Clinical Focus


  • Pediatric Rheumatology

Academic Appointments


Professional Education


  • Residency: Children's Hospital of Orange County (2002) CA
  • Fellowship: Stanford University Pediatric Rheumatology Fellowship (2005) CA
  • Internship: Children's Hospital of Orange County (2000) CA
  • Medical Education: University of Connecticut School of Medicine Registrar (1999) CT
  • Board Certification: American Board of Pediatrics, Pediatrics (2002)
  • Board Certification: American Board of Pediatrics, Pediatric Rheumatology (2006)
  • Ph.D., University of Connecticut, Biomedical Science (1999)
  • M.D., University of Connecticut (1999)

Current Research and Scholarly Interests


Pediatric systemic lupus erythematosus;
Autoimmune disease;
Proteomics and autoantigen microarray technology

Clinical Trials


  • Observational Study of Pediatric Rheumatic Diseases: The CARRA Registry Recruiting

    Continuation of the CARRA Registry as described in the protocol will support data collection on patients with pediatric-onset rheumatic diseases. The CARRA Registry will form the basis for future CARRA studies. In particular, this observational registry will be used to answer pressing questions about therapeutics used to treat pediatric rheumatic diseases, including safety questions.

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Graduate and Fellowship Programs


  • Pediatric Rheumatology (Fellowship Program)

All Publications


  • DNASE1L3 RELATED AUTOIMMUNE SYNDROME: A CASE REPORT AND REVIEW OF THE LITERATURE Schymick, J., Bonner, D., Majcherska, M., McCormack, C., Fresard, L., Smith, K., Montgomery, S., Fisher, P., Ashley, E., Ud, N., Maller, J., Hsu, J., Balboni, I., Wheeler, M., Bernstein, J. BMJ PUBLISHING GROUP. 2019: 80–81
  • Autoantibody Profiling in Lupus Patients using Synthetic Nucleic Acids SCIENTIFIC REPORTS Klecka, M., Thybo, C., Macaubas, C., Solov'yov, I., Simard, J., Balboni, I., Fox, E., Voss, A., Mellins, E. D., Astakhova, K. 2018; 8: 5554

    Abstract

    Autoantibodies to nuclear components of cells (antinuclear antibodies, ANA), including DNA (a-DNA), are widely used in the diagnosis and subtyping of certain autoimmune diseases, including systemic lupus erythematosus (SLE). Despite clinical use over decades, precise, reproducible measurement of a-DNA titers remains difficult, likely due to the substantial sequence and length heterogeneity of DNA purified from natural sources. We designed and tested a panel of synthetic nucleic acid molecules composed of native deoxyribonucleotide units to measure a-DNA. ELISA assays using these antigens show specificity and reproducibility. Applying the ELISA tests to serological studies of pediatric and adult SLE, we identified novel clinical correlations. We also observed preferential recognition of a specific synthetic antigen by antibodies in SLE sera. We determined the probable basis for this finding using computational analyses, providing valuable structural information for future development of DNA antigens. Synthetic nucleic acid molecules offer the opportunity to standardize assays and to dissect antibody-antigen interactions.

    View details for PubMedID 29615791

  • Resilience and Transition Readiness in Pediatric SLE Patients Lai, J., Nelson, L., Balboni, I., Lee, T., Hsu, J. WILEY. 2017
  • Mass cytometry identifies a distinct monocyte cytokine signature shared by clinically heterogeneous pediatric SLE patients. Journal of autoimmunity O'Gorman, W. E., Kong, D. S., Balboni, I. M., Rudra, P., Bolen, C. R., Ghosh, D., DAVIS, M. M., Nolan, G. P., Hsieh, E. W. 2017

    Abstract

    Systemic Lupus Erythematosus (SLE) is a heterogeneous autoimmune disease with heightened disease severity in children. The incomplete understanding of the precise cellular and molecular events that drive disease activity pose a significant hurdle to the development of targeted therapeutic agents. Here, we performed single-cell phenotypic and functional characterization of pediatric SLE patients and healthy controls blood via mass cytometry. We identified a distinct CD14(hi) monocyte cytokine signature, with increased levels of monocyte chemoattractant protein-1 (MCP1), macrophage inflammatory protein-1β (Mip1β), and interleukin-1 receptor antagonist (IL-1RA). This signature was shared by every clinically heterogeneous patient, and reproduced in healthy donors' blood upon ex-vivo exposure to plasma from clinically active patients only. This SLE-plasma induced signature was abrogated by JAK1/JAK2 selective inhibition. This study demonstrates the utility of mass cytometry to evaluate immune dysregulation in pediatric autoimmunity, by identification of a multi-parametric immune signature that can be further dissected to delineate the events that drive disease pathogenesis.

