Common Variable Immunodeficiency Disorders Patients Research Articles

Portal hypertension in common variable immunodeficiency disorders - a single center analysis on clinical and immunological parameter in 196 patients.

Liver manifestations and in particular portal hypertension (PH) contribute significantly to morbidity and mortality of patients with common variable immunodeficiency disorders (CVID). Screening strategies and early detection are limited due to the lack of specific diagnostic tools. We evaluated clinical, immunological, histological, and imaging parameters in CVID patients with clinical manifestation of portal hypertension (CVID+PH). Portal hypertension was present in 5.6% of CVID patients and was associated with high clinical burden and increased mortality (18%). Longitudinal data on clinical and immunological parameters in patients before and during clinically manifest portal hypertension revealed a growing splenomegaly and increasing gamma-glutamyl transferase (GGT) and soluble interleukin 2 receptor (SIL-2R) levels with decreasing platelets over time. While ultrasound of the liver failed to detect signs of portal hypertension in most affected patients, transient elastography was elevated in all patients. All CVID+PH patients had reduced naïve CD45RA+CD4+ T-cells (mean of 6,2%). The frequency of severe B-lymphocytopenia (Euroclass B-) was higher in CVID+PH patients. The main histological findings included lymphocytic infiltration, nodular regenerative hyperplasia-like changes (NRH-LC), and porto(-septal) fibrosis. CVID patients with lower naïve CD45RA+CD4+ T-cells or severely reduced B-cells might be at higher risk for portal hypertension. The combination of biochemical (increasing sIL-2R, GGT, and decreasing platelets) and imaging parameters (increasing splenomegaly) should raise suspicion of the beginning of portal hypertension.

Intravenous Immunoglobulins Promote an Expansion of Monocytic Myeloid-Derived Suppressor Cells (MDSC) in CVID Patients

Common variable immunodeficiency disorders (CVID), the most common primary immune deficiency, includes heterogeneous syndromes characterized by hypogammaglobulinemia and impaired antibody responses. CVID patients frequently suffer from recurrent infections and inflammatory conditions. Currently, immunoglobulin replacement therapy (IgRT) is the first-line treatment to prevent infections and aminorate immune alterations in CVID patients. Intravenous Immunoglobulin (IVIg), a preparation of highly purified poly-specific IgG, is used for treatment of immunodeficiencies as well as for autoimmune and inflammatory disorders, as IVIg exerts immunoregulatory and anti-inflammatory actions on innate and adaptive immune cells. To determine the mechanism of action of IVIg in CVID in vivo, we determined the effect of IVIg infusion on the transcriptome of peripheral blood mononuclear cells from CVID patients, and found that peripheral blood monocytes are primary targets of IVIg in vivo, and that IVIg triggers the acquisition of an anti-inflammatory gene profile in human monocytes. Moreover, IVIg altered the relative proportions of peripheral blood monocyte subsets and enhanced the proportion of CD14+ cells with a transcriptional, phenotypic, and functional profile that resembles that of monocytic myeloid-derived suppressor cells (MDSC). Therefore, our results indicate that CD14 + MDSC-like cells might contribute to the immunoregulatory effects of IVIg in CVID and other inflammatory disorders.

Predictive Factors for and Complications of Bronchiectasis in Common Variable Immunodeficiency Disorders

Bronchiectasis is a frequent complication of common variable immunodeficiency disorders (CVID). In a cohort of patients with CVID, we sought to identify predictors of bronchiectasis. Secondly, we sought to describe the impact of bronchiectasis on lung function, infection risk, and quality of life. We conducted an observational cohort study of 110 patients with CVID and an available pulmonary computed tomography scan. The prevalence of bronchiectasis was 53%, with most of these patients (54%) having mild disease. Patients with bronchiectasis had lower median serum immunoglobulin (Ig) concentrations, especially long-term IgM (0 vs 0.25 g/l; p < 0.01) and pre-treatment IgG (1.3 vs 3.7 g/l; p < 0.01). CVID patients with bronchiectasis had worse forced expiratory volume in one second (2.10 vs 2.99 l; p < 0.01) and an annual decline in forced expiratory volume in one second of 25 ml/year (vs 8 ml/year in patients without bronchiectasis; p = 0.01). Patients with bronchiectasis also reported more annual respiratory tract infections (1.77 vs 1.25 infections/year, p = 0.04) and a poorer quality of life (26 vs 14 points in the St George’s Respiratory Questionnaire; p = 0.02). Low serum immunoglobulin M concentration identifies patients at risk for bronchiectasis in CVID and may play a role in pathogenesis. Bronchiectasis is relevant because it is associated with frequent respiratory tract infections, poorer lung function, a greater rate of lung function decline, and a lower quality of life.

