Project description:Based on the findings of increased IEL in duodenal biopsies in CVID, an overlap with celiac disease has been suggested. In the present study, increased IEL, in particular in the pars descendens of the duodenum, was one of the most frequent histopathological finding. We therefore examined the gene expression profile in pars descendens of duodenum in CVID patients with increased IEL (n=12, IEL mean 34 [range 22-56] IEL/100 EC), CVID with normal levels of IEL (n=8), celiac disease (n=10, Marsh grade 3a or above) and healthy controls (n=17) by gene expression microarray
Project description:Based on the findings of increased IEL in duodenal biopsies in CVID, an overlap with celiac disease has been suggested. In the present study, increased IEL, in particular in the pars descendens of the duodenum, was one of the most frequent histopathological finding. We therefore examined the gene expression profile in pars descendens of duodenum in CVID patients with increased IEL (n=13, IEL mean 34 [range 22-56] IEL/100 EC), CVID with normal levels of IEL (n=7), celiac disease (n=10, Marsh grade 3a or above) and healthy controls (n=17) by gene expression microarray GI histopathological findings in 53 CVID patients that underwent upper and lower endoscopic examination were addressed. For the microarray analysis 20 CVID (7 CVID_normal and 13 CVID with incresed IEL), 10 patients with celiac diseases and 17 healthy controls were included.
Project description:Autoantibody-mediated cytopenias (AICs) regularly occur in profoundly IgG-deficient common variable immunodeficiency (CVID) patients. The isotypes, antigenic targets, and origin(s) of disease-causing autoantibodies in this patient population are unclear. Herein, we report that erythrocytes and platelets from CVID patients with AICs (CVID+AIC) are coated with autoreactive IgM. Glycan array-based analyses of CVID+AIC plasma IgM revealed narrow reactivities to erythrocytic I/i antigens and platelet expressed I/i antigen-related glycans but starkly lower binding to hundreds of other pathogen and tumor-associated carbohydrates. Polyclonal B-cell receptors with corresponding I/i antigen reactivities were highly enriched among CVID+AIC circulating marginal zone (MZ) B cells. Within secondary lymphoid tissues, MZ B cells secreted copious IgM when activated by IL-10 secreting FOXP3-CD25hiTfh cells. In lymph nodes from immunocompetent controls, MZ B cells localized outside of GCs near rare FOXP3-CD25+ cells and plentiful FOXP3+ regulatory T cells. In CVID+AIC lymph nodes, counterpart cells localized to similar anatomic positions but CD25hiTfh cells greatly outnumbered regulatory T cells. In total, our findings indicate glycan-reactive IgM autoantibodies produced outside of GC borders may contribute to the autoimmune pathogenesis of CVID.
Project description:BackgroundCommon variable immunodeficiency (CVID) is one of the most common primary immunodeficiency syndromes, affecting one in 25,000-50,000 people. Renal insufficiency occurs in approximately 2% of patients with CVID. To date, there are no case series of renal biopsies from patients with CVID, making it difficult to determine whether individual cases of renal disease in CVID represent sporadic events or are related to the underlying pathophysiology. We performed a retrospective analysis of renal biopsy specimens in our database from patients with a clinical history of CVID (n=22 patients, 27 biopsies).MethodsLight, immunofluorescence, and electron microscopy were reviewed. IgG subclasses, PLA2R immunohistochemistry, and THSD7A, EXT1, and NELL1 immunofluorescence were performed on all membranous glomerulopathy cases. CD3, CD4, CD8, and CD20 immunohistochemistry was performed on cases of tubulointerstitial nephritis.ResultsAKI and proteinuria were the leading indications for renal biopsy in patients with CVID. Immune-complex glomerulopathy was present in 12 of 22 (54.5%) cases, including nine cases with membranous glomerulopathy, one case with a C3 glomerulopathy, and one case with membranoproliferative GN with IgG3κ deposits. All membranous glomerulopathy cases were PLA2R, THSD7A, EXT1, and NELL1 negative. The second most common renal biopsy diagnosis was chronic tubulointerstitial nephritis, affecting 33% of patients. All tubulointerstitial nephritis cases showed tubulitis and a lymphocytic infiltrate with >90% CD3+ T cells. Other renal biopsy diagnoses within our cohort included acute tubular injury (n=1), amyloid light-chain amyloidosis (n=1), diabetic glomerulosclerosis (n=1), thin basement membranes (n=1), pauci-immune GN (n=1), and arterionephrosclerosis (n=1).ConclusionsMembranous glomerulopathy and tubulointerstitial nephritis were the predominant pathologic findings in patients with CVID. Membranous glomerulopathy cases in patients with CVID were IgG1 subclass dominant and showed mesangial immune deposits. Four of the membranous glomerulopathy cases had associated proliferation, with mesangial and/or endocapillary hypercellularity, with or without crescent formation. CVID should be considered as a potential cause when membranous glomerulopathy or chronic tubulointerstitial nephritis is seen in a young patient with a history of recurrent infections.
