Autoimmune and Lymphoproliferative Complications of Common Variable Immunodeficiency

Proof-of-concept study evaluating humoral primary immunodeficiencies via CJ:KREC ratio and serum BAFF level

Humoral primary immunodeficiencies are the most prevalent form of primary immunodeficiency (PID). Currently, there is no convenient method to quantify newly formed B cells. The aim of this proof-of-concept study was to quantitate the ratio of coding joints (CJs) to Kappa-deleting recombination excision circles (KRECs) and serum B cell activating factor (BAFF) in patients with humoral primary immunodeficiency and assess if they correlate with disease severity. This IRB-approved study was conducted at one academic children's hospital. Patients with humoral PIDs and healthy controls were included. CJ and KREC levels were measured via qPCR. Serum BAFF levels were measured using Mesoscale. 16 patients with humoral PID and 5 healthy controls were included. The mean CJ:KREC ratio in the CVID, antibody deficiency syndromes, and controls groups, respectively were 13.04 ± 9.5, 5.25 ± 4.1, and 4.38 ± 2.5 (p = 0.059). The mean serum BAFF levels in CVID, antibody deficiency syndromes and controls were 216.3 ± 290 pg/mL, 107.9 ± 94 pg/mL and 50.9 ± 12 pg/mL, respectively (p = 0.271). When the CVID patients were subdivided into CVID with or without lymphoproliferative features, the BAFF level was substantially higher in the CVID with lymphoproliferation cohort (mean 372.4 ± 361 pg/mL, p = 0.031). Elevated CJ:KREC ratio was observed in CVID, although statistical significance was not achieved, likely due to the small sample size. Serum BAFF levels were significantly higher in CVID patients with lymphoproliferative features. We speculate that the CJ:KREC ratio and serum BAