Development Of Common Variable Immunodeficiency Research Articles

Gut antibody deficiency in CD19−/− mice results in a spontaneous Celiac-Like sprue

Abstract Primary immunodeficiencies are heritable disorders of the immune response that most commonly manifest as an inability to generate immunoglobulin A (IgA). Despite its prevalence, IgA deficiency is considered a benign form of antibody deficiency due to a lack of easily observed clinical symptoms. CD19 is an important co-receptor that facilitates B cell receptor signaling and B cell development into antibody-secreting plasma cells. CD19 deficiency is a known genetic risk factor for the development of common variable immunodeficiency (CVID). Here, we utilize the CD19−/− mouse model to quantify the role of IgA deficiency on gut homeostasis. Our results indicate that CD19−/− mice develop a severe gut IgA deficiency associated with aberrant anti-commensal IgA responses that result in the outgrowth of anaerobic bacteria in the gut. More importantly, anaerobic expansion results in intestinal malabsorption under steady-state conditions. Intestinal malabsorption is associated with defects in normal hepatobiliary circulation, vitamin deficiency, and dyslipidemia. Additionally, results from histological analysis and RNAseq experiments indicate that CD19−/− mice develop intestinal epithelial cell (IEL) lymphocytosis mediated by CD8aa+TCRgd lymphocytes. Finally, CD19−/− mice, while deficient in anti-gliadin antibody (AGA) production compared to WT mice, demonstrate a significantly stronger relationship between serum AGA titers and total serum IgG and IgA production compared to WT animals and have significantly elevated ileal expression of tissue transglutaminase 2. Collectively, we believe that we have identified a novel mouse model of sero-negative celiac disease that will be of great value to the celiac research community.

AICDA single nucleotide polymorphism in common variable immunodeficiency and selective IgA deficiency

BackgroundPrimary antibody deficiencies (PADs) are a heterogeneous group of disorders, characterised by increased susceptibility to recurrent bacterial infections. Common variable immunodeficiency (CVID) is the most important PAD from the clinical point of view and selective IgA deficiency (IgAD) is the most common PAD. However, the underlying gene defect in both is still unknown. As a recent study in Europe showed an association between a single nucleotide polymorphism (SNP) of AICDA gene with PADs, this study was performed to evaluate such an association in Iranian patients. MethodsFifty-eight patients with PAD, including 39 CVID and 19 IgAD, as well as 34 healthy volunteers, were enrolled in this study. Genotyping was done in all groups for an intronic SNP in AICDA (rs2580874), using real-time PCR genotyping assay. ResultsThe less frequent genotype of AICDA in IgAD patients was AA, seen in 10.5% of the patients, which was much lower than the 30.8% in CVID patients and 38.2% in the controls. However, these differences were not significant. Indeed the GG genotype in the patients with PADs was seen in 20.7%, compared to 8.8% in the controls without any significant difference. ConclusionsThere was no significant association between the previously reported genetic variant of AICDA gene and the development of CVID or IgAD, but further multi-center studies are also needed.

Evaluation of class switch recombination in B lymphocytes of patients with common variable immunodeficiency

Common variable immunodeficiency (CVID) is a heterogeneous group of disorders characterized by hypogammaglobulinemia and recurrent bacterial infections. Impaired antibody production in these patients is due to defect in B-cell differentiation into specific plasma cells. Class switch recombination (CSR), which plays a critical role in the production of different immunoglobulin isotypes, may be defective in a group of CVID patients. The aim of this study was to investigate the CSR process in B cells of CVID patients, by evaluating the expression of IgE mRNA and production of its protein in an IgE inductive medium. Peripheral blood mononuclear cells (PBMCs) from 29 CVID patients and 21 healthy controls were isolated and cultured in the presence of rhIL-4 and CD40L. IgE mRNA and IgE protein were measured by RT-PCR and ELISA techniques, respectively. Normal production of IgE mRNA was recorded in 23 out of 29 patients (79.31%) as well as all controls; while the remaining 6 patients (20.69%) were unable to express IgE mRNA indicating a defect in CSR. PBMCs of 16 out of 29 patients (55.2%) could not produce normal amounts of IgE compared with controls, after being stimulated by IL-4 and CD40L. Post B cell stimulation IgE production was impaired in about half of studied CVID patients. Defects in processes occur following the CSR process such as IgE mRNA transcription, protein production, and secretion can be the causative mechanism of CVID in patients with normal mRNA expression of the immunoglobulin but impaired protein production. Determination of these defects can help to clarify the various underlying mechanisms responsible for the development of CVID.

