk myelodysplastic syndrome
2011; 118 (13): 3622-3633
Reduced gene dosage of ribosomal protein subunits has been implicated in 5q- myelodysplastic syndrome and Diamond Blackfan anemia, but the cellular and pathophysiologic defects associated with these conditions are enigmatic. Using conditional inactivation of the ribosomal protein S6 gene in laboratory mice, we found that reduced ribosomal protein gene dosage recapitulates cardinal features of the 5q- syndrome, including macrocytic anemia, erythroid hypoplasia, and megakaryocytic dysplasia with thrombocytosis, and that p53 plays a critical role in manifestation of these phenotypes. The blood cell abnormalities are accompanied by a reduction in the number of HSCs, a specific defect in late erythrocyte development, and suggest a disease-specific ontogenetic pathway for megakaryocyte development. Further studies of highly purified HSCs from healthy patients and from those with myelodysplastic syndrome link reduced expression of ribosomal protein genes to decreased RBC maturation and suggest an underlying and common pathophysiologic pathway for additional subtypes of myelodysplastic syndrome.
View details for DOI 10.1182/blood-2010-11-318584
View details for PubMedID 21788341
Dose-dependent activation of capsid-specific T cells after AAV serotype 8 vector administration in a clinical study for hemophilia B
WILEY-BLACKWELL. 2011: 761–62
View details for Web of Science ID 000208992803155
IMMUNE-MEDIATED THROMBOCYTOPENIA IN CHILDREN LESS THAN 1 YEAR OF AGE: A SINGLE-INSTITUTION 10-YEAR EXPERIENCE
WILEY-BLACKWELL. 2011: 915–15
View details for Web of Science ID 000288463100067
A phase i/ii clinical trial entailing peripheral vein administration of a novel self complementary adeno-associated viral vector encoding human fix for haemophilia b gene therapy
MARY ANN LIEBERT INC. 2011: A7–A8
View details for Web of Science ID 000291388300017
Functional characterization and modified rescue of novel AE1 mutation R730C associated with overhydrated cation leak stomatocytosis
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
2011; 300 (5): C1034-C1046
We report the novel, heterozygous AE1 mutation R730C associated with dominant, overhydrated, cation leak stomatocytosis and well-compensated anemia. Parallel elevations of red blood cell cation leak and ouabain-sensitive Na(+) efflux (pump activity) were apparently unaccompanied by increased erythroid cation channel-like activity, and defined ouabain-insensitive Na(+) efflux pathways of nystatin-treated cells were reduced. Epitope-tagged AE1 R730C at the Xenopus laevis oocyte surface exhibited severely reduced Cl(-) transport insensitive to rescue by glycophorin A (GPA) coexpression or by methanethiosulfonate (MTS) treatment. AE1 mutant R730K preserved Cl(-) transport activity, but R730 substitution with I, E, or H inactivated Cl(-) transport. AE1 R730C expression substantially increased endogenous oocyte Na(+)-K(+)-ATPase-mediated (86)Rb(+) influx, but ouabain-insensitive flux was minimally increased and GPA-insensitive. The reduced AE1 R730C-mediated sulfate influx did not exhibit the wild-type pattern of stimulation by acidic extracellular pH (pH(o)) and, unexpectedly, was partially rescued by exposure to sodium 2-sulfonatoethyl methanethiosulfonate (MTSES) but not to 2-aminoethyl methanethiosulfonate hydrobromide (MTSEA) or 2-(trimethylammonium)ethyl methanethiosulfonate bromide (MTSET). AE1 R730E correspondingly exhibited acid pH(o)-stimulated sulfate uptake at rates exceeding those of wild-type AE1 and AE1 R730K, whereas mutants R730I and R730H were inactive and pH(o) insensitive. MTSES-treated oocytes expressing AE1 R730C and untreated oocytes expressing AE1 R730E also exhibited unprecedented stimulation of Cl(-) influx by acid pH(o). Thus recombinant cation-leak stomatocytosis mutant AE1 R730C exhibits severely reduced anion transport unaccompanied by increased Rb(+) and Li(+) influxes. Selective rescue of acid pH(o)-stimulated sulfate uptake and conferral of acid pH(o)-stimulated Cl(-) influx, by AE1 R730E and MTSES-treated R730C, define residue R730 as critical to selectivity and regulation of anion transport by AE1.
View details for DOI 10.1152/ajpcell.00447.2010
View details for Web of Science ID 000289884300011
View details for PubMedID 21209359
View details for PubMedCentralID PMC3093938
Development of Antibodies to Human Thrombin and Factor V in a Patient Exposed to Topical Bovine Thrombin
PEDIATRIC BLOOD & CANCER
2010; 55 (6): 1195-1197
Bovine topical thrombin is commonly used for local hemostasis in pediatric surgery. Acquired inhibitors to coagulation factors, particularly to factor V and bovine thrombin, have been infrequently reported in the pediatric population. We report a 3-year-old male who developed a coagulopathy and clinical bleeding after cardiothoracic surgery, during which bovine topical thrombin was used for local hemostasis. Laboratory tests revealed elevated prothrombin, partial thromboplastin, and thrombin times, and a low factor V activity level. He was found to have both human-thrombin and factor V inhibitors, among the first reported cases of these combined inhibitors secondary to bovine topical thrombin. He was treated with intravenous immunoglobulin and steroids with a rapid and durable response.
View details for DOI 10.1002/pbc.22699
View details for PubMedID 20979176
Adrenal and renal corticomedullary junction iron deposition in red cell aplasia
2010; 40 (12): 1955-1957
Iron deposition can occur in the kidneys as a result of hemolysis or extensive iron overload from transfusions. With T2* MRI, renal iron deposition can be visualized. In this report, renal corticomedullary junction iron deposition is noted using T2* MRI in a boy with red cell aplasia. The renal corticomedullary junction iron deposition is an indication of the severity of his iron overload. This is an unusual finding and brings clinical attention to the boy's renal function for further evaluation.
View details for DOI 10.1007/s00247-010-1824-2
View details for PubMedID 20852855
Haploinsufficiency of Ribosomal Protein S6 In Mice Mimics Bone Marrow Failure Syndromes In Humans
52nd Annual Meeting and Exposition of the American-Society-of-Hematology (ASH)
AMER SOC HEMATOLOGY. 2010: 89–89
View details for Web of Science ID 000289662200195
Array Comparative Genomic Hybridization of Ribosomal Protein Genes In Diamond-Blackfan Anemia Patients; Evidence for Three New DBA Genes, RPS8, RPS14 and RPL15, with Large Deletion or Duplication
AMER SOC HEMATOLOGY. 2010: 443
View details for Web of Science ID 000289662201110
Early Clinical Trial Results Following Administration of a Low Dose of a Novel Self Complementary Adeno-Associated Viral Vector Encoding Human Factor IX In Two Subjects with Severe Hemophilia B
52nd Annual Meeting and Exposition of the American-Society-of-Hematology (ASH)
AMER SOC HEMATOLOGY. 2010: 114–14
View details for Web of Science ID 000289662200249
Ribosomal Protein Genes RPS10 and RPS26 Are Commonly Mutated in Diamond-Blackfan Anemia
AMERICAN JOURNAL OF HUMAN GENETICS
2010; 86 (2): 222-228
Diamond-Blackfan anemia (DBA), an inherited bone marrow failure syndrome characterized by anemia that usually presents before the first birthday or in early childhood, is associated with birth defects and an increased risk of cancer. Although anemia is the most prominent feature of DBA, the disease is also characterized by growth retardation and congenital malformations, in particular craniofacial, upper limb, heart, and urinary system defects that are present in approximately 30%-50% of patients. DBA has been associated with mutations in seven ribosomal protein (RP) genes, RPS19, RPS24, RPS17, RPL35A, RPL5, RPL11, and RPS7, in about 43% of patients. To continue our large-scale screen of RP genes in a DBA population, we sequenced 35 ribosomal protein genes, RPL15, RPL24, RPL29, RPL32, RPL34, RPL9, RPL37, RPS14, RPS23, RPL10A, RPS10, RPS12, RPS18, RPL30, RPS20, RPL12, RPL7A, RPS6, RPL27A, RPLP2, RPS25, RPS3, RPL41, RPL6, RPLP0, RPS26, RPL21, RPL36AL, RPS29, RPL4, RPLP1, RPL13, RPS15A, RPS2, and RPL38, in our DBA patient cohort of 117 probands. We identified three distinct mutations of RPS10 in five probands and nine distinct mutations of RPS26 in 12 probands. Pre-rRNA analysis in lymphoblastoid cells from patients bearing mutations in RPS10 and RPS26 showed elevated levels of 18S-E pre-rRNA. This accumulation is consistent with the phenotype observed in HeLa cells after knockdown of RPS10 or RPS26 expression with siRNAs, which indicates that mutations in the RPS10 and RPS26 genes in DBA patients affect the function of the proteins in rRNA processing.
View details for DOI 10.1016/j.ajhg.2009.12.015
View details for Web of Science ID 000274637200011
View details for PubMedID 20116044
View details for PubMedCentralID PMC2820177
Ribosomal Protein Genes S10 and S26 Are Commonly Mutated in Diamond-Blackfan Anemia
AMER SOC HEMATOLOGY. 2009: 78
View details for Web of Science ID 000272725800176
Monthly recombinant tissue plasminogen activator administration to implantable central venous access devices decreases infections in children with haemophilia
2009; 15 (6): 1272-1280
Central venous access devices (CVAD) have been effectively used in the care of haemophilia patients. This is particularly true in children, who often have difficult venous access. CVAD complications (infection and thrombosis), risk factors, and complication rates, have been well-documented. However, effective interventions which decrease complication rates have not been identified. In this study, we review our experience with the use of monthly recombinant tissue plasminogen activator (rtPA) administration in haemophilia patients with fully implanted CVADs. Data on 19 haemophilia patients with 24 CVADs were available for analysis, with a total of 24 520 CVAD days. An infection rate of 0.04 infections per 1000 CVAD days and a thrombosis rate of 0.04 thrombi per 1000 CVAD days was observed. The observed infectious complication rate is at least one logarithm lower than many published CVAD infection rates in haemophilia patients who have not received rtPA administration. No bleeding complications were noted. Monthly rtPA is safe and appears to be effective in decreasing CVAD infection rates. Larger, randomized controlled studies are indicated to validate this finding.
View details for DOI 10.1111/j.1365-2516.2009.02063.x
View details for PubMedID 19601989
FACING THE BLEEDING OBVIOUS: AAV-MEDIATED GENE THERAPY FOR HAEMOPHILIA B
6th Meeting of the Australasian-Gene-Therapy-Society
JOHN WILEY & SONS LTD. 2009: 843–43
View details for Web of Science ID 000270043300034
One Year Follow-Up of Children and Adolescents With Chronic Immune Thrombocytopenic Purpura (ITP) Treated With Rituximab
PEDIATRIC BLOOD & CANCER
2009; 52 (2): 259-262
We previously showed in a prospective study that rituximab appears to be effective in some children and adolescents with severe chronic immune thrombocytopenia. Eleven of 36 patients achieved and maintained platelet counts over 50,000/mm(3) within the first 12 weeks. These patients were followed for the next year.Platelet counts were monitored monthly and all subsequent bleeding manifestations and need for further treatment was noted.Eight of the 11 initial responders maintained a platelet count over 150,000/mm(3) without further treatment intervention. Three patients had a late relapse. One initial non-responder achieved a remission after 16 weeks, and two additional patients maintained platelet counts around 50,000/mm(3) without the need for further intervention.Rituximab resulted in sustained efficacy with platelet counts of 50,000/mm(3) or higher in 11 of 36 patients (31%).
View details for DOI 10.1002/pbc.21757
View details for Web of Science ID 000261796000025
View details for PubMedID 18937333
Ribosomal Protein L5 and L11 Mutations Are Associated with Cleft Palate and Abnormal Thumbs in Diamond-Blackfan Anemia Patients
AMERICAN JOURNAL OF HUMAN GENETICS
2008; 83 (6): 769-780
Diamond-Blackfan anemia (DBA), a congenital bone-marrow-failure syndrome, is characterized by red blood cell aplasia, macrocytic anemia, clinical heterogeneity, and increased risk of malignancy. Although anemia is the most prominent feature of DBA, the disease is also characterized by growth retardation and congenital anomalies that are present in approximately 30%-50% of patients. The disease has been associated with mutations in four ribosomal protein (RP) genes, RPS19, RPS24, RPS17, and RPL35A, in about 30% of patients. However, the genetic basis of the remaining 70% of cases is still unknown. Here, we report the second known mutation in RPS17 and probable pathogenic mutations in three more RP genes, RPL5, RPL11, and RPS7. In addition, we identified rare variants of unknown significance in three other genes, RPL36, RPS15, and RPS27A. Remarkably, careful review of the clinical data showed that mutations in RPL5 are associated with multiple physical abnormalities, including craniofacial, thumb, and heart anomalies, whereas isolated thumb malformations are predominantly present in patients carrying mutations in RPL11. We also demonstrate that mutations of RPL5, RPL11, or RPS7 in DBA cells is associated with diverse defects in the maturation of ribosomal RNAs in the large or the small ribosomal subunit production pathway, expanding the repertoire of ribosomal RNA processing defects associated with DBA.
View details for DOI 10.1016/j.ajhg.2008.11.004
View details for Web of Science ID 000261822100012
View details for PubMedID 19061985
View details for PubMedCentralID PMC2668101
Identification of New Rare Sequence Changes in RP Genes in Diamond-Blackfan Anemia and Association of the RPL5 and RPL11 Mutations with Craniofacial and Thumb Malformations
AMER SOC HEMATOLOGY. 2008: 21
View details for Web of Science ID 000262104700040
Diagnosing and treating Diamond Blackfan anaemia: results of an international clinical consensus conference
BRITISH JOURNAL OF HAEMATOLOGY
2008; 142 (6): 859-876
Diamond Blackfan anaemia (DBA) is a rare, genetically and clinically heterogeneous, inherited red cell aplasia. Classical DBA affects about seven per million live births and presents during the first year of life. However, as mutated genes have been discovered in DBA, non-classical cases with less distinct phenotypes are being described in adults as well as children. In caring for these patients it is often difficult to have a clear understanding of the treatment options and their outcomes because of the lack of complete information on the natural history of the disease. The purpose of this document is to review the criteria for diagnosis, evaluate the available treatment options, including corticosteroid and transfusion therapies and stem cell transplantation, and propose a plan for optimizing patient care. Congenital anomalies, mode of inheritance, cancer predisposition, and pregnancy in DBA are also reviewed. Evidence-based conclusions will be made when possible; however, as in many rare diseases, the data are often anecdotal and the recommendations are based upon the best judgment of experienced clinicians. The recommendations regarding the diagnosis and management described in this report are the result of deliberations and discussions at an international consensus conference.
View details for DOI 10.1111/j.1365-2141.2008.07269.x
View details for Web of Science ID 000258604200001
View details for PubMedID 18671700
View details for PubMedCentralID PMC2654478
Cold agglutinin syndrome in pediatric liver transplant recipients
2007; 11 (8): 931-936
Anemia is a common finding in post-liver transplant patients. Causes for the anemia include nutritional deficiencies, red cell aplasia as well as immune-mediated hemolysis. One of the immunologic causes of hemolytic anemia is drug-induced hemolysis. Tacrolimus is a common immunosuppressant used in post-liver transplant patients to prevent graft rejection. There have been reports of tacrolimus-associated hemolytic anemia secondary to hemolytic uremic syndrome as well as autoimmune hemolysis. There are also case-reports of severe hemolytic anemia related to cold agglutinin production in post-liver transplant patients. We described in this paper three cases of severe cold agglutinin hemolytic anemia in three pediatric liver transplant patients. Steroid therapy, plasmapheresis and withdrawal of tacrolimus led to resolution of the severe hemolytic process in each case. Whether the immune-mediated hemolysis is related to tacrolimus is not clear and needs to be characterized further.
View details for DOI 10.1111/j.1399-3046.2007.00795.x
View details for PubMedID 17976131
Ribosomal protein S24 gene is mutated in diamond-blackfan anemia
AMERICAN JOURNAL OF HUMAN GENETICS
2006; 79 (6): 1110-1118
Diamond-Blackfan anemia (DBA) is a rare congenital red-cell aplasia characterized by anemia, bone-marrow erythroblastopenia, and congenital anomalies and is associated with heterozygous mutations in the ribosomal protein (RP) S19 gene (RPS19) in approximately 25% of probands. We report identification of de novo nonsense and splice-site mutations in another RP, RPS24 (encoded by RPS24 [10q22-q23]) in approximately 2% of RPS19 mutation-negative probands. This finding strongly suggests that DBA is a disorder of ribosome synthesis and that mutations in other RP or associated genes that lead to disrupted ribosomal biogenesis and/or function may also cause DBA.
View details for Web of Science ID 000242131600013
View details for PubMedID 17186470
View details for PubMedCentralID PMC1698708
Cold agglutinin syndrome in post-liver transplant patients on tacrolimus.
48th Annual Meeting of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2006: 288A–289A
View details for Web of Science ID 000242440001227
Successful transduction of liver in hemophilia by AAV-Factor IX and limitations imposed by the host immune response (vol 12, pg 342, 2006)
2006; 12 (5): 592-592
View details for Web of Science ID 000238149100046
Prospective phase 1/2 study of rituximab in childhood and adolescent chronic immune thrombocytopenic purpura
18th Annual Meeting of the American-Society-of-Pediatric-Hematology-Oncology
AMER SOC HEMATOLOGY. 2006: 2639–42
We assessed safety and efficacy of rituximab in a prospective study of 36 patients, age 2.6 to 18.3 years, with severe chronic immune thrombocytopenic purpura (ITP). The primary outcome of sustained platelets above 50 x 10(9)/L (50,000/mm3) during 4 consecutive weeks, starting in weeks 9 to 12, was achieved by 11 of 36 patients (31%, confidence interval [CI], 16% to 48%). Median response time was 1 week (range, 1 to 7 weeks). Attainment of the primary outcome was not associated with age, prior pharmacologic responses, prior splenectomy, ITP duration, screening platelet count, refractoriness, or IgM reduction. First-dose, infusion-related toxicity was common (47%) despite premedication. Significant drug-related toxicities included third-dose hypotension (n = 1) and serum sickness (n = 2). Peripheral B cells were depleted in all subjects. IgM decreased 3.4% per week, but IgG did not significantly decrease. Rituximab was well tolerated, with manageable infusion-related side effects, but 6% of subjects developed serum sickness. Rituximab is beneficial for some pediatric patients with severe, chronic ITP.
View details for Web of Science ID 000236656900019
View details for PubMedID 16352811
View details for PubMedCentralID PMC1895391
Successful transduction of liver in hemophilia by AAV-factor IX and limitations imposed by the host immune response
2006; 12 (3): 342-347
We have previously shown that a single portal vein infusion of a recombinant adeno-associated viral vector (rAAV) expressing canine Factor IX (F.IX) resulted in long-term expression of therapeutic levels of F.IX in dogs with severe hemophilia B. We carried out a phase 1/2 dose-escalation clinical study to extend this approach to humans with severe hemophilia B. rAAV-2 vector expressing human F.IX was infused through the hepatic artery into seven subjects. The data show that: (i) vector infusion at doses up to 2 x 10(12) vg/kg was not associated with acute or long-lasting toxicity; (ii) therapeutic levels of F.IX were achieved at the highest dose tested; (iii) duration of expression at therapeutic levels was limited to a period of approximately 8 weeks; (iv) a gradual decline in F.IX was accompanied by a transient asymptomatic elevation of liver transaminases that resolved without treatment. Further studies suggested that destruction of transduced hepatocytes by cell-mediated immunity targeting antigens of the AAV capsid caused both the decline in F.IX and the transient transaminitis. We conclude that rAAV-2 vectors can transduce human hepatocytes in vivo to result in therapeutically relevant levels of F.IX, but that future studies in humans may require immunomodulation to achieve long-term expression.
View details for DOI 10.1038/nm1358
View details for Web of Science ID 000235802900035
View details for PubMedID 16474400
Lessons from a clinical trial of liver-directed AAV gene transfer in hemophilia B
4th Meeting of the Australasian-Gene-Therapy-Society
WILEY-BLACKWELL. 2005: 1117–18
View details for Web of Science ID 000231477900022
Human immune responses to AAV-2 capsid may limit duration of expression in liver-directed gene transfer in humans with hemophilia B.
46th Annual Meeting of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2004: 121A–121A
View details for Web of Science ID 000225127500416
Immune responses to AAV and to Factor IX in a phase I study of AAV-mediated, liver-directed gene transfer for hemophilia B
7th Annual Meeting of the American-Society-of-Gene-Therapy
NATURE PUBLISHING GROUP. 2004: S383–S384
View details for Web of Science ID 000222316601003
Immune responses to AAV and to factor IX in a phase I study of AAV-mediated, liver-directed gene transfer for hemophilia B.
45th Annual Meeting and Exhibition of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2003: 154A–155A
View details for Web of Science ID 000186536700532
Australian patients in a multi-centre phase I/II trial of AAV-mediated gene transfer to the liver for severe hemophilia B
3rd Meeting of the Australasian-Gene-Therapy-Society
WILEY-BLACKWELL. 2003: S3–S4
View details for Web of Science ID 000183493100012
AAV-mediated factor IX gene transfer to skeletal muscle in patients with severe hemophilia B
2003; 101 (8): 2963-2972
Hemophilia B is an X-linked coagulopathy caused by absence of functional coagulation factor IX (F.IX). Previously, we established an experimental basis for gene transfer as a method of treating the disease in mice and hemophilic dogs through intramuscular injection of a recombinant adeno-associated viral (rAAV) vector expressing F.IX. In this study we investigated the safety of this approach in patients with hemophilia B. In an open-label dose-escalation study, adult men with severe hemophilia B (F.IX < 1%) due to a missense mutation were injected at multiple intramuscular sites with an rAAV vector. At doses ranging from 2 x 10(11) vector genomes (vg)/kg to 1.8 x 10(12) vg/kg, there was no evidence of local or systemic toxicity up to 40 months after injection. Muscle biopsies of injection sites performed 2 to 10 months after vector administration confirmed gene transfer as evidenced by Southern blot and transgene expression as evidenced by immunohistochemical staining. Pre-existing high-titer antibodies to AAV did not prevent gene transfer or expression. Despite strong evidence for gene transfer and expression, circulating levels of F.IX were in all cases less than 2% and most were less than 1%. Although more extensive transduction of muscle fibers will be required to develop a therapy that reliably raises circulating levels to more than 1% in all subjects, these results of the first parenteral administration of rAAV demonstrate that administration of AAV vector by the intramuscular route is safe at the doses tested and effects gene transfer and expression in humans in a manner similar to that seen in animals.
View details for DOI 10.1182/blood-2002-10-3296
View details for Web of Science ID 000182101400015
View details for PubMedID 12515715
Approach to the bleeding child
PEDIATRIC CLINICS OF NORTH AMERICA
2002; 49 (6): 1239-?
Because bruising and bleeding are normal events of childhood, the pediatrician must be able to determine whether a child's symptoms are normal or perhaps indicative of a defective hemostasis. A thorough medical history and physical examination should enable the clinician to choose those patients warranting further evaluation. Rather than referral to a hematologist at that point in time, pediatricians should be quite capable of performing the initial laboratory evaluation and making the correct diagnosis in a majority of cases.
View details for Web of Science ID 000180724600006
View details for PubMedID 12580364
A phase I/II clinical trial for liver directed AAV-mediated gene transfer for severe hemophilia B.
