International Consensus Document (ICON): Common Variable Immunodeficiency Disorders

GVHD, IBD and primary immunodeficiencies: The gut as a target of immunopathology resulting from impaired immunity

The intestinal tract is the largest immunological organ in the body and has a central function of regulating local immune responses, as the intestinal epithelial barrier is a location where the immune system interacts with the gut microbiome including bacteria, fungi and viruses. Impaired immunity in the intestinal tract can lead to immunopathology, which manifests in different diseases such as inflammatory bowel disease (IBD) or intestinal graft-versus-host disease (GVHD). A disturbed communication between epithelial cells, immune cells and microbiome will shape pathogenic immune responses to antigens, which need to be counterbalanced by tolerogenic mechanisms and repair mechanisms. Here, we review how impaired intestinal immune function leads to immunopathology with a specific focus on innate immune cells, the role of the microbiome and the resulting clinical manifestations including intestinal GVHD, IBD and enteropathy in primary immunodeficiency. This article is protected by copyright. All rights reserved.

Protocol for the unclassified primary antibody deficiency (unPAD) study: Characterization and classification of patients using the ESID online Registry

Background

Primary antibody deficiencies (PADs) without an identified monogenetic origin form the largest and most heterogeneous group of primary immunodeficiencies. These patients often remain undiagnosed for years and many present to medical attention in adulthood after several infections risking structural complications. Not much is known about their treatment, comorbidities, or prognosis, nor whether the various immunological forms (decreased total IgG, IgG subclass(es), IgM, IgA, specific antibody responses, alone or in combination(s)) should be considered as separate, clearly definable subgroups. The unclassified primary antibody deficiency (unPAD) study aims to describe in detail all PAD patients without an identified specific monogenetic defect regarding their demographical, clinical, and immunological characteristics at presentation and during follow-up. In constructing these patterns, the unPAD study aims to reduce the number of missed and unidentified PAD patients in the future. In addition, this study will focus on subclassifying unPAD to support the identification of patients at higher risk for infection or immune dysregulation related complications, enabling the development of personalized follow-up and treatment plans.

Methods and analysis

We present a protocol for a multicenter observational cohort study using the ESID online Registry. Patients of all ages who have given informed consent for participation in the ESID online Registry and fulfill the ESID Clinical Working Definitions for ‘unclassified antibody deficiency’, ‘deficiency of specific IgG’, ‘IgA with IgG subclass deficiency’, ‘isolated IgG subclass deficiency’, ‘selective IgM deficiency’, ‘selective IgA deficiency’ or ‘common variable immunodeficiency’ will be included. For all patients, basic characteristics can be registered at first registration and yearly thereafter in level 1 forms. Detailed characteristics of the patients can be registered in level 2 forms. Consecutive follow-up forms can be added indefinitely. To ensure the quality of the collected data, all data will be fully monitored before they are exported from the ESID online Registry for analysis. Outcomes will be the clinical and immunological characteristics of unPAD at presentation and during follow-up. Subgroup analyses will be made based on demographical, clinical and immunological characteristics.

Seeking Relevant Biomarkers in Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is the most common symptomatic form of primary immunodeficiency. More than 50% of patients in some series suffer from autoimmune or inflammatory complications (the "CVID+" phenotype), and these are not adequately addressed by current treatments. Despite major advancements in genetics, the pathogenesis of the CVID+ phenotype has remained unexplained for most patients, necessitating the need for relevant biomarkers in both the clinic and research settings. In the clinics, reduced isotype-switched memory B cells (≤ 0.55% of B cells) and reduced T cells (CD4) can be utilized to identify those with increased complication risks. Additionally, condition-specific markers have also been suggested for lymphoma (normal or elevated IgM) and progressive interstitial lung disease (increased BAFF, normal or elevated IgM). Additional biomarkers have provided insights into disease pathogenesis, demonstrating wider systemic inflammation (increased LBP, sCD14, and sCD25; expanded ILC3), mucosal defects (increased zonulin, I-FABP), and perhaps reduced anti-inflammatory capability (reduced HDL) in CVID. Most recently, efforts have revealed elevated circulating bioactive bacterial DNA levels - marking microbial translocation and potentially linking the causation of multiple inflammatory changes previously observed in CVID. The implementation of high throughput profiling techniques may accelerate the search of relevant biomarker profiles in CVID and lead to better clinical risk stratification, revealing disease insights, and identifying potential therapeutic targets.

Common Variable Immunodeficiency in Elderly Patients: A Long-Term Clinical Experience

Background: Common variable immunodeficiency (CVID) is a complex, predominantly antibody deficiency usually diagnosed between 20−40 years. Few data about elderly patients are reported in the literature. Our aim was to evaluate the clinical phenotypes of elderly patients with CVID. Method: A retrospective analysis of adult patients with CVID was performed in our Referral Centre, focusing on the main differences between “older” patients (≥65 years at the diagnosis) and “younger” patients (<65 years). Results: The data from 65 younger and 13 older patients followed up for a median period of 8.5 years were available. At diagnosis, recurrent infections represented the only clinical manifestation in 61% and 69% of younger and older patients, respectively. The incidence of autoimmune diseases was higher in elderly patients compared with younger ones (30 vs. 18%, respectively). During the follow-up, the incidence of autoimmune disorders and enteropathy increased in the younger patients whereas neoplasia became the most prevalent complication in the elderly (38%). All patients received a replacement therapy with immunoglobulin, with good compliance. Conclusion: CVID occurrence in elderly patients is rarely described; therefore, the clinical characteristics are not completely known. In our series, neoplasia became the most prevalent complication in the elderly during the follow-up. In elderly patients, 20% SCIg was as safe as in the younger ones, with good compliance. A genetic analysis is important to confirm the diagnosis, identify specific presentations in the different ages, clarify the prognosis and guide the treatment. Future clinical research in this field may potentially help to guide their care.

Monitoring patients with uncomplicated common variable immunodeficiency: a systematic review

BACKGROUND

Non-infectious complications have become a major cause of morbidity and mortality in patients with Common Variable Immunodeficiency (CVID). The monitoring of patients with CVID prior to the development of non-infectious complications is not well defined.

OBJECTIVE

Our objectives were to systematically review the current literature on the monitoring of CVID patients without non-infectious complications and to develop recommendations for such monitoring.

METHODS

MEDLINE and EMBASE were searched from January 1^st, 2000 to March 25^th, 2021. Studies on any aspects of CVID monitoring were included. Studies that included only children, on monitoring CVID patients with existing non-infectious complications, or in the format of case reports were excluded.

RESULTS

Nine studies on CVID monitoring, including 3 cohort studies, 3 experts' opinions, 2 consensus statements and a single guideline report were identified. These studies revealed that clinical assessment and bloodwork were preformed every 6 to 12 months in asymptomatic patients. Some centers performed computerized tomography scan of the chest every 2-5 years to identify chronic lung disease, although the majority did chest imaging in accordance with clinical indications. Pulmonary function tests were done annually at most centers. Most studies did not address the role of abdominal imaging to screen for liver diseases or endoscopy to screen for gastric cancer in asymptomatic patients with uncomplicated CVID.

CONCLUSIONS

There is paucity of evidence-based information to guide the routine monitoring of CVID patients without non-infectious complications. Prospective studies are needed to determine the best monitoring practices in this group of patients.

