Autoimmunity in common variable immunodeficiency: epidemiology, pathophysiology and management

Clinical and immunological characterisation of patients with common variable immunodeficiency related immune thrombocytopenia

Primary Immune thrombocytopenia (ITP) is an autoimmune disease. Secondary ITP occurs in patients with underlying diseases such as common variable immunodeficiency (CVID). CVID is one of the most common symptomatic primary immunodeficiencies in adults, characterised by infectious and non-infectious symptoms. Amongst CVID patients, ITP is the most frequent autoimmune manifestation. In this single-centre study, we performed a clinical and immunological characterisation of 20 patients with CVID-related ITP and 20 ITP patients without CVID to compare severity and remission rates. We found that patients with CVID-related ITP had a higher WHO Bleeding Scale at initial diagnosis yet showed higher remission rates and required less treatment. Patients with ITP needed up to seven therapy options and were often treated with second-line drug therapy, whilst only one CVID-related ITP patient required second-line drug therapy. Therefore, we show that the course of thrombocytopenia in patients with CVID-related ITP is milder. Furthermore, we show that soluble interleukin-2 receptor (sIL-2R, CD25) was higher in CVID-related ITP compared to ITP patients and could accurately classify patient cohorts with an Area Under the Receiver Operating Characteristic of 0.92. Whilst none of the ITP patients had a history of immunodeficiency, we found immunological abnormalities in 12 out of 18 patients. Therefore, we recommend screening ITP patients for CVID and other immunodeficiencies to detect immune abnormalities early, as we found patients with reduced immunoglobulin levels as well as severe lymphocytopenia in our ITP cohort.

Systemic Disease and the Liver Part 2: Pregnancy-Related Liver Injury, Sepsis/Critical Illness, Hypoxia, Psoriasis, Scleroderma/Sjogren's Syndrome, Sarcoidosis, Common Variable Immune Deficiency, Cystic Fibrosis, Inflammatory Bowel Disease, and Hematologic Disorders

The liver is involved in many multisystem diseases and commonly may manifest with abnormal liver chemistry tests. The liver test perturbations may be multifactorial in nature, however, as patients are receiving many different medications and can also have intrinsic liver disease that may be exacerbated by the systemic disorder. Some disorders have typical histologic findings that can be diagnosed on liver biopsy, whereas others will show a more nonspecific histology. Clinicians should be aware of these conditions so as to consider the performance of a liver biopsy at the most opportune time and setting to help establish the diagnosis of acute or chronic liver disease.

The Autoimmune Manifestations in Patients with Genetic Defects in the B Cell Development and Differentiation Stages

PURPOSE

Primary B cell defects manifesting as predominantly antibody deficiencies result from variable inborn errors of the B cell lineage and their development, including impairments in early bone marrow development, class switch recombination (CSR), or terminal B cell differentiation. In this study, we aimed to investigate autoimmunity in monogenic patients with B cell development and differentiation defects.

METHODS

Patients with known genetic defects in the B cell development and differentiation were recruited from the Iranian inborn errors of immunity registry.

RESULTS

A total of 393 patients with a known genetic defect in the B cell development and differentiation (257 males; 65.4%) with a median age of 12 (6-20) years were enrolled in this study. After categorizing patients, 109 patients had intrinsic B cell defects. More than half of the patients had defects in one of the ATM (85 patients), BTK (76 patients), LRBA (34 patients), and DOCK8 (33 patients) genes. Fifteen patients (3.8%) showed autoimmune complications as their first manifestation. During the course of the disease, autoimmunity was reported in 81 (20.6%) patients at a median age of 4 (2-7) years, among which 65 patients had mixed intrinsic and extrinsic and 16 had intrinsic B cell defects. The comparison between patients with the mentioned four main gene defects showed that the patient group with LRBA defect had a significantly higher frequency of autoimmunity compared to those with other gene defects. Based on the B cell defect stage, 13% of patients with early B cell defect, 17% of patients with CSR defect, and 40% of patients who had terminal B cell defect presented at least one type of autoimmunity.

CONCLUSION

Our results demonstrated that gene mutations involved in human B cell terminal stage development mainly LRBA gene defect have the highest association with autoimmunity.

Autoimmune disorders associated with common variable immunodeficiency: prediction, diagnosis, and treatment

INTRODUCTION

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency. Due to the wide spectrum of the CVID manifestations, the differential diagnosis becomes complicated, ends in a diagnostic delay and increased morbidity and mortality rates. Autoimmunity is one of the important complications associated with CVID. While immunoglobulin replacement therapy has considerably decreased the mortality rate in CVID patients, mainly infection-related mortality, other complications such as autoimmunity appeared prevalent and, in some cases, life threatening.

AREAS COVERED

In this article, genetics, responsible immune defects, autoimmune manifestations in different organs, and the diagnosis and treatment processes in CVID patients are reviewed, after searching the literature about these topics.

EXPERT OPINION

Considering the many phenotypes of CVID and the fact that it remained undiagnosed until older ages, it is important to include various manifestations of CVID in the differential diagnosis. Due to the different manifestations of CVID, including autoimmune diseases, interdisciplinary collaboration of physicians from different fields is highly recommended, as discussed in the manuscript. Meanwhile, it is important to determine which patients could benefit from genetic diagnostic studies since such studies are not necessary for establishing the diagnosis of CVID.

An Expert Opinion/Approach: Clinical Presentations, Diagnostic Considerations, and Therapeutic Options for Gastrointestinal Manifestations of Common Variable Immune Deficiency

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency. It is characterized by impaired B-cell differentiation. Although patients can be diagnosed with CVID anytime during their lifetime, most patients have symptoms for 5-9 years before their diagnosis. The diagnosis of CVID starts with a detailed history focusing on the infectious and noninfectious manifestations of the disease. In patients who are suspected to experience CVID, quantitative immunoglobulins (Ig) should be checked to confirm the diagnosis. IgG should be at least 2 times less than the age-specific SD along with either a low IgA or IgM and with evidence of impaired vaccine response. CVID is usually associated with infectious and/or noninfectious conditions, the latter of which can be inflammatory, autoimmune, lymphoproliferative, or malignant, among other manifestations. Ig therapy has positively affected the disease course of patients with infectious complications but has limited effect on the noninfectious manifestations because the noninfectious complications are related to immune dysregulation involving B cells and T cells rather than primarily due to antibody deficiency. When the gastrointestinal (GI) system is involved, patients with CVID may display signs and symptoms that mimic several GI conditions such as celiac disease, pernicious anemia, or inflammatory bowel diseases. The inflammatory bowel disease-like condition is usually treated with steroids, 5-aminosalicylates, thiopurines, or biologic agents to control the inflammation. In this review, the clinical presentations, diagnostic considerations, and therapeutic options for GI manifestations of CVID will be discussed to facilitate the individualized management of these often-complex patients.

Current clinical spectrum of common variable immunodeficiency in Spain: The multicentric nationwide GTEM-SEMI-CVID registry

Common variable immunodeficiency (CVID) constitutes a heterogenic group of primary immunodeficiency disorders with a wide-ranging clinical spectrum. CVID-associated non-infectious morbidity constitutes a major challenge requiring a full understanding of its pathophysiology and its clinical importance and global variability, especially considering the broad clinical, genetic, and regional heterogeneity of CVID disorders. This work aimed to develop a nationwide, multicenter, retrospective study over a 3-year period describing epidemiological, clinical, laboratory, therapeutic, and prognostic features of 250 CVID patients in Spain. The mean diagnostic delay was around 10 years and most patients initially presented with infectious complications followed by non-infectious immune disorders. However, infectious diseases were not the main cause of morbimortality. Non-infectious lung disease was extraordinarily frequent in our registry affecting approximately 60% of the patients. More than one-third of the patients in our cohort showed lymphadenopathies and splenomegaly in their follow-up, and more than 33% presented immune cytopenias, especially Evans' syndrome. Gastrointestinal disease was observed in more than 40% of the patients. Among biopsied organs in our cohort, benign lymphoproliferation was the principal histopathological alteration. Reaching 15.26%, the global prevalence of cancer in our registry was one of the highest reported to date, with non-Hodgkin B lymphoma being the most frequent. These data emphasize the importance of basic and translational research delving into the pathophysiological pathways involved in immune dysregulation and diffuse lymphocytic infiltration. This would reveal new tailored strategies to reduce immune complications, and the associated healthcare burden, and ensure a better quality of life for CVID patients.