Development of common variable immunodeficiency in IgA- and IgG2-deficient patients with systemic lupus erythematosus

BackgroundThere have been few reports on children who developed common variable immunodeficiency (CVID) in association with immunoglobulin A (IgA) and IgG2 deficiencies and systemic lupus erythematosus (SLE).Case-Diagnosis/TreatmentOur patient experienced nephrotic syndrome and acute respiratory distress syndrome (ARDS) caused by influenza A/H1N1 virus infection at 5 years of age. A diagnosis of IgA and IgG2 deficiency and SLE was made on the basis of severe proteinuria, hematuria, hypocomplementemia, high anti-DNA antibody and antinuclear antibody (ANA) titers, and malar rash. However, these clinical signs and symptoms and laboratory features disappeared after the administration of methylprednisolone pulse therapy and prednisolone. For the 5 years following the initial treatment for SLE, the patient experienced a number of infections and had a low serum total IgG level; she was eventually diagnosed with CVID. The administration of intravenous immunoglobulin (IVIG) was required to prevent subsequent infections, and no relapse of SLE was observed.ConclusionWe report the development of CVID in an IgA- and IgG2-deficient patient with SLE on the basis of multiple episodes of infection. To prevent the development of CVID in IgA- and IgG2-deficient patients with SLE, it is important to prevent immune dysregulation by the avoidance of infections through the use of IVIG therapy.

Transmembrane activator and CAML interactor (TACI) haploinsufficiency results in B-cell dysfunction in patients with Smith-Magenis syndrome

Heterozygous deleterious mutations in the gene encoding the tumor necrosis factor receptor superfamily member 13b (TNFRSF13B), or transmembrane activator and CAML interactor (TACI), have been associated with the development of common variable immunodeficiency. Smith-Magenis syndrome (SMS) is a genetic disorder characterized by developmental delay, behavioral disturbances, craniofacial anomalies, and recurrent respiratory tract infections. Eighty percent of subjects have a chromosome 17p11.2 microdeletion, which includes TACI. The remaining subjects have mutations sparing this gene. We examined TACI protein expression and function in patients with SMS to define the role of TACI haploinsufficiency in B-cell function. We studied TACI expression and function in a cohort of 29 patients with SMS. In patients with SMS with only 1 TACI allele, we found decreased B-cell extracellular and intracellular expression of TACI, reduced binding of a proliferation-inducing ligand, and decreased TACI-induced expression of activation-induced cytidine deaminase mRNA, but these were normal for cells from patients with SMS and 2 TACI alleles. Impaired upregulation of B-cell surface TACI expression by a Toll-like receptor 9 agonist was also observed in cells from patients with 1 TACI allele. Gene sequence analysis of the remaining TACI allele revealed common polymorphisms, with the exception of 1 patient with an amino acid change of uncertain significance. Patients with SMS with the lowest TACI expression had significantly reduced antibody responses to pneumococcal vaccine serotypes. Our findings suggest that haploinsufficiency of the TACI gene results in humoral immune dysfunction, highlighting the role of genomic copy number variants in complex traits.

Systemic lupus erythematosus as a first presentation of common variable immunodeficiency associated with infrequent mannose-binding lectin gene polymorphisms

The association of common variable immunodeficiency (CVID) and systemic lupus erythematosus (SLE) is infrequent. Mannose-binding lectin (MBL) has been shown to play a role in CVID and SLE. The purpose of this study is to describe two cases of CVID who presented as SLE and also evaluate the presence of MBL polymorphisms and MBL serum levels in those patients. In both patients, SLE was the first manifestation of CVID. In these patients the SLE immunological markers and disease activity disappeared after the development of CVID. They carried the very infrequent MBL haplotype 4Q-57Glu. One of them had a homozygous genotype, whereas the other patient was heterozygous and also presented the haplotype 4P-57Glu that had never been previously detected. Interestingly, this last patient was presenting frequent respiratory tract infections, developed bronchiectasis and had low levels of circulating MBL. These results may support the role of MBL in the development of autoimmunity in CVID. Further genetic studies are needed to clarify the role of the MBL polymorphisms in the development of autoimmunity in CVID.

