Autoimmunity in common variable immunodeficiency

BACKGROUND: Autoimmunity has been increasingly recognized as a major issue in patients with common variable immunodeficiency (CVID), the most common symptomatic primary immunodeficiency in adulthood. Different authors report high prevalences of autoimmune diseases in CVID, and several mechanisms have been proposed to explain this apparent paradox. Genetic predisposition, under current surveillance, innate and adaptive immunity deficiencies leading to persistent/recurrent infections, variable degrees of immune dysregulation, and possible failure in central and peripheral mechanisms of tolerance induction or maintenance may all contribute to increased autoimmunity. CONCLUSIONS: Data on the clinical/immunological profile of affected patients and treatment are available mostly concerning autoimmune cytopenias, the most common autoimmune diseases in CVID. Treatment is based on conventional alternatives, in association with short experience with new agents, including rituximab and infliximab. Benefits of early immunoglobulin substitutive treatment and hypothetical premature predictors of autoimmunity are discussed as potential improvements to CVID patients' follow-up.     

Chromosomal radiosensitivity in patients with common variable immunodeficiency

Common variable immunodeficiency (CVID) is a heterogeneous group of primary immunodeficiency disorders. In addition to recurrent infections and autoimmunity, cancers are more prevalent in these patients than the normal population. Increased radiosensitivity may be a reason for the increased malignancies. To analyze chromosomal radiosensitivity of CVID patients, lymphocytes were cultured from 20 CVID patients. After irradiation (50, 100 cGy), metaphases were evaluated for chromosomal aberrations. Results were compared in patients, healthy individuals, and ataxia telangiectasia as positive controls.

Before irradiation there was no difference between groups of patients, but after radiation, the incidence of all kinds of aberrations was higher in the CVID patients and this was statistically significant at 100 cGy (P<0.05). CVID patients appear to be susceptible to in vitro irradiation. These patients should be protected from unnecessary radiographic diagnostic and therapeutic procedures. Also, radiosensitivity may help classifying CVID patients.     

Lymphocyte characteristics in children with common variable immunodeficiency

The diagnosis of common variable immunodeficiency (CVID) is reserved for patients who suffer from undefined B cell dysfunction. Division of the CVID population into subgroups enables research for underlying disease causes. We studied clinical features and lymphocyte characteristics in 38 children with CVID and compared them to 30 children with less severe antibody deficiencies (e.g. specific antibody deficiency combined with IgG subclass deficiency) and with 65 pediatric controls. Most pediatric immune phenotypes were comparable to adult CVID phenotypes, including a selective increase in newly formed B cells and a decrease in memory B cells and CD4⁺ T cells. Eighteen percent of pediatric patients had a mutation in the TNFRSF13B gene, which requires further investigation. Finally, pediatric patients with decreased class-switched memory B cells had significantly more complications.     

Granulomatous disease in common variable immunodeficiency

Granulomatous disease occurs in 8–22% of patients with common variable immunodeficiency (CVID). We examined the clinical and immunologic information of all 37 of 455 (8.1%) CVID subjects with this complication. The median age at diagnosis of CVID was 26 (2–59). 14 had granulomas 1–18 years before diagnosis of CVID. In 6 detection of granulomas coincided with this diagnosis; for 17, granulomas were documented later. 54% had lung granulomas, 43% in lymph nodes and 32% in liver. 54% of the group had had autoimmune diseases, mostly immune thrombocytopenia and hemolytic anemia. 24% had had a splenectomy. Nineteen (51.3%) required steroid treatment for granulomas; other immune suppressants were used in some. Over 25 years 28.5% died (median age 37.5), but not significantly more when compared to our CVID patients without granulomas (19.8%). Those with lung granulomas had similar mortality to those with granulomas in other tissues.     