Predictive Value of B reg and Serum IL-10 Concentration Levels for Acute ITP Progression to Chronic Phase

INTRODUCTION

Pediatric immune thrombocytopenia (ITP) is a potentially life threating autoimmune disorder with different responses to therapy and different bleeding phenotypes in critical organs. The molecular basis for the variable response has not yet been fully elucidated. This study was designed to address the predictive value of regulatory B-cell (B reg ) count and interleukin-10 (IL-10) serum levels for acute ITP patients who progress to chronic phase. The present study included 80 children with acute ITP )38 males and 42 females (with median age of 8 years and 40 matched healthy controls. Assessment of B reg (CD19 + CD24 hi CD38 hi ) was carried out by a multicolor flowcytometry, however, IL-10 serum levels were evaluated by enzyme-linked immunosorbent assay. A significant reduction of B reg percentage and a significant increase in serum IL-10 levels were identified in children with acute ITP as compared with controls ( P <0.001 for both). Fourteen ITP patients passed to chronic phase, while 66 patients achieved remission within 6 months. The absolute B reg was significantly lower, while IL-10 was significantly higher in patients with acute ITP who progressed to chronic phase in comparison with acute ITP patients who achieved complete remission. Cox proportional hazards for ITP chronicity revealed that IL-10 OR was 2.46 (confidence interval: 1.42-4.27; P =0.001) and absolute B reg OR was 0.147 (confidence interval: 0.128-0.624; P =0.005) in the peripheral blood. Therefore, they could predict chronicity in ITP cases.

CONCLUSION

Reduced B reg count and elevated IL-10 levels in patients with acute ITP at diagnosis can predict chronicity.

Autoimmune Cytopenias in Common Variable Immunodeficiency Are a Diagnostic and Therapeutic Conundrum: An Update

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency (PID). CVID is a heterogenous condition and clinical manifestations may vary from increased susceptibility to infections to autoimmune manifestations, granulomatous disease, polyclonal lymphoproliferation, and increased risk of malignancy. Autoimmune manifestations may, at times, be the first and only clinical presentation of CVID, resulting in diagnostic dilemma for the treating physician.

Autoimmune cytopenias (autoimmune haemolytic anaemia and/or thrombocytopenia) are the most common autoimmune complications seen in patients with CVID. Laboratory investigations such as antinuclear antibodies, direct Coomb’s test and anti-platelet antibodies may not be useful in patients with CVID because of lack of specific antibody response. Moreover, presence of autoimmune cytopenias may pose a significant therapeutic challenge as use of immunosuppressive agents can be contentious in these circumstances. It has been suggested that serum immunoglobulins must be checked in all patients presenting with autoimmune cytopenia such as immune thrombocytopenia or autoimmune haemolytic anaemia.

It has been observed that patients with CVID and autoimmune cytopenias have a different clinical and immunological profile as compared to patients with CVID who do not have an autoimmune footprint. Monogenic defects have been identified in 10-50% of all patients with CVID depending upon the population studied. Monogenic defects are more likely to be identified in patients with CVID with autoimmune complications. Common genetic defects that may lead to CVID with an autoimmune phenotype include nuclear factor kappa B subunit 1 (NF-kB1), Lipopolysaccharide (LPS)-responsive beige-like anchor protein (LRBA), cytotoxic T lymphocyte antigen 4 (CTLA4), Phosphoinositide 3-kinase (PI3K), inducible T-cell costimulatory (ICOS), IKAROS and interferon regulatory factor-2 binding protein 2 (IRF2BP2).

In this review, we update on recent advances in pathophysiology and management of CVID with autoimmune cytopenias.

Contribution of Helicobacter pylori to the Inflammatory Complications of Common Variable Immunodeficiency

Common Variable Immunodeficiency (CVID), the most prevalent symptomatic primary immunodeficiency, is frequently associated with severe inflammatory complications that determine its morbidity and mortality. We hypothesize that Helicobacter pylori (HP), a very common worldwide infection, may contribute to the clinical and immune phenotype of CVID. We stratified 41 CVID patients into HP+ (n=26) and HPneg (n=15) groups, according to previous urease breath test and/or gastric biopsies, and compared their clinical manifestations and immune profile evaluated by flow cytometry. No genetic variants with known potential impact in HP infection were found upon WES/WGS. Gastric complications were significantly more frequent in HP+ patients. Importantly, the six CVID patients with gastric cancer were infected with HP. In contrast, a significantly higher frequency of cytopenias was observed in the HPneg. Moreover, HP+ did not feature higher prevalence of organ auto-immunity, as well as of lung, liver or intestinal inflammatory manifestations. We observed the same B-cell profiles in HP+ and HPneg groups, accompanied by marked CD4 and CD8 T-cell activation, increased IFNγ production, and contraction of naïve compartments. Notably, HP+ patients featured low CD25 despite preserved Foxp3 levels in CD4 T cells. Overall, HP impact in CVID inflammatory complications was mainly restricted to the gastric mucosa, contributing to increased incidence of early onset gastric cancer. Thus, early HP screening and eradication should be performed in all CVID patients irrespective of symptoms.

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.

Common variable immunodeficiency: different faces of the same disease

Introduction

Common variable immunodeficiency (CVID) is one of the primary humoral immunodeficiencies. Despite the inborn nature, the first symptoms may appear in both children and adults. It is characterized by hypogammaglobulinaemia, severe infections, autoimmunity, allergies, and a predisposition to cancer. A delay in diagnosis is a significant problem: the time from the first symptoms of the disease to diagnosis and the implementation of proper treatment is usually very long. The consequence can be irreversible complications, which is why it is so important to promote knowledge on this immunodeficiency.

Aim

To present the clinical and laboratory manifestation of primary immunodeficiencies such as common variable immunodeficiency.

Material and methods

The study presents the clinical and laboratory phenotype of 14 patients diagnosed with CVID, aged 5 to 58 years. A detailed medical history was taken, and clinical symptoms, immunological test results and complications were analysed in each patient. According to the ESID guidelines, in the differential diagnosis process of CVID the secondary hypogammaglobulinaemia was excluded.

Results

The follow-up period ranged from 39 to 133 months (median: 79 months). The median delay for the entire group was 5 years, which was shorter in children than in adults. In the presented group, the infectious phenotype (pneumonia, sinusitis) was dominant. Autoimmune and allergic diseases, malignant tumours and enteropathies have also been observed.

Conclusions

The diagnostic delay is still too long, especially in adults, which can lead to serious and irreversible complications. Early diagnosis and appropriate treatment with intravenous and subcutaneous immunoglobulins reduces the frequency of infections and their potential complications.

Granulomatous Lymphocytic Interstitial Lung Disease in a Spectrum of Pediatric Primary Immunodeficiencies

BACKGROUND

Granulomatous lymphocytic interstitial lung disease (GLILD) has been increasingly recognized in children affected with primary immunodeficiencies (PIDs). In this study, we aimed to better characterize the spectrum of pediatric PIDs coexisting with GLILD including clinical and immunological predictors, thoracic imaging findings, and histopathologic features.

METHODS

We respectively reviewed records of six representative cases of children, three of them affected with common variable immunodeficiency (CVID) and three with syndromic immunodeficiencies, in whom a diagnosis of GLILD was established based on clinical, radiological, and histopathologic findings. Clinical and immunological predictors for GLILD were also analyzed in the patients studied.