44th Annual Meeting of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2002: 115A–115A
View details for Web of Science ID 000179184700427
Assessing the risk of inadvertent germline transmission of vector DNA following intravascular delivery of rAAV vector.
44th Annual Meeting of the American-Society-of-Hematology
AMER SOC HEMATOLOGY. 2002: 869A–869A
View details for Web of Science ID 000179184703427
Resolution of severe Donath-Landsteiner autoimmune hemolytic anemia temporally associated with institution of plasmapheresis
CRITICAL CARE MEDICINE
2002; 30 (4): 931-934
To report a case of severe postinfectious autoimmune hemolytic anemia (AIHA) owing to the Donath-Landsteiner (DL) antibody resolving with plasmapheresis, and to review the pathophysiology of this underrecognized cause of pediatric AIHA and its potential susceptibility to plasmapheresis therapy.Descriptive case report.A pediatric intensive care unit in a university children's hospital.A 5-yr-old Hispanic female had gastroenteritis followed by progressive intravascular hemolysis, initially attributed to acute postinfectious cold hemagglutinin (immunoglobulin M) disease.With no slowing in the rate of hemolysis, a continued need for frequent transfusions, and a lack of response to corticosteroid and intravenous immunoglobulin therapy, a 3-day course of plasmapheresis was administered.The patient presented to an emergency department with an initial hematocrit of 22%, which fell to 12% by hospital admission. She received nine transfusions over 7 days, with her hematocrit reaching a nadir of 11% on the 5th day of hospitalization. Once plasmapheresis was initiated, she required no further transfusion. Analysis of serum from initial presentation demonstrated biphasic hemolysis, confirming the presence of the DL antibody.In AIHA, in which the direct antiglobulin test detects primarily C3 rather than immunoglobulin G, especially in children, the DL antibody must be considered. Confirming the diagnosis rapidly may be critical, especially in cases of severe hemolysis, because this may help direct therapy. A low titer of DL antibody can mediate severe intravascular hemolysis given its propensity to sensitize, detach, and rebind erythrocytes with changes in temperature in the microcirculation. However, given the transient and relatively brief production of the DL antibody in postviral illness, early clearance of the offending antibody may be possible with plasmapheresis, without the expectation for significant rebound antibody production, potentially decreasing the length of hospital stay and the need for transfusions.
View details for Web of Science ID 000174957500039
View details for PubMedID 11940774
Bilateral microtia and cleft palate in cousins with Diamond-Blackfan anemia
AMERICAN JOURNAL OF MEDICAL GENETICS
2001; 101 (3): 268-274
We report on maternal first cousins with bilateral microtia, micrognathia, cleft palate and hematologic findings of Diamond-Blackfan anemia (DBA). The similarity of findings shared between our cases and a female reported by Hasan and Inoue  suggests that this is a distinctive syndrome, rather than a chance association. DBA is a heterogeneous disorder, caused in about 25% of cases by heterozygous mutations in the RPS19 gene (DBA1). Mutation analysis in our cases did not show an RPS19 mutation, and 2 alleles were present in each. Segregation analysis for DBA1 on chromosome 19 and DBA2 on 8p23 was not consistent with linkage. We conclude that this syndrome of microtia, cleft palate and DBA is not allelic to known DBA loci.
View details for Web of Science ID 000169475600014
View details for PubMedID 11424144
Evidence for linkage of familial Diamond-Blackfan anemia to chromosome 8p23.3-p22 and for non-19q non-8p disease
2001; 97 (7): 2145-2150
Diamond-Blackfan anemia (DBA) is a rare congenital hypoplastic anemia that usually presents early in infancy and is inherited in 10% to 20% of cases. Linkage analysis has shown that DBA in many of both dominant and recessive DBA families mapped to chromosome 19q13.2 leading to the cloning of a gene on chromosome 19q13.2 that encodes a ribosomal protein, RPS19. However, subsequently, mutations of the RPS19 gene have only been identified in 25% of all patients with DBA. This study analyzed 14 multiplex DBA families, 9 of which had 19q13.2 haplotypes inconsistent with 19q linkage. A genome-wide search for linked loci suggested the presence of a second DBA locus in a 26.4-centimorgan (cM) interval on human chromosome 8p. Subsequently, 24 additional DBA families were ascertained and all 38 families were analyzed with additional polymorphic markers on chromosome 8p. In total, 18 of 38 families were consistent with linkage to chromosome 8p with a maximal LOD score with heterogeneity of 3.55 at D8S277 assuming 90% penetrance. The results indicate the existence of a second DBA gene in the 26.4-cM telomeric region of human chromosome 8p23.3-p22, most likely within an 8.1-cM interval flanked by D8S518 and D8S1825. Seven families were inconsistent with linkage to 8p or 19q and did not reveal mutations in the RPS19 gene, suggesting further genetic heterogeneity. (Blood. 2001;97:2145-2150)
View details for Web of Science ID 000168516000034
View details for PubMedID 11264183
A phase I trial of AAV-mediated muscle directed gene transfer for hemophilia B.
AMER SOC HEMATOLOGY. 2000: 801A–801A
View details for Web of Science ID 000165256103458
A proposed rAAV-liver directed clinical trial for hemophilia B.
AMER SOC HEMATOLOGY. 2000: 798A–799A
View details for Web of Science ID 000165256103448
AAV-mediated gene therapy for hemophilia B.
FEDERATION AMER SOC EXP BIOL. 2000: A1310
View details for Web of Science ID 000087005400031
Evidence for gene transfer and expression of factor IX in haemophilia B patients treated with an AAV vector
2000; 24 (3): 257-261
Pre-clinical studies in mice and haemophilic dogs have shown that introduction of an adeno-associated viral (AAV) vector encoding blood coagulation factor IX (FIX) into skeletal muscle results in sustained expression of F.IX at levels sufficient to correct the haemophilic phenotype. On the basis of these data and additional pre-clinical studies demonstrating an absence of vector-related toxicity, we initiated a clinical study of intramuscular injection of an AAV vector expressing human F.IX in adults with severe haemophilia B. The study has a dose-escalation design, and all patients have now been enrolled in the initial dose cohort (2 x 10(11) vg/kg). Assessment in the first three patients of safety and gene transfer and expression show no evidence of germline transmission of vector sequences or formation of inhibitory antibodies against F.IX. We found that the vector sequences are present in muscle by PCR and Southern-blot analyses of muscle biopsies and we demonstrated expression of F.IX by immunohistochemistry. We observed modest changes in clinical endpoints including circulating levels of F.IX and frequency of FIX protein infusion. The evidence of gene expression at low doses of vector suggests that dose calculations based on animal data may have overestimated the amount of vector required to achieve therapeutic levels in humans, and that the approach offers the possibility of converting severe haemophilia B to a milder form of the disease.
View details for PubMedID 10700178
A phase I trial of AAV-mediated muscle-directed gene therapy for hemophilia B.
AMER SOC HEMATOLOGY. 1999: 642A–642A
View details for Web of Science ID 000083790302901
Evidence for linkage of familial Diamond-Blackfan Anemia to chromosome 8p23.2-23.1 and for non-19q non-8p disease.
AMER SOC HEMATOLOGY. 1999: 673A
View details for Web of Science ID 000083790303032
Hemolytic anemia in children
CLINICS IN LABORATORY MEDICINE
1999; 19 (1): 87-?
This article provides an overview of hemolytic anemia in children. Main focus areas include acquired immune-mediated hemolysis, hemolytic anemia due to hereditary RBC disorders, hereditary hemolytic disorders caused by enzyme abnormalities, and hereditary hemolytic anemia due to hemoglobin abnormalities.
View details for PubMedID 10403076
Home treatment of mild to moderate bleeding episodes using recombinant factor VIIa (Novoseven) in haemophiliacs with inhibitors
THROMBOSIS AND HAEMOSTASIS
1998; 80 (6): 912-918
To assess the safety and efficacy of a fixed dose of recombinant activated factor VII (rFVIIa; NovoSeven) in the home setting for mild to moderately severe joint, muscle; and mucocutaneous bleeding episodes in patients with haemophilia A or B with inhibitors.Multicentre, open-label, single arm, phase III study of one year duration. METHODS; Patients or their caregivers administered up to three doses of rFVIIa (90 microg/kg i.v.) at 3 h intervals within 8 h of the onset of a mild to moderate bleeding episode. Once the subject considered that rFVIIa had been "effective" with regard to haemostasis (after 1-3 injections), one further (maintenance) dose of rFVIIa was administered.Of 60 patients enrolled, 56 experienced at least one bleed, and 46 completed the one year study. 614 of 877 bleeds (70%) were evaluable according to protocol definitions. Haemostasis was rated as "effective" in 92% (566/614) of evaluable bleeds after a mean of 2.2 injections. For successfully treated episodes, the time from onset of bleeding until administration of the first injection was 1.1+/-2.0 h (mean+/-SD). Twenty-four hours after initial successful response, haemostasis was reported as having been maintained in 95% of cases. Efficacy was comparable for muscle, joint and target joint, and mucocutaneous bleeding episodes. In an intent-to-treat analysis of all 877 bleeding events, efficacy outcomes were equivalent to the evaluable bleeds, with an effective response in 88% of treated episodes. Treatment-related adverse events occurred in 32 (3% of all) bleeding episodes and consisted of re-bleeds/new bleeds in more than 50% (18/32) of these events. A single episode of superficial thrombophlebitis was the only thrombotic complication encountered, and there were no patient withdrawals due to adverse events. Development of FVII(a) antibodies could not be detected, and hypersensitivity reactions to rFVIIa were not reported.rFVIIa is effective and well tolerated when used in the home setting to treat mild to moderate bleeding episodes in patients with haemophilia A or B with inhibitors.
View details for Web of Science ID 000077403200010
View details for PubMedID 9869160
Bone marrow transplant in thalassemia - A role for radiation?
7th Cooleys Anemia Symposium
NEW YORK ACAD SCIENCES. 1998: 503–505
View details for PubMedID 9668596
- Acute idiopathic thrombocytopenic purpura - Management in childhood BLOOD 1997; 89 (4): 1464-1465
Hereditary xerocytosis in pediatric patients.
WILLIAMS & WILKINS. 1997: 11
View details for Web of Science ID A1997WD48601120
Bone marrow transplant in thalassemia at Stanford University: A role for radiation?
AMER SOC HEMATOLOGY. 1996: 2467–67
View details for Web of Science ID A1996VT98302467
Diagnose of hereditary xerocytosis by ektacytometry.
W B SAUNDERS CO. 1996: 1218
View details for Web of Science ID A1996VT98301218
Loss of elbow and wrist motion in hemophilia
CLINICAL ORTHOPAEDICS AND RELATED RESEARCH
The longitudinal changes in elbow and wrist motion for 48 patients with hemophilia were reviewed to determine the effect of recurrent hemarthroses. The average age of the patients at the time of followup was 23 years 9 months. The average duration of followup was 10.8 years. The patients were divided into 3 age groups: younger than age 15 years (14 patients), age 15 to 25 years (11 patients), and older than age 25 years (23 patients). For patients older than age 25 years, pronation, supination, elbow flexion and extension, wrist flexion and extension, and ulnar deviation were significantly decreased relative to patients younger than age 15 years. Pronation was the first motion to show a significant change, decreasing by 19% in patients age 15 to 25 years and by 31% in patients older than age 25 years. Loss of elbow extension showed the greatest change. In cases of severe hemophilic arthropathy of the elbow, synovectomy and radial head excision decreased elbow pain and bleeding episodes and improved supination and pronation.
View details for PubMedID 8653985
Hematologic disorders in children from Southeast Asia
PEDIATRIC CLINICS OF NORTH AMERICA
1996; 43 (3): 665-?