Autoimmune manifestations in common variable immunodeficiency

INTRODUCTION: About 20% of subjects with common variable immune deficiency (CVID) develop an autoimmune complication, most often immune thrombocytopenia or hemolytic anemia. While the pathogenesis of autoreactivity is unknown for CVID subjects in general, and to a greater extent in those with autoimmunity, there is a loss of switched memory B cells. DISCUSSION: About 7-8% of CVID subjects have mutations in the transmembrane activator and calcium-modulating cyclophilin ligand interactor (TACI), a significant association with this immune defect, although the same mutations may be found in normal relatives and rarely in healthy blood donors. In addition to generalized B cell dysfunction, defective elimination of autoimmune B cells has been demonstrated.     

CMV complications in common variable immunodeficiency

A patient suffering from common variable immunodeficiency is described, who developed a myelitis under treatment with glucocorticosteroids. Later on, autoimmune complications had to be treated with azathioprine. An exacerbation of the myelitis, retinitis, encephalitis and colitis was observed and a cytomegalovirus infection diagnosed. This infection does not represent a typical complication of common variable immunodeficiency. A functional NK cell defect was detected that may contribute to susceptibility for cytomegalovirus infection in addition to immunosuppressive therapy.     

Genetic defects in common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most frequent clinically manifested primary immunodeficiency. According to clinical and laboratory findings, CVID is a heterogeneous group of diseases. Recently, the defects of molecules regulating activation and terminal differentiation of B lymphocytes have been described in some patients with CVID. In this study, we show the overview of deficiencies of inducible costimulator, transmembrane activator and calcium-modulator and cytophilin ligand interactor, CD19 molecules, their genetic basis, pathogenesis and clinical manifestations.     

Disseminated bronchiectasis in an adult with common variable immunodeficiency

Primary immunodeficiencies (PID) are traditionally considered childhood diseases; however, adults account for 35% of all patients with PID. Antibody deficiencies, especially Common Variable Immunodeficiency (CVID), which have their peak incidence in adulthood, require a high suspicion index. Even though the estimated frequency of CVID is not high (1:25,000), high rates of under diagnosis and under reporting are very likely. The delay in diagnosis increases the morbidity and mortality; therefore, adult physicians should be able to suspect, identify and initiate management of individuals with PID. Here we report the case of a 37 year-old man presenting to the emergency room with dyspnea, fever and cough; he developed respiratory failure requiring mechanical ventilation. He complained of recurring pneumonia associated with widespread bronchiectasis since he was 18 years old. Serum immunoglobulins quantification showed severe hypogammaglobulinemia (total IgG <140 mg/dL; total IgA, 2.9 mg/dL; and total IgM <5 mg/dL). Treatment with Human Intravenous Immunoglobulin (IVIG) 10% was started, and with antibiotic treatment for severe pneumonia (during 14 days) was also prescribed. His clinical evolution has been favorable after one year follow-up. Common Variable Immunodeficiency (CVID) diagnosis was made.     

Panhypopituitarism in a child with common variable immunodeficiency.

BACKGROUND: Common variable immunodeficiency (CVID) represents a group of heterogeneous, still undifferentiated, syndromes that are all characterized by defective antibody formation. It is often associated with autoimmune disease. METHODS: An African-American girl was diagnosed with CVID at age 3 years. She was seen during an adrenal crisis precipitated by pneumonia at the age of 8 years and 10 months. The diagnosis of panhypopituitarism was established soon after. RESULTS: Panhypopituitarism in this patient was believed to be the result of the autoimmune process known as lymphocytic hypophysitis. This hypothesis was suggested by the results of magnetic resonance imaging. CONCLUSIONS: Awareness of the possibility of this process in children or adults with CVID may lead to earlier diagnosis of panhypopituitarism. These patients also have failure to thrive, and earlier diagnosis may avoid a life-threatening event.     

Immunological analysis in familial common variable immunodeficiency

Immunological and genetic studies were performed in nine members from three generations of the family of a patient with common variable immunodeficiency (CVI). Two additional symptomatic members (mother and grandmother) had CVI. Among other six asymptomatic members, two had CVI and one had selective IgA deficiency. The proportions of monoclonal antibody defined total T cells (Leu 1+), helper phenotype (Leu 3+) suppressor phenotype (Leu 2+) T cells, natural killer cells (Leu 7+) and surface Ig+ B cells and proliferative response to phytohaemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM) and in mixed lymphocyte reaction (MLR) were comparable to controls. Addition of purified interleukin-2 (IL-2) resulted in augmentation of PHA-induced proliferation of T lymphocytes similar to that seen in the controls, however with IL-2 freshly isolated T cells in the absence of PHA demonstrated markedly increased proliferative response, suggesting the presence of in vivo activated T cells. Study of HLA phenotype did not reveal any linkage. This study demonstrates the genetic nature, possibly autosomal dominant inheritance, of common variable immunodeficiency; however the immunodeficiency is not linked to any specific HLA antigen.     

Mannose-binding lectin polymorphisms in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a heterogeneous group of disorders, characterized by hypogammaglobulinemia and increased susceptibility to infections, autoimmunity and malignancies. This study was performed to analyze the Mannose-binding lectin (MBL) polymorphisms in Iranian patients with CVID. Thirty-five CVID patients who were treated at Children’s Medical Center and 100 matched controls were enrolled in this study. Sixth single-nucleotide polymorphisms of the MBL gene were analyzed using PCR–SSP method. Comparison of MBL exon 1 coding alleles between patients and controls revealed that A allele (wild-type) was significantly decreased in CVID group, whereas B allele was overrepresented in the patient group. High frequency of heterozygous (A/O) in the patient group and high frequency of homozygous for wild-type coding regions in the control group were detected. Comparison of MBL haplotype promoters between CVID patients and controls showed that LYPB haplotype was significantly overrepresented in the CVID group. Mutant and low-producing MBL alleles and haplotypes might reflect as an associated genetic factor in CVID patients, which could play as a susceptibility factor in CVID.     

Antibody response in common variable immunodeficiency.

BACKGROUND: Common variable immunodeficiency (CVID) describes a heterogeneous group of immunologic disorders of unknown etiology. It is characterized by low levels of serum immunoglobulin (Ig) and impaired antibody response. OBJECTIVE: To describe antibody response and the kinetics of IgG decline in patients identified with CVID. METHODS: Clinical and immunologic observations of four patients identified with CVID were obtained by chart review. RESULTS: Antibody response to polysaccharide antigens in patients identified with CVID is lost earlier than the antibody response to protein antigens, which may be preserved even in the face of profound hypogammaglobulinemia. In three patients who were followed prospectively, the Ig loss was progressive. CONCLUSIONS: Absence of antibody response to polysaccharide antigens may be a universal finding in patients with CVID, whereas preservation of T cell-dependent protein antibody response may be seen.     

Molecular basis of common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most prevalent human primary immunodeficiency requiring medical attention. Until recently, the only known genetic defect specific to CVID was the inducible costimulatory receptor (ICOS) deficiency, which accounts for less than 1% of the patients. Recently, mutations in the TNF receptor family member transmembrane activator and calcium-modulator and cyclophilin ligand interactor (TACI), which mediates isotype switching in B cells, were found to be present in 10% to 20% of patients with CVID. Mutations in TACI were also found in relatives of patients with CVID who had IgA deficiency (IgAD), as well as in a patient with isolated IgAD. In the majority of patients described to date, only one TACI allele is mutated, showing an autosomal dominant transmission of the disease. B cells from individuals with TACI mutations did not produce IgG and IgA in response to the TACI ligand a proliferation-inducing ligand (APRIL), probably reflecting impaired isotype switching. These results suggest that TACI mutations can lead to CVID and IgAD.     

Type I diabetes in an adolescent with common variable immunodeficiency

A male adolescent with common variable immunodeficiency developed type I diabetes approximately 1 year after the initiation of immunoglobulin therapy. Immunologic evaluation revealed decreased numbers of T cells and an intrinsic B cell defect in immunoglobulin production. Lymphocytes from the patient failed to generate normal suppressor activity. There were no insulin or islet cell antibodies present in the patient's serum or in the commercial immunoglobulin preparations he received. The patient's HLA phenotype included HLA-DR3 and 4, placing him genetically at high risk for type I diabetes.