Shared Pathogenetic Features Between Common Variable Immunodeficiency and Sjögren's Syndrome: Clues for a Personalized Medicine.

Common variable immunodeficiency disorders (CVID) are a group of rare diseases of the immune system and the most common symptomatic primary antibody deficiency in adults. The “variable” aspect of CVID refers to the approximately half of the patients who develop non-infective complications, mainly autoimmune features, in particular organ specific autoimmune diseases including thyroiditis, and cytopenias. Among these associated conditions, the incidence of lymphoma, including mucosal associated lymphoid tissue (MALT) type, is increased. Although these associated autoimmune disorders in CVID are generally attributed to Systemic Lupus Erythematosus (SLE), we propose that Sjogren’s syndrome (SS) is perhaps a better candidate for the associated disease. SS is an autoimmune disorder characterized by the lymphocytic infiltrates of lacrimal and salivary glands, leading to dryness of the eyes and mouth. Thus, it is a lymphocyte aggressive disorder, in contrast to SLE where pathology is generally attributed to auto-antibody and complement activation. Although systemic lupus erythematosus (SLE) shares these features with SS, a much higher frequency of MALT lymphoma distinguishes SS from SLE. Also, the higher frequency of germ line encoded paraproteins such as the monoclonal rheumatoid factor found in SS patients would be more consistent with the failure of B-cell VDJ switching found in CVID; and in contrast to the hypermutation that characterizes SLE autoantibodies. Thus, we suggest that SS may fit as a better “autoimmune” association with CVID. Examining the common underlying biologic mechanisms that promote lymphoid infiltration by dysregulated lymphocytes and lymphoma in CVID may provide new avenues for treatment in both the diseases. Since the diagnosis of SLE or rheumatoid arthritis is usually based on specific autoantibodies, the associated autoimmune features of CVID patients may not be recognized in the absence of autoantibodies.

Treatment Strategies for GLILD in Common Variable Immunodeficiency: A Systematic Review.

IntroductionBesides recurrent infections, a proportion of patients with Common Variable Immunodeficiency Disorders (CVID) may suffer from immune dysregulation such as granulomatous-lymphocytic interstitial lung disease (GLILD). The optimal treatment of this complication is currently unknown. Experienced-based expert opinions have been produced, but a systematic review of published treatment studies is lacking.GoalsTo summarize and synthesize the published literature on the efficacy of treatments for GLILD in CVID.MethodsWe performed a systematic review using the PRISMA guidelines. Papers describing treatment and outcomes in CVID patients with radiographic and/or histologic evidence of GLILD were included. Treatment regimens and outcomes of treatment were summarized.Results6124 papers were identified and 42, reporting information about 233 patients in total, were included for review. These papers described case series or small, uncontrolled studies of monotherapy with glucocorticoids or other immunosuppressants, rituximab monotherapy or rituximab plus azathioprine, abatacept, or hematopoietic stem cell transplantation (HSCT). Treatment response rates varied widely. Cross-study comparisons were complicated because different treatment regimens, follow-up periods, and outcome measures were used. There was a trend towards more frequent GLILD relapses in patients treated with corticosteroid monotherapy when compared to rituximab-containing treatment regimens based on qualitative endpoints. HSCT is a promising alternative to pharmacological treatment of GLILD, because it has the potential to not only contain symptoms, but also to resolve the underlying pathology. However, mortality, especially among immunocompromised patients, is high.ConclusionsWe could not draw definitive conclusions regarding optimal pharmacological treatment for GLILD in CVID from the current literature since quantitative, well-controlled evidence was lacking. While HSCT might be considered a treatment option for GLILD in CVID, the risks related to the procedure are high. Our findings highlight the need for further research with uniform, objective and quantifiable endpoints. This should include international registries with standardized data collection including regular pulmonary function tests (with carbon monoxide-diffusion), uniform high-resolution chest CT radiographic scoring, and uniform treatment regimens, to facilitate comparison of treatment outcomes and ultimately randomized clinical trials.

Managing Granulomatous-Lymphocytic Interstitial Lung Disease in Common Variable Immunodeficiency Disorders: e-GLILDnet International Clinicians Survey.

BackgroundGranulomatous–lymphocytic interstitial lung disease (GLILD) is a rare, potentially severe pulmonary complication of common variable immunodeficiency disorders (CVID). Informative clinical trials and consensus on management are lacking.AimsThe European GLILD network (e-GLILDnet) aims to describe how GLILD is currently managed in clinical practice and to determine the main uncertainties and unmet needs regarding diagnosis, treatment and follow-up.MethodsThe e-GLILDnet collaborators developed and conducted an online survey facilitated by the European Society for Immunodeficiencies (ESID) and the European Respiratory Society (ERS) between February–April 2020. Results were analyzed using SPSS.ResultsOne hundred and sixty-one responses from adult and pediatric pulmonologists and immunologists from 47 countries were analyzed. Respondents treated a median of 27 (interquartile range, IQR 82–maximum 500) CVID patients, of which a median of 5 (IQR 8–max 200) had GLILD. Most respondents experienced difficulties in establishing the diagnosis of GLILD and only 31 (19%) had access to a standardized protocol. There was little uniformity in diagnostic or therapeutic interventions. Fewer than 40% of respondents saw a definite need for biopsy in all cases or performed bronchoalveolar lavage for diagnostics. Sixty-six percent used glucocorticosteroids for remission-induction and 47% for maintenance therapy; azathioprine, rituximab and mycophenolate mofetil were the most frequently prescribed steroid-sparing agents. Pulmonary function tests were the preferred modality for monitoring patients during follow-up.ConclusionsThese data demonstrate an urgent need for clinical studies to provide more evidence for an international consensus regarding management of GLILD. These studies will need to address optimal procedures for definite diagnosis and a better understanding of the pathogenesis of GLILD in order to provide individualized treatment options. Non-availability of well-established standardized protocols risks endangering patients.

Serum Free Light Chains in Common Variable Immunodeficiency Disorders: Role in Differential Diagnosis and Association With Clinical Phenotype.

We report on an observational, multicenter study of 345 adult CVID patients, designed to assess the diagnostic value and the clinical association of serum free light chain (sFLC) pattern in Common Variable Immunodeficiency disorders (CVID). Sixty CVID patients were tested twice in order to assess intraindividual variability of sFLC. As control groups we included 138 patients affected by undefined primary antibody defects (UAD), lymphoproliferative diseases (LPDs), and secondary antibody deficiencies not related to hematological malignancies (SID). CVID patients presented lower κ and λ chain concentration compared to controls, showing low intraindividual sFLC variability. On the basis of the sFLC pattern, patients were classified into four groups: κ−λ+, κ+λ−, κ−λ−, κ+λ+. The most common pattern in CVID patients was κ−λ− (51%), followed by κ−λ+, (25%), κ+λ+ (22%), and κ+λ− (3%). In UAD, LPD, and SID groups κ+λ+ was the most common pattern observed. By analyzing the possible association between sFLC patterns and disease-related complications of CVID, we observed that patients belonging to the κ−λ− group presented more commonly unexplained enteropathy compared to the κ+λ+ group and showed higher frequency of bronchiectasis and splenomegaly compared to both the κ−λ+ and κ+λ+ patients. When compared to the other groups, κ−λ− had also lower serum IgG, IgA, and IgM concentrations at diagnosis, lower frequency of CD27+IgD–IgM– switched memory B cells, and higher frequency of CD21low B cells, receiving earlier CVID diagnosis. Thus, lower levels of sFLC might be an epiphenomenon of impairment in B cell differentiation, possibly leading κ−λ− patients to a higher risk for bacterial infections and chronic lung damage. Based on these results, we suggest adding sFLC assay to the diagnostic work-up of hypogammaglobulinemia and during follow-up. The assay may be useful to differentiate CVID from other causes of hypogammaglobulinemia and to early detect monoclonal lymphoproliferation occurring over years. Moreover, since the sFLC pattern seems to be related to disease phenotypes and clinical manifestations of CVID and after confirmation by further studies, sFLC assay might be considered a promising prognostic tool for identifying patients at higher risk of developing enteropathy and chronic lung damage or splenomegaly. This will allow designing a tailored follow-up for CVID patients.