RESULTS

All the children with GLILD had a history of autoimmune phenomena, organ-specific immunopathology, and immune dysregulation. Defective B-cell maturation and deficiency of memory B cells were found in all the children with GLILD. The radiological and histopathological features consistent with the diagnosis of GLILD, granulomatous disease, and lymphoid hyperplasia, were accompanied by chronic airway disease with bronchiectasis in children with CVID and syndromic PIDs.

CONCLUSIONS

Our study shows that both CVID and syndromic PIDs may be complicated with GLILD. Further studies are required to understand the predictive value of coexisting autoimmunity and immune dysregulation in the recognition of GLILD in children with PIDs.

Diagnostic Barriers in Children with Immunodeficiencies in Central Asia: A Case-Based Discussion

Common variable immunodeficiency (CVID) is a primary immune deficit (PID) mainly characterized by hypogammaglobulinemia. In addition to increased susceptibility to infections and several immune-mediated manifestations, patients with CVID frequently develop bronchiectasis because of recurrent respiratory infections. This occurrence could be more likely if the diagnosis of CVID is delayed, as it often happens in less resourced clinical settings. A 15-year-old female patient was admitted to a tertiary hospital in Kazakhstan for consultation regarding a previous and established diagnosis of bronchiectasis. The clinical history was characterized by recurrent respiratory infections for several years, in addition to the development of a mixed restrictive-obstructive respiratory syndrome. Therefore, she underwent chest computerized tomography, which confirmed the presence of multiple and bilateral bronchiectasis. The clinical discussion on this patient highlighted that serum immunoglobulins were never measured previously and, thus, their assessment was strongly recommended. Based on that, a diagnosis of CVID was finally achieved, and the patient started the appropriate immunoglobulin replacement therapy. To our knowledge, this report is the first English-language publication on CVID and bronchiectasis from Central Asia. Bronchiectasis is currently an important medical problem in developing countries and populations with low socioeconomic status, where the diagnosis of the underlying cystic fibrosis and non-cystic fibrosis comorbidities can be delayed and more difficult than in countries with more accessible health care systems and facilities. This case report emphasized this important clinical issue in Central Asia and should raise the medical attention and awareness of this health problem, in order to improve the diagnostic timing and rate.

Pulmonary Hypertension in Patients with Common Variable Immunodeficiency

PURPOSE

Common variable immunodeficiency (CVID) is known to cause infectious, inflammatory, and autoimmune manifestations. Pulmonary hypertension (PH) is an unusual complication of CVID with largely unknown characteristics and mechanisms.

METHODS

We report the clinical, functional, hemodynamics, radiologic and histologic characteristics, and outcomes of CVID-associated PH patients from the French PH Network.

RESULTS

Ten patients were identified. The median (range) age at CVID diagnosis was 36.5 (4-49) years and the median delay between CVID and PH diagnosis was 12 (0-30) years. CVID-associated PH affected predominantly women (female-to-male ratio 9:1). Most patients were New York Heart Association functional class III with a severe hemodynamic profile and frequent portal hypertension (n = 6). Pulmonary function tests were almost normal in 70% of patients and showed a mild restrictive syndrome in 30% of patients while the diffusing capacity for carbon monoxide was decreased in all but one patient. High-resolution computed tomography found enlarged mediastinal nodes, mild interstitial infiltration with reticulations and nodules. Two patients had a CIVD-interstitial lung disease, and one presented with bronchiectasis. Pathologic assessment of lymph nodes performed in 5 patients revealed the presence of granulomas (n = 5) and follicular lymphoid hyperplasia (n = 3). At last follow-up (median 24.5 months), 9 patients were alive, and one patient died of Hodgkin disease.

CONCLUSION

PH is a possible complication of CVID whose pathophysiological mechanisms, while still unclear, would be due to the inflammatory nature of CVID. CVID-associated PH presents as precapillary PH with multiple possible causes, acting in concert in some patients: a portal hypertension, a pulmonary vascular remodeling, sometimes a pulmonary parenchymal involvement and occasionally an extrinsic compression by mediastinal lymphadenopathies, which would be consistent with its classification in group 5 of the current PH classification.

Perspective: Application of the American College of Medical Genetics Variant Interpretation Criteria to Common Variable Immunodeficiency Disorders

Common variable immunodeficiency disorders (CVIDs) are rare primary immunodeficiency diseases (PIDs) mostly associated with late onset antibody failure leading to immune system failure. Patients with CVID are predisposed to disabling complications such as bronchiectasis and systemic autoimmunity. In recent years a large number of genetic defects have become associated with these disorders. Patients with a causative mutation are deemed to have CVID-like disorders, while those with mutations predisposing to or modifying disease severity remain within the spectrum of CVID as defined by current diagnostic criteria. Next-generation sequencing (NGS) allows simultaneous analysis of multiple genes. Potential mutations identified from NGS are commonly evaluated with the American College of Medical Genetics (ACMG) variant interpretation criteria to determine their pathogenicity (causality). Patients with CVID and CVID-like disorders have marked genetic, allelic, and phenotypic heterogeneity. Although all patients with a CVID phenotype should undergo genetic testing, the complexity of the genetics associated with these disorders is challenging. Variants of unknown significance (VUS) remain a significant barrier to realising the full potential of NGS in CVID and CVID-like disorders. Here we explore the nuances of applying the ACMG criteria to patients with CVID and CVID-like disorders. Close collaboration between the clinician, bioinformatics, and genetics professionals will improve the diagnostic yield from genetic testing and reduce the frequency of VUS.

Allergic-like disorders and asthma in patients with common variable immunodeficiency: a multi-center experience

OBJECTIVE

Common variable immune deficiency (CVID) encompasses a variety of diseases characterized by disturbed immunoglobulin (Ig) production and various immune dysregulations. Scarce data are available regarding relationships between CVID and allergic diseases. Here we examined possible associations between allergies and CVID.

METHODS

For this multicenter study, we prospectively enrolled 79 adult CVID patients (≥18 years) who were diagnosed and treated between 2002-2017 at the Hadassah-Hebrew University and Shaare Zedek Medical Centers, Jerusalem, Israel. These patients were examined for allergic manifestations. Patient evaluation comprised medical history, physical examination, skin allergen testing, complete blood count, serum immunoglobulins, IgE levels, and pulmonary function tests.

RESULTS

After implementing exclusion criteria, 29 patients were included in the final analysis. Allergic-like disorders were diagnosed in 65% of CVID patients with non-elevated serum IgE levels. Moreover, allergic CVID patients exhibited a higher prevalence of bronchiectasis on chest CT. Autoimmunity was diagnosed in 41.3% of CVID subjects. The type I allergy detected in our study was non-IgE mediated.

CONCLUSIONS

Timely diagnosis and stratification of allergy in CVID patients is expected to improve their outcome and quality of life, as well as promote appropriate treatment and better management of pulmonary exacerbations.

Autoimmunity in common variable immunodeficiency: a systematic review and meta-analysis

Objectives: Common variable immunodeficiency (CVID) is the most common symptomatic inborn error of immunity characterized by variable clinical manifestations. Methods: Web of Science, Scopus, and PubMed databases were searched systemically to find eligible studies from the earliest available date to February 2020 with standard keywords. Pooled estimates of the autoimmunity prevalence and the corresponding 95% confidence intervals (CI) were calculated using random-effects models. Results: The overall prevalence of autoimmunity was 29.8% (95% CI: 26.4-33.3; I2 = 82.8%). The prevalences of hematologic autoimmune diseases, autoimmune gastrointestinal disorders, autoimmune rheumatologic disorders, autoimmune skin disorders, and autoimmune endocrinopathy in CVID patients were 18.9%, 11.5%, 6.4%, 5.9%), and 2.5%, respectively. There were significantly higher lymphocyte, CD3 + T cell, and CD4 + T cell count among CVID patients without autoimmunity (p< 0.05). Furthermore, failure to thrive, organomegaly, enteropathy, and meningitis was significantly higher in CVID patients with autoimmunity(p< 0.05). Conclusions: Many CVID patients could present with autoimmunity as part of the disease or even as the first or only clinical manifestation of the disease. Care providers may need to pay particular attention to the possible association of these two disorders since the co-occurrence of CVID and autoimmunity could be a misleading clue.

Primary Humoral Immune Deficiencies: Overlooked Mimickers of Chronic Immune-Mediated Gastrointestinal Diseases in Adults

In recent years, the incidence of immune-mediated gastrointestinal disorders, including celiac disease (CeD) and inflammatory bowel disease (IBD), is increasingly growing worldwide. This generates a need to elucidate the conditions that may compromise the diagnosis and treatment of such gastrointestinal disorders. It is well established that primary immunodeficiencies (PIDs) exhibit gastrointestinal manifestations and mimic other diseases, including CeD and IBD. PIDs are often considered pediatric ailments, whereas between 25 and 45% of PIDs are diagnosed in adults. The most common PIDs in adults are the selective immunoglobulin A deficiency (SIgAD) and the common variable immunodeficiency (CVID). A trend to autoimmunity occurs, while gastrointestinal disorders are common in both diseases. Besides, the occurrence of CeD and IBD in SIgAD/CVID patients is significantly higher than in the general population. However, some differences concerning diagnostics and management between enteropathy/colitis in PIDs, as compared to idiopathic forms of CeD/IBD, have been described. There is an ongoing discussion whether CeD and IBD in CVID patients should be considered a true CeD and IBD or just CeD-like and IBD-like diseases. This review addresses the current state of the art of the most common primary immunodeficiencies in adults and co-occurring CeD and IBD.

Common variable immunodeficiency presenting as sarcoidosis in a 9-year-old child

BACKGROUND

Granulomatous diseases are a heterogeneous group of conditions characterized by an inflammatory infiltrate with a core of macrophages, epithelioid, giant cells and a corona of fibroblasts and lymphocytes. They are associated with a wide range of disorders such as mycobacterial and fungal infections, neoplasms, immunodeficiencies and systemic inflammatory disorders as sarcoidosis.

CASE REPORT

We report the case of a previously healthy 9-year-old male child who presented with persistent cough, diffuse lymphadenopathy, enlargement of liver and spleen and protracted fever. Anemia, lymphopenia and reduced platelet count was reported, with an increase of inflammatory markers. High levels of Angiotensin-converting enzyme and chitotriosidases were noted. A PET-CT scan showed increased uptake of ¹⁸ F-FDG glucose in multiple lymph nodes in thorax and abdomen and in the spleen. Biopsy of inguinal and bronchial nodes showed nodal granulomatous inflammation. The child was diagnosed with sarcoidosis and treated with corticosteroids with only transient efficacy. Further tests reported panhypogammaglobulinaemia and a reduced pool of B-memory lymphocytes. Thus, the diagnosis was revised to common variable immunodeficiency (CVID).

CONCLUSION

Common variable immunodeficiency is a heterogeneous condition with a highly variable clinical phenotype and a strong association with autoimmune disorders. The presence of noncaseating granuloma and pulmonary lesions, along with extrapulmonary features required a step by step approach to differentiate between CVID and sarcoidosis. This enables early introduction of immunoglobulin replacement therapy and decreases the morbidity and mortality of CVID.

Evaluation of ERAP1 gene single nucleotide polymorphisms in immunomodulation of pro-inflammatory and anti-inflammatory cytokines profile in ankylosing spondylitis

BACKGROUND

Ankylosing spondylitis (AS) is a prototype of chronic inflammatory arthritis termed seronegative spondyloarthropathies that typically affects the joints. Among the non-Human leukocyte antigen (HLA) loci, the strongest association has been observed with Endoplasmic reticulum aminopeptidase 1 (ERAP1) gene single nucleotide polymorphisms (SNPs). Moreover, the effect of ERAP1 gene SNPs on the pro-inflammatory and anti-inflammatory cytokines in AS disease has still been poorly elucidated. In this study, we aimed to determine the association of ERAP1 gene SNPs (rs30187 and rs2287987) with AS risk as well as their effect on the mRNA expression of pro-inflammatory and anti-inflammatory cytokines, with emphasis on the immunoregulation of the IL-17/IL-23 pathway, in an Iranian population.

METHODS

We performed Single specific primer (SSP)-PCR for genotyping of 160 AS patients and 160 healthy controls. After isolation of peripheral blood mononuclear cells (PBMCs), total RNA of PBMCs was isolated, complementary DNA (cDNA) was synthesized, and quantitative analyses of mRNA expression of cytokines were performed by Real-time PCR for 40 HLA-B27 positive AS patients and 40 healthy individuals as controls.

RESULTS

It was seen that T allele of rs30187 (OR = 1.54, 95% CI = 1.07-2.22, P =  0.017) and C allele of rs2287987 (OR 1.50, 95% CI 1.05-2.14, P = 0.024) were associated with the risk of AS. Both of these alleles were associated more strongly in the HLA-B27 positive AS patients. There was a significant overexpression of mRNAs of pro-inflammatory (IL-17A, IL-17F, IL-23, TNF-α and IFN-γ), while downregulation of anti-inflammatory cytokines (IL-10 and TGF-β) in PBMCs from 40 HLA-B27 positive AS patients in comparison to controls. AS patients with rs30187 SNP TT genotype expressed mRNA of IL-17A, IL-17F, and IL-23 significantly higher than patents with CT and CC genotypes for this SNP.

CONCLUSIONS

This study represented the association of ERAP1 gene rs30187 and rs2287987 polymorphism with the risk of AS. Additionally, it appears that rs30187 polymorphism may be involved in the immunomodulation of the IL-17/IL-23 pathway in the AS disease.

Progression or suppression: Two sides of the innate lymphoid cells in cancer

Innate lymphoid cells (ILCs) as key players in innate immunity have been shown to be significantly associated with inflammation, lymphoid neogenesis, tissue remodeling, mucosal immunity and lately have been considered a remarkable nominee for either tumor-promoting or tumor-inhibiting functions. This dual role of ILCs, which is driven by intrinsic and extrinsic factors like plasticity of ILCs and the tumor microenvironment, respectively, has aroused interest in ILCs subsets in past decade. So far, numerous studies in the cancer field have revealed ILCs to be key players in the initiation, progression and inhibition of tumors, therefore providing valuable insights into therapeutic approaches to utilize the immune system against cancer. Herein, the most recent achievements regarding ILCs subsets including new classifications, their transcription factors, markers, cytokine release and mechanisms that led to either progression or inhibition of many tumors have been evaluated. Additionally, the available data regarding ILCs in most prevalent cancers and new therapeutic approaches are summarized.

Malignancy in common variable immunodeficiency: a systematic review and meta-analysis

Background: Common variable immunodeficiency (CVID) is the most common clinically significant primary immunodeficiency (PID) disorder characterized by variable clinical manifestations including recurrent infections, autoimmune disorders, enteropathy, lymphoproliferative disorders, and malignancy. The aim of this study is to estimate the overall prevalence of malignancy in patients with CVID. Methods: PubMed, Web of Science and Scopus were searched systemically to find eligible studies from the earliest available date to March 2019 with standard keywords. Pooled estimates of the malignancy prevalence and the corresponding 95% confidence intervals (CI) were calculated using random effects models. Results: Forty-eight studies with a total of 8123 CVID patients met the inclusion criteria and were finally included in the meta-analysis. Overall prevalence of malignancy was 8.6% (95% CI: 7.1-10.0; I² = 79.2%). The prevalence of lymphoma, gastric cancer, and breast cancer in CVID patients were 4.1% (95% CI: 3.3-4.9; I² = 62.6%), 1.5% (95% CI: 0.78-2.2; I² = 68.9%), and 1.3% (95% CI: 0.64-1.9; I² = 54.9%), respectively. Moreover, autoimmunity and malabsorption were more frequent in patients with malignancy than those without malignancy. Conclusion: The prevalence of malignancy has increased in CVID patients due to recent improvement in survival rate and the lymphoma is the most common type. This research highlighted the significance of malignancy screening and management in CVID patients.