    View details for DOI 10.1016/j.jaut.2017.03.010

    View details for PubMedID 28389038

  • Synthetic oligonucleotide antigens modified with locked nucleic acids detect disease specific antibodies SCIENTIFIC REPORTS Samuelsen, S. V., Solov'yov, I. A., Balboni, I. M., Mellins, E., Nielsen, C. T., Heegaard, N. H., Astakhova, K. 2016; 6

    Abstract

    New techniques to detect and quantify antibodies to nucleic acids would provide a significant advance over current methods, which often lack specificity. We investigate the potential of novel antigens containing locked nucleic acids (LNAs) as targets for antibodies. Particularly, employing molecular dynamics we predict optimal nucleotide composition for targeting DNA-binding antibodies. As a proof of concept, we address a problem of detecting anti-DNA antibodies that are characteristic of systemic lupus erythematosus, a chronic autoimmune disease with multiple manifestations. We test the best oligonucleotide binders in surface plasmon resonance studies to analyze binding and kinetic aspects of interactions between antigens and target DNA. These DNA and LNA/DNA sequences showed improved binding in enzyme-linked immunosorbent assay using human samples of pediatric lupus patients. Our results suggest that the novel method is a promising tool to create antigens for research and point-of-care monitoring of anti-DNA antibodies.

    View details for DOI 10.1038/srep35827

    View details for Web of Science ID 000385923800001

    View details for PubMedID 27775006

    View details for PubMedCentralID PMC5075775

  • Multiplex giant magnetoresistive biosensor microarrays identify interferon-associated autoantibodies in systemic lupus erythematosus SCIENTIFIC REPORTS Lee, J., Haddon, D. J., Wand, H. E., Price, J. V., Diep, V. K., Hall, D. A., Petri, M., Baechler, E. C., Balboni, I. M., Utz, P. J., Wang, S. X. 2016; 6

    Abstract

    High titer, class-switched autoantibodies are a hallmark of systemic lupus erythematosus (SLE). Dysregulation of the interferon (IFN) pathway is observed in individuals with active SLE, although the association of specific autoantibodies with chemokine score, a combined measurement of three IFN-regulated chemokines, is not known. To identify autoantibodies associated with chemokine score, we developed giant magnetoresistive (GMR) biosensor microarrays, which allow the parallel measurement of multiple serum antibodies to autoantigens and peptides. We used the microarrays to analyze serum samples from SLE patients and found individuals with high chemokine scores had significantly greater reactivity to 13 autoantigens than individuals with low chemokine scores. Our findings demonstrate that multiple autoantibodies, including antibodies to U1-70K and modified histone H2B tails, are associated with IFN dysregulation in SLE. Further, they show the microarrays are capable of identifying autoantibodies associated with relevant clinical manifestations of SLE, with potential for use as biomarkers in clinical practice.

    View details for DOI 10.1038/srep27623

    View details for Web of Science ID 000377358700002

    View details for PubMedID 27279139

  • Novel Phospholipid-Protein Conjugates Allow Improved Detection of Antibodies in Patients with Autoimmune Diseases. PloS one Samuelsen, S. V., Maity, A., Nybo, M., Macaubas, C., Lønstrup, L., Balboni, I. M., Mellins, E. D., Astakhova, K. 2016; 11 (6)

    Abstract

    Reliable measurement of clinically relevant autoimmune antibodies toward phospholipid-protein conjugates is highly desirable in research and clinical assays. To date, the development in this field has been limited to the use of natural heterogeneous antigens. However, this approach does not take structural features of biologically active antigens into account and leads to low reliability and poor scientific test value. Here we describe novel phospholipid-protein conjugates for specific detection of human autoimmune antibodies. Our synthetic approach includes mild oxidation of synthetic phospholipid cardiolipin, and as the last step, coupling of the product with azide-containing linker and copper-catalyzed click chemistry with β2-glycoprotein I and prothrombin. To prove utility of the product antigens, we used enzyme-linked immunosorbent assay and three cohorts of samples obtained from patients in Denmark (n = 34) and the USA (n = 27 and n = 14). Afterwards we analyzed correlation of the obtained autoantibody titers with clinical parameters for each patient. Our results prove that using novel antigens clinically relevant autoantibodies can be detected with high repeatability, sensitivity and specificity. Unlike previously used antigens the obtained autoantibody titers strongly correlate with high disease activity and in particular, with arthritis, renal involvement, anti-Smith antibodies and high lymphocyte count. Importantly, chemical composition of antigens has a strong influence on the correlation of detected autoantibodies with disease activity and manifestations. This confirms the crucial importance of antigens' composition on research and diagnostic assays, and opens up exciting perspectives for synthetic antigens in future studies of autoimmunity.

    View details for DOI 10.1371/journal.pone.0156125

    View details for PubMedID 27257889

    View details for PubMedCentralID PMC4892602

  • Single-cell systems-level analysis of human Toll-like receptor activation defines a chemokine signature in patients with systemic lupus erythematosus JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY O'Gorman, W. E., Hsieh, E. W., Savig, E. S., Gherardini, P. F., Hernandez, J. D., Hansmann, L., Balboni, I. M., Utz, P. J., Bendall, S. C., Fantl, W. J., Lewis, D. B., Nolan, G. P., Davis, M. M. 2015; 136 (5): 1326-1336

    Abstract

    Activation of Toll-like receptors (TLRs) induces inflammatory responses involved in immunity to pathogens and autoimmune pathogenesis, such as in patients with systemic lupus erythematosus (SLE). Although TLRs are differentially expressed across the immune system, a comprehensive analysis of how multiple immune cell subsets respond in a system-wide manner has not been described.We sought to characterize TLR activation across multiple immune cell subsets and subjects, with the goal of establishing a reference framework against which to compare pathologic processes.Peripheral whole-blood samples were stimulated with TLR ligands and analyzed by means of mass cytometry simultaneously for surface marker expression, activation states of intracellular signaling proteins, and cytokine production. We developed a novel data visualization tool to provide an integrated view of TLR signaling networks with single-cell resolution. We studied 17 healthy volunteer donors and 8 patients with newly diagnosed and untreated SLE.Our data revealed the diversity of TLR-induced responses within cell types, with TLR ligand specificity. Subsets of natural killer cells and T cells selectively induced nuclear factor κ light chain enhancer of activated B cells in response to TLR2 ligands. CD14(hi) monocytes exhibited the most polyfunctional cytokine expression patterns, with more than 80 distinct cytokine combinations. Monocytic TLR-induced cytokine patterns were shared among a group of healthy donors, with minimal intraindividual and interindividual variability. Furthermore, autoimmune disease altered baseline cytokine production; newly diagnosed untreated SLE patients shared a distinct monocytic chemokine signature, despite clinical heterogeneity.Mass cytometry defined a systems-level reference framework for human TLR activation, which can be applied to study perturbations in patients with inflammatory diseases, such as SLE.

    View details for DOI 10.1016/j.jaci.2015.04.008

    View details for Web of Science ID 000364787200023

    View details for PubMedID 26037552

  • Broad-spectrum antibodies against self-antigens and cytokines in RAG deficiency JOURNAL OF CLINICAL INVESTIGATION Walter, J. E., Rosen, L. B., Csomos, K., Rosenberg, J. M., Mathew, D., Keszei, M., Ujhazi, B., Chen, K., Lee, Y. N., Tirosh, I., Dobbs, K., Al-Herz, W., Cowan, M. J., Puck, J., Bleesing, J. J., Grimley, M. S., Malech, H., De Ravin, S. S., Gennery, A. R., Abraham, R. S., Joshi, A. Y., Boyce, T. G., Butte, M. J., Nadeau, K. C., Balboni, I., Sullivan, K. E., Akhter, J., Adeli, M., El-Feky, R. A., El-Ghoneimy, D. H., Dbaibo, G., Wakim, R., Azzari, C., Palma, P., Cancrini, C., Capuder, K., Condino-Neto, A., Costa-Carvalho, B. T., Oliveira, J. B., Roifman, C., Buchbinder, D., Kumanovics, A., Luis Franco, J., Niehues, T., Schuetz, C., Kuijpers, T., Yee, C., Chou, J., Masaad, M. J., Geha, R., Uze, G., Gelman, R., Holland, S. M., Recher, M., Utz, P. J., Browne, S. K., Notarangelo, L. D. 2015; 125 (11): 4135-4148

    Abstract

    Patients with mutations of the recombination-activating genes (RAG) present with diverse clinical phenotypes, including severe combined immune deficiency (SCID), autoimmunity, and inflammation. However, the incidence and extent of immune dysregulation in RAG-dependent immunodeficiency have not been studied in detail. Here, we have demonstrated that patients with hypomorphic RAG mutations, especially those with delayed-onset combined immune deficiency and granulomatous/autoimmune manifestations (CID-G/AI), produce a broad spectrum of autoantibodies. Neutralizing anti-IFN-α or anti-IFN-ω antibodies were present at detectable levels in patients with CID-G/AI who had a history of severe viral infections. As this autoantibody profile is not observed in a wide range of other primary immunodeficiencies, we hypothesized that recurrent or chronic viral infections may precipitate or aggravate immune dysregulation in RAG-deficient hosts. We repeatedly challenged Rag1S723C/S723C mice, which serve as a model of leaky SCID, with agonists of the virus-recognizing receptors TLR3/MDA5, TLR7/-8, and TLR9 and found that this treatment elicits autoantibody production. Altogether, our data demonstrate that immune dysregulation is an integral aspect of RAG-associated immunodeficiency and indicate that environmental triggers may modulate the phenotypic expression of autoimmune manifestations.

    View details for DOI 10.1172/JCI80477

    View details for Web of Science ID 000364110000017

    View details for PubMedID 26457731

  • Autoantigen microarrays reveal autoantibodies associated with proliferative nephritis and active disease in pediatric systemic lupus erythematosus ARTHRITIS RESEARCH & THERAPY Haddon, D. J., Diep, V. K., Price, J. V., Limb, C., Utz, P. J., Balboni, I. 2015; 17

    Abstract

    Pediatric systemic lupus erythematosus (pSLE) patients often initially present with more active and severe disease than adults, including a higher frequency of lupus nephritis. Specific autoantibodies, including anti-C1q, anti-DNA and anti-alpha-actinin, have been associated with kidney involvement in SLE, and DNA antibodies are capable of initiating early-stage lupus nephritis in severe combined immunodeficiency (SCID) mice. Over 100 different autoantibodies have been described in SLE patients, highlighting the need for comprehensive autoantibody profiling. Knowledge of the antibodies associated with pSLE and proliferative nephritis will increase the understanding of SLE pathogenesis, and may aid in monitoring patients for renal flare.We used autoantigen microarrays composed of 140 recombinant or purified antigens to compare the serum autoantibody profiles of new-onset pSLE patients (n = 45) to healthy controls (n = 17). We also compared pSLE patients with biopsy-confirmed class III or IV proliferative nephritis (n = 23) and without significant renal involvement (n = 18). We performed ELISA with selected autoantigens to validate the microarray findings. We created a multiple logistic regression model, based on the ELISA and clinical information, to predict whether a patient had proliferative nephritis, and used a validation cohort (n = 23) and longitudinal samples (88 patient visits) to test its accuracy.Fifty autoantibodies were at significantly higher levels in the sera of pSLE patients compared to healthy controls, including anti-B cell-activating factor (BAFF). High levels of anti-BAFF were associated with active disease. Thirteen serum autoantibodies were present at significantly higher levels in pSLE patients with proliferative nephritis than those without, and we confirmed five autoantigens (dsDNA, C1q, collagens IV and X and aggrecan) by ELISA. Our model, based on ELISA measurements and clinical variables, correctly identified patients with proliferative nephritis with 91 % accuracy.Autoantigen microarrays are an ideal platform for identifying autoantibodies associated with both pSLE and specific clinical manifestations of pSLE. Using multiple regression analysis to integrate autoantibody and clinical data permits accurate prediction of clinical manifestations with complex etiologies in pSLE.

    View details for DOI 10.1186/s13075-015-0682-6

    View details for Web of Science ID 000357456500001

    View details for PubMedID 26081107

    View details for PubMedCentralID PMC4493823

  • Autoantigen microarrays reveal autoantibodies associated with proliferative nephritis and active disease in pediatric systemic lupus erythematosus. Arthritis research & therapy Haddon, D. J., Diep, V. K., Price, J. V., Limb, C., Utz, P. J., Balboni, I. 2015; 17: 162-?

    Abstract

    Pediatric systemic lupus erythematosus (pSLE) patients often initially present with more active and severe disease than adults, including a higher frequency of lupus nephritis. Specific autoantibodies, including anti-C1q, anti-DNA and anti-alpha-actinin, have been associated with kidney involvement in SLE, and DNA antibodies are capable of initiating early-stage lupus nephritis in severe combined immunodeficiency (SCID) mice. Over 100 different autoantibodies have been described in SLE patients, highlighting the need for comprehensive autoantibody profiling. Knowledge of the antibodies associated with pSLE and proliferative nephritis will increase the understanding of SLE pathogenesis, and may aid in monitoring patients for renal flare.We used autoantigen microarrays composed of 140 recombinant or purified antigens to compare the serum autoantibody profiles of new-onset pSLE patients (n = 45) to healthy controls (n = 17). We also compared pSLE patients with biopsy-confirmed class III or IV proliferative nephritis (n = 23) and without significant renal involvement (n = 18). We performed ELISA with selected autoantigens to validate the microarray findings. We created a multiple logistic regression model, based on the ELISA and clinical information, to predict whether a patient had proliferative nephritis, and used a validation cohort (n = 23) and longitudinal samples (88 patient visits) to test its accuracy.Fifty autoantibodies were at significantly higher levels in the sera of pSLE patients compared to healthy controls, including anti-B cell-activating factor (BAFF). High levels of anti-BAFF were associated with active disease. Thirteen serum autoantibodies were present at significantly higher levels in pSLE patients with proliferative nephritis than those without, and we confirmed five autoantigens (dsDNA, C1q, collagens IV and X and aggrecan) by ELISA. Our model, based on ELISA measurements and clinical variables, correctly identified patients with proliferative nephritis with 91 % accuracy.Autoantigen microarrays are an ideal platform for identifying autoantibodies associated with both pSLE and specific clinical manifestations of pSLE. Using multiple regression analysis to integrate autoantibody and clinical data permits accurate prediction of clinical manifestations with complex etiologies in pSLE.

    View details for DOI 10.1186/s13075-015-0682-6

    View details for PubMedID 26081107

    View details for PubMedCentralID PMC4493823

  • Protein microarray analysis reveals BAFF-binding autoantibodies in systemic lupus erythematosus JOURNAL OF CLINICAL INVESTIGATION Price, J. V., Haddon, D. J., Kemmer, D., Delepine, G., Mandelbaum, G., Jarrell, J. A., Gupta, R., Balboni, I., Chakravarty, E. F., Sokolove, J., Shum, A. K., Anderson, M. S., Cheng, M. H., Robinson, W. H., Browne, S. K., Holland, S. M., Baechler, E. C., Utz, P. J. 2013; 123 (12): 5135-5145

    Abstract

    Autoantibodies against cytokines, chemokines, and growth factors inhibit normal immunity and are implicated in inflammatory autoimmune disease and diseases of immune deficiency. In an effort to evaluate serum from autoimmune and immunodeficient patients for Abs against cytokines, chemokines, and growth factors in a high-throughput and unbiased manner, we constructed a multiplex protein microarray for detection of serum factor-binding Abs and used the microarray to detect autoantibody targets in SLE. We designed a nitrocellulose-surface microarray containing human cytokines, chemokines, and other circulating proteins and demonstrated that the array permitted specific detection of serum factor-binding probes. We used the arrays to detect previously described autoantibodies against cytokines in samples from individuals with autoimmune polyendocrine syndrome type 1 and chronic mycobacterial infection. Serum profiling from individuals with SLE revealed that among several targets, elevated IgG autoantibody reactivity to B cell-activating factor (BAFF) was associated with SLE compared with control samples. BAFF reactivity correlated with the severity of disease-associated features, including IFN-α-driven SLE pathology. Our results showed that serum factor protein microarrays facilitate detection of autoantibody reactivity to serum factors in human samples and that BAFF-reactive autoantibodies may be associated with an elevated inflammatory disease state within the spectrum of SLE.

    View details for DOI 10.1172/JCI70231

    View details for Web of Science ID 000327826100020

    View details for PubMedID 24270423

    View details for PubMedCentralID PMC3859403

  • Interferon-a induction and detection of anti-ro, anti-la, anti-sm, and anti-rnp autoantibodies by autoantigen microarray analysis in juvenile dermatomyositis. Arthritis and rheumatism Balboni, I., Niewold, T. B., Morgan, G., Limb, C., Eloranta, M., Rönnblom, L., Utz, P. J., Pachman, L. M. 2013; 65 (9): 2424-2429

    Abstract

    Objective. To evaluate serum interferon-alpha (interferon-α) activity in the context of autoantibody profiles in juvenile dermatomyositis (JDM) patients. Methods. Sera from 36 JDM patients were analyzed. Autoantibody profiles were determined by probing microarrays, fabricated with ~80 distinct autoantigens, with serum and a Cy3-conjugated secondary antibody. Arrays were scanned and analyzed to determine antigen reactivity. Serum interferon-α activity was measured using a functional reporter cell assay. Sera were assayed alone or in combination with cellular material released from necrotic U937 cells to stimulate peripheral blood mononuclear cells in vitro from healthy donors, and interferon-α production in culture was measured by a dissociation-enhanced lanthanide fluorescent immunoassay (DELFIA). Results. 75% of JDM sera reacted to at least one of forty-one autoantigens on the microarray, including Ro52, Ro60, La, Smith and ribonucleoprotein (RNP). Seven samples were positive in the reporter cell assay. There was a significant association between reactivity against Ro, La, Smith and proliferating cell nuclear antigen and serum interferon-α activity in this assay (p=0.005). Significance analysis of microarrays (SAM) identified increased reactivity against Smith, RNP, Ro52, U1-C and Mi-2 in these sera. Sixteen samples induced interferon-α production as measured by DELFIA. There was a significant association between reactivity against Ro, La, Smith and RNP and the induction of interferon-α with serum and necrotic cell material (p=0.035). SAM identified increased reactivity against Ro60 in these sera. Conclusion. These data support the hypothesis that nucleic-acid associated autoantibodies, including the Ro/La and Smith/RNP complexes, may stimulate the production of active interferon- α in children with JDM. © 2013 American College of Rheumatology.

    View details for DOI 10.1002/art.38038

    View details for PubMedID 23740815

  • Type I interferon receptor controls B-cell expression of nucleic acid-sensing Toll-like receptors and autoantibody production in a murine model of lupus ARTHRITIS RESEARCH & THERAPY Thibault, D. L., Graham, K. L., Lee, L. Y., Balboni, I., Hertzog, P. J., Utz, P. J. 2009; 11 (4)

    Abstract

    Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of high-titer IgG autoantibodies directed against nuclear autoantigens. Type I interferon (IFN-I) has been shown to play a pathogenic role in this disease. In the current study, we characterized the role of the IFNAR2 chain of the type I IFN (IFN-I) receptor in the targeting of nucleic acid-associated autoantigens and in B-cell expression of the nucleic acid-sensing Toll-like receptors (TLRs), TLR7 and TLR9, in the pristane model of lupus.Wild-type (WT) and IFNAR2-/- mice were treated with pristane and monitored for proteinuria on a monthly basis. Autoantibody production was determined by autoantigen microarrays and confirmed using enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation. Serum immunoglobulin isotype levels, as well as B-cell cytokine production in vitro, were quantified by ELISA. B-cell proliferation was measured by thymidine incorporation assay.Autoantigen microarray profiling revealed that pristane-treated IFNAR2-/- mice lacked autoantibodies directed against components of the RNA-associated autoantigen complexes Smith antigen/ribonucleoprotein (Sm/RNP) and ribosomal phosphoprotein P0 (RiboP). The level of IgG anti-single-stranded DNA and anti-histone autoantibodies in pristane-treated IFNAR2-/- mice was decreased compared to pristane-treated WT mice. TLR7 expression and activation by a TLR7 agonist were dramatically reduced in B cells from IFNAR2-/- mice. IFNAR2-/- B cells failed to upregulate TLR7 as well as TLR9 expression in response to IFN-I, and effector responses to TLR7 and TLR9 agonists were significantly decreased as compared to B cells from WT mice following treatment with IFN-alpha.Our studies provide a critical link between the IFN-I pathway and the regulation of TLR-specific B-cell responses in a murine model of SLE.

    View details for DOI 10.1186/ar2771

    View details for Web of Science ID 000270936400027

    View details for PubMedID 19624844

    View details for PubMedCentralID PMC2745794

  • Evaluation of microarray surfaces and arraying parameters for autoantibody profiling PROTEOMICS Balboni, I., Limb, C., Tenenbaum, J. D., Utz, P. J. 2008; 8 (17): 3443-3449

    Abstract

    Autoantigen microarrays are being used increasingly to study autoimmunity. Significant variation has been observed when comparing microarray surfaces, printing methods, and probing conditions. In the present study, 24 surfaces and several arraying parameters were analyzed using >500 feature autoantigen microarrays printed with quill pins. A small subset of slides, including FAST, PATH, and SuperEpoxy2, performed well while maintaining the sensitivity and specificity of autoantigen microarrays previously demonstrated by our laboratory. By optimizing the major variables in our autoantigen microarray platform, subtle differences in serum samples can be identified that will shed light on disease pathogenesis.

    View details for DOI 10.1002/pmic.200800146

    View details for Web of Science ID 000259172400004

    View details for PubMedID 18752214

    View details for PubMedCentralID PMC3335271

  • Protein microarrays address the elephant in the room CLINICAL CHEMISTRY Kattah, M. G., Utz, P. J., Balboni, I. 2008; 54 (6): 937-939

    View details for DOI 10.1373/clinchem.2008.104067

    View details for Web of Science ID 000256325800001

    View details for PubMedID 18509011

  • IRF9 and STAT1 are required for IgG autoantibody production and B cell expression of TLR7 in mice JOURNAL OF CLINICAL INVESTIGATION Thibault, D. L., Chu, A. D., Graham, K. L., Balboni, I., Lee, L. Y., Kohlmoos, C., Landrigan, A., Higgins, J. P., Tibshirani, R., Utz, P. J. 2008; 118 (4): 1417-1426

    Abstract

    A hallmark of SLE is the production of high-titer, high-affinity, isotype-switched IgG autoantibodies directed against nucleic acid-associated antigens. Several studies have established a role for both type I IFN (IFN-I) and the activation of TLRs by nucleic acid-associated autoantigens in the pathogenesis of this disease. Here, we demonstrate that 2 IFN-I signaling molecules, IFN regulatory factor 9 (IRF9) and STAT1, were required for the production of IgG autoantibodies in the pristane-induced mouse model of SLE. In addition, levels of IgM autoantibodies were increased in pristane-treated Irf9 -/- mice, suggesting that IRF9 plays a role in isotype switching in response to self antigens. Upregulation of TLR7 by IFN-alpha was greatly reduced in Irf9 -/- and Stat1 -/- B cells. Irf9 -/- B cells were incapable of being activated through TLR7, and Stat1 -/- B cells were impaired in activation through both TLR7 and TLR9. These data may reveal a novel role for IFN-I signaling molecules in both TLR-specific B cell responses and production of IgG autoantibodies directed against nucleic acid-associated autoantigens. Our results suggest that IFN-I is upstream of TLR signaling in the activation of autoreactive B cells in SLE.

    View details for DOI 10.1172/JCI30065

    View details for Web of Science ID 000254588600035

    View details for PubMedID 18340381

    View details for PubMedCentralID PMC2267033

  • Systemic hyalinosis: A distinctive early childhood-onset disorder characterized by mutations in the anthrax toxin receptor 2 gene (ANTRX2) PEDIATRICS Shieh, J. T., Swidler, P., Martignetti, J. A., Ramirez, M. C., Balboni, I., Kaplan, J., Kennedy, J., Abdul-Rahman, O., Enns, G. M., Sandborg, C., Slavotinek, A., Hoyme, H. E. 2006; 118 (5): E1485-E1492

    Abstract

    We sought to further characterize the phenotype and facilitate clinical recognition of systemic hyalinosis in children who present with chronic pain and progressive contractures in early childhood.We report on 3 children who presented in infancy with symptoms and signs that initially were not recognized to be those of systemic hyalinosis. Although the children were evaluated for a variety of problems, including lysosomal storage disorders and nonaccidental trauma, all eventually underwent genetic analysis of the anthrax toxin receptor 2 gene (ANTRX2) and were diagnosed as having systemic hyalinosis.We describe the recognizable but variable clinical phenotype of systemic hyalinosis and associated mutations in ANTRX2. Affected individuals presented in early infancy with severe pain and progressive contractures. Initial diagnostic evaluations were unrevealing; however, hyperpigmented skin over bony prominences, skin nodules, and fleshy perianal masses suggested a diagnosis of systemic hyalinosis. ANTRX2 analysis confirmed the diagnosis in each case. Although 2 of the children died in infancy as a result of complications of chronic diarrhea, the third child has survived into midchildhood. These data suggest that some ANTRX2 mutations, such as that identified in the long-term survivor, may be associated with a less severe course of disease.Although some aspects of systemic hyalinosis may resemble lysosomal storage disorders, the clinical features of systemic hyalinosis are distinctive, and detection of an ANTRX2 mutation can confirm the diagnosis. Early recognition of affected individuals should allow for aggressive pain control and expectant management of the multiple associated problems, including gastrointestinal dysfunction.