All Patients With Common Variable Immunodeficiency Disorders (CVID) Should Be Routinely Offered Diagnostic Genetic Testing.

Common Variable Immunodeficiency Disorders (CVID) are a rare group of primary immunodeficiency disorders (PIDs) where late onset antibody failure leads to immune system failure (1). Onset of symptoms can occur from early childhood to the eighth decade or later (2). Current estimates suggest a prevalence between 1: 25 000 to 1: 100 000 in Caucasians (3, 4). For reasons that are unclear, CVID appears to be less frequent in Asian and African populations, although there may be ascertainment bias. The majority of patients with CVID present with recurrent and severe infections. Untreated, patients are predisposed to chronic suppuration of the respiratory tract, often resulting in chronic sinus disease and bronchiectasis. Approximately 25% of CVID patients suffer autoimmune or inflammatory sequelae, consequent to immune dysregulation (5). There is also an increased risk of malignancy (6). There is no single clinical feature or laboratory test, which is pathognomonic for CVID. The identification of CVID therefore relies on diagnostic criteria. There are currently three new sets of diagnostic criteria for CVID (7–9). The Ameratunga et al. (7) criteria require symptomatic primary hypogammaglobulinemia with relevant laboratory tests to establish the diagnosis. The threshold for IgG was set at 5 g/l for adults. The revised European Society for immunodeficiencies (8) are similar to the Ameratunga et al. criteria. The most recent International Consensus Document (9) CVID criteria claim to be able to make a definite diagnosis on the basis of a single abnormal vaccine challenge result in a patient with primary hypogammaglobulinemia (9). The latter two criteria have set the threshold for IgG at 2 sd below the mean. Although immunoglobulin levels do not follow a Gaussian distribution (10), this is generally accepted as an IgG below 7 g/l. These criteria also exclude late onset combined immunodeficiency (LOCID) from the diagnosis. The immunoglobulin levels are also required to be repeated in these latter criteria. There is ongoing debate about the utility these diagnostic criteria, the variability of IgG levels over time, the unreliability of vaccine challenge responses and flow cytometry in the diagnosis of CVID. As discussed below, this variability in protein-based assays is a strong argument for genetic testing of all patients with a CVID phenotype.

30-Year Review of Pediatric- and Adult-Onset CVID: Clinical Correlates and Prognostic Indicators.

To evaluate mortality risk factors in pediatric-onset common variable immunodeficiency disorders (CVID), we evaluated the largest single-institution cohort of pediatric-onset CVID patients. Previous publications on CVID have provided valuable descriptive data, but lack risk stratification to guide physicians in management of these patients. Retrospective chart review of 198 subjects with CVID at a single institution, of whom 91 had disease onset at a pediatric age. Clinical and laboratory data were collected at diagnosis and in follow-up. Odds ratios and Fisher tests were utilized to examine trends. This study was approved by an institutional review board. Clinical features and laboratory results for subjects diagnosed with CVID at a pediatric age are similar to those who had adult-onset CVID. However, majority of the deceased subjects (13/18) were at a pediatric age at CVID symptom onset. These subjects had a lower age at mortality, multiple comorbidities, and often depression. The most common cause of death was infection. Lung disease (OR 5, p < 0.05) and infection with severe/opportunistic organisms (OR 9, p < 0.05) are directly related to increased mortality. Delay in diagnosis of CVID is also correlated with mortality. Intermediary markers correlating with mortality include anemia, GERD, and depression. There are many similarities between patients with pediatric- and adult-onset CVID; however, the mortality of pediatric CVID in our cohort is striking. This is the first study to identify specific factors correlated with mortality in pediatric-onset CVID to guide pediatricians and subspecialists in managing these immunodeficient patients.

Neutrophil and Granulocytic Myeloid-Derived Suppressor Cell-Mediated T Cell Suppression Significantly Contributes to Immune Dysregulation in Common Variable Immunodeficiency Disorders.