Clinical Courses of IKAROS and CTLA4 Deficiencies: A Systematic Literature Review and Retrospective Longitudinal Study

IKAROS and CTLA4 deficiencies are inborn errors of immunity and show similar clinical phenotypes, including hypogammaglobulinemia and autoimmune diseases (ADs). However, the differences in clinical features and pathogenesis of these are not fully understood. Therefore, we performed systematic literature reviews for IKAROS and CTLA4 deficiencies. The reviews suggested that patients with IKAROS deficiency develop AD earlier than hypogammaglobulinemia. However, no study assessed the detailed changes in clinical manifestations over time; this was likely due to the cross-sectional nature of the studies. Therefore, we conducted a retrospective longitudinal study on IKAROS and CTLA4 deficiencies in our cohort to evaluate the clinical course over time. In patients with IKAROS deficiency, AD and hypogammaglobulinemia often develop in that order, and AD often resolves before the onset of hypogammaglobulinemia; these observations were not found in patients with CTLA4 deficiency. Understanding this difference in the clinical course helps in the clinical management of both. Furthermore, our results suggest B- and T-cell-mediated ADs in patients with IKAROS and CTLA4 deficiencies, respectively.

Antigen-Specific CD4+ T-Cell Activation in Primary Antibody Deficiency After BNT162b2 mRNA COVID-19 Vaccination

Previous studies on immune responses following COVID-19 vaccination in patients with common variable immunodeficiency (CVID) were inconclusive with respect to the ability of the patients to produce vaccine-specific IgG antibodies, while patients with milder forms of primary antibody deficiency such as immunoglobulin isotype deficiency or selective antibody deficiency have not been studied at all. In this study we examined antigen-specific activation of CXCR5-positive and CXCR5-negative CD4⁺ memory cells and also isotype-specific and functional antibody responses in patients with CVID as compared to other milder forms of primary antibody deficiency and healthy controls six weeks after the second dose of BNT162b2 vaccine against SARS-CoV-2. Expression of the activation markers CD25 and CD134 was examined by multi-color flow cytometry on CD4⁺ T cell subsets stimulated with SARS-CoV-2 spike peptides, while in parallel IgG and IgA antibodies and surrogate virus neutralization antibodies against SARS-CoV-2 spike protein were measured by ELISA. The results show that in CVID and patients with other milder forms of antibody deficiency normal IgG responses (titers of spike protein-specific IgG three times the detection limit or more) were associated with intact vaccine-specific activation of CXCR5-negative CD4⁺ memory T cells, despite defective activation of circulating T follicular helper cells. In contrast, CVID IgG nonresponders showed defective vaccine-specific and superantigen-induced activation of both CD4⁺T cell subsets. In conclusion, impaired TCR-mediated activation of CXCR5-negative CD4⁺ memory T cells following stimulation with vaccine antigen or superantigen identifies patients with primary antibody deficiency and impaired IgG responses after BNT162b2 vaccination.

Replacement and Immunomodulatory Activities of 20% Subcutaneous Immunoglobulin Treatment: A Single-Center Retrospective Study in Autoimmune Myositis and CVID Patients

Background

Immunoglobulin (Ig) replacement therapy represents a life-saving treatment in primary antibody deficiencies. The introduction of subcutaneous Ig (SCIg) administration brings a major improvement in quality of life for patients, compared to the traditional intravenous administration. In recent years, an additional role has been proposed for Ig therapy for various inflammatory and immune-mediated diseases. Consequently, the use of SCIg has expanded from immunodeficiencies to immune-mediated diseases, such as polymyositis (PM) and dermatomyositis (DM). Given the rarity of these conditions, it is still difficult to evaluate the real impact of SCIg treatment on PM and DM, and additional data are constantly required on this topic, particularly for long-term treatments in real-life settings.

Aim

This study aimed to increase the knowledge about the anti-inflammatory and immunomodulatory effects of SCIg treatment for myositis. To this aim, a long-term evaluation of the effectiveness of 20% human SCIg treatment (20% SCIg, Hizentra^®, CSL Behring) was carried out in patients with PM/DM in care at our Center. In addition, an evaluation of the 20% SCIg therapy in CVID patients was provided. This analysis, beside adding knowledge about the use of SCIg therapy in this real-life setting, was intended as a term of comparison, regarding the safety profile.

Results

Results support the beneficial effect and tolerability of long-term 20% SCIg therapy in PM/DM patients, reporting a significant improvement in creatine kinase levels, muscle strength, skin conditions, dysphagia, disease activity (MITAX score) and disability (HAQ-DI score). None of the patients reported systemic reactions. The duration of the reported local reactions was a few hours in 80% of the patients, and all resolved spontaneously. CVID patients reported an improvement in all the considered effectiveness parameters at the end of 20% SCIg therapy. The frequency of the adverse events reported by PM/DM patients was not different from what reported in CVID patients, where the use of SCIg therapy is more consolidated

Conclusions

This study suggests that 20% SCIg treatment represents a viable and safe treatment for PM/DM patients and a valid therapeutic alternative to IVIg, with important advantages for patients’ quality of life.

Rare case of interstitial nephritis in a young adult under IgG therapy

Immunoglobulin replacement therapy is an important therapeutic approach used in different diseases, such as immunodeficiency diseases. We report a case of a 19-year-old female patient with suspected common variable immunodeficiency who started replacement therapy with IgG. During the follow-up, she developed interstitial nephritis and the subsequent workup excluded other diseases or triggers except IgG therapy.

Role of rare immune cells in common variable immunodeficiency

Common variable immunodeficiency disorder (CVID) is a heterogeneous disorder and the most common symptomatic antibody deficiency disease characterized with hypogammaglobulinemia and a broad range of clinical manifestations. Multiple genetic, epigenetic, and immunological defects are involved in the pathogenesis of CVID. These immunological defects include abnormalities in the number and/or function of B lymphocytes, T lymphocytes, and other rare immune cells. Although some immune cells have a relatively lower proportion among total immune subsets in the human body, they could have important roles in the pathogenesis of immunological disorders like CVID. To the best of our knowledge, this is the first review that described the role of rare immune cells in the pathogenesis and clinical presentations of CVID.

Primary Hypogammaglobulinaemia with Inflammatory Bowel Disease-Like Features: An ECCO CONFER Multicentre Case Series

BACKGROUND

Hypogammaglobulinaemia is a disorder characterized by low serum immunoglobulin levels and a high prevalence of gastrointestinal manifestations. In some cases, clinical and endoscopic features are indistinguishable from those of inflammatory bowel disease [IBD].

METHODS

This was a multicentre case series performed as a part of the European Crohn's and Colitis Organisation [ECCO] Collaborative Network of Exceptionally Rare case reports [CONFER] project.

RESULTS

This report includes 27 patients with primary hypogammaglobulinaemia and IBD-like features: 20 males and seven females, median age 45.6 years (interquartile range [IQR] 35.2-59). Crohn's disease-like features were noted in 23 patients, and four patients had ulcerative colitis-like features. The diagnosis of hypogammaglobulinaemia preceded a diagnosis of IBD-like features in 20 patients [median of 7 years prior, IQR 2.6-20.6 years], and followed the appearance of IBD-like features in seven cases [median of 1 year after, IQR 0.45-5.6 years]. Hypogammaglobulinaemia aetiologies were common variable immunodeficiency [66.6%], agammaglobulinaemia [7.4%], selective IgA-deficiency [11.1%], Good's syndrome [7.4%], IgG subclass deficiency with IgA deficiency [3.7%] and hyper-IgM [3.7%]. In addition to antibiotics and intravenous immunoglobulin [IVIG] for hypogammaglobulinaemia, 12 patients received IBD-related treatment including 5-aminosalicylate agents [two patients], corticosteroids [one patient], thiopurines [three patients], anti-tumour necrosis factor [four patients] and vedolizumab [two patients]. By the end of the follow-up (44.5 months [IQR 18-81]), 21/27 [77%] patients were in clinical remission.

CONCLUSION

This case series describes IBD-like features in patients with hypogammaglobulinaemia. The diagnosis of IBD-like features mainly occurred after that of hypogammaglobulinaemia, with successful recovery in the majority of cases after appropriate treatment.

The Immune Response to SARS-CoV-2 Vaccination: Insights Learned From Adult Patients With Common Variable Immune Deficiency

CVID patients have an increased susceptibility to vaccine-preventable infections. The question on the potential benefits of immunization of CVID patients against SARS-CoV-2 offered the possibility to analyze the defective mechanisms of immune responses to a novel antigen. In CVID, as in immunocompetent subjects, the role of B and T cells is different between infected and vaccinated individuals. Upon vaccination, variable anti-Spike IgG responses have been found in different CVID cohorts. Immunization with two doses of mRNA vaccine did not generate Spike-specific classical memory B cells (MBCs) but atypical memory B cells (ATM) with low binding capacity to Spike protein. Spike-specific T-cells responses were also induced in CVID patients with a variable frequency, differently from specific T cells produced after multiple exposures to viral antigens following influenza virus immunization and infection. The immune response elicited by SARS-CoV-2 infection was enhanced by subsequent immunization underlying the need to immunize convalescent COVID-19 CVID patients after recovery. In particular, immunization after SARS-Cov-2 infection generated Spike-specific classical memory B cells (MBCs) with low binding capacity to Spike protein and Spike-specific antibodies in a high percentage of CVID patients. The search for a strategy to elicit an adequate immune response post-vaccination in CVID patients is necessary. Since reinfection with SARS-CoV-2 has been documented, at present SARS-CoV-2 positive CVID patients might benefit from new preventing strategy based on administration of anti-SARS-CoV-2 monoclonal antibodies.

TNFRSF13B gene mutation in adult patient with common variable immunodeficiency. Case report

Common variable immunodeficiency (CVID) is one form of the primary immunodeficiencies (PIDs). CVID is characterized by variable clinical manifestations. Genetic alteration is a cause of the disease in many cases. In the current paper we described Patient N of 45 years old, who have been suffering from frequent various infections and therefore attended an immunologist and clinical geneticist. Immunoglobulins (Ig) A, M, and G deficiency was found in the patient. As a result of medical genetic counselling primary immunodeficiency has been suggested as a diagnosis. Further molecular genetic testing using clinical exome sequencing (Next Generation Sequencing method) revealed a likely-pathogenic variant c.204dupA (p.Leu69ThrfsX12, rs72553875) of TNFRSF13B gene in the patient. The gene variant was found in homozygous state. According to the international medical literature and genomic databases TNFRSF13B gene mutations lead to the CVID development and in some patients are characterized by isolated IgA deficiency and in the other group of patients can lead to decrease of IgA, IgM, and IgG. The patient had a family history of cancer and autoimmune inflammatory bowel disease (erosive-ulcerative enterocolitis). Moreover, one sibling of the patient died at the age of 3 weeks from complications of toxoplasmosis infection. The other sibling of 51 years old have been also suffering from recurrent infectious diseases. Thus, the genetic cause of the disease was identified in the proband. It has been shown that homozygosity for variant c.204dupA of TNFRSF13B gene is characterized by the deficiency of all three classes of Ig. Medical genetic counselling and modern molecular genetic methods application is an important step in management of people with signs of immunodeficiency. Such approach helps to make a diagnosis to the patient, to find an exact molecular reason of the condition, to use effective treatment, and to perform preventive measures in patient`s family.

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.

Evaluation of malnutrition risk and nutrition status in adult patients with common variable immunodeficiency

BACKGROUND

The aim of this study is to determine the prevalence of malnutrition in outpatients with common variable immunodeficiency (CVID) and the utility of nutrition screening tools to detect malnutrition in these patients.

METHODS

Fifty outpatients with CVID were included in the study. Nutrition risk for each patient was evaluated using four nutrition screening tools: Malnutrition Screening Tool (MST), Malnutrition Universal Screening Tool (MUST), Short Nutritional Assessment Questionnaire (SNAQ), and Nutritional Risk Screening 2002 (NRS-2002).

RESULTS

According to MUST, MST, SNAQ, and NRS-2002, malnutrition risk was determined to be 48% (n = 24), 26% (n = 13), 20% (n = 10), and 20% (n = 10), respectively. Malnutrition was detected in 54% (n = 27) of the patients. It was found that MUST showed a better correlation in detecting malnutrition in outpatients with CVID (κ = 0.482, P = 0.001). MUST has a higher positive and negative predictive value than other nutrition screening tools (79% and 70%, respectively). In the multivariate logistic regression analysis, it was found that low serum immunoglobulin A (IgA) levels at diagnosis increased the risk of malnutrition by ∼15 times, and low CD19⁺ B-cell counts increased the risk by approximately eight times.

CONCLUSION

The prevalence of malnutrition in patients with CVID was found to be quite high, and there was a strong correlation between malnutrition and low CD19⁺ B-cell counts and low serum IgA levels. Given the high rate of malnutrition in patients with CVID, nutrition assessment is recommended rather than starting with nutrition screening.

Gut inflammation in CVID: causes and consequences

INTRODUCTION

There is a wide spectrum of noninfectious gastrointestinal pathology, causing considerable morbidity and mortality in CVID, where both etiology and effective therapy are under debate.

AREAS COVERED

This review will focus on the noninfectious inflammation in the GI tract in CVID patients, covering the both the upper and lower GI tract inflammation, including the liver. The controversy of the CVID enteropathy definition and that of gluten-free diet for celiac-like disease in CVID will be discussed. Furthermore, the review will cover the link between GI inflammation and GI cancer. Finally, the role of gut microbiota, IgA, and genetics and its relationship with CVID enteropathy is scrutinized. The authors reviewed literature from PubMed.

EXPERT OPINION

The heterogeneity and the unknown mechanism behind CVID enteropathy, and thereby the lack of effective treatment, is one of the key challenges in the field of CVID. Celiac-like disease in CVID is due to immune dysregulation, and a gluten-free diet is therefore not indicated. Gut microbial dysbiosis and mucosal IgA can initiate systemic and local inflammation and is involved in the immune dysregulation in CVID. Considering the heterogeneity of CVID enteropathy, personalized medicine is probably the future for these patients.

Severe diabetic ketoacidosis and autoimmune pancreatitis with SIRS in an adolescent with LRBA deficiency – A rare complication of a common primary immunodeficiency disease

Common variable immunodeficiency is the most common primary immunodeficiency disorder. Lipopolysaccharide (LPS)-responsive beige-like anchor protein (LRBA) deficiency is categorized as a common variable immunodeficiency associated with autoimmune manifestations and inflammatory bowel diseases. We report a rare case, an adolescent presenting with severe diabetic ketoacidosis (DKA) and acute pancreatitis with multiorgan dysfunction with common variable immunodeficiency (CVID) with homozygous LRBA mutation.

Clinical and laboratory parameter analysis in patients with common Variable Immunodeficiency

Introduction: Common Variable Immunodeficiency (CVID) is the most prevalent primary immunodeficiency in adult population. The diagnosis is based on low concentration of at least 2 immunoglobulin classes, mostly IgG, with low IgA and/or IgM. Beside recurrent infections, patients with CVID usually suffer from different respiratory, gastrointestinal, autoimmune and malignant diseases. Leading therapeutic approach to managing CVID is regular intravenous (IVIG) and subcutaneous (SCIG) immunoglobulin replacement therapy. Aim: The aim of the study was to analyze clinical and laboratory parameters in patients with CVID. Material and methods: The present study included 24 patients with CVID who were treated at Clinic of Allergy and Immunology, University Clinical Center of Serbia from 2012 to 2022. Demographic data, clinical and laboratory parameters were obtained from the patients' medical records. The concentrations of IgG, IgM and IgA were measured by nephelometry. Statistical analysis was performed using descriptive methods, Student t test for independent samples and Fisher exact test. Results: Respiratory manifestations were found in 70.8% of patients, gastrointestinal in 45.8%, autoimmune in 29.2% and malignancies in 20.8%. The presence of autoimmune diseases was the most common within the patients aged between 20 to 30 years, and it was statistically significantly higher comparing to other age groups (p = 0.014). Serum IgG concentration of 7.6 ± 2.7 g/l was measured. Statistically significantly higher IgG concentrations were observed in patients receiving SCIG (10.2 ± 1.6), compared to those receiving IVIG (6.7 ± 2.4) (t = -3.3, p = 0.003). Premedication was required in 44.4% of patients receiving IVIG. Conclusion: The most common complication of CVID are chronic lung diseases. Autoimmune diseases are the most frequently diagnosed in patients between the ages of 20 and 30. The use of SCIG is identified as better form of immunoglobulin replacement therapy. Total immunoglobulin serum concentration measuring in patients with recurrent infections and autoimmune diseases can contribute to timely diagnosis.

Immune Dysregulation in Pediatric Common Variable Immunodeficiency: Implications for the Diagnostic Approach

Infections and infectious complications are hallmarks of common variable immunodeficiency (CVID) and the leading cause of morbidity and mortality in affected patients at any age. However, the pediatric CVID is no longer perceived as a primary immunodeficiency associated solely with infectious manifestations; autoimmune, allergic, lymphoproliferative, and malignant disorders and organ-specific immunopathology also characterize the spectrum of non-infectious complications. In this study, we sought to determine the role of immune dysregulation and frequency of non-infectious sequelae in children affected with CVID. We also aimed at providing an insight into the pathogenesis of non-infectious complications and at delineating the diagnostic approach to pediatric CVID with immune dysregulation. An in-depth retrospective analysis of clinical manifestations and their correlations with selected immune parameters was performed in a group of 39 CVID children, followed by our pediatric immunology department. Whereas recurrent sinopulmonary infections were present in all (100%) of the children studied, an unexpectedly high rate of non-infectious disorders and immune dysregulation phenotypes were observed in as many as 32 (82.05%) patients, compared with infection-only phenotypes limited to 7 (17.95%) male patients. The most common inflammatory comorbidity was asthma, diagnosed in 21 (53.85%) patients. The second most frequent immune dysregulation group was autoimmune disorders, present in 18 (46.15%) of the children studied with a high rate of autoimmune thyroiditis in as many as 10 (25.64%) of the CVID-affected children. Lymphoproliferation was seen in 14 children (35.90%), and, among them, lymphadenopathy occurred in nine (23.08%) cases and granulomatous lymphocytic interstitial lung disease in seven (17.95%) cases. Finally, malignancies occurred in two female patients (5.13%), papillary thyroid cancer in the first one and T-cell lymphoblastic leukemia in the other one. The most prominent abnormalities in the B- and T-cell compartment contributing to complex immune deficiency and immune dysregulation phenotypes were seen in the autoimmunity group, showing significant reductions in the switched memory B cell, naive T helper cell, and regulatory T-cell subsets. Herein, we document the previously unreported high rate of immune dysregulation in pediatric CVID as a clinical and diagnostic challenge with the variability of defects in the humoral and cellular immune responses.

Acute Cerebellitis and Myeloradiculitis Associated With SARS-CoV-2 Infection in Common Variable Immunodeficiency—A Case Report

The role of the adaptive immune system in mediating COVID-19 is largely unknown. Therefore, it is difficult to predict the clinical course in patients with common variable immunodeficiency (CVID), a disease characterized by dysfunctional lymphocytes and impaired antibody production. We report a case of SARS-CoV-2 infection presenting as isolated neurological symptoms in a patient with CVID. The patient subsequently improved following steroids, intravenous immunoglobulin, and convalescent plasma (CP). The latter has been shown to be safe and efficacious in treating COVID-19 in patients with primary immunodeficiency. Recent data suggest that the mechanism of CNS injury in COVID-19 may be due to immunological dysregulation rather than direct viral-mediated injury. This case exemplifies the complex interaction between the brain, the immune system, and the SARS-CoV-2 virus.

A Direct MS-Based Approach to Profile Human Milk Secretory Immunoglobulin A (IgA1) Reveals Donor-Specific Clonal Repertoires With High Longitudinal Stability

Recently, a mass spectrometry-based approach was introduced to directly assess the IgG1 immunoglobulin clonal repertoires in plasma. Here we expanded upon this approach by describing a mass spectrometry-based technique to assess specifically the clonal repertoire of another important class of immunoglobulin molecules, IgA1, and show it is efficiently and robustly applicable to either milk or plasma samples. Focusing on two individual healthy donors, whose milk was sampled longitudinally during the first 16 weeks of lactation, we demonstrate that the total repertoire of milk sIgA1 is dominated by only 50-500 clones, even though the human body theoretically can generate several orders of magnitude more clones. We show that in each donor the sIgA1 repertoire only changes marginally and quite gradually over the monitored 16-week period of lactation. Furthermore, the observed overlap in clonal repertoires between the two individual donors is close to non-existent. Mothers provide protection to their newborn infants directly by the transfer of antibodies via breastfeeding. The approach introduced here, can be used to visualize the clonal repertoire transferred from mother to infant and to detect changes in-time in that repertoire adapting to changes in maternal physiology.

Immunological evaluation of patients with orthopedic infections: taking the Cierny-Mader classification to the next level

Introduction: Cierny–Mader osteomyelitis classification is used to label A, B, or C hosts based on comorbidities. This study's purpose was to define the “true” host status of patients with orthopedic infection using serologic markers to quantify the competence of their immune system while actively infected. Methods: Retrospective chart review identified patients at a single-surgeon practice who were diagnosed with orthopedic infection between September 2013 and March 2020 and had immunological laboratory results. All patients were A or B hosts who underwent surgery to eradicate infection. Medical history, physical examination, and Cierny–Mader classification were recorded. Laboratory results included complement total, C3, C4, immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin A (IgA), immunoglobulin E (IgE), rheumatoid factor, and antineutrophil cytoplasmic antibodies (ANCA) panel. Clinically significant results were defined as flagged abnormal. Normal complement levels and normal IgG levels were considered abnormal when infection was present. Results: Of 105 patients, 99 (94 %) had documented lab abnormalities. Clinically significant abnormalities were found in 33 of 34 (97 %) type-A hosts and 66 of 71 (93 %) type-B hosts. Eleven of 105 (10.5 %) patients were formally diagnosed with primary immunodeficiency by a hematologist. IgG deficiency, of either low or normal value, in the face of infection comprised 91 % (30 of 34) type-A hosts and 86 % (56 of 71) type-B hosts. Six (5.7 %) patients received IgG replacement therapy. Twenty-eight patients had abnormal total complement levels (low or normal): 7.4 % (2 of 34) A hosts and 40 % (26 of 71) B hosts (p=0.002). B hosts had statistically significantly lower complement levels and significantly more no-growth cultures (p<0.03). Thirteen of 14 patients with recurrent infections had low or normal IgG levels. IgM was significantly lower between reinfected patients and those without reinfection (p=0.0005). Conclusions: Adding immunologic evaluation to the Cierny–Mader classification more accurately determines patients' true host status and better quantifies risk and outcome with respect to orthopedic infection. Immunologically deficient A hosts should be quantified as B hosts. IgG deficiencies may be addressed when deemed appropriate by the consulting hematologist/immunologist. Patients with recurrent infections had significantly lower IgM levels than their nonrecurrent infection counterparts.