The overall laboratory features of the common RBC disorders occurring in Southeast Asians is summarized in Table 4. These erythrocyte disorders will continue to be important public health issues, and it has been predicted that most new cases of thalassemia in the United States will occur in this population group. The fertility rate in Southeast Asian families is very high, with an average of more than five children delivered by each married woman. This number of children is consistent with perceptions of ideal family size, and, to date, no evidence suggests any change in the size of Southeast Asian families who now reside in the United States. Moreover, attitudes about health care, reasons why one seeks medical attention, and a variety of other cultural issues may impair the effectiveness of genetic counseling and other preventive measures designed to reduce the incidence of serious blood diseases. Genetic screening and prenatal diagnosis clearly have led to a markedly decreased incidence of homozygous thalassemia disorders in high-risk Mediterranean populations throughout the world. With further assimilation into Western culture, a similar disease may occur in the Southeast Asian population also.
View details for PubMedID 8649904
A trial of gene therapy in a patient with complementation group C Fanconi anemia (FAC)
AMER SOC HEMATOLOGY. 1995: 1169–69
View details for Web of Science ID A1995TH91001171
A COMPARISON OF CONSERVATIVE AND AGGRESSIVE TRANSFUSION REGIMENS IN THE PERIOPERATIVE MANAGEMENT OF SICKLE-CELL DISEASE
NEW ENGLAND JOURNAL OF MEDICINE
1995; 333 (4): 206-213
Preoperative transfusions are frequently given to prevent perioperative morbidity in patients with sickle cell anemia. There is no consensus, however, on the best regimen of transfusions for this purpose.We conducted a multicenter study to compare the rates of perioperative complications among patients randomly assigned to receive either an aggressive transfusion regimen designed to decrease the hemoglobin S level to less than 30 percent (group 1) or a conservative regimen designed to increase the hemoglobin level to 10 g per deciliter (group 2).Patients undergoing a total of 604 operations were randomly assigned to group 1 or group 2. The severity of the disease, compliance with the protocol, and the types of operations were similar in the two groups. The preoperative hemoglobin level was 11 g per deciliter in group 1 and 10.6 g per deciliter in group 2. The preoperative value for hemoglobin S was 31 percent in group 1 and 59 percent in group 2. The most frequent operations were cholecystectomies (232), head and neck surgery (156), and orthopedic surgery (72). With the exception of transfusion-related complications, which occurred in 14 percent of the operations in group 1 and in 7 percent of those in group 2, the frequency of serious complications was similar in the two groups (31 percent in group 1 and 35 percent in group 2). The acute chest syndrome developed in 10 percent of both groups and resulted in two deaths in group 1. A history of pulmonary disease and a higher risk associated with surgery were significant predictors of the acute chest syndrome.A conservative transfusion regimen was as effective as an aggressive regimen in preventing perioperative complications in patients with sickle cell anemia, and the conservative approach resulted in only half as many transfusion-associated complications.
View details for Web of Science ID A1995RK42300002
INCREASED FREQUENCY OF INHIBITORS IN AFRICAN-AMERICAN HEMOPHILIA-A PATIENTS
W B SAUNDERS CO. 1994: A239
View details for Web of Science ID A1994PR75400941
FREQUENCY OF INHIBITOR DEVELOPMENT IN HEMOPHILIACS TREATED WITH LOW-PURITY FACTOR-VIII
1993; 342 (8869): 462-464
Clinical studies evaluating highly purified monoclonal-antibody-derived and recombinant-DNA-derived clotting factor concentrates in previously untreated (PUPS) severe factor VIII (FVIII) deficient haemophilia patients, have documented an increased frequency of inhibitors compared with that seen in patients who have received less pure products. However, a valid comparison of inhibitor frequency in patients treated with pure and less pure products has not been possible because appropriate studies have not been done in PUPS treated with the less pure products. To determine the frequency of inhibitor development in PUPS treated solely with less pure plasma-derived products (specific activities < 5 FVIII U/mg protein), we reviewed the records of all haemophilia patients born between 1975 and 1985 and treated with such products at any of seven centres. 89 patients with severe FVIII deficiency (< 1%) were observed and tested for inhibitors from birth to 5 years old or until 30 bleeding episodes had been treated. 25 of the 89 patients developed inhibitors (28%), and 21 of these 25 were high-titre responders (> 5 Bethesda units). This frequency of inhibitor development is greater than that reported in patients treated with monoclonal FVIII products, but the latter patients may not have been followed as long as the patients in our report. Our data may make possible a meaningful comparison with the frequency of inhibitor development in PUPS treated solely with recombinant-DNA-derived FVIII.
View details for Web of Science ID A1993LU07500010
View details for PubMedID 8102429
INCREASED RED-BLOOD-CELL (RBC) ADENOSINE-DEAMINASE (ADA) ACTIVITY IS USEFUL IN DISTINGUISHING DIAMOND-BLACKFAN ANEMIA (DBA) AND TRANSIENT ERYTHROBLASTOPENIA OF CHILDHOOD (TEC) IN CHILDREN LESS THAN 6 MONTHS OF AGE
SLACK INC. 1993: A310
View details for Web of Science ID A1993KW76101089
LANGERHANS CELL HISTIOCYTOSIS PRESENTING WITH THE SUPERIOR VENA-CAVA SYNDROME - A CASE-REPORT
MEDICAL AND PEDIATRIC ONCOLOGY
1993; 21 (6): 456-459
A case of Langerhans' cell histiocytosis confined to the mediastinum and presenting with de novo superior cava syndrome is reported. The causes of superior vena cava syndrome in childhood are discussed as is the importance of obtaining pathologic diagnosis prior to initiating therapy.
View details for PubMedID 8515729
Arthropathy of the ankle in hemophilia.
journal of bone and joint surgery. American volume
1991; 73 (7): 1008-1015
Seventy-five patients who had hemophilia were followed clinically and roentgenographically to assess the prevalence of hemarthrosis and the prevalence and severity of arthropathy of the ankle. The mean age of the patients at the time of follow-up was twenty-two years and seven months. The patients were divided into four age-groups: less than ten years (eleven patients), ten to nineteen years (twenty-one patients), twenty to thirty years (twenty-four patients), and more than thirty years (nineteen patients). Intra-articular bleeding occurred more frequently in the joints of the lower extremities than in the joints of the upper extremities. During the second decade of life, hemarthroses occurred more often in the ankle than in the knee. A history of recurrent bleeding into the ankle joint, chronic synovitis, and overgrowth of the medial portion of the distal tibial epiphysis was associated with an early onset of arthropathy. In older patients, compression arthrodesis of the ankle joint was helpful in eliminating pain, recurrent bleeding, and equinus deformity.
View details for PubMedID 1908466
ARTHROPATHY OF THE ANKLE IN HEMOPHILIA
JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME
1991; 73A (7): 1008-1015
View details for Web of Science ID A1991GC97300007
CRYPTOCOCCUS INFECTION IN A 9-YEAR-OLD CHILD WITH HEMOPHILIA AND THE ACQUIRED-IMMUNODEFICIENCY-SYNDROME
PEDIATRIC INFECTIOUS DISEASE JOURNAL
1991; 10 (1): 76-77
View details for PubMedID 2003061
- TREATMENT OF NEUTROPENIA ASSOCIATED WITH DYSKERATOSIS CONGENITA WITH GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR LANCET 1990; 336 (8717): 751-752
HEMATOLOGIC MALIGNANCIES IN DIAMOND BLACKFAN ANEMIA
WILLIAMS & WILKINS. 1990: A142
View details for Web of Science ID A1990CW36200830
RED-BLOOD-CELL APLASIAS IN CHILDREN
1990; 19 (3): 168-?
View details for PubMedID 2157189
CONGENITAL HYPOPLASTIC (DIAMOND-BLACKFAN) ANEMIA IN 7 MEMBERS OF ONE KINDRED
AMERICAN JOURNAL OF MEDICAL GENETICS
1990; 35 (2): 251-256
Congenital hypoplastic (Diamond-Blackfan) anemia is a rare macrocytic anemia, generally presenting during infancy or childhood. The condition usually occurs sporadically or in a pattern consistent with autosomal recessive inheritance, although autosomal dominant transmission has been proposed in some kindreds. We report the largest known kindred of congenital hypoplastic anemia, with at least 7 affected individuals over 3 generations, and propose that studies of this kindred may be useful for identifying the mechanism by which their genetic abnormality results in congenital hypoplastic anemia. Erythropoietic investigations on relatives show no inhibitors of erythropoiesis in serum, T-lymphocytes, or macrophages. Their erythroid progenitor cells (CFU-E and BFU-E) were generally quantitatively normal, and were capable of rapid proliferation, as judged by cell-cycle shortening. However, their erythroid progenitors displayed a relative insensitivity to recombinant erythropoietin, and produced relatively few normoblasts per erythroid progenitor cell. We propose that these and subsequent studies may be helpful in selecting candidate genes responsible for the molecular defect in this kindred.
View details for Web of Science ID A1990CL21500020
View details for PubMedID 2309764
SUP-HD1 - A NEW HODGKINS DISEASE-DERIVED CELL-LINE WITH LYMPHOID FEATURES PRODUCES INTERFERON-GAMMA
1989; 74 (8): 2733-2742
A new cell line, SUP-HD1, was established from the pleural effusion of a patient with nodular sclerosing Hodgkin's disease (NSHD). The SUP-HD1 cells had the characteristic morphology of Reed-Sternberg cells and contained acid phosphatase and nonspecific esterase. The cells lacked the Epstein-Barr virus (EBV) genome and reacted with monoclonal antibodies (MoAbs) against CD15 (Leu-M1), CD25 (Tac), CD71 (OKT9), Ki67, and HLA-Dr. However, the SUP-HD1 cells were nonreactive with MoAbs that specifically identify T lymphocytes, B lymphocytes, and macrophage/myeloid cells. Karyotype analysis of the cell line showed clonal abnormalities involving 1p13, 7p15, 8q22, and 11q23, chromosomal locations, at which breakpoints have been reported in HD. Southern blot analysis demonstrated rearrangement of the immunoglobulin heavy chain and kappa light chain genes as well as the gene for the beta chain of the T-cell receptor (TCR). Transcriptional analysis showed expression of RNAs for kappa light chain, interferon-gamma (IFN-gamma), and interleukin-2 receptor (IL-2R) but not IL-2. The SUP-HD1 cells lacked cytoplasmic and surface immunoglobulin heavy chain, but a small amount of cytoplasmic kappa light chain was detected. The presence of nuclear factor kappa B (NF kappa B), a B-lymphocyte-associated transcription factor, was demonstrated in stimulated and unstimulated cells. In addition, the SUP-HD1 cell line, produced IFN-gamma, a T-lymphocyte-associated lymphokine. Based on these data, the SUP-HD1 cells appear to be aberrant lymphocytes with characteristics of both activated B and T lymphocytes. Elaboration of lymphokines such as IFN-gamma by the malignant cells may represent one explanation for the unique clinical and pathologic features of HD.
View details for PubMedID 2554995
- REDUCED NEUTROPHIL COUNTS IN CHILDREN WITH TRANSIENT ERYTHROBLASTOPENIA OF CHILDHOOD JOURNAL OF PEDIATRICS 1989; 115 (5): 746-748
FAMILIAL BONE-MARROW MONOSOMY-7 - EVIDENCE THAT THE PREDISPOSING LOCUS IS NOT ON THE LONG ARM OF CHROMOSOME-7
JOURNAL OF CLINICAL INVESTIGATION
1989; 84 (3): 984-989
Loss of expression of a tumor-suppressing gene is an attractive model to explain the cytogenetic and epidemiologic features of cases of myelodysplasia and acute myelogenous leukemia (AML) associated with bone marrow monosomy 7 or partial deletion of the long arm (7q-). We used probes from within the breakpoint region on 7q-chromosomes (7q22-34) that detect restriction fragment length polymorphisms (RFLPs) to investigate three families in which two siblings developed myelodysplasia with monosomy 7. In the first family, probes from the proximal part of this region identified DNA derived from the same maternal chromosome in both leukemias. The RFLPs in these siblings diverged at the more distal J3.11 marker due to a mitotic recombination in one patient, a result that suggested a critical region on 7q proximal to probe J3.11. Detailed RFLP mapping of the implicated region was then performed in two additional unrelated pairs of affected siblings. In these families, DNA derived from different parental chromosome 7s was retained in the leukemic bone marrows of the siblings. We conclude that the familial predisposition to myelodysplasia is not located within a consistently deleted segment on the long arm of chromosome 7. These data provide evidence implicating multiple genetic events in the pathogenesis of myelodysplasia seen in association with bone marrow monosomy 7 or 7q-.