Common variable immunodeficiency disorders (CVID) represent a group of primary immunodeficiency diseases characterized by hypogammaglobulinemia and impaired specific Ab response, resulting in recurrent infections due to dysfunctional immune response. The specific mechanisms mediating immune deficiency in CVID remain to be determined. Previous studies indicated that immune dysregulation in CVID patients is associated with chronic microbial translocation, systemic immune activation, and altered homeostasis of lymphocytic and myeloid lineages. A detailed phenotypic, functional characterization of plasma markers and immune cell populations was performed in 46 CVID patients and 44 healthy donors. CVID patients displayed significantly elevated plasma levels of a marker of neutrophil activation neutrophil gelatinase-associated lipocalin. Neutrophils from CVID patients exhibited elevated surface levels of CD11b and PD-L1 and decreased levels of CD62L, CD16, and CD80, consistent with a phenotype of activated neutrophils with suppressive properties. Neutrophils from CVID patients actively suppressed T cell activation and release of IFN-γ via the production of reactive oxygen species. Furthermore, CVID was associated with an increased frequency of low-density neutrophils (LDNs)/granulocytic myeloid-derived suppressor cells. LDN/granulocytic myeloid-derived suppressor cell frequency in CVID patients correlated with reduced T cell responsiveness. Exogenous stimulation of whole blood with bacterial LPS emulated some but not all of the phenotypic changes observed on neutrophils from CVID patients and induced neutrophil population with LDN phenotype. The presented data demonstrate that neutrophils in the blood of CVID patients acquire an activated phenotype and exert potent T cell suppressive activity. Specific targeting of myeloid cell-derived suppressor activity represents a novel potential therapeutic strategy for CVID.

Common variable immunodeficiency patients display elevated plasma levels of granulocyte activation markers elastase and myeloperoxidase.

Common variable immunodeficiency disorders (CVIDs) represent a group of primary immunodeficiency diseases characterized by hypogammaglobulinemia and dysfunctional immune response to invading pathogens. Previous studies have indicated that CVID is associated with microbial translocation and systemic myeloid cell activation.The goal of this study was to determine whether patients with CVID display elevated systemic levels of markers of granulocyte activation and whether the levels are further influenced by intravenous immunoglobulin (IVIg) infusions. The plasma levels of granulocyte activation markers elastase and myeloperoxidase were determined using enzyme-linked immunosorbent assay (ELISA) in 46 CVID patients and 44 healthy controls. All CVID patients were in a stable state with no apparent acute infection. In addition, granulocyte activation markers’ plasma levels in 24 CVID patients were determined prior to and 1 h following IVIg administration. Neutrophil elastase and myeloperoxidase plasma levels were significantly higher in CVID patients than in healthy controls. Systemic elastase levels were further increased following IVIg administration. In vitro stimulation of 13 CVID patients’ whole blood using IVIg in a therapeutically relevant dose for 2 h resulted in a significant increase in plasma elastase levels compared to unstimulated blood. The data presented here indicate that CVID is associated with chronic granulocytic activation which is further exacerbated by administering IVIg. Increased myeloperoxidase and elastase levels may contribute to associated comorbidities in CVID patients.

Imaging of Bronchial Pathology in Antibody Deficiency: Data from the European Chest CT Group.

Studies of chest computed tomography (CT) in patients with primary antibody deficiency syndromes (ADS) suggest a broad range of bronchial pathology. However, there are as yet no multicentre studies to assess the variety of bronchial pathology in this patient group. One of the underlying reasons is the lack of a consensus methodology, a prerequisite to jointly document chest CT findings. We aimed to establish an international platform for the evaluation of bronchial pathology as assessed by chest CT and to describe the range of bronchial pathologies in patients with antibody deficiency. Ffteen immunodeficiency centres from 9 countries evaluated chest CT scans of patients with ADS using a predefined list of potential findings including an extent score for bronchiectasis. Data of 282 patients with ADS were collected. Patients with common variable immunodeficiency disorders (CVID) comprised the largest subgroup (232 patients, 82.3%). Eighty percent of CVID patients had radiological evidence of bronchial pathology including bronchiectasis in 61%, bronchial wall thickening in 44% and mucus plugging in 29%. Bronchiectasis was detected in 44% of CVID patients aged less than 20years. Cough was a better predictor for bronchiectasis than spirometry values. Delay of diagnosis as well as duration of disease correlated positively with presence of bronchiectasis. The use of consensus diagnostic criteria and a pre-defined list of bronchial pathologies allows for comparison of chest CT data in multicentre studies. Our data suggest a high prevalence of bronchial pathology in CVID due to late diagnosis or duration of disease.