Development of Common Variable Immunodeficiency in an 8-year-old Boy Treated with Rituximab for Idiopathic Thrombocytopenia

We present the case of an 8-year-old boy who developed common variable immunodeficiency (CVID) following rituximab therapy for the treatment of idiopathic thrombocytopenia (ITP). Since rituximab can cause prolonged hypogammaglobulinemia and increased susceptibility to infections, monitoring of immunoglobulin levels, antibody responses, B cells, and memory B cell subpopulations is recommended. This may be especially true when rituximab is used in the treatment of immune cytopenia such as ITP, which may occur in CVID.

Resolution of Juvenile Idiopathic Arthritis-Associated Uveitis after Development of Common Variable Immunodeficiency

To describe the occurrence of common variable immunodeficiency (CVID) in a patient with juvenile idiopathic arthritis (JIA) and JIA-associated uveitis. Case report. A 29-year-old woman was followed-up since the age of 10 years because of right eye JIA-associated recurrent anterior uveitis. She was treated with steroids and immunosuppressants with good control of uveitis and arthritis. At the age of 17 years, she did not experience any further relapse of uveitis or arthritis and both diseases were considered to be in remission. Concomitantly, she started to have recurrent infections and later she underwent splenectomy because of autoimmune hemolytic anemia and thrombocytopenia. Liver biopsy disclosed granulomatous hepatitis. She was ultimately diagnosed with CVID at the age of 23 years when her blood tests revealed neutropenia and severe panhypogammaglobulinemia. She has been treated since then with intravenous immunoglobulins with good control of the disease. Since the development of CVID, she has had no relapses of uveitis or arthritis during a follow-up period of 12 years. Common variable immunodeficiency (CVID) is the most common primary immunodeficiency where defective antibody formation is the most common feature with B-cell differentiation failure. Ocular complications have been rarely documented and included bacterial conjunctivitis, retinal vasculitis and multifocal choroiditis. We herein report on the occurrence of JIA-associated uveitis as a comorbid manifestation of CVID. We speculate a role for B cells in the pathogenesis of JIA and JIA-associated uveitis here, as this patient had total remission of both conditions with the onset of CVID.

Common Variable Immunodeficiency in Systemic Lupus Erythematosus

The development of common variable immunodeficiency (CVID) or hypogammaglobulinemia in systemic lupus erythematosus (SLE) is rare. The purpose of this article is to provide a detailed review of lupus-associated CVID and to identify clinical characteristics and laboratory features in patients with SLE-associated CVID. We describe 2 patients with SLE and CVID and review the cases published in the English literature highlighting both the demographic and the clinical characteristics and the laboratory and therapeutic aspects of this disorder. Detailed descriptions of 18 patients were available; 89% were females with a mean age at the onset of SLE of 23.8 years. In 50% of patients CVID developed within the first 5 years after the diagnosis of SLE. All patients had been treated with corticosteroids and 72% had also received immunosuppressive therapy. Sinopulmonary infections were the most frequent symptom. SLE disease activity decreased after the development of CVID in 67% of patients. Most patients (89%) were treated with gammaglobulin therapy. The most notable immunological feature was a reduced number or percentage of B-cells in 60% of patients. CVID should be suspected in any SLE patient with recurrent sinopulmonary infections in the absence of SLE activity and/or immunosuppressive treatment.

Selective IgA deficiency with unusual features: Development of common variable immunodeficiency, Sjögren's syndrome, autoimmune hemolytic anemia and immune thrombocytopenic purpura

We report on a girl with selective IgA deficiency and persistently low complement component 4 (C4) levels compatible with heterozygous C4 deficiency. Deterioration of her serum immunoglobulin levels and transition to common variable immunodeficiency were observed within a 5 year follow-up. She also developed Sjögren's syndrome, autoimmune hemolytic anemia and immune thrombocytopenic purpura. While these abnormalities have been described before in various combinations, to our knowledge, they have not been reported in a single individual.