View details for Web of Science ID A1989AN25900035
View details for PubMedID 2569483
View details for PubMedCentralID PMC329745
HEMOGLOBIN FM-FORT-RIPLEY - ANOTHER LESSON FROM THE NEONATE
1989; 83 (5): 792-793
View details for PubMedID 2470018
CHARACTERIZATION OF THE ERYTHROPOIETIC DEFECT IN THE LARGEST KNOWN KINDRED OF CONGENITAL HYPOPLASTIC (DIAMOND-BLACKFAN) ANEMIA
NATURE PUBLISHING GROUP. 1989: A158–A158
View details for Web of Science ID A1989T947100931
ELEVATED ERYTHROCYTE ADENOSINE-DEAMINASE (ADA) ACTIVITY IS NOT A MARKER OF HUMAN IMMUNODEFICIENCY VIRUS (HIV) INFECTION IN HEMOPHILIAC PATIENTS
WILLIAMS & WILKINS. 1989: A150
View details for Web of Science ID A1989T947100888
HB F-M-OSAKA OR ALPHA-2G-GAMMA-263(E7)HIS-]TYR IN A CAUCASIAN MALE INFANT
1989; 13 (7-8): 769-773
View details for PubMedID 2483933
CHARACTERIZATION OF THE ERYTHROPOIETIC DEFECT IN THE LARGEST KNOWN KINDRED OF CONGENITAL HYPOPLASTIC-ANEMIA
SLACK INC. 1989: A188–A188
View details for Web of Science ID A1989R585101100
- TRANSIENT ERYTHROBLASTOPENIA OF CHILDHOOD WESTERN JOURNAL OF MEDICINE 1988; 149 (4): 453-454
PHILADELPHIA CHROMOSOME-POSITIVE ACUTE LYMPHOBLASTIC-LEUKEMIA CELL-LINES WITHOUT CLASSICAL BREAKPOINT CLUSTER REGION REARRANGEMENT
1988; 48 (10): 2876-2879
The Philadelphia (Ph) chromosome translocation which is classically observed in chronic myeloid leukemia (CML) is sporadically found in acute lymphoblastic leukemia (ALL). In CML the translocation breakpoint on chromosome 22 is within the breakpoint cluster region, while in childhood ALL, no detectable change in breakpoint cluster region is routinely observed. In order to investigate the nature of this difference, we have established and characterized two cell lines from a child with Ph positive ALL. The cell lines have retained the cytochemical staining pattern, enzyme activity, monoclonal antibody profile, and immunoglobulin gene rearrangements of the child's malignant cells. The cell lines had the same Ph translocation t(9;22) (q34;q11) as the child's malignant cells along with additional chromosome changes. Southern blot analysis showed that the Ph translocation did not involve the 5.8-kilobase breakpoint cluster region segment characteristically seen in CML. The cell lines reported here will be a valuable resource in ascertaining the biological significance of the Ph translocation seen in ALL.
View details for PubMedID 3162827
CLINICAL AND BIOLOGIC CHARACTERIZATION OF T-CELL NEOPLASIAS WITH REARRANGEMENTS OF CHROMOSOME-7 BAND Q34
1988; 71 (2): 395-402
In T cell malignancy, rearrangements of chromosome 14 have been observed with a break in the band that contains the alpha chain gene for the T cell receptor (TCR). Because the beta chain TCR gene is in chromosome band 7q34, we searched for and report finding specific rearrangements of 7q34 exclusively in T cell malignancies. The rearrangements were reciprocal translocations between 7q34 and other points: 1p34, 9q32, 9q34, 15q22, and 19p13. The malignancies containing a 7q34 translocation were either T cell acute lymphoblastic leukemias or T cell lymphoblastic lymphomas that had similarities in clinical, enzyme, immunologic, and cellular characteristics. Hybridization using a probe to the beta-TCR gene disclosed unique rearrangements consistent with clonality in every case. A common pattern with chromosome breakpoints involving TCR genes may be emerging in T cell neoplasia.
View details for PubMedID 2962650
ELEVATED RED-CELL ADENOSINE-DEAMINASE ACTIVITY - A MARKER OF DISORDERED ERYTHROPOIESIS IN DIAMOND-BLACKFAN ANEMIA AND OTHER HEMATOLOGIC DISEASES
BRITISH JOURNAL OF HAEMATOLOGY
1988; 68 (2): 165-168
Red-cell adenosine deaminase (ADA) activity in children with Diamond-Blackfan anaemia is significantly increased (1.91 +/- 0.90 U/g Hb) compared to that seen in transient erythroblastopenia of childhood (0.80 +/- 0.16 U/g Hb) or normal individuals (0.61 +/- 0.13 U/g). These data thus further support that measurement of this purine metabolic enzyme is useful in diagnosing the cause of pure RBC aplasia in children. Of interest, however, elevated RBC-ADA activity also is seen in some children with acute leukaemia and other haematologic disorders. In children with acute lymphoblastic leukaemia (ALL), the increase in RBC-ADA activity is proportional to the degree of anaemia. However, the elevated RBC-ADA activity in this leukaemic population is not related to the fetal haemoglobin concentration. These data suggest increased RBC-ADA activity may be a non-specific manifestation of abnormal erythroid stem cell function, an alteration distinct from that seen with reactivation of fetal erythropoiesis. However, since almost all patients with Diamond-Blackfan anaemia manifest elevated RBC-ADA activity, this chemical alteration yet may reflect the specific erythroid differentiation lesion in this disorder.
View details for PubMedID 3348976
Diagnosis and management of red cell aplasia in children.
Hematology/oncology clinics of North America
1987; 1 (3): 431-447
The vast majority of pediatric RBC hypoplastic anemias are accounted for by red blood cell aplasia associated with chronic hemolysis, Diamond-Blackfan anemia, and transient erythroblastopenia of childhood. However, other causes of hypoplastic anemia occur in children, and some of these are similar to what is seen in adult RBC aplasia. For example, it has been reported that a 5-year-old girl with an aregenerative anemia had a thymoma and later developed pancytopenia. RBC aplasia also has been seen in children receiving anticonvulsant drug therapy, children recovering from severe protein malnutrition, children with hepatitis, and in children with leukemia during maintenance therapy. In addition, it is not uncommon for pediatric hematologists to observe children with RBC aplasia where there is no obvious diagnosis, although many are considered to be variants of Diamond-Blackfan anemia. Several important questions about RBC hypoplastic anemias in children need to be resolved; it is hoped that this will be accomplished in the next decade. Do RBC hypoplastic crises associated with hemolytic anemia occur with viral infections other than HPV? What is the cellular pathophysiology in DBA and TEC? Does the apparent heterogeneity of these disorders reflect limitations of laboratory techniques or are we looking at several different diseases? Is acute leukemia a real complication of Diamond-Blackfan anemia? Is TEC a completely benign entity or will we see other long-term problems in these children? Is the incidence of TEC actually increasing? Will TEC-like problems be seen in other aged children? As a case in point, we recently observed a 16-year-old girl who presented with pure RBC aplasia that required RBC transfusion support for 5 months; she also received prednisone therapy. After 7 months, however, this young lady had a spontaneous remission, and now 4 years later she is normal and free of any hematologic abnormalities. This was a most unusual event in our experience and, in view of the apparent increasing incidence of TEC in young children, we queried whether we were observing an adolescent equivalent of this disorder. During the next several years the answer to this and the other questions posed herein should be available.
View details for PubMedID 3129394
ESTABLISHMENT AND CHARACTERIZATION OF A COMMON ACUTE LYMPHOBLASTIC-LEUKEMIA CELL-LINE WITH A DELETION OF CHROMOSOME-3 BAND Q26
1987; 47 (6): 1652-1656
This paper describes the establishment and characterization of a new cell line (SUP-B7) which was established from a child with "common" acute lymphoblastic leukemia. The SUP-B7 cells (and the patient's tumor) have been characterized by cytochemical staining, monoclonal antibodies, enzyme analyses, gene rearrangement studies, and karyotype analysis. The SUP-B7 cells are periodic acid-Schiff positive, common acute lymphoblastic leukemia antigen positive, and terminal deoxynucleotidyl transferase positive, and they lack the Epstein-Barr virus genome. In addition, the SUP-B7 cells lack cytoplasmic and surface immunoglobulins, and the immunoglobulin gene rearrangement studies showed rearranged heavy chain genes with germ line light chain genes. Concordance between the cell line and the patient's tumor was established by the immunoglobulin gene rearrangement studies. Using Southern blot analysis of the DNA from the patient's tumor and the SUP-B7 cells, there was comigration of the bands representing the rearranged immunoglobulin heavy chain gene. In addition, the SUP-B7 cells possess a single chromosome abnormality: del(3)(q26q28), with the chromosome breakpoint at or near the transferrin receptor gene. Since the SUP-B7 cell line is concordant with the patient's malignancy and since these cells possess a single chromosomal abnormality, the SUP-B7 cell line may be a useful tool in determining the biological significance of the chromosome deletion: del(3)(q26q28).
View details for Web of Science ID A1987G548300030
View details for PubMedID 3469019
TRANSIENT ERYTHROBLASTOPENIA OF ADOLESCENCE
1986; 25 (11): 563-565
This case report describes a 16-year-old girl with pure red cell aplasia of 7 months duration. The erythrocyte characteristics and in vitro culture of erythroid progenitors was similar to that found in transient erythroblastopenia of childhood (TEC), a disorder most commonly seen in children 2 to 6 years of age. This case may represent the adolescent equivalent of TEC.
View details for Web of Science ID A1986E720400005
View details for PubMedID 3095011
PYRUVATE-KINASE DEFICIENCY IN DOG AND HUMAN-ERYTHROCYTES - EFFECTS OF ENERGY DEPLETION ON CATION COMPOSITION AND CELLULAR HYDRATION
AMERICAN JOURNAL OF HEMATOLOGY
1986; 23 (3): 217-221
Pyruvate kinase-(PK) deficient human reticulocytes incubated 4 hr under conditions where mitochondrial oxidative phosphorylation is inhibited become ATP-depleted. Concomitantly, these energy-depleted red blood cells (RBC) lose massive amounts of potassium and water. PK-deficient reticulocyte-rich RBC from a Basenji dog, incubated under the same conditions, also manifest ATP-depletion and K-loss. In contrast to the cation changes in human cells, however, K-loss in PK-deficient dog reticulocyte-rich RBC is balanced by an equivalent Na gain, and consequently these canine erythrocytes do not undergo any change in cellular hydration. Potassium depletion and dehydration, which may be related to membrane injury in human RBC, do not appear to be involved in the hemolysis of PK-deficient dog erythrocytes.
View details for Web of Science ID A1986E650300004
View details for PubMedID 3766523
PREDNISONE STIMULATION OF ERYTHROPOIESIS IN LEUKEMIC CHILDREN DURING REMISSION
AMERICAN JOURNAL OF HEMATOLOGY
1986; 23 (2): 179-181
Children with acute leukemia in remission manifest reticulocytosis and a significant increase in hemoglobin concentration (mean increment of 2.3 +/- 1.1 g/dl) following prednisone pulse therapy. This hemoglobin increment is not associated with changes in serum erythropoietin activity. It is speculated that this stimulation of red cell production may be a direct effect of steroids on erythroid progenitor cells.