High-resolution computed tomography findings in humoral primary immunodeficiencies and correlation with pulmonary function tests.

AIMTo compare high-resolution computed tomography (HRCT) findings between humoral primary immunodeficiencies (hPIDs) subtypes; to correlate these findings to pulmonary function tests (PFTs).METHODSWe retrospectively identified 52 consecutive adult patients with hPIDs who underwent 64-row HRCT and PFTs at the time of diagnosis. On a per-patient basis, an experienced radiologist recorded airway abnormalities (bronchiectasis, airway wall thickening, mucus plugging, tree-in-bud, and air-trapping) and parenchymal-interstitial abnormalities (consolidations, ground-glass opacities, linear and/or irregular opacities, nodules, and bullae/cysts) found on HRCT. The chi-square test was performed to compare the prevalence of each abnormality among patients with different subtypes of hPIDs. Overall logistic regression analysis was performed to assess whether HRCT findings predicted obstructive and/or restrictive PFTs results (absent-to-mild vs moderate-to-severe).RESULTSThirty-eight of the 52 patients with hPIDs showed common variable immunodeficiency disorders (CVID), while the remaining 14 had CVID-like conditions (i.e., 11 had isolated IgG subclass deficiencies and 3 had selective IgA deficiencies). The prevalence of most HRCT abnormalities was not significantly different between CVID and CVID-like patients (P > 0.05), except for linear and/or irregular opacities (prevalence of 31.6% in the CVID group and 0 in the CVID-like group; P = 0.0427). Airway wall thickening was the most frequent HRCT abnormality found in both CVID and CVID-like patients (71% of cases in both groups). The presence of tree-in-bud abnormalities was an independent predictor of moderate-to-severe obstructive defects at PFTs (Odds Ratio, OR, of 18.75, P < 0.05), while the presence of linear and/or irregular opacities was an independent predictor of restrictive defects at PFTs (OR = 13.00; P < 0.05).CONCLUSIONCVID and CVID-like patients showed similar HRCT findings. Tree-in-bud and linear and/or irregular opacities predicted higher risks of, respectively, obstructive and restrictive defects at PFTs.

Assessing Disease Severity in Common Variable Immunodeficiency Disorders (CVID) and CVID-Like Disorders.

Common Variable Immunodeficiency Disorders (CVID) are the most frequent symptomatic primary immune deficiency (PID) in adults. Current estimates suggest a prevalence of ~1:25,000, although a recent study has suggested an even greater frequency than previous estimates (1). The majority of CVID patients suffer recurrent infections because of late onset antibody failure (LOAF) leading to immune system failure (ISF). Current criteria do not allow CVID to be diagnosed before 4 years although some patients have symptoms dating back to infancy. Most patients experience recurrent or severe bacterial infections and less commonly autoimmunity as a result of CVID. Some patients present with a sarcoidosis-like disorder or enteritis (2, 3). A proportion of patients with CVID have a prominent T cell defect leading to severe viral or opportunistic infections. These patients have been deemed to have late onset combined immunodeficiency (LOCID) (4). LOCID is currently separated from CVID although I have argued LOCID should be included as a subset of CVID (5). In spite of major progress in the last decade, the genetic basis of CVID is unknown in most patients. A causative mutation has been identified in up to 30% (6). If a causative defect is identified, these patients are removed from the umbrella diagnosis of CVID and are reclassified as having a CVID-like disorder caused by a specific mutation. To fulfill a diagnosis, all current CVID criteria require exclusion of other immunodeficiencies including NFKB1, NFKB1, CTLA4 etc. It is however likely earlier series of patients with CVID included many with CVID-like disorders, whose mutations were undiscovered. We have recently discovered new genetic defects in two NZ families with CVID-like disorders. In the first family, we have confirmed the existence of quantitative epistasis in humans (7). Epistasis is the non-linear, synergistic interaction of two or more genetic loci either leading to a much more severe disorder or a novel phenotype (8, 9). The existence of epistasis was first predicted by William Bateson in 1909 but has remained highly controversial because of the lack of well characterized examples in humans (10). In this family, the synergistic interaction of TNFRSF13B/TACI and TCF3 mutations resulted in a severe immunodeficiency and systemic lupus erythematosus (SLE) in the proband (Figure ​(Figure1).1). Other members of the family who have various permutations of the two mutated genes had a milder phenotype, which was reflected in their in vitro B cell differentiation and antibody production studies (7). Open in a separate window Figure 1 Family with a digenic CVID-like disorder caused by epistatic interactions of TNFRSF13B/TACI and TCF3 genes. The proband (arrow) suffers from both a severe immunodeficiency as well as SLE. Other members are as described in our previous publications including a mild symptomatic brother (II.3) with severe hypogammaglobulinemia caused by homozygous C104R mutations of the TNFRSF13B/TACI gene. CDSS, CVID disease severity score; CS, clinical score. The CS was suggested as means of determining eligibility for SCIG/IVIG but we have used it as a surrogate marker of disease severity (5, 7, 11).

Review: Diagnosing Common Variable Immunodeficiency Disorder in the Era of Genome Sequencing

Common variable immunodeficiency disorders (CVID) are an enigmatic group of often heritable conditions, which may manifest for the first time in early childhood or as late as the eighth decade of life. In the last 5years, next generation sequencing (NGS) has revolutionised identification of genetic disorders. However, despite the best efforts of researchers around the globe, CVID conditions have been slow to yield their molecular secrets. We have previously described the many clinical advantages of identifying the genetic basis of primary immunodeficiency disorders (PIDs). In a minority of CVID patients, monogenic defects have now been identified. If a causative mutation is identified, these conditions are reclassified as CVID-like disorders. Here we discuss recent advances in the genetics of CVID and discuss how NGS can be optimally deployed to identify the causal mutations responsible for the protean clinical manifestations of these conditions. Diagnostic criteria such as the Ameratunga et al. criteria will continue to play an important role in patient management as well as case selection and sequencing strategy design until the genetic conundrum of CVID is solved.

Epistatic interactions between mutations of TACI (TNFRSF13B) and TCF3 result in a severe primary immunodeficiency disorder and systemic lupus erythematosus.

Common variable immunodeficiency disorders (CVID) are a group of primary immunodeficiencies where monogenetic causes account for only a fraction of cases. On this evidence, CVID is potentially polygenic and epistatic although there are, as yet, no examples to support this hypothesis. We have identified a non-consanguineous family, who carry the C104R (c.310T>C) mutation of the Transmembrane Activator Calcium-modulator and cyclophilin ligand Interactor (TACI, TNFRSF13B) gene. Variants in TNFRSF13B/TACI are identified in up to 10% of CVID patients, and are associated with, but not solely causative of CVID. The proband is heterozygous for the TNFRSF13B/TACI C104R mutation and meets the Ameratunga et al. diagnostic criteria for CVID and the American College of Rheumatology criteria for systemic lupus erythematosus (SLE). Her son has type 1 diabetes, arthritis, reduced IgG levels and IgA deficiency, but has not inherited the TNFRSF13B/TACI mutation. Her brother, homozygous for the TNFRSF13B/TACI mutation, is in good health despite profound hypogammaglobulinemia and mild cytopenias. We hypothesised that a second unidentified mutation contributed to the symptomatic phenotype of the proband and her son. Whole-exome sequencing of the family revealed a de novo nonsense mutation (T168fsX191) in the Transcription Factor 3 (TCF3) gene encoding the E2A transcription factors, present only in the proband and her son. We demonstrate mutations of TNFRSF13B/TACI impair immunoglobulin isotype switching and antibody production predominantly via T-cell-independent signalling, while mutations of TCF3 impair both T-cell-dependent and -independent pathways of B-cell activation and differentiation. We conclude that epistatic interactions between mutations of the TNFRSF13B/TACI and TCF3 signalling networks lead to the severe CVID-like disorder and SLE in the proband.

The role of genomics in common variable immunodeficiency disorders.

The advent of next-generation sequencing (NGS) and 'omic' technologies has revolutionized the field of genetics, and its implementation in health care has the potential to realize precision medicine. Primary immunodeficiencies (PID) are a group of rare diseases which have benefited from NGS, with a massive increase in causative genes identified in the past few years. Common variable immunodeficiency disorders (CVID) are a heterogeneous form of PID and the most common form of antibody failure in children and adults. While a monogenic cause of disease has been identified in a small subset of CVID patients, a genomewide association study and whole genome sequencing have found that, in the majority, a polygenic cause is likely. Other NGS technologies such as RNA sequencing and epigenetic studies have contributed further to our understanding of the contribution of altered gene expression in CVID pathogenesis. We believe that to unravel further the complexities of CVID, a multi-omic approach, combining DNA sequencing with gene expression, methylation, proteomic and metabolomics data, will be essential to identify novel disease-associated pathways and therapeutic targets.

Delay in diagnosis affects the clinical outcome in a cohort of cvid patients with marked reduction of iga serum levels

Common variable immunodeficiency disorders (CVID) represent a collection of diseases leading to an absent or strongly impaired antibody production. CVID presents a wide range of immunological abnormalities and clinical manifestations, including infections, inflammatory and autoimmune diseases, and malignancies. The aim of this observational study was to analyze the epidemiological and clinical features of a cohort of 75 Italian CVID patients, and evaluate the correlation with comorbidity and mortality. Clinical data were retrospectively collected: the cohort was followed-up for a maximum of 30years (mean time of 10.24years, median of 9years). An higher age at the diagnosis of CVID and an higher age at onset of symptoms were significantly associated with a reduction of patients survival if stratified per median of IgA (less than or >8.00mg/dl). Thus IgA levels at diagnosis are correlated with patients survival contributing to identify a subset with a worse prognostic outcome.

Application of whole genome and RNA sequencing to investigate the genomic landscape of common variable immunodeficiency disorders

Common Variable Immunodeficiency Disorders (CVIDs) are the most prevalent cause of primary antibody failure. CVIDs are highly variable and a genetic causes have been identified in <5% of patients. Here, we performed whole genome sequencing (WGS) of 34 CVID patients (94% sporadic) and combined them with transcriptomic profiling (RNA-sequencing of B cells) from three patients and three healthy controls. We identified variants in CVID disease genes TNFRSF13B, TNFRSF13C, LRBA and NLRP12 and enrichment of variants in known and novel disease pathways. The pathways identified include B-cell receptor signalling, non-homologous end-joining, regulation of apoptosis, T cell regulation and ICOS signalling. Our data confirm the polygenic nature of CVID and suggest individual-specific aetiologies in many cases. Together our data show that WGS in combination with RNA-sequencing allows for a better understanding of CVIDs and the identification of novel disease associated pathways.

CT screening for pulmonary pathology in common variable immunodeficiency disorders and the correlation with clinical and immunological parameters.

Pulmonary disease is common in patients with common variable immunodeficiency disorders (CVID) and involves infections, chronic airway disease and interstitial lung disease. Chronic pulmonary disease is associated with excess morbidity and early mortality and therefore early detection and monitoring of progression is essential. Thin slice CT scan and pulmonary function were used to determine the prevalence and spectrum of chronic (pre-clinical) pulmonary disease in adult CVID patients regardless of symptoms. CT Scans were scored for airway abnormalities (AD) and interstitial lung disease (ILD). Other CVID related complications and B and T lymphocyte subsets were analyzed to identify patients at risk for pulmonary disease. Significant pulmonary abnormalities were detected in 24 of the 47 patients (51%) consisting of AD in 30% and ILD in 34% of cases. In only 7 (29%) of these 24 patients pulmonary function test proved abnormal. The presence of AD was correlated to (recurrent) lower respiratory tract infections despite IgG therapy. The presence of ILD was correlated to autoimmune disease and a reduction in the numbers of CD4 + T cells, naïve CD4 + T cells, naïve CD8 + T cells and memory B cells and lower IgG through levels over time. Preclinical signs of AD and ILD are common in CVID patients despite Ig therapy and do not correlate to pulmonary function testing. Patients at risk for ILD might be identified by the presence of autoimmunity or a deranged T cell pattern. Larger studies are needed to confirm these findings and to determine thresholds for the T lymphocyte subsets.