Project description:PURPOSE:Patients with Common Variable Immunodeficiency (CVID) are subject to the development of a liver disease syndrome known as nodular regenerative hyperplasia (NRH). The purpose of this study was to define the characteristics and course of this complication of CVID. METHODS:CVID patients were evaluated by retrospective and prospective clinical course review. Liver biopsy specimens were evaluated for evidence of NRH and studied via RT-PCR for cytokine analysis. RESULTS:NRH in our CVID patient population occurred in approximately 5 % of the 261 patients in our total CVID study group, initially presenting in most cases with an elevated alkaline phosphatase level. While in some patients the disease remained static, in a larger proportion a more severe disease developed characterized by portal hypertension, the latter leading to hypersplenism with neutropenia and thrombocytopenia and, in some cases, to ascites. In addition, a substantial proportion of patients either developed or presented initially with an autoimmune hepatitis-like (AIH-like) liver disease that resulted in severe liver dysfunction and, in most cases to death due to infections. The liver histologic findings in these AIH-like patients were characterized by underlying NRH pattern with superimposed interface hepatitis, lymphocytic infiltration and fibrosis. Immunologic studies of biopsies of NRH patients demonstrated the presence of infiltrating T cells producing IFN-?, suggesting that the NRH is due to an autoimmune process. CONCLUSION:Overall, these studies provide evidence that NRH may not be benign but, can be a severe and potentially fatal disease complication of CVID that merits close monitoring and intervention.
Project description:The homeostasis of circulating B cell subsets in the peripheral blood of healthy adults is well regulated, but in disease it can be severely disturbed. Thus, a subgroup of patients with common variable immunodeficiency (CVID) presents with an extraordinary expansion of an unusual B cell population characterized by the low expression of CD21. Since these circulating atypical B cells in the blood of CVID patients could not be assigned to any certain B cell differentiation stage in the periphery, they were designated as CD21low B cells. Although, CD21low B cells are polyclonal and unmutated IgM+IgD+ B cells like naive B cells in the peripheral blood, they reveal several distinct phenotypic and functional features. In order to uncover the the global programme of gene expression underlying these differences and changes in CD21low B cells we have performed microarray hybridization experiments and identified differentially expressed genes which define a distinct gene expression profile in CD21low B cells compared to naive B cells.
Project description:The homeostasis of circulating B cell subsets in the peripheral blood of healthy adults is well regulated, but in disease it can be severely disturbed. Thus, a subgroup of patients with common variable immunodeficiency (CVID) presents with an extraordinary expansion of an unusual B cell population characterized by the low expression of CD21. Since these circulating atypical B cells in the blood of CVID patients could not be assigned to any certain B cell differentiation stage in the periphery, they were designated as CD21low B cells. Although, CD21low B cells are polyclonal and unmutated IgM+IgD+ B cells like naive B cells in the peripheral blood, they reveal several distinct phenotypic and functional features. In order to uncover the the global programme of gene expression underlying these differences and changes in CD21low B cells we have performed microarray hybridization experiments and identified differentially expressed genes which define a distinct gene expression profile in CD21low B cells compared to naive B cells. Leucocytes were separated by Ficoll gradient from peripheral blood of healthy donors (HD) and CVID patients. CD19+CD27-CD38+CD21+ naive B cells of HD as well as naive and CD19hiCD27-CD38lowCD21low (CD21low) B cells of CVID patients were sorted using a MoFlow cell sorter. RNA was extracted from sorted ex vivo B cell subpopulations and hybridized on Affymetrix microarrays. Gene expression profiles were compared between CD21low B cells and naive B cells of CVID patients as well as HD naive B cells.
Project description:Common variable immunodeficiency (CVID), characterized by recurrent infections, low serum class-switched immunoglobulin isotypes and poor antigen specific antibody responses, comprises a heterogeneous patient population in terms of clinical presentation and underlying etiology. The diagnosis is regularly associated with a severe decrease of germinal center (GC) derived B-cell populations in peripheral blood. However, data from B-cell differentiation within GC is limited. We present a multiplex approach combining histology, flow cytometry and B-cell receptor repertoire analysis of sorted GC B-cell populations allowing the modelling of distinct disturbances in GCs of three CVID patients. Our results reflect pathophysiological heterogeneity underlying the reduced circulating pool of post-GC memory B cells and plasmablasts in the three patients. In patient 1, quantitative and qualitative B-cell development in GCs is relatively normal. In patient 2, irregular shaped GCs are associated with reduced somatic hypermutation (SHM), antigen selection and class-switching, while in patient 3, high SHM, impaired antigen selection and class-switching with large single clones imply increased re-cycling of cells within the irregular shaped GCs. In lymph nodes of patients 2 and 3, only limited numbers of memory B cells and plasma cells are formed. While reduced numbers of circulating post GC B cells is a general phenomenon in CVID, the integrated approach exemplified distinct defects during GC maturation ranging from near normal morphology and function to severe disturbances with different facets of impaired maturation of memory B cells and/or plasma cells. Integrated dissection of disturbed GC B-cell maturation by histology, flowcytometry and BCR repertoire analysis reveals essential steps during memory formation.
Project description:Identification of IVIg regulated genes in human peripheral blood monocytes by gene expression analysis before and after IVIg infusion in CVID patients
Project description:Combined immunodeficiency (CID) presents a unique challenge to clinicians. Two patients presented with the prior clinical diagnosis of common variable immunodeficiency (CVID) disorder marked by an early age of presentation, opportunistic infections, and persistent lymphopenia. Due to the presence of atypical clinical features, next generation sequencing was applied documenting RAG deficiency in both patients.Two different genetic analysis techniques were applied in these patients including whole exome sequencing in one patient and the use of a gene panel designed to target genes known to cause primary immunodeficiency disorders (PIDD) in a second patient. Sanger dideoxy sequencing was used to confirm RAG1 mutations in both patients.Two young adults with a history of recurrent bacterial sinopulmonary infections, viral infections, and autoimmune disease as well as progressive hypogammaglobulinemia, abnormal antibody responses, lymphopenia and a prior diagnosis of CVID disorder were evaluated. Compound heterozygous mutations in RAG1 (1) c256_257delAA, p86VfsX32 and (2) c1835A>G, pH612R were documented in one patient. Compound heterozygous mutations in RAG1 (1) c.1566G>T, p.W522C and (2) c.2689C>T, p. R897X) were documented in a second patient post-mortem following a fatal opportunistic infection.Astute clinical judgment in the evaluation of patients with PIDD is necessary. Atypical clinical findings such as early onset, granulomatous disease, or opportunistic infections should support the consideration of atypical forms of late onset CID secondary to RAG deficiency. Next generation sequencing approaches provide powerful tools in the investigation of these patients and may expedite definitive treatments.