View details for Web of Science ID A1986E046700012
View details for PubMedID 3463202
COMPARATIVE ACTIVITY OF ERYTHROCYTE ADENOSINE-DEAMINASE AND OROTIDINE DECARBOXYLASE IN DIAMOND-BLACKFAN ANEMIA
AMERICAN JOURNAL OF HEMATOLOGY
1986; 23 (2): 135-139
It previously has been reported that red blood cells (RBC) of patients with Diamond-Blackfan syndrome (DBS) have increased activity of orotidine decarboxylase (ODC) and adenosine deaminase (ADA). The studies reported here compared the activity of these two enzymes in DBS erythrocytes, cord blood, and reticulocytes. The activity of ODC, although increased in some DBS erythrocytes, was not significantly different from that seen in cord RBC or reticulocytes. In contrast, RBC-ADA activity was increased in 23 of 26 DBS patients; and this enzyme elevation was distinct from that seen in cord blood and reticulocytes. Moreover, ADA activity was normal in 26 of 27 patients with transient erythroblastopenia of childhood (TEC). Taken together, these data indicate RBC-ADA activity is more sensitive than ODC as a marker of DBS. In addition, RBC-ADA activity continues to be useful for distinguishing DBS and TEC in most patients with RBC hypoplasia.
View details for Web of Science ID A1986E046700007
View details for PubMedID 3752068
- SCREENING FOR ANEMIA AND ERYTHROCYTE DISORDERS IN CHILDREN PEDIATRICS 1986; 78 (2): 368-369
DIFFERENTIAL ERYTHROCYTE AGGLUTINATION AS AN AID IN THE DIAGNOSIS (DX) OF RED-BLOOD-CELL (RBC) ENZYMOPATHIES IN TRANSFUSED (TXD) CHILDREN
WILLIAMS & WILKINS. 1986: A279
View details for Web of Science ID A1986A712000761
CHRONIC INFECTIOUS-MONONUCLEOSIS SYNDROME, PANCYTOPENIA, AND POLYCLONAL B-LYMPHOPROLIFERATION TERMINATING IN ACUTE LYMPHOBLASTIC-LEUKEMIA
AMERICAN JOURNAL OF PEDIATRIC HEMATOLOGY ONCOLOGY
1986; 8 (1): 18-27
A 17-year-old previously healthy girl is reported who developed acute infectious mononucleosis followed by progressive ill health over 20 months, associated with pancytopenia and a polyclonal B-lymphoproliferation, terminating in acute lymphoblastic leukemia (ALL). Epstein-Barr virus (EBV) was recovered from the patient's nasopharyngeal secretions; serologic titers of antibodies to EBV-associated antigens were compatible with a chronic persistent EBV infection. Plasma interferon levels were markedly elevated. EBV-specific cell-mediated immunity, as well as Natural killer (NK) cell activity were markedly deficient. Other studies of cell-mediated immunity revealed notable abnormalities, including abnormalities in T-cell subset ratios, and a serum blocker of autologous mitogen-induced lymphoproliferation. Humoral (plasma)-mediated, but not cell-mediated, suppression of hemopoiesis was demonstrated using in vitro erythroid and myeloid colony culture techniques. Immunophenotyping of the patient's bone marrow cells preterminally was consistent with ALL. Autopsy revealed pathologic changes of ALL in marrow and multiple organs. We conclude that our patient developed an EBV-driven lymphoproliferative disorder, with associated defective cell-mediated immunity and hemopoiesis. Ultimately, the patient's documented polyclonal lymphoproliferative state was superimposed by acute lymphoblastic leukemia.
View details for Web of Science ID A1986C028900004
View details for PubMedID 3013037
- PANCYTOPENIA WITH MYELOFIBROSIS - AN UNUSUAL PRESENTATION OF CHILDHOOD HODGKINS-DISEASE CLINICAL PEDIATRICS 1986; 25 (2): 106-108
MONO-VALENT CATION CHANGES IN SICKLE ERYTHROCYTES - A DIRECT REFLECTION OF ALPHA-GLOBIN GENE NUMBER
JOURNAL OF LABORATORY AND CLINICAL MEDICINE
1985; 106 (1): 75-79
It has been suggested that the less severe anemia that exists in patients with sickle cell anemia who also have alpha-thalassemia is related to an effect on the sickling of erythrocytes. To test this hypothesis, we used as a measure of sickling the change in sickle erythrocyte sodium and potassium content that occurs during deoxygenation. Sickle cells from individuals with four, three, or two alpha-globin genes were deoxygenated, and the change in monovalent cation content measured to determine whether a relationship exists between alpha-globin gene number and sickling. In samples of cells depleted of irreversibly sickled cells, the alpha-globin gene number was directly related to the magnitude of mean cation change and inversely related to the ratio of membrane surface area to cell volume. These data indicate that alpha-thalassemia is associated with a diminished degree of sickling in individuals with sickle cell anemia. They also suggest that excess cell membrane may play a role in this protective effect.
View details for Web of Science ID A1985ALL4000012
View details for PubMedID 4009025
- COMPARATIVE ACTIVITY OF ADENOSINE-DEAMINASE (ADA) AND OROTIDINE DECARBOXYLASE (ODC) IN RED BLOOD-CELLS (RBC) FROM PATIENTS WITH DIAMOND-BLACKFAN SYNDROME (DBS) WILLIAMS & WILKINS. 1985: A262
NEURO-BLASTOMA IN INFANTS - WHEN IS THERAPY NECESSARY
INT PEDIATRIC RESEARCH FOUNDATION, INC. 1985: A257–A257
View details for Web of Science ID A1985AEU1800880
- CHILDHOOD BONE-MARROW MONOSOMY-7 SYNDROME - A FAMILIAL DISORDER JOURNAL OF PEDIATRICS 1985; 107 (4): 578-580
FATAL MYOCARDIAL-INFARCTION FOLLOWING THERAPY WITH PROTHROMBIN COMPLEX CONCENTRATES IN A YOUNG MAN WITH HEMOPHILIA-A
1984; 74 (2): 279-281
A fatal myocardial infarction in a 22-year-old man with hemophilia A and a factor VIII inhibitor is described. The catastrophic event occurred while the patient was receiving high doses of unactivated prothrombin complex concentrates. Autopsy examination revealed myocardial hemorrhage with no evidence of coronary artery disease or thrombosis. There also was postmortem evidence of previous myocardial infarctions. This is the fourth documented case of myocardial infarction occurring in a young hemophiliac patient using unactivated prothrombin complex concentrates. It is concluded that utilization of prothrombin complex concentrates in hemophiliac patients must be limited and closely monitored. Therapeutic guidelines are recommended.
View details for Web of Science ID A1984TC76400018
View details for PubMedID 6431390
BIOCHEMICAL AND RADIOLOGIC-DIAGNOSIS OF LEUKEMIA IN A HEMATOLOGICALLY NORMAL-CHILD
SLACK INC. 1984: A104–A104
View details for Web of Science ID A1984RZ82200617
- IMMUNE THROMBOCYTOPENIA ASSOCIATED WITH ACUTE NONLYMPHOCYTIC LEUKEMIA JOURNAL OF PEDIATRICS 1984; 105 (5): 776-778
MONOCLONAL-ANTIBODY AND ENZYMATIC PROFILES OF HUMAN-MALIGNANT LYMPHOID-T CELLS AND DERIVED CELL-LINES
1984; 44 (12): 5657-5660
Recently, four distinct cell lines were established from patients whose malignancies had been defined by immunological and biochemical markers. Each patient had a distinct subtype of a T-cell cancer, and each possessed elevated adenosine deaminase and reduced nucleoside phosphorylase activity. Cell lines cultured in vitro possessed the same basic immunophenotype and biochemical enzyme activity as the patients' original malignant cells. In a direct comparison of the immunophenotype of the cell lines and the patients' malignant cells, full concordance existed for 48 of 52 paired antibody tests performed. However, when compared to the corresponding patient's sample, each cell line showed some minor changes in antigen expression or enzyme level. Antigen loss, de novo antigen expression, or elevated adenosine deaminase levels occurred in the cell lines, and these changes were stable on repeated analysis. While there was good general concordance between the patient's cancer and the established cell line, minor biological differences in the cell lines may reflect cellular maturation or subpopulation selection in vitro.
View details for Web of Science ID A1984TU47100032
View details for PubMedID 6437672
ACUTE NONLYMPHOCYTIC LEUKEMIA DEVELOPING DURING THE COURSE OF EWINGS-SARCOMA
MEDICAL AND PEDIATRIC ONCOLOGY
1984; 12 (3): 194-200
Two children with Ewing's sarcoma developed acute nonlymphocytic leukemia (ANLL) during the course of their illness. One patient developed ANLL after apparently successful treatment of his primary malignancy with radiation therapy and multiagent chemotherapy. In the second patient, acute leukemia developed before the administration of radiotherapy or systemic chemotherapy. The development of secondary ANLL after Ewing's sarcoma has been reported only twice previously, most likely representing a therapy-induced complication. The occurrence of ANLL in Patient 2 prior to therapy suggests that these two disorders may have a more than treatment-related association. Close follow-up of long-term survivors of Ewing's sarcoma with surveillance for secondary acute leukemia is advised.
View details for Web of Science ID A1984SW62300009
View details for PubMedID 6727775
COMPARATIVE MONO-VALENT CATION-TRANSPORT IN NEONATAL AND ADULT RED-BLOOD-CELLS
1984; 18 (8): 778-780
Active transport of Na and K under physiologic and maximally stressed conditions was identical in normal adult red blood cells (RBC) and term neonatal erythrocytes. These results are consistent with the previous observation that Na-K ATPase is the same in normal adult RBC and term neonatal erythrocytes. These data, however, are at variance with a previous observation that active K transport is impaired in neonatal erythrocytes. The most reasonable explanation for this difference relates to inherent problems with the use of radioisotopes which were used in previous in vitro studies of cation transport.
View details for Web of Science ID A1984TB61300023
View details for PubMedID 6089084
ELEVATED ERYTHROCYTE ADENOSINE-DEAMINASE ACTIVITY IN CONGENITAL HYPOPLASTIC-ANEMIA
NEW ENGLAND JOURNAL OF MEDICINE
1983; 309 (24): 1486-1490
Abnormalities of adenosine deaminase, a critical enzyme of the purine salvage pathway, have been reported in association with immune dysfunction, acute leukemia, and hereditary hemolytic anemia. We report data showing that erythrocyte adenosine deaminase activity is also abnormal in congenital hypoplastic anemia (the Diamond-Blackfan syndrome). Adenosine deaminase activity in erythrocytes from 12 patients (mean +/- S.D., 2.20 +/- 0.77 IU per gram of hemoglobin) was substantially greater than that observed in 50 controls (0.62 +/- 0.13 IU per gram). Enzyme activity in affected patients was also greater than that seen in cord blood or in erythrocytes from patients with hemolytic anemia, acquired aplastic anemia, Fanconi's hypoplastic anemia, acquired pure red-cell aplasia, or transient erythroblastopenia of childhood. These observations indicate that erythrocyte adenosine deaminase activity may be a unique marker for identifying congenital hypoplastic anemia.
View details for Web of Science ID A1983RU40500004
View details for PubMedID 6646173
IMMUNE THROMBOCYTOPENIA ASSOCIATED WITH ACUTE NON-LYMPHOCYTIC LEUKEMIA (ANNL)
SLACK INC. 1983: A115
View details for Web of Science ID A1983PU88600683
PLATELET-ASSOCIATED IMMUNOGLOBULIN-G IN CHILDHOOD IDIOPATHIC THROMBOCYTOPENIC PURPURA
JOURNAL OF PEDIATRICS
1983; 102 (3): 366-370
Platelet-associated IgG was studied in children with acute and chronic ITP and in patients with thrombocytopenic SLE, using the microtiter solid-phase radioimmunoassay. Of the children with acute ITP, 85% had elevated PAIgG levels. The degree of elevation of PAIgG at onset of disease did not correlate with the development of chronicity. Of the children with acute ITP, clinically and hematologically indistinguishable from the rest, 15% had normal PAIgG values. All of 22 children with chronic ITP had elevated PAIgG values. Although there was good correlation between the platelet count and the PAIgG value in children with chronic ITP, the association was not as striking in those with acute ITP; thus, factors in addition to the level of PAIgG may contribute to the thrombocytopenia in the latter group. Patients with SLE and thrombocytopenia had higher values of PAIgG than would be predicted from the platelet count; the PAIgG value is probably not the only factor determining the degree of immune thrombocytopenia.