Primary Immunodeficiency in a 74-Year-Old Male With Chronic Productive Cough: A Rare Case of Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency. It presents with variable degrees of immunodeficiency resulting in a variety of clinical presentations and complications. This report describes the case of newly diagnosed CVID in a 74-year-old man with no history of recurrent infections or hospitalizations. He presented with chronic productive cough, wheezing, shortness of breath and fatigue. Physical examination showed bilateral rhonchi and scattered wheezes. Pulmonary function tests showed moderate obstructive defect with partial reversibility and decreased diffusion lung capacity for carbon monoxide (DLCO). Chest computed tomography (CT) showed bilateral lower lobe peribronchial thickening and mildly enlarged lymph nodes in the mediastinum and upper abdomen. Bronchoscopy with alveolar lavage was done and respiratory samples grew Moraxella. He had negative acid fast bacillus stain and negative tuberculosis and fungal cultures. He received a course of antibiotics resulting in brief improvement in symptoms followed by another exacerbation. Repeat sputum cultures grew Pseudomonas. Further testing showed severely depressed levels of immunoglobulin. His symptoms ultimately improved with immunoglobulin replacement therapy. A broad differential, including CVID, needs to be considered in working up a patient with a chronic productive cough and recurrent lower respiratory tract infection. 

CD19+IgD+CD27- Naïve B Cells as Predictors of Humoral Response to COVID 19 mRNA Vaccination in Immunocompromised Patients

Immunocompromised patients are considered high-risk and prioritized for vaccination against COVID-19. We aimed to analyze B-cell subsets in these patients to identify potential predictors of humoral vaccination response. Patients (n=120) suffering from hematologic malignancies or other causes of immunodeficiency and healthy controls (n=79) received a full vaccination series with an mRNA vaccine. B-cell subsets were analyzed prior to vaccination. Two independent anti-SARS-CoV-2 immunoassays targeting the receptor-binding domain (RBD) or trimeric S protein (TSP) were performed three to four weeks after the second vaccination. Seroconversion occurred in 100% of healthy controls, in contrast to 67% (RBD) and 82% (TSP) of immunocompromised patients, while only 32% (RBD) and 22% (TSP) achieved antibody levels comparable to those of healthy controls. The number of circulating CD19+IgD+CD27- naïve B cells was strongly associated with antibody levels (ρ=0.761, P<0.001) and the only independent predictor for achieving antibody levels comparable to healthy controls (OR 1.07 per 10-µL increase, 95%CI 1.02-1.12, P=0.009). Receiver operating characteristic analysis identified a cut-off at ≥61 naïve B cells per µl to discriminate between patients with and without an optimal antibody response. Consequently, measuring of naïve B cells in immunocompromised hematologic patients could be useful in predicting their humoral vaccination response.

A Critical Review on the Standardization and Quality Assessment of Nonfunctional Laboratory Tests Frequently Used to Identify Inborn Errors of Immunity

Inborn errors of immunity (IEI), which were previously termed primary immunodeficiency diseases, represent a large and growing heterogeneous group of diseases that are mostly monogenic. In addition to increased susceptibility to infections, other clinical phenotypes have recently been associated with IEI, such as autoimmune disorders, severe allergies, autoinflammatory disorders, benign lymphoproliferative diseases, and malignant manifestations. The IUIS 2019 classification comprises 430 distinct defects that, although rare individually, represent a group affecting a significant number of patients, with an overall prevalence of 1:1,200-2,000 in the general population. Early IEI diagnosis is critical for appropriate therapy and genetic counseling, however, this process is deeply dependent on accurate laboratory tests. Despite the striking importance of laboratory data for clinical immunologists, several IEI-relevant immunoassays still lack standardization, including standardized protocols, reference materials, and external quality assessment programs. Moreover, well-established reference values mostly remain to be determined, especially for early ages, when the most severe conditions manifest and diagnosis is critical for patient survival. In this article, we intend to approach the issue of standardization and quality control of the nonfunctional diagnostic tests used for IEI, focusing on those frequently utilized in clinical practice. Herein, we will focus on discussing the issues of nonfunctional immunoassays (flow cytometry, enzyme-linked immunosorbent assays, and turbidimetry/nephelometry, among others), as defined by the pure quantification of proteins or cell subsets without cell activation or cell culture-based methods.

COVID-19 in a patient with Good's syndrome and in 13 patients with common variable immunodeficiency

Antibody deficiencies constitute the majority of primary immunodeficiencies in adults. These patients have a well-established increased risk of bacterial infections but there is a lack of knowledge regarding the relative risks upon contracting COVID-19. In this monocentric study the disease course of COVID-19 in 1 patient with Good's syndrome and in 13 patients with common variable immunodeficiency (CVID) is described. The severity of disease ranged from very mild to severe. Several patients required hospitalization and immunomodulatory treatment but all survived. Although viral infections are not a typical feature of humoral immunodeficiencies we recommend that vigilance is increased in the management of patients with Good's syndrome and CVID during the COVID-19 pandemic.

Serum immunoglobulin levels, complement components 3 and 4, HLA-B27 allele and spondyloarthropathy in patients with non-infectious anterior uveites

OBJECTIVE

To identify the relationship between serum immunoglobulin levels, complement components 3 and 4, the presence of the HLA-B27 allele and diagnosis of spondyloarthropathies in patients with non-infectious anterior uveitis.

MATERIALS AND METHODS

The participants were 197 patients with a non-infectious anterior uveitis. The concentrations of serum immunoglobulins, C3 and C4 proteins of the complement were determined by turbidimetry. The personal history of suspected immunodeficiency, ophthalmological complications, arthralgia, family history of spondyloarthropathies and the presence of the HLA-B27 allele were collected.

RESULTS

A family history of spondyloarthropathy, axial arthralgias, and ophthalmological complications were more frequent in HLA-B27 positive patients (P=.0005, P≤.0001, P≤.0001 respectively) and in patients with spondyloarthropathy diagnoses (P≤.0001, P≤.0001, P≤.0001 respectively). A personal history of recurrent sepsis, and gastrointestinal abnormalities was associated with the presence of the HLA-B27 allele (P≤.0001, P=.0240 respectively) and with the diagnosis of spondyloarthropathy (P=.0492, P=.0017 respectively). IgG decrease was observed (χ²=18.5, OR=5.03, 95% CI=2.32-10.89, P=.0001) and M (OR=7.13, 95% CI=1.40-36.4; P=.0128) in patients positive for the HLA-B27 allele and in patients with a diagnosis of SpA (P=.0364 and P=.0028 respectively). The decrease of C3 proteins (OR=4.82; CI 95%=1.35-17.11; P=.0328) and C4 (OR=9.09; CI 95%=2.13-38.88; P=.0074) were associated with a spondyloarthropathies diagnosis.

CONCLUSIONS

Patients with non-infectious anterior uveitis, positive for the HLA-B27 allele and diagnosed with spondyloarthropathies have alterations in serum immunoglobulin levels and complement components 3 and 4, which could contribute to the perpetuation and worse clinical course of this disease.

COVID-19 in complex common variable immunodeficiency patients affected by lung diseases

PURPOSE OF REVIEW

In the general population, the risk of severe COVID-19 is associated with old age, male sex, hypertension, obesity and chronic diseases. Chronic lung diseases are listed as additional risk factors for hospitalization and ICU admission. The purpose of this review is to define whether chronic lung diseases, such as bronchiectasis and interstitial diseases, represent a risk for a severe SARS-CoV-2 infection in patients affected by common variable immunodeficiency (CVID), the most common symptomatic primary antibody defect.

RECENT FINDINGS

CVID patients with SARS-CoV-2 infection have been reported since the beginning of the pandemic with a wide range of clinical presentations ranging from asymptomatic to mild/moderate and severe COVID-19. The meta-analysis of 88 CVID cases described in large cohorts and case reports demonstrated that CVID patients with chronic lung involvement have an increased risk for severe COVID-19 in comparison to CVID without lung diseases (50 vs. 28%, relative risk 1.75, 95% confidence interval 1.04--2.92, P = 0.043). Differently from the general population, age and metabolic comorbidities did not represent a risk factor for severe course in this patient's population.

SUMMARY

Underlying chronic lung diseases but not age represent a risk factor for severe COVID-19 in CVID. Prompt therapeutic intervention should be adopted in SARS-CoV-2 positive CVID patients with chronic lung diseases independently of their age.

Immunogenicity of Anti-SARS-CoV-2 Vaccines in Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia and/or a defective antibody response to T-dependent and T-independent antigens. CVID response to immunization depends on the antigen type, the vaccine mechanism, and the specific patient immune defect. In CVID patients, humoral and cellular responses to the currently used COVID-19 vaccines remain unexplored. Eighteen CVID subjects receiving 2-dose anti-SARS-CoV-2 vaccines were prospectively studied. S1-antibodies and S1-specific IFN-γ T cell response were determined by ELISA and FluoroSpot, respectively. The immune response was measured before the administration and after each dose of the vaccine, and it was compared to the response of 50 healthy controls (HC). The development of humoral and cellular responses was slower in CVID patients compared with HC. After completing vaccination, 83% of CVID patients had S1-specific antibodies and 83% had S1-specific T cells compared with 100% and 98% of HC (p = 0.014 and p = 0.062, respectively), but neutralizing antibodies were detected only in 50% of the patients. The strength of both humoral and cellular responses was significantly lower in CVID compared with HC, after the first and second doses of the vaccine. Absent or discordant humoral and cellular responses were associated with previous history of autoimmunity and/or lymphoproliferation. Among the three patients lacking humoral response, two had received recent therapy with anti-B cell antibodies. Further studies are needed to understand if the response to COVID-19 vaccination in CVID patients is protective enough. The 2-dose vaccine schedule and possibly a third dose might be especially necessary to achieve full immune response in these patients.

Granulomatous-Lymphocytic Interstitial Lung Disease Mimicking Sarcoidosis

Common variable immunodeficiency (CVID) is one of the most common primary immunodeficiency disorders characterized by hypogammaglobulinemia and inadequate antibody response to immunizations. The impaired antibody response occurs due to the failure of B cells to differentiate into plasma cells resulting in low immunoglobulins levels and increased frequency of infections. Granulomatous and Lymphocytic Interstitial Lung Disease (GLILD) is a non-infectious complication of CVID that is seen in 10-30% of cases. GLILD is a multisystem inflammatory disease involving the lungs, lymph node, liver, spleen and gastrointestinal tract that mimics sarcoidosis. This report describes a series of cases who presented with dyspnea, recurrent respiratory infections or autoimmunity and on further evaluation revealed features suggestive of GLILD. There is very limited understanding of GLILD in terms of clinical presentation, the histo-pathological logical findings, and the diagnostic criteria by itself are limited. A diagnosis of GLILD is established in cases of CVID when there is evidence of lymphoproliferation, cytopenia, autoimmune processes and a lung biopsy demonstrating lymphocytic interstitial pneumonia, follicular bronchiolitis, lymphoid hyperplasia, and/or non-necrotizing granulomas. We review the treatment strategies, including replacement of immunoglobulin and agents targeting B and T lymphocytes. Systematic characterization of GLILD cases and long term follow up studies are sorely needed to understand the natural history of GLILD.

Common variable immunodeficiency disorders: What generalists should know

Primary immune deficiency disorders (PIDDs) are common and underdiagnosed. Predominant antibody deficiencies (PADs) are the most common type of immune deficiency and comprise 55% of the immune deficiencies diagnosed.^[1] Although immunoglobulin A (IgA) deficiency remains the most common type of PID, common variable immunodeficiency disorders remain the most common symptomatic PID for which medical therapy is sought.

Lymphoid malignancy in common variable immunodeficiency in a single-center cohort

One of the complications of common variable immunodeficiency (CVID) is the development of lymphoid malignancy. In this retrospective, single-center study of 647 CVID subjects followed over 4 decades, we present immunologic and clinical phenotypes, pathology, treatment, and outcomes of 45 patients (15 males and 30 females, 7%) who developed 49 lymphoid malignancies. The mean age at CVID diagnosis was 42.6 years) and at lymphoma diagnosis was 48.8 years. Of the 41 with known follow up, 29 (70%) have died, 27 of these due to this diagnosis. Twelve are alive, in remission or have achieved cure; four others were alive at last encounter. Some patients had a history of only recurrent infections (36.3%); others had autoimmunity (33%), enteropathy (20%), and/or granulomatous disease (11%). Six had previously been treated for another cancer. This report also includes 6 additional living CVID patients who had been diagnosed with NHL; 4 were given treatment for this. However, on pathology review, the initial diagnosis was reversed, as the findings were more consistent with a benign lymphoproliferative process. This study outlines the high incidence of lymphoma in this single CVID cohort, and some of the diagnostic challenges presented due to immune dysregulation characteristic of this immune defect.

Biochemically deleterious human NFKB1 variants underlie an autosomal dominant form of common variable immunodeficiency

Autosomal dominant (AD) NFKB1 deficiency is thought to be the most common genetic etiology of common variable immunodeficiency (CVID). However, the causal link between NFKB1 variants and CVID has not been demonstrated experimentally and genetically, as there has been insufficient biochemical characterization and enrichment analysis. We show that the cotransfection of NFKB1-deficient HEK293T cells (lacking both p105 and its cleaved form p50) with a κB reporter, NFKB1/p105, and a homodimerization-defective RELA/p65 mutant results in p50:p65 heterodimer–dependent and p65:p65 homodimer–independent transcriptional activation. We found that 59 of the 90 variants in patients with CVID or related conditions were loss of function or hypomorphic. By contrast, 258 of 260 variants in the general population or patients with unrelated conditions were neutral. None of the deleterious variants displayed negative dominance. The enrichment in deleterious NFKB1 variants of patients with CVID was selective and highly significant (P = 2.78 × 10⁻¹⁵). NFKB1 variants disrupting NFKB1/p50 transcriptional activity thus underlie AD CVID by haploinsufficiency, whereas neutral variants in this assay should not be considered causal.