Novel inhibitors of leukocyte transendothelial migration

Leukocyte transendothelial migration is one of the most important step in launching an inflammatory immune response and chronic inflammation can lead to devastating diseases. Leukocyte migration inhibitors are considered as promising and potentially effective therapeutic agents to treat inflammatory and auto-immune disorders. In this study, based on previous trioxotetrahydropyrimidin based integrin inhibitors that suboptimally blocked leukocyte adhesion, twelve molecules with a modified scaffold were designed, synthesized, and tested in vitro for their capacity to block the transendothelial migration of immune cells. One of the molecules, namely, methyl 4-((2-(tert-butyl)-6-((2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene) methyl) phenoxy) methyl) benzoate, (compound 12), completely blocked leukocyte transendothelial migration, without any toxic effects on immune or endothelial cells (IC₅₀ = 2.4 µM). In vivo, compound 12 exhibited significant therapeutic effects in inflammatory bowel disease (IBD)/Crohn's disease, multiple sclerosis, fatty liver disease, and rheumatoid arthritis models. A detailed acute and chronic toxicity profile of the lead compound in vivo did not reveal any toxic effects. Such a type of molecule might therefore provide a unique starting point for designing a novel class of leukocyte transmigration blocking agents with broad therapeutic applications in inflammatory and auto-immune pathologies.

The role of immune regulatory molecules in multiple sclerosis

Multiple sclerosis (MS) is the most common demyelinating disease which mainly impacts the integrity of central nervous system (CNS). MS etiology is not clearly known but genetic, environmental factors and immune system are the most frequently explored risk factors. Adaptive immune responses have a critical role in MS pathogenesis in which auto-reactive T-cells and autoantibodies are main orchestrators. Immune responses are modulated by inhibitory molecules which regulates adaptive system activation and hemostasis interface. These molecules suppress immune responses through inhibition of cytokine secretion and T cell proliferation and subsequently reducing the inflammation and respective damage. Therefore the critical role of inhibitory molecules in regulating the healthy and safe immune responses make them very attractive target for immunotherapy. In this review paper, the role of inhibitory molecules expressed on the various immune cell types in MS pathogenesis and experimental autoimmune encephalomyelitis (EAE) animal model will be summarized.

The imbalance between regulatory memory B cells reveals possible pathogenesis involvement in pediatric immune thrombocytopenia

Introduction: CD19⁺CD24^hiCD38^hi regulatory B cells (B_regs) and CD19⁺CD27⁺ memory B cells (B_mems) are B cell subsets with specific immunoregulatory properties. In this study, the balance of these subsets was investigated in pediatric immune thrombocytopenia (ITP) patients, and the frequencies of B_regs and B_mems before and after first-line therapy were measured. Methods: Forty-nine pediatric ITP patients and 19 normal controls were enrolled in this study. The total CD19⁺ B cells, B_regs and B_mems in the peripheral blood (PB) of all cases were measured by flow cytometry. Results: We found higher frequencies of total CD19⁺ B cells and B_mems in newly diagnosed ITP patients than those in normal controls (p < 0.01), whereas the frequencies of CD19⁺CD24^hiCD38^hi B_regs was significantly lower in ITP patients (p < 0.001). After therapy with MP + IVIG, the level of CD19⁺CD24^hiCD38^hi B_regs and B_mems were almost normalized. Conclusion: Our results indicated that pediatric ITP patients were characterized by a decline in CD19⁺CD24^hiCD38^hi Bregs and increment of CD19⁺CD27⁺Bmems, and an increase of total CD19⁺ B cells in their peripheral blood.

[Treatment of ITP and AIHA in CVID: A systematic literature review]

INTRODUCTION

Ten to 15% of common variable immunodeficiencies (CVID) develop auto-immune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP). Treatment is based on immunosuppressants, which produce blocking effects in the CVID. Our objective was to assess their risk-benefit ratio in these immunocompromised patients.

METHODS

We identified 17 articles detailing the treatment of AIHA and/or ITP in patients suffering from CVID through a systematic review of the MEDLINE database.

RESULTS

The increased infectious risk with corticosteroids does not call into question their place in the first line of treatment of ITP and AIHA in CVID. High-doses immunoglobulin therapy remain reserved for ITP with a high risk of bleeding. In second-line treatment, rituximab appears to be effective, with a lower infectious risk than the splenectomy. Immunosuppressants (azathioprine, methotrexate, mycophenolate, cyclophosphamide, vincristine, ciclosporine) are moderately effective and often lead to severe infections, meaning that their use is justified only in resistant cases and steroid-sparing. Dapsone, danazol and anti-D immunoglobulins have an unfavorable risk-benefit ratio. The place of TPO receptor agonists is still to be defined. The establishment of immunoglobulin replacement in the place of immunosuppressants (except for short-term corticotherapy) or splenectomy appears to be essential to limit the risk of infections, including in the absence of previous infections.

CONCLUSION

The presence of CVID does not mean that it is necessary to give up on corticosteroids as a first-line treatment and rituximab as a second-line treatment for AIHA and ITP, but it should be in addition to immunoglobulin replacement. A splenectomy should be reserved as a third-line treatment.

Idiopathic, Refractory Sweet's Syndrome Associated with Common Variable Immunodeficiency: a Case Report and Literature Review

PURPOSE OF REVIEW

Sweet's syndrome (SS) is classically considered a hypersensitivity reaction often associated with autoimmune disorders and malignancy. SS has also been increasingly reported to occur with immunodeficiencies. We present a case of treatment-refractory, systemic SS as the initial manifestation in a young child with common variable immunodeficiency (CVID). We also review current literature about SS and concurrent immunodeficiencies and autoimmunity in CVID patients.

RECENT FINDINGS

Few case reports exist regarding the co-occurrence of Sweet's syndrome and primary immunodeficiencies. SS is characterized by a pro-inflammatory state with a neutrophil predominance resulting in a spectrum of clinical manifestations. CVID is a multifactorial antibody deficiency that can be associated with autoimmunity, which some studies have proposed to be secondary to altered CD21 expression. SS occurring in patients with CVID has been infrequently reported, and one case study demonstrated improvement of Sweet's associated skin lesions with immunoglobulin replacement. In our case, the patient had multi-system SS refractory to multiple immunomodulatory therapies. To our knowledge, this is the first report of the effective and safe use of intravenous tocilizumab and oral lenalidomide to treat SS in a child with CVID. Immunoglobulin replacement reduced the frequency of infections and may have contributed to the opportunity to wean the immunosuppressive therapies for Sweet's syndrome. Sweet's syndrome as an initial manifestation of co-occurring immunodeficiencies is rare, and providers need a high index of suspicion. In addition, treatment of SS associated with an immunodeficiency can be a challenge. Treatment with immunoglobulin replacement reduces the frequency of infections, and in some patients with concurrent SS may improve skin lesions and reduce the need for immunomodulator therapy. Further study is necessary to better understand the pathogenesis of CVID in patients with SS and to identify possible biomarkers that predict who with SS are at risk for developing hypogammaglobulinemia.

The profile of IL-4, IL-5, IL-10 and GATA3 in patients with LRBA deficiency and CVID with no known monogenic disease: Association with disease severity

BACKGROUND

Common variable immunodeficiency (CVID) is the most common symptomatic form of primary immunodeficiency (PID). LPS-responsive beige-like anchor protein (LRBA) deficiency is an autosomal recessive disease characterized by a CVID-like phenotype. T cell abnormality was reported in patients with CVID and LRBA deficiency. The study's aim was to evaluate IL-4, IL-5, IL-10 and GATA3 expression in patients with LRBA deficiency and CVID with no known monogenic disease, and further evaluate its relevance with immunological futures and clinical complications of patients.