View details for Web of Science ID A1983QF66500007
View details for PubMedID 6681837
INCREASED ADENOSINE-DEAMINASE ACTIVITY AS A UNIQUE ERYTHROCYTE MARKER IN DIAMOND-BLACKFAN SYNDROME
SLACK INC. 1982: A123–A123
View details for Web of Science ID A1982MX91200724
SUDDEN CARDIAC DEATH IN A YOUNG MAN WITH HEMOPHILIA-A RECEIVING PROTHROMBIN-COMPLEX CONCENTRATE
SLACK INC. 1982: A124
View details for Web of Science ID A1982MX91200729
THE RED-BLOOD-CELL AS A BIOPSY TOOL
CLINICS IN HAEMATOLOGY
1981; 10 (1): 209-222
During the past several years, there has been much emphasis on understanding the relationship between abnormalities in RBC metabolism and hereditary haemolytic anaemias. More recently, attention has focused on utilizing erythrocyte biochemical abnormalities in the diagnosis of systemic disorders not necessarily associated with altered RBC function. In this chapter, we have enumerated several non-erythrocytic clinical conditions clearly associated with altered RBC metabolic products or enzyme activity. Specifically, we have described the use of erythrocytes (1) to diagnose inborn errors of metabolism, (2) to assess many nutritional disorders, (3) to monitor hyperglycaemia in patients with diabetes mellitus, and (4) to discriminate between essential and non-essential hypertension. As Eric Ponder said many years ago (Ponder, 1948), 'I have been told that I tend to speak of the red cell as if it were a microcosm, as if an understanding of its nature and properties would include an understanding of nearly everything else in the cellular world. To some extent this is true.' When the list of conditions for which the red cell can be used as a biopsy tool is reassessed several years from now, most assuredly many new clinical conditions will be added to the diseases we have discussed. For example, our knowledge of normal membrane structure and function currently is in its infancy, yet it already appears that analysis of RBC membranes may be useful in detecting certain neurological disorders such as muscular dystrophy (Roses, Herbstreith and Appel, 1975). Needless to say, to the delight of Dr Eric Ponder, the utility of the erythrocyte as an investigative tool appears to be without limit.
View details for Web of Science ID A1981LL32600011
View details for PubMedID 6452240
ERYTHROCYTE ENZYME DISORDERS IN CHILDREN
PEDIATRIC CLINICS OF NORTH AMERICA
1980; 27 (2): 449-462
Erythrocyte metabolic abnormalities should be considered as a possible cause of hemolysis when there is no evidence of an immune-mediated hemolytic anemia, no consumptive red blood cell disorder, no morophologic or laboratory data to suggest a problem of the red cell membrane, and no evidence of a quantitative or qualitative defect in hemoglobin synthesis. Glucose-6-phosphate dehydrogenase deficiency is clearly the most common enzyme deficiency causing clinical problems.
View details for Web of Science ID A1980JV66600015
View details for PubMedID 6247687
CLINICAL AND PATHOPHYSIOLOGIC FEATURES OF HEMOLYSIS ASSOCIATED WITH HEMOGLOBIN BRISTOL
WILLIAMS & WILKINS. 1980: 541
View details for Web of Science ID A1980JL99400691
RED-BLOOD-CELL (RBC) CATION CONTENT AS AN INDEPENDENT DETERMINANT OF CELLULAR RIGIDITY
WILLIAMS & WILKINS. 1980: 541
View details for Web of Science ID A1980JL99400692
- HEREDITARY SPHEROCYTOSIS PEDIATRIC ANNALS 1980; 9 (8): 308-311
Erythrocyte disorders leading to potassium loss and cellular dehydration.
Progress in clinical and biological research
1979; 30: 503-513
RBC K loss and cellular dehydration are associated with a variety of normal and abnormal erythrocyte conditions. In some cases (normal RBC aging, pyruvate-kinase-deficient RBCs and irreversibly sickled cells) cation and water changes are related to adenosine triphosphate (ATP) depletion and to increased RBC calcium content. In other disorders, such as hereditary xerocytosis, cation depletion and cellular hydration are not related to altered energy or calcium metabolism. Rather, this condition is thought to be due to a structural membrane defect which is manifested by imbalanced cation leaks (K less greater than Na gain) for which the active cation transport is unable to compensate. None of the disorders described here are associated with known structural membrane alterations. The fact that K loss and cellular dehydration are common to several RBC disorders suggests that this phenomenon may have a direct role in membrane injury. This hypothesis is supported by two separate observations: 1)Formation of irreversible sickled cells in vitro is prevented if K and water loss are inhibited, and these effects are independent of ATP depletion and calcium accumulation; 2) the mean critical hemolytic volume is markedly reduced in K- and water-depleted normal RBCs. RBC dehydration without intracellular cation depletion, however, is not associated with changes in mean critical hemolytic volume. These data thus indicate that K loss may have a direct role in RBC membrane injury. The mechanism by which this occurs and the associated alterations in membrane structure, however, remain to be identified.
View details for PubMedID 531041
CALCIUM DEPENDENT AND INDEPENDENT EFFECTS OF PROPRANOLOL - EVIDENCE FOR SEPARATE RED-CELL SODIUM AND POTASSIUM CHANNELS
SLACK INC. 1979: A108
View details for Web of Science ID A1979GC72700634
MICROCYTOSIS ASSOCIATED WITH SICKLE-CELL ANEMIA
AMERICAN JOURNAL OF CLINICAL PATHOLOGY
1979; 72 (1): 63-64
Sickle cell (Hb SS) anemia is considered a normochromic-normocytic hemolytic disorder. In 53 patients with Hb SS (mean reticulocyte values 16.8%), the authors observed that mean corpuscular hemoglobin (MCH) was 29.8 +/- 2.4 mu microgram and mean corpuscular hemoglobin (MCV) was 88.1 +/- 6.8 cu micrometers. In contrast, patients in a comparable hemolytic-disease group unrelated to hemoglobinopathies (mean reticulocyte count = 15.7%) had a higher MCH (33.0 +/- 1.8 mu microgram) and larger MCV (97 +/- 5.3 cu micrometers). These data indicate that Hb SS disease is associated with "relative microcytosis," presumably a consequence of reduced hemoglobin production.
View details for Web of Science ID A1979HC87000011
View details for PubMedID 453112
- EOSINOPHILIA IN CHILDREN PEDIATRIC ANNALS 1979; 8 (6): 39-?
LEUKOCYTE COUNTS IN CHILDREN WITH SICKLE-CELL DISEASE - COMPARATIVE VALUES IN STEADY-STATE, VASO-OCCLUSIVE CRISIS, AND BACTERIAL-INFECTION
AMERICAN JOURNAL OF DISEASES OF CHILDREN
1978; 132 (4): 396-398
Total and differential WBC counts were measured in 88 children with sickle cell hemoglobinopathies during the steady state, vaso-occlusive crisis, and bacterial infection. Steady state leukocyte values were lower than anticipated on the basis of currently available information. Total and segmented leukocyte numbers were greatly increased during vaso-occlusive crisis and infection, but only with bacterial infection was there a consistent increase in bands or nonsegmented leukocytes (mean, 4,580/microliter). On the basis of these data we believe that total and differential leukocyte counts are of value for identifying those children with potentially serious bacterial infections.
View details for Web of Science ID A1978EW29500013
View details for PubMedID 645659
RED-BLOOD-CELL SIZE AND GLYCOLYTIC ENZYME-ACTIVITY - RELATIONSHIP TO NUMBER OF INTRA-MEDULLARY CELL DIVISIONS
1978; 12 (4): 308-309
In order to assess how the number of cell divisions influences the red blood cell (RBC) content of proteins other than hemoglobin, we measured the activity of two age-independent glycolytic enzymes in macrocytic, normal, and microcytic RBCs. The enzymes measured were phosphoglycerate kinase (PGK) and lactic dehydrogenase (LDH). In macrocytes, both PGK and LDH activity/10(10) RBCs were increased 1.6-fold over normal RBCs. In microcytes, however, the activity of these enzymes was identical to that seen in normal RBCs.
View details for Web of Science ID A1978EV11400012
View details for PubMedID 652413
ENERGY RESERVE AND CATION COMPOSITION OF IRREVERSIBLY SICKLED CELLS INVIVO
BRITISH JOURNAL OF HAEMATOLOGY
1978; 40 (4): 527-532
Cation composition, cellular hydration, and adenosinetriphosphate (ATP) content were measured in irreversible sickle cells (ISC's) separated from the blood of patients with sickle cell anaemia. Total monovalent cation (Na+ + K+) content was markedly reduced in ISC's and this largely was due to cell K+ depletion. Corresponding to the reduced cation content, cells were dehydrated as indicated by a reduced mean cell volume. ISC's also appeared to be grossly depleted of ATP. These biochemical characteristics allow us to expand the definition of ISC's beyond morphologic characteristics. In addition, these chemical alterations provide a means for elucidating the mechanism of ISC production in vitro.
View details for Web of Science ID A1978FX09000003
View details for PubMedID 728369
CATION PERMEABILITY ALTERATIONS DURING SICKLING - RELATIONSHIP TO CATION COMPOSITION AND CELLULAR HYDRATION OF IRREVERSIBLY SICKLED CELLS
1978; 51 (5): 983-989
Sickle erythrocytes (RBC) incubated under 100% nitrogen for 4 hr manifested marked Na gain with an equivalent K loss. There were no changes in cell total cation or water content under these conditions, and no irreversible sickle cells (ISC) were formed. In contrast, sickle RBC incubated for 24 hr under 100% nitrogen in a glucose-free Na medium containing calcium manifested marked ISC formation. ISC formed under these conditions also had elevated Na content, although K content was much more reduced, and consequently ISC were cation depleted and dehydrated. When sickle RBC were incubated 24 hr under 100% nitrogen in a glucose-free K medium containing calcium no ISC formed and there were no major changes in cation or water content. These studies indicate that the Na+K content and dehydration of ISC was not directly related to the increased cation permeability associated with sickling. Rather, the ISC changes appear to reflect the well-known Gardos effect (K and water loss occurring in ATP-depleted RBC incubated with calcium). In addition, these studies suggest that ISC formation per se is related to K and water loss, since no ISC were formed when ATP-depleted sickle RBC were deoxygenated in calcium-containing high-K media that prevented K loss and dehydration.
View details for Web of Science ID A1978EZ04900020
View details for PubMedID 638256
- HEMOLYTIC DISORDERS OF INFANCY CLINICS IN HAEMATOLOGY 1978; 7 (1): 35-61
PHYSIOLOGIC FEATURES OF HEMOLYSIS ASSOCIATED WITH ALTERED CATION AND 2,3-DIPHOSPHOGLYCERATE CONTENT
1978; 52 (1): 135-141
A hemolytic disorder characterized by altered RBC cation composition (increases Na, decreases K), reduced monovalent cation content (decreased Na + K/liter RBC), and decreased levels of 2,3-diphosphoglycerate (2,3-DPG) is described. The etiology of these RBC abnormalities was not elucidated following extensive laboratory evaluation, although two important physiologic principles were manifested by this case: (1) Hemolysis was relatively well compensated (41% hematocrit) despite a significantly decreased RBC survival (51 Cr t 1/2 = 10.5 days). This effect presumably was due to reduced 2,3-DPG content (1.9 mumol/ml RBC) and the associated increase in whole blood oxygen affinity (P50 = 19.6 mm hg). (2) RBC size and water content were normal in spite of marked cation depletion. This anomaly was thought to reflect the osmotic effects of reduced polyvalent anion (2,3-DPG) content.