    View details for DOI 10.1542/peds.2006-0824

    View details for PubMedID 17043134

  • A new two-color Fab labeling method for autoantigen protein microarrays NATURE METHODS Kattah, M. G., Alemi, G. R., Thibault, D. L., Balboni, I., Utz, P. J. 2006; 3 (9): 745-751

    Abstract

    Antigen microarrays hold great promise for profiling the humoral immune response in the settings of autoimmunity, allergy and cancer. This approach involves immobilizing antigens on a slide surface and then exposing the array to biological fluids containing immunoglobulins. Although these arrays have proven extremely useful as research tools, they suffer from several sources of variability. To address these issues, we have developed a new two-color Fab labeling method that allows two samples to be applied simultaneously to the same array. This straightforward labeling approach improves reproducibility and reliably detects changes in autoantibody concentrations. Using this technique we profiled serum from a mouse model of systemic lupus erythematosus (SLE) and detected both expected and previously unrecognized reactivities. The improved labeling and detection method described here overcomes several problems that have hindered antigen microarrays and should facilitate translation to the clinical setting.

    View details for DOI 10.1038/nmeth910

    View details for Web of Science ID 000240290300020

    View details for PubMedID 16929321

  • Multiplexed protein array platforms for analysis of autoimmune diseases ANNUAL REVIEW OF IMMUNOLOGY Balboni, I., Chan, S. M., Kattah, M., Tenenbaum, J. D., Butte, A. J., Utz, P. J. 2006; 24: 391-418

    Abstract

    Several proteomics platforms have emerged in the past decade that show great promise for filling in the many gaps that remain from earlier studies of the genome and from the sequencing of the human genome itself. This review describes applications of proteomics technologies to the study of autoimmune diseases. We focus largely on biased technology platforms that are capable of analyzing a large panel of known analytes, as opposed to techniques such as two-dimensional gel electrophoresis (2DIGE) or mass spectroscopy that represent unbiased approaches (as reviewed in 1). At present, the main analytes that can be systematically studied in autoimmunity include autoantibodies, cytokines and chemokines, components of signaling pathways, and cell-surface receptors. We review the most commonly used platforms for such studies, citing important discoveries and limitations that exist. We conclude by reviewing advances in biomedical informatics that will eventually allow the human proteome to be deciphered.

    View details for DOI 10.1146/annurev.immunol.24.021605.090709

    View details for Web of Science ID 000237583300013

    View details for PubMedID 16551254

  • A sea anemone's environment affects discharge of its isolated nematocysts COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY Greenwood, P. G., Balboni, I. M., Lohmann, C. 2003; 134 (2): 275-281

    Abstract

    Nematocysts were isolated from individuals of Calliactis tricolor maintained under different feeding schedules or in different salinities in an attempt to determine how these culture conditions influence the discharge of isolated nematocysts. In addition, the discharge frequencies of nematocysts isolated from two different populations of sea anemones found in two different environments were also compared. Undischarged acontial nematocysts were isolated by extrusion into 1 M sodium citrate and were then treated with 5 mM EGTA to initiate discharge. Nematocysts isolated from anemones maintained under three different feeding schedules showed significantly different responses to the test solution. Nematocysts isolated from anemones maintained in two different salinities did not differ significantly in discharge frequency. Nematocysts isolated from individuals from two separate populations of C. tricolor responded significantly differently to 5 mM EGTA and to deionized water, and these responses also depended upon the isolation solution used. Environmental conditions are known to have an impact on the physiological state of most organisms, but this is the first study providing evidence that the environment or feeding state of an anemone affects discharge of isolated nematocysts. Inherent differences in ionic and osmotic characteristics among nematocysts could explain some of the ambiguities when comparing past studies of isolated nematocyst discharge.

    View details for Web of Science ID 000181525500005

    View details for PubMedID 12547257