METHODS

The study population comprised patients with CVID, LRBA deficiency and age-sex matched healthy controls. Mutation analysis was done by whole exome sequencing in CVID patients to rule out monogenic PIDs. After CD4+ T cell stimulation with anti-CD3 and anti-CD28 monoclonal antibodies, gene expression of IL-4, IL-5, IL-10 and transcription factor GATA3 was evaluated by real-time polymerase chain reaction. The protein of mentioned cytokines was assessed by enzyme-linked immunosorbent assay.

RESULTS

The main clinical presentations of CVID patients were infections only and lymphoproliferations phenotypes, but in LRBA patients were autoimmune and enteropathy phenotype. The frequencies of CD4⁺ T cells were significantly reduced in LRBA and CVID patients. There were no statistically significant differences among GATA3, IL4, and IL5 gene expressions by CD4⁺ T cells of patients and controls, however, the IL10 expressions in CVID patients was significantly lower than in LRBA patients and HCs. As compared with HCs, CVID patients showed a prominent decrease in IL-4 and IL-10 production by CD4⁺ T cells.

CONCLUSIONS

Our findings demonstrated that patients with CVID and LRBA deficiency (even with severe infectious and inflammatory complications) have not imbalance in Th2 response, which is in parallel with lower frequency of allergy and asthma in these patients.

Primary immunodeficiency and autoimmunity: A comprehensive review

The primary immunodeficiency diseases (PIDs) include many genetic disorders that affect different components of the innate and adaptive responses. The number of distinct genetic PIDs has increased exponentially with improved methods of detection and advanced laboratory methodology. Patients with PIDs have an increased susceptibility to infectious diseases and non-infectious complications including allergies, malignancies and autoimmune diseases (ADs), the latter being the first manifestation of PIDs in several cases. There are two types of PIDS. Monogenic immunodeficiencies due to mutations in genes involved in immunological tolerance that increase the predisposition to develop autoimmunity including polyautoimmunity, and polygenic immunodeficiencies characterized by a heterogeneous clinical presentation that can be explained by a complex pathophysiology and which may have a multifactorial etiology. The high prevalence of ADs in PIDs demonstrates the intricate relationships between the mechanisms of these two conditions. Defects in central and peripheral tolerance, including mutations in AIRE and T regulatory cells respectively, are thought to be crucial in the development of ADs in these patients. In fact, pathology that leads to PID often also impacts the Treg/Th17 balance that may ease the appearance of a proinflammatory environment, increasing the odds for the development of autoimmunity. Furthermore, the influence of chronic and recurrent infections through molecular mimicry, bystander activation and super antigens activation are supposed to be pivotal for the development of autoimmunity. These multiple mechanisms are associated with diverse clinical subphenotypes that hinders an accurate diagnosis in clinical settings, and in some cases, may delay the selection of suitable pharmacological therapies. Herein, a comprehensively appraisal of the common mechanisms among these conditions, together with clinical pearls for treatment and diagnosis is presented.

G2-lymphocyte chromosomal radiosensitivity in patients with LPS responsive beige-like anchor protein (LRBA) deficiency

Lipopolysaccharide-responsive, beige-like anchor protein (LRBA) deficiency is an autosomal recessive primary immunodeficiency disease characterized by a CVID-like phenotype, particularly severe autoimmunity and inflammatory bowel disease. This study was undertaken to evaluate radiation sensitivity in 11 LRBA-deficient patients. Therefore, stimulated lymphocytes of the studied subjects were exposed to a low dose γ-radiation (100 cGy) in the G₂ phase of the cell cycle and chromosomal aberrations were scored. Lymphocytes of age-sex matched healthy individuals used in the same way as controls. Based on the G₂-assay, six (54.5%) of the patients had higher radiosensitivity score comparing to the healthy control group, forming the radiosensitive LRBA-deficient patients. This chromosomal radiosensitivity showed that these patients are predisposed to autoimmunity and/or malignancy, and should be protected from unnecessary diagnostic and therapeutic procedures using ionizing radiation and exposure to other DNA damaging agents.

Increased IRF4 expression in isolated B cells from common variable immunodeficiency (CVID) patients

BACKGROUND

Common variable immunodeficiency (CVID) is a heterogeneous disorder characterized by low serum levels of immunoglobulins (Igs) and recurrent infection. In most CVID patients, a defect in the differentiation of B cells into plasma cells has been observed. Several factors play an important role in the proliferation and differentiation of B cells, including IRF4 and XBP1 transcription factors.

METHODS

In the present study we investigated the expression of IRF4 and XBP1 in the B-cells of CVID and healthy controls (HCs). For this purpose, we assessed the expression of IRF4 and XBP1 at both mRNA and protein levels by real time-PCR and flow cytometry, respectively.

RESULTS

We found that IRF4 expression was significantly increased in CVID patients compared with controls. Although the XBP1 protein level was lower in patients in comparison to controls, this difference was not significant.

CONCLUSION

Taken together, increased IRF4 expression could be involved in defective functions of B cells in CVID patients.

Features and roles of T helper 9 cells and interleukin 9 in immunological diseases

T helper 9 (T_H9) cells are considered as newly classified helper T cells that have an important role in the regulation of immune responses. Since these cells preferentially produce IL-9, these cells are termed T_H9 cells. Recently, the role of T_H9 and its signature cytokine (IL-9) has been investigated in a wide range of diseases, including autoimmunity, allergy, infections, cancer and immunodeficiency. Herein, we review the most recent data concerning T_H9 cells and IL-9 as well as their roles in disease. These insights suggest that T_H9 cells are a future target for therapeutic intervention.

Common Variable Immunodeficiency and Liver Involvement

Common variable immunodeficiency (CVID) is a primary B-cell immunodeficiency disorder, characterized by remarkable hypogammaglobulinemia. The disease can develop at any age without gender predominance. The prevalence of CVID varies widely worldwide. The underlying causes of CVID remain largely unknown; primary B-cell dysfunctions, defects in T cells and antigen-presenting cells are involved. Although some monogenetic defects have been identified in some CVID patients, it is likely that CVID is polygenic. Patients with CVID develop recurrent and chronic infections (e.g., bacterial infections of the respiratory or gastrointestinal tract), autoimmune diseases, lymphoproliferation, malignancies, and granulomatous lesions. Interestingly, autoimmunity can be the only clinical manifestation of CVID at the time of diagnosis and may even develop prior to hypogammaglobulinemia. The diagnosis of CVID is largely based on the criteria established by European Society for Immunodeficiencies and Pan-American Group for Immunodeficiency (ESID/PAGID) and with some recent modifications. The disease can affect multiple organs, including the liver. Clinical features of CVID patients with liver involvement include abnormal liver biochemistries, primarily elevation of alkaline phosphatase (ALP), nodular regenerative hyperplasia (NRH), or liver cirrhosis and its complications. Replacement therapy with immunoglobulin (Ig) and anti-infection therapy are the primary treatment regimen for CVID patients. No specific therapy for liver involvement of CVID is currently available, and liver transplantation is an option only in select cases. The prognosis of CVID varies widely. Further understanding in the etiology and pathophysiology will facilitate early diagnosis and treatments to improve prognosis.

Enzymatic Transition States and Drug Design

Transition state theory teaches that chemically stable mimics of enzymatic transition states will bind tightly to their cognate enzymes. Kinetic isotope effects combined with computational quantum chemistry provides enzymatic transition state information with sufficient fidelity to design transition state analogues. Examples are selected from various stages of drug development to demonstrate the application of transition state theory, inhibitor design, physicochemical characterization of transition state analogues, and their progress in drug development.

Evans syndrome: clinical perspectives, biological insights and treatment modalities

Evans syndrome (ES) is a rare and chronic autoimmune disease characterized by autoimmune hemolytic anemia and immune thrombocytopenic purpura with a positive direct anti-human globulin test. It is classified as primary and secondary, with the frequency in patients with autoimmune hemolytic anemia being 37%–73%. It predominates in children, mainly due to primary immunodeficiencies or autoimmune lymphoproliferative syndrome. ES during pregnancy is associated with high fetal morbidity, including severe hemolysis and intracranial bleeding with neurological sequelae and death. The clinical presentation can include fatigue, pallor, jaundice and mucosal bleeding, with remissions and exacerbations during the person’s lifetime, and acute manifestations as catastrophic bleeding and massive hemolysis. Recent molecular theories explaining the physiopathology of ES include deficiencies of CTLA-4, LRBA, TPP2 and a decreased CD4/CD8 ratio. As in other autoimmune cytopenias, there is no established evidence-based treatment and steroids are the first-line therapy, with intravenous immunoglobulin administered as a life-saving resource in cases of severe immune thrombocytopenic purpura manifestations. Second-line treatment for refractory ES includes rituximab, mofetil mycophenolate, cyclosporine, vincristine, azathioprine, sirolimus and thrombopoietin receptor agonists. In cases unresponsive to immunosuppressive agents, hematopoietic stem cell transplantation has been successful, although it is necessary to consider its potential serious adverse effects. In conclusion, ES is a disease with a heterogeneous course that remains challenging to patients and physicians, with prospective clinical trials needed to explore potential targeted therapy to achieve an improved long-term response or even a cure.

Monogenic polyautoimmunity in primary immunodeficiency diseases

Primary immunodeficiency diseases (PIDs) consist of a large group of genetic disorders that affect distinct components of the immune system. PID patients are susceptible to infection and non-infectious complications, particularly autoimmunity. A specific group of monogenic PIDs are due to mutations in genes that are critical for the regulation of immunological tolerance and immune responses. This group of monogenic PIDs is at high risk of developing polyautoimmunity (i.e., the presence of more than one autoimmune disease in a single patient) because of their impaired immunity. In this review, we discuss the mechanisms of autoimmunity in PIDs and the characteristics of polyautoimmunity in the following PIDs: IPEX; monogenic IPEX-like syndrome; LRBA deficiency; CTLA4 deficiency; APECED; ALPS; and PKCδ deficiency.

A Novel Hypothesis on Excessive Activation of Residual B Lymphocytes in Common Variable Immunodeficiency Concurrent with Aseptic, Erosive Polyarthritis

Background

The aim of this study was to report aseptic, erosive polyarthritis in a patient with common variable immunodeficiency (CVID), which is quite different from the vastly more common nonerosive form.

Material/Methods

Peripheral blood mononuclear cells of the patient were isolated. Flow cytometry was used to analyze the proportion and function of lymphocytes. A Parker-Pearson needle biopsy was performed on the right knee. Four of her unaffected family members were enrolled as controls.

Results

A 21-year-old woman was admitted for recurrent polyarthritis of 3-year duration. The right knee, hip, wrist, proximal interphalangeal joints, and left elbow were involved, with progressive joint destruction. She was diagnosed as having CVID based on her recurrent infections, poor response to vaccines, and marked hypogammaglobulinemia. No bacterium or mycobacterium was detected in synovium or synovial fluid. The synovium was infiltrated by lymphocytes rather than neutrophils. Polyarthritis did not resolve by adequate intravenous immunoglobulin substitution and empirical antibiotic treatment, but resolved gradually after treatment with methylprednisolone and tacrolimus, supporting the diagnosis of aseptic polyarthritis. Further analyses showed that although only 0.5% of residual B lymphocytes were existent in peripheral blood of the patient, expressions of activation marker CD69 and production of IL-1β, IL-6, and TNF-α were high. Marked infiltration with CD19+B lymphocytes (as well as CD4+ or CD8+ T lymphocytes) was detected in the synovium. The proportion of IL21⁺CD4⁺Th cells from peripheral blood of the patient was high. CD4⁺ Th cells from the patient secreted nearly 3 times more IL-21 than the same cell type analyzed from unaffected family members, perhaps due to excessive compensation to assist the function of residual B lymphocytes.

Conclusions

A novel hypothesis in CVID concurrent with aseptic, erosive polyarthritis is that excessive activation of residual B lymphocytes infiltrate into the synovium of the involved joints and lead to polyarthritis and joint destruction.

In vitro chromosomal radiosensitivity in patients with common variable immunodeficiency

Common variable immunodeficiency (CVID) is one of the predominant antibody deficiency disorders, some evidence of which indicates that chromosome instability is present in these patients. An increased risk of cancer in patients with CVID has been documented. This study was undertaken to highlight radiation sensitivity in CVID patients and to clarify the genetic basis of this defect in these cases. Stimulated lymphocytes of the studied subjects were exposed to low-dose gamma-rays in the G2 phase or the G0 phase of the cell cycle and chromosomal aberrations were scored. Lymphocytes of healthy individuals, ataxia telangiectasia (AT) cases and a group of acute lymphoblastic leukemia (ALL) patients were investigated in the same way as controls. By two methods of analysis (one-way ANOVA and unpaired t-test), the CVID cases were significantly more radiosensitive than healthy controls based on the results of the G2 and the G0 assays. First-degree relatives of CVID patients were radiosensitive by the micronucleus assay which showed a significant difference as compared with normal controls (p = 0.001). In conclusion, this study may support that chromosomal radiosensitivity in CVID patients is a marker of genetic predisposition to the disease. The results might be a clue to describe the increased risk of cancer in CVID patients.

The imbalance of circulating T helper subsets and regulatory T cells in patients with LRBA deficiency: Correlation with disease severity

Patients with lipopolysaccharides responsive beige-like anchor protein (LRBA) deficiency suffer from a variety of immunological abnormalities. In the current study, we investigated the role of T helper (Th) cell subsets and regulatory T (Treg) cells and their related cytokines and transcription factors in the immune dysregulation of LRBA deficiency. The study population comprised of 13 LRBA-deficient patients and 13 age- and sex-matched healthy controls (HCs). Th subsets and Treg were examined by flow cytometry. The expression of determinant cytokines (interferon-γ [IFN-γ], interleukin [IL]-17, IL-22, and IL-10), and cell subset-specific transcription factors were evaluated before and after proliferation and activation stimuli. The frequencies of Th1, Th1-like Th17 and Th22 cells along with the expression of T-box transcription factor (TBET) and runt-related transcription factor 1 (RUNX1) were significantly increased in patients with LRBA. Moreover, IFN-γ and IL-22 production in LRBA-deficient CD4⁺ T cells were elevated after lymphocyte stimulation, particularly in patients with enteropathy. However, CD4⁺ CD25⁺ FoxP3⁺ CD127^- cells were significantly decreased in LRBA-deficient patients compared with those of HCs, particularly in patients with autoimmunity. There was a negative correlation between the frequencies of CD4⁺ CD25⁺ FoxP3⁺ CD127^- cells and Th1-like Th17 cells in LRBA-deficient patients, and an overlapping phenotype of autoimmunity and enteropathy were observed in ~70% of patients. The frequency of Th17 cells was lower in patients with enteropathy, while Th1-like Th17 cells were higher than in those without enteropathy. Our findings demonstrated an imbalance in Th subsets, mainly in Th1-like Th17 and Treg cells and their corresponding cytokines in LRBA deficiency, which might be important in the immunopathogenesis of autoimmunity and enteropathy.

Rheumatologic complications in a cohort of 227 patients with common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most prevalent symptomatic type of human primary immunodeficiency diseases (PID). Clinically, CVID is characterized by increased susceptibility to infections and a wide variety of autoimmune and rheumatologic disorders. All patients with CVID registered in Iranian PID Registry (IPIDR) were enrolled in this retrospective cohort study. We investigated the frequency of rheumatologic diseases and its association with immunological and clinical phenotypes in patients with CVID. A total of 227 patients with CVID were enrolled in this study. The prevalence of rheumatologic disorders was 10.1% with a higher frequency in women than men. Most common rheumatologic manifestations were juvenile idiopathic arthritis (JIA) and adult rheumatoid arthritis (RA) followed by juvenile spondyloarthritis (JSpA) and undifferentiated inflammatory arthritis (UIA). Septic arthritis in patients with CVID with a history of RA and JIA was higher than patients without rheumatologic complication. Patients with CVID with a history of autoimmunity (both rheumatologic and non-rheumatologic autoimmunity) had lower regulatory T cells counts in comparison with patients without autoimmune disorders. There was an association between defect in specific antibody responses and negative serologic test results in patients with rheumatologic manifestations. JIA, RA, JSpA and UIA are the most frequent rheumatologic disorders in patients with CVID. Due to antibody deficiency, serologic tests may be negative in these patients. Therefore, these conditions pose significant diagnostic and therapeutic challenges for immunologists and rheumatologists in charge of the care for these patients.

Evaluation of Clinical and Immunological Characteristics of Children with Common Variable Immunodeficiency

Background

Common variable immunodeficiency (CVID) is a primary immunodeficiency disorder (PID) that typically presents with hypogammaglobulinemia and impaired antibody production.

Objectives

This study aimed to promote the awareness of CVID, whose clinical spectrum is quite broad.

Methods

The demographic, clinical, and laboratory characteristics of 12 children (seven males and five females) with CVID were analyzed retrospectively. The patients were diagnosed using the diagnostic criteria of the European Society for Primary Immunodeficiencies.

Results

The median disease onset age was 7.2 ± 4.1 years, and the mean diagnosis age was 11.6 ± 3.7 years. The diagnosis delay was 4.3 ± 2.6 years, and the parental consanguinity rate was 75%. Most patients presented with recurrent infections, including upper respiratory tract infections (n = 8), lower respiratory tract infections (n = 9), and gastroenteritis (n = 5). In addition, growth retardation (n = 9) and bronchiectasis (n = 5) were common comorbidities. Two patients presented with autoimmune thrombocytopenia and anemia, and one patient exhibited lung empyema. All the patients had immunoglobulin G deficiencies.

Conclusion

CVID is a heterogeneous disease, so the diagnosis is frequently delayed. In the CVID patients with pulmonary complications, relationships were seen with the diagnosis delay, symptom onset age, and lung infection prevalence. Overall, the early diagnosis and treatment of PIDs can preclude life-threatening complications.

Evaluation of the TLR negative regulatory network in CVID patients

Common variable immunodeficiency (CVID), a clinically symptomatic primary immunodeficiency disease (PID), is characterized by hypogammaglobulinemia leading to recurrent infections and various complications. Recently, some defects in the signaling of TLRs have been identified in CVID patients which led us to investigate the expression of TLR4 and 9 negative regulatory molecules and their upregulation status following their activation. Using TaqMan real-time PCR, SOCS1, TNFAIP3, RFN216, and IRAK-M transcripts among peripheral blood mononuclear cells (PBMCs) were measured with/without TLR4 and 9 activations. TLR4 and 9 were activated by lipopolysaccharide (LPS) and unmethylated CpG-oligodeoxynucleotide (CpG-ODN), respectively. Production of IFN-α and TNF-α cytokines, as a part of the functional response of mentioned TLRs, was also measured using ELISA. Deficient transcripts of IRAK-M and TNFAIP3 in unstimulated PBMCs and lower production of TNF-α and IFN-α after treatments were observed. Upregulation of RFN216 and TNFAIP3 after TLR9 activation was abnormal compared to healthy individuals. Significant correlations were found between abnormal IRAK-M and TNFAIP3 transcripts, and lymphadenopathy and inflammatory scenarios in patients, respectively. It seems that the transcriptional status of some negative regulatory molecules is disturbed in CVID patients, and this could be caused by the underlying pathogenesis of CVID and could involve complications like autoimmunity and inflammatory responses.

Approach to a Child with Primary Immunodeficiency Made Simple

Primary immunodeficiency disorders (PIDs) are a group of disorders affecting the capability to fight against infection. These include defects in T cells and B cells affecting cell-mediated and humoral immunity, respectively, combined humoral and cell-mediated immunodeficiency, defects in phagocytosis, complement defects, and defects in cytokine or cytokine signalling pathways which are detrimental for immune function. Depending upon the type and severity, age at onset of symptoms can vary from neonatal period to late childhood. Clinically, this group of disorders can involve any organ system of an individual such as respiratory system, gastrointestinal system, skin and mucous membrane, bone and joints, endocrine organs, and nervous system. Common dermatological manifestations include eczema, warts, molluscum contagiosum, mucocutaneous candidiasis, recurrent nonhealing ulcers, skin abscesses, erythroderma, petechiae, and nail changes. The common skin manifestations of various PIDs include eczema (seen in Wiskott-Aldrich syndrome and autosomal dominant hyper IgE syndrome); erythroderma (in Omen syndrome); viral warts or molluscum contagiosum (in autosomal recessive hyper IgE syndrome); chronic mucocutaneous candidiasis (in hyper IgE syndrome, autoimmune polyendocrinopathy candidiasis ectodermal dysplasia syndrome, Th17 cell defects); recurrent nonhealing ulcers (in leucocyte adhesion defect); skin abscesses (in antibody defects, hyper IgE syndrome, and chronic granulomatous disease); petechial or purpuric spots (in Wiskott-Aldrich syndrome).

A Comparison of Clinical and Immunologic Phenotypes in Familial and Sporadic Forms of Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is the most frequent symptomatic primary immunodeficiency disease, and its prevalence varies significantly among different population. Minority of CVID patients present a familial aggregation suggesting a higher probability of heritable genetic defects. A total of 235 registered CVID patients were evaluated in this cohort study. Familial and sporadic patients were stratified, and demographic information, clinical records, laboratory and molecular data were compared among these two groups of patients. Multiple cases were identified in 12 families (30 patients) and sporadic presentation in 120 cases. The rate of parental consanguinity (83.3%) and clinical presentation of lymphoid malignancy (20.7%) were predominant in familial CVID patients, whereas significantly increased recurrent upper respiratory infections were recorded in sporadic patients (0.3 infections per year). Probands of familial group were presented with a higher severity score resulting in a profound mortality rate (41.7% after 30-year follow-up) comparing to the non-proband CVID patients in the same families with a lowered diagnostic delay. Familial CVID patients had a specific signature in clinical presentation and immunologic profile, and a high consanguinity in this group of patients suggests a Mendelian trait with an autosomal recessive inheritance pattern. Diagnosis of an index patient within a multiple case families significantly improves the diagnostic process and outcomes of the yet asymptomatic patients.

Clinical, immunologic, molecular analyses and outcomes of iranian patients with LRBA deficiency: A longitudinal study

BACKGROUND

LPS-responsive beige-like anchor protein (LRBA) deficiency is a combined immunodeficiency caused by mutation in LRBA gene. The patients have a variety of clinical symptoms including hypogammaglobulinemia, recurrent infections, autoimmunity, and enteropathy.

METHODS

A total of 17 LRBA-deficient patients were enrolled in this longitudinal study. For all patients, demographic information, clinical records, laboratory, and molecular data were collected.

RESULT

Hypogammaglobulinemia was reported in 14 (82.4%), CD4⁺ T-cell deficiency in five (29.4%), NK cell deficiency in three (21.4%), and CD19⁺ B-cell deficiency in 11 (64.7%) patients. All patients had history of infectious complications; pneumonia was the most common (76.5%) occurring infection. A history of lymphoproliferative disorders was observed in 14 (82.3%), enteropathy in 13 (76.5%), allergic symptoms in six (35.5%), neurologic problems in four (23.5), and autoimmunity (mostly autoimmune cytopenia) in 13 (76.5%) patients. Sirolimus treatment improved enteropathy of patients with remarkable success. The 20-year overall survival rate declined to 70.6%.

CONCLUSION

LRBA deficiency has a very broad and variable phenotype and should be considered, especially in children with early-onset hypogammaglobulinemia, severe autoimmune manifestations, enteropathy, lymphoproliferation, and recurrent respiratory tract infections.