View details for Web of Science ID A1978FF13200014
View details for PubMedID 656623
CATION SPECIFICITY OF PROPRANOLOL-INDUCED CHANGES IN RBC MEMBRANE-PERMEABILITY - COMPARATIVE EFFECTS IN HUMAN, DOG AND CAT ERYTHROCYTES
JOURNAL OF CELLULAR PHYSIOLOGY
1977; 91 (2): 317-321
Propranolol, in the presence of calcium, causes marked K efflux from human red blood cells (high K, low Na). The studies reported here indicate this effect of propranolol is specific for K and does not represent a nonspecific permeability increase for intracellular cations to leave the cell. Amphotericin-treated human RBC's (high Na, low K) and dog RBC's (high Na, low K) both gain K and increase in size when incubated in a K-medium containing propranolol and calcium. No effect was noted when cat RBC's (high Na, low K) were similarly treated. Propranolol, independent of added calcium, also inhibited the normally increased Na efflux observed when dog RBC's are suspended in K-medium. These species differences in response to propranolol thus may serve as a focus for elucidating the mechanism by which this drug alters normal membrane physiology. The unique drug effect on Na permeability of canine erythrocytes also may be a useful probe for the study of dog RBC volume regulation.
View details for Web of Science ID A1977DD60000015
View details for PubMedID 558987
BENIGN COURSE OF EXTREME HYPERBILIRUBINEMIA IN SICKLE-CELL ANEMIA - ANALYSIS OF 6 CASES
JOURNAL OF PEDIATRICS
1977; 91 (1): 21-24
Since the approach to the management and outcome of extreme hyperbilirubinemia in patients with sickle cell anemia is not clearly defined, we reviewed our experience with marked hyperbilirubinemia in six children with sickle cell disease. Intrahepatic sickling (sickle hepatopathy) rather than hepatitis or biliary stones appeared primarily responsible for the extreme jaundice in at least four children and possibly in all six. Signs and symptoms were few, and laboratory abnormalities were not striking other than marked hyperbilirubinemia (total serum bilirubin concentrations ranging from 20.4 to 57.6 mg/dl with approximately one half conjugated). All of the children improved within days to weeks and currently are well, without recurrence of hyperbilirubinemia or evidence of chronic liver disease. The patients described here suggest that sickling within the liver, previously reported to be a serious and even fatal syndrome, usually is a benign and self-limited process.
View details for Web of Science ID A1977DL33900004
View details for PubMedID 874660
Care of the critically ill child: the bleeding neonate.
1976; 58 (4): 548-555
Serious bleeding episodes in newborn infants can usually be diagnosed following careful clinical assessment and a few simple laboratory tests. Certain conditions are found almost exclusively in "sick" infants, whereas other coagulation abnormalities occur in otherwise "healthy" neonates. Successful management of hemorrhage necessitates a correct diagnosis which thereby dictates appropirate therapy. In some cases, such as in DIC, successful outcome ultimately depends on correction of the underlying pathophysiology which triggered the coagulation disturbance.
View details for PubMedID 972796
- EVALUATION OF HEMOLYTIC ROLE OF ASPIRIN IN GLUCOSE-6-PHOSPHATE-DEHYDROGENASE DEFICIENCY JOURNAL OF PEDIATRICS 1976; 89 (6): 1027-1028
1976; 58 (4): 548-555
View details for Web of Science ID A1976CG81000014
SALICYLATE-INDUCED INJURY OF PYRUVATE-KINASE-DEFICIENT ERYTHROCYTES
NEW ENGLAND JOURNAL OF MEDICINE
1976; 294 (17): 916-918
Salicylate is known to uncouple mitochondrial oxidative phosphorylation. Since the viability of pyruvate-kinase-deficient reticulocytes depends on ATP generated by mitochondrial metabolism, this study examined the effects of salicylate on erythrocytes deficient in pyruvate kinase. When deficient erythrocytes from patients with severe hemolysis were incubated with salicylate (2 to 30 mg per deciliter), there was a marked decrease (25 to 75 percent) in ATP. In addition, this drug-induced ATP depletion produced cell potassium and water loss, and the normal oxidant responsiveness of the hexose-monophosphate shunt was blunted. Since these cellular abnormalities are associated with accelerated hemolysis in vivo, the data suggest that aspirin therapy may aggravate hemolysis in patients with pyruvate kinase deficiency whose erythrocyte manifest sensitivity to salicylate in vitro.
View details for Web of Science ID A1976BN28300002
View details for PubMedID 1256482
ENERGY METABOLISM IN HUMAN ERYTHROCYTES - ROLE OF PHOSPHOGLYCERATE KINASE IN CATION-TRANSPORT
1975; 46 (2): 271-278
Three models of disturbed erythrocyte metabolism, triose-depleted normal, phosphoglycerate kinase (PGK)-deficient, and pyruvate kinase (PK)-deficient cells, have been studied to examine further the role of PGK in erythrocyte cation transport. Sodium (Na-+) and potassium (K-+) transport were reduced only in cells fully depleted of triose. In such cells the PGK step presumably was inoperative due to total lack of substrate; 2,3-diphosphoglycerate (2,3-DPG) then became the sole substrate source for remaining steps in glycolysis. At increased intracellular Na-+ concentrations which normally stimulate transport and glycolysis, triose-depleted cells had marked impairment of cation transport and ouabain-inhibitable lactate and pyruvate production from 2,3-DPG. PGK-deficient cells and normal cells with high intracellular Na-+ concentrations had similar increases in transport and ouabain-inhibitable lactate production. PK-deficient cells with high intracellular Na-+ concentrations showed an appropriate increase in transport but less stimulation of lactate production. Transport was not related to total cellular adenosine triphosphate (ATP) concentration. These data suggested that normal coupled cation transport occurred despite diminished metabolite flow through PGK, as in PGK- or PK-deficient cells. Transport was diminished only in triose-depleted cells where metabolite flow through PGK was presumably absent. These data, therefore, support the concept that transport and glycolysis interact at the PGK step, although impairment of PGK must be profound before its effect on transport is evident.
View details for Web of Science ID A1975AL13400011
View details for PubMedID 166715
INVIVO HEPATIC AND INTESTINAL TOXICITY OF SODIUM CYANATE IN RATS - CYANATE-INDUCED ALTERATIONS IN HEPATIC GLYCOGEN-METABOLISM
JOURNAL OF LABORATORY AND CLINICAL MEDICINE
1975; 85 (1): 140-154
To determine the hepatic and intestinal toxicity of sodium cyanate, this compound was administered to rats by orogastric tube (PO) or intraperitoneal injection (IP). At low dosage (50 mg. per kilogram per day PO for 8 weeks), the animals showed no clinical effects other than mild lethargy. They had normal intestinal absorption studies, but demonstrated decreased liver G6PD activity and a slight increase in hepatic glycogen. At higher dose levels (200 mg. per kilogram per day PO for 10 days, 400 mg. per kilogram per day PO for 3 days, and 100 mg. per kilogram per day IP for 10 days), the animals became very lethargic and developed hind-limb paralysis; many animals died during the period of dosing. The severity and rate of onset of symptoms increased proportionally with the dose level. Liver sections from rats receiving these higher doses showed striking increases in glycogen deposition. Activities of hepatic enzymes involved in glycogen synthesis and degradation were measured in rats receiving 200 mg. per kilogram per day PO or 100 mg. per kilogram per day IP. Significant decreases were noted in the activities of glucose-6-phosphatase and G6PD in PO-dosed rats. The activities of phosphorylase, UDPG-pyrophosphorylase, glycogen synthetase, phosphoglucomutase, and debrancher did not differ from control rats. In IP-dosed rats, significant decreases were observed in the activities of glucose-6-phosphatase, G6PD, phosphorylase, and UDPG-pyrophosphorylase, but not in the other glycogen-related enzymes. Our data suggest that sodium cyanate affects several enzymes of hepatic glycogen metabolism but that the enzymes vary in their susceptibility (glucose-6-phosphatase and G6PD greater than phosphorylase and UDPG pyrophosphorylase.
View details for Web of Science ID A1975V287200017
View details for PubMedID 237970
- ROLE OF ELEVATED GLUCOSE CONCENTRATIONS IN HEMOLYSIS OF GLUCOSE-6-PHOSPHATE-DEHYDROGENASE DEFICIENT ERYTHROCYTES PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE 1975; 148 (1): 50-53
- HEMOLYSIS DUE TO PYRUVATE-KINASE DEFICIENCY AND OTHER GLYCOLYTIC ENZYMOPATHIES CLINICS IN HAEMATOLOGY 1975; 4 (1): 123-138
- CONGENITAL HEMOLYTIC-ANEMIA ASSOCIATED WITH DEHYDRATED ERYTHROCYTES AND INCREASED POTASSIUM LOSS NEW ENGLAND JOURNAL OF MEDICINE 1974; 291 (10): 491-496
- ONCORNA VIRUS DISEASE - SYNDROME OF HEMOLYTIC-ANEMIA AND LYMPH-NODE CYSTIC-DISEASE LABORATORY INVESTIGATION 1974; 30 (5): 626-638
- EFFECT OF CYANATE ON ERYTHROCYTE DEFORMABILITY BLOOD 1974; 43 (2): 277-280
CONGENITAL HEMOLYTIC-ANEMIA WITH POTASSIUM LOSS - REPLY
NEW ENGLAND JOURNAL OF MEDICINE
1974; 291 (25): 1361-1361
View details for Web of Science ID A1974V010300017
- EFFECT OF CYANATE ON ERYTHROCYTE-MEMBRANE SURFACE CHARGE PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE 1973; 144 (1): 249-251
- INTRAVASCULAR HEMOLYSIS ASSOCIATED WITH INTRAVENOUS UREA INFUSIONS IN NORMAL INDIVIDUALS BLOOD 1973; 41 (3): 461-464
- HEMOLYSIS BY DIPHENYLSULFONES - COMPARATIVE EFFECTS OF DDS AND HYDROXYLAMINE-DDS JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1973; 81 (2): 267-272
- DECREASED GLUTATHIONE PEROXIDASE IN NEONATAL ERTHYROCYTES - LACK OF RELATION TO HYDROGEN-PEROXIDE METABOLISM PEDIATRIC RESEARCH 1972; 6 (12): 900-904
- CYANATE INHIBITION OF ERYTHROCYTE GLUCOSE-6-PHOSPHATE DEHYDROGENASE NATURE 1972; 237 (5354): 336-?
- MECHANISM OF METHEMOGLOBIN FORMATION BY DIPHENYLSULFONES - EFFECT OF 4-AMINO-4'-HYDROXYAMINODIPHENYLSULFONE AND OTHER P-SUBSTITUTED DERIVATIVES BIOCHEMICAL PHARMACOLOGY 1972; 21 (9): 1265-?
- EFFECT OF COBALT UPON IRON ABSORPTION PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE 1970; 134 (3): 741-?
Observations on the effect of testosterone and hydrocortisone on erythropoiesis.
Annals of the New York Academy of Sciences
1968; 149 (1): 383-388
View details for PubMedID 5240725
OBSERVATIONS ON EFFECT OF TESTOSTERONE AND HYDROCORTISONE ON ERYTHROPOIESIS
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
1968; 149 (A1): 383-?
View details for Web of Science ID A1968B043700046
- ROLE OF CELLULAR PI IN PI TRANSPORT AND METABOLISM IN HUMAN RED CELLS BIOCHIMICA ET BIOPHYSICA ACTA 1968; 150 (3): 524-?
- PHOSPHATE RELEASE FROM HUMAN ERYTHROCYTES BIOCHIMICA ET BIOPHYSICA ACTA 1968; 163 (1): 30-?
- 2,4-DINITROPHENOL INHIBITION OF P32 RELEASE FROM HUMAN RED CELLS EXPERIENTIA 1968; 24 (3): 244-?