B Cell Response Induced by SARS-CoV-2 Infection Is Boosted by the BNT162b2 Vaccine in Primary Antibody Deficiencies

Background: Patients with primary antibody deficiencies are at risk in the current COVID-19 pandemic due to their impaired response to infection and vaccination. Specifically, patients with common variable immunodeficiency (CVID) generated poor spike-specific antibody and T cell responses after immunization. Methods: Thirty-four CVID convalescent patients after SARS-CoV-2 infection, 38 CVID patients immunized with two doses of the BNT162b2 vaccine, and 20 SARS-CoV-2 CVID convalescents later and immunized with BNT162b2 were analyzed for the anti-spike IgG production and the generation of spike-specific memory B cells and T cells. Results: Spike-specific IgG was induced more frequently after infection than after vaccination (82% vs. 34%). The antibody response was boosted in convalescents by vaccination. Although immunized patients generated atypical memory B cells possibly by extra-follicular or incomplete germinal center reactions, convalescents responded to infection by generating spike-specific memory B cells that were improved by the subsequent immunization. Poor spike-specific T cell responses were measured independently from the immunological challenge. Conclusions: SARS-CoV-2 infection primed a more efficient classical memory B cell response, whereas the BNT162b2 vaccine induced non-canonical B cell responses in CVID. Natural infection responses were boosted by subsequent immunization, suggesting the possibility to further stimulate the immune response by additional vaccine doses in CVID.

[Splenectomy for the treatment of common variable immunodeficiency complicated with cytopenia: report of one case and literature review]

Objective: To improve the understanding of splenectomy for treating common variable immunodeficiency complicated with cytopenia. Methods: A case of common variable immunodeficiency complicated with cytopenia was reported, and the literature was reviewed. Results: The patient, female, 16 years old, was hospitalized for eight years due to thrombocytopenia; she manifested recurrent thrombocytopenia with leukopenia since adolescence. The patient was diagnosed with common variable immunodeficiency with repeated mild infections, splenomegaly, and significantly reduced plasma immunoglobulin levels. Additionally, splenectomy was performed with adequate immunoglobulin replacement therapy, and the pathology confirmed hypersplenism; her blood cell level returned to normal after surgery. Conclusions: Common variable immunodeficiency has various clinical manifestations and can be complicated with cytopenia. Under the premise of adequate immunoglobulin replacement therapy, splenectomy is a safe and effective treatment for common variable immunodeficiency in patients with recurrent cytopenia.

Circulating bioactive bacterial DNA is associated with immune activation and complications in common variable immunodeficiency

Common variable immunodeficiency (CVID) is characterized by profound primary antibody defects and frequent infections, yet autoimmune/inflammatory complications of unclear origin occur in 50% of individuals and lead to increased mortality. Here, we show that circulating bacterial 16S rDNA belonging to gut commensals was significantly increased in CVID serum (P < 0.0001), especially in patients with inflammatory manifestations (P = 0.0007). Levels of serum bacterial DNA were associated with parameters of systemic immune activation, increased serum IFN-γ, and the lowest numbers of isotype-switched memory B cells. Bacterial DNA was bioactive in vitro and induced robust host IFN-γ responses, especially among patients with CVID with inflammatory manifestations. Patients with X-linked agammaglobulinemia (Bruton tyrosine kinase [BTK] deficiency) also had increased circulating bacterial 16S rDNA but did not exhibit prominent immune activation, suggesting that BTK may be a host modifier, dampening immune responses to microbial translocation. These data reveal a mechanism for chronic immune activation in CVID and potential therapeutic strategies to modify the clinical outcomes of this disease.

Common Variable Immunodeficiency Disorders, T-Cell Responses to SARS-CoV-2 Vaccines, and the Risk of Chronic COVID-19

COVID-19 has had a calamitous effect on the global community. Despite intense study, the immunologic response to the infection is only partially understood. In addition to older age and ethnicity, patients with comorbidities including obesity, diabetes, hypertension, coronary artery disease, malignancy, renal, and pulmonary disease may experience severe outcomes. Some patients with primary immunodeficiency (PID) and secondary immunodeficiency also appear to be at increased risk from COVID-19. In addition to vulnerability to SARS-CoV-2, patients with PIDs often have chronic pulmonary disease and may not respond to vaccines, which exacerbates their long-term risk. Patients with common variable immunodeficiency disorders, the most frequent symptomatic PID in adults and children, have a spectrum of B- and T-cell defects. It may be possible to stratify their risk for severe COVID-19 based on age, ethnicity, the severity of the T-cell defect, and the presence of other comorbidities. Patients with common variable immunodeficiency disorders and other immunodeficiencies are at risk for Chronic COVID-19, a dangerous stalemate between a suboptimal immune response and SARS-CoV-2. Intra-host viral evolution could result in the rapid emergence of vaccine-resistant mutants and variants of high consequence; it is a public health emergency. Vaccination and prevention of Chronic COVID-19 in immunodeficient patients is therefore of the utmost priority. Having a reliable diagnostic assay for T-cell immunity to SARS-CoV-2 is critical for evaluating responses to vaccines in these patients. New treatments for SARS-CoV-2 such as NZACE2-Pātari are likely to be particularly beneficial for immunodeficient patients, especially those who fail to mount a robust T-cell response to COVID-19 vaccines.

Common variable immunodeficiency (CVID) with granulomatous interstitial lung disease (GLILD) and SARS COVID-19 infection: case report and review of literature

Background

We present a case of CVID complicated by granulomatous interstitial lung disease (GLILD). This patient clinical course was further complicated by COVID-19 infection. This is only the 2nd known case report of COVID 19 in CVID with GLILD. The clinical course and outcome of COVID 19 infection with common variable immunodeficiency (CVID) and GLILD is not well known.

Case presentation

Our patient met the clinical features of CVID secondary to low IgG/IgA, recurrent infections, and failure to respond to pneumococcal vaccination. He was treated with monthly maintenance IVIG therapy. Our patient also was diagnosed with co-existing GLILD that despite IVIG treatment was progressing. The patient needed to be started on Rituxan and Mycophenolate mofetil to achieve control but unfortunately became infected with COVID19 delaying his treatment for GLILD. Our patient only suffered from mild COVID 19 infection and was able to make antibodies to this. We believe severe infection was avoided as his CVID was well controlled with IVIG therapy despite progression of his granulomatous interstitial lung disease.

Conclusion

In conclusion, our patient with CVID with co-existing biopsy proven granulomatous interstitial lung disease despite being very high risk for severe COVID 19 infections only had mild infection. This was believed to be due to well controlled CVID with IVIG therapy.

Determinants and Reference Ranges of Serum Immunoglobulins in Middle-Aged and Elderly Individuals: a Population-Based Study

Purpose

In clinical practice, currently one reference range for serum immunoglobulin (Ig) A, G, and M is applied to all adults, although various factors may influence Ig serum levels. Population-based data on determinants of IgA, IgG, and IgM and recommendations for subgroup specific reference ranges are lacking. We aimed to provide an overview of determinants of IgA, IgG, and IgM in community-dwelling middle-aged and elderly individuals and explore determinants that influence Ig reference ranges.

Methods

Within the Rotterdam Study, we performed linear regression analyses for the association of demographic, lifestyle, and cardiovascular factors with serum IgA, IgG, and IgM. We furthermore calculated Ig reference ranges (based on percentiles), both overall and within relevant subgroups.

Results

We included 8768 participants (median age 62 years). IgA and IgG increased non-linearly with higher age (P < .0001 for both). Women had lower IgA (beta: − 0.24; 95% confidence interval [95% CI]: − 0.29; − 0.20) and IgG (beta: − 0.33; 95% CI: − 0.44; − 0.23), but higher IgM levels (beta: 0.08; 95% CI: 0.04;0.13) than men. Former and particularly current smoking were associated with lower IgA and IgG (betas between − 0.07 and − 1.03). Higher alcohol consumption was associated with lower IgG (beta for heavy drinking: − 0.70; 95% CI: − 0.91; − 0.48). Corticosteroid use was associated with lower IgG (beta: − 1.12; 95% CI: − 1.58; − 0.66). Associations with cardiovascular factors were heterogeneous and differed between sexes.

Conclusion

Age, sex, smoking, alcohol consumption, corticosteroid use, and cardiovascular factors are determinants that should be considered when interpreting serum Ig levels in middle-aged and elderly individuals and may require adjusted reference ranges.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-021-01120-5.

Gut Microbiome and Common Variable Immunodeficiency: Few Certainties and Many Outstanding Questions

Common variable immunodeficiency (CVID) is the most common symptomatic primary antibody immunodeficiency, characterized by reduced serum levels of IgG, IgA, and/or IgM. The vast majority of CVID patients have polygenic inheritance. Immune dysfunction in CVID can frequently involve the gastrointestinal tract and lung. Few studies have started to investigate the gut microbiota profile in CVID patients. Overall, the results suggest that in CVID patients there is a reduction of alpha and beta diversity compared to controls. In addition, these patients can exhibit increased plasma levels of lipopolysaccharide (LPS) and markers (sCD14 and sCD25) of systemic immune cell activation. CVID patients with enteropathy exhibit decreased IgA expression in duodenal tissue. Mouse models for CVID unsatisfactorily recapitulate the polygenic causes of human CVID. The molecular pathways by which gut microbiota contribute to systemic inflammation and possibly tumorigenesis in CVID patients remain poorly understood. Several fundamental questions concerning the relationships between gut microbiota and the development of chronic inflammatory conditions, autoimmune disorders or cancer in CVID patients remain unanswered. Moreover, it is unknown whether it is possible to modify the microbiome and the outcome of CVID patients through specific therapeutic interventions.

An enzyme-linked immunospot assay to evaluate Pneumovax response when on intravenous immunoglobulin

BACKGROUND

Testing for common variable immunodeficiency (CVID) requires evaluation of specific antibody responses to vaccines. Current practice of evaluating pneumococcal serotype-specific immunoglobulin (Ig)G levels after Pneumovax (P23) has several limitations and is not accurate for patients already on immunoglobulin replacement. In contrast, the enzyme-linked immunospot (ELISPOT) assay can be interpreted in patients on immunoglobulin replacement as ex vivo measurement of specific antibody-secreting cells (ASCs).

OBJECTIVE

To optimize and test an ELISPOT assay to evaluate vaccination response to P23 and compare with P23 serotype-specific IgG for patients on intravenous immunoglobulin (IVIG).

METHODS

We prospectively enrolled a total of 15 adults: normal controls (n = 8), patients with CVID on IVIG replacement (n = 2), patients on IVIG replacement for recurrent infections who did not meet diagnostic criteria for CVID, considered IgG deficiency (n = 2), and patients without immunodeficiency on high-dose IVIG for other diagnosis (n = 3). We measured P23 serotype-specific IgG before and 4 weeks after P23 and ELISPOT ASCs before and 1 week after P23 (with B-cell subpopulation analysis by flow cytometry in patients on IVIG).

RESULTS

Normal controls had a vaccination response by P23 serotype-specific IgG, whereas patients on IVIG did not. Except for true patients with CVID on IVIG, a P23 ELISPOT ASC response was found in normal controls (highest) and most patients on IVIG for recurrent infections or other diagnosis.

CONCLUSION

Our pilot study suggests that an optimized ELISPOT protocol has utility to evaluate the P23-specific antibody response after vaccination. Our ELISPOT assay seemed reliable for patients on IVIG and may help differentiate true patients with CVID from those with a less stringent diagnosis while on IVIG.

Clinical heterogeneity among pediatric patients with autoimmune type 1 diabetes stratified by immunoglobulin deficiency

BACKGROUND

Type 1 diabetes (T1D) may coexist with primary immunodeficiencies, indicating a shared genetic background.

OBJECTIVE

To evaluate the prevalence and clinical characteristics of immunoglobulin deficiency (IgD) among children with T1D.

METHODS

Serum samples and medical history questionnaires were obtained during routine visits from T1D patients aged 4-18 years. IgG, IgA, IgM, and IgE were measured by nephelometry and enzyme-linked immunosorbent assay (ELISA). IgG and IgM deficiency (IgGD, IgMD) were defined as IgG/IgM >2 standard deviations (SD) below age-adjusted mean. IgE deficiency was defined as IgE <2 kIU/L. IgA deficiency (IgAD) was defined as IgA >2 SD below age-adjusted mean irrespective of other immunoglobulin classes (absolute if <0.07 g/L, partial otherwise) and as selective IgAD when IgA >2 SD below age-adjusted mean with normal IgG and IgM (absolute if <0.07 g/L, partial otherwise).

RESULTS

Among 395 patients (53.4% boys) with the median age of 11.2 (8.4-13.7) and diabetes duration 3.6 (1.1-6.0) years, 90 (22.8%) were found to have hypogammaglobulinemia. The IgGD and IgAD were the most common each in 40/395 (10.1%). Complex IgD was found in seven patients. Increased odds of infection-related hospitalization (compared to children without any IgD) was related to having any kind of IgD and IgAD; OR (95%CI) = 2.1 (1.2-3.7) and 3.7 (1.8-7.5), respectively. Furthermore, IgAD was associated with having a first-degree relative with T1D OR (95%CI) = 3.3 (1.4-7.6) and suffering from non-autoimmune comorbidities 3.3 (1.4-7.6), especially neurological disorders 3.5 (1.2-10.5).

CONCLUSIONS

IgDs frequently coexist with T1D and may be associated with several autoimmune and nonimmune related disorders suggesting their common genetic background.

Lymphocytes subsets in correlation with clinical profile in CVID patients without monogenic defects

Objectives: Common variable immunodeficiency (CVID) patients experience clinical manifestations rather than recurrent respiratory infections including autoimmunity, enteropathy, and lymphoproliferation. We evaluated the correlation of lymphocyte subpopulations with such manifestations.Methods: Twenty-six genetically unsolved CVID patients were subdivided into four phenotypes: infection only (IO), autoimmunity (AI), chronic enteropathy (CE), and lymphoproliferative disorders (LP) and examined for lymphocyte subsets by flow cytometry and TCD4⁺ proliferation by Carboxyfluorescein succinimidyl ester (CFSE) test.Results: We detected reduced memory B and increased total, effector memory (EM), cytotoxic, and activated TCD8⁺ in IO, AI and CE, decreased plasmablasts, total and naive TCD4⁺, Regulatory TCD4⁺ (Treg) and naive TCD8⁺ in IO and CE, elevated CD21^low B and terminally differentiated effector memory (T_EMRA) TCD8⁺ in IO and AI, increased helper T (Th2) and Th17 in IO, decreased Th1 in AI and defective total and naive B and central memory (CM) TCD4⁺ in CE. IO showed reduced TCD4⁺ proliferation response.Conclusions: In genetically unsolved CVID patients, increased Th2 and Th17 and reduced Treg is associated with IO, increased CD21^low B and T_EMRA TCD8⁺ and reduced Th1 is contributed to AI and reduced total and naive B, CM TCD4⁺ and naive TCD8⁺ and expanded total TCD8⁺ is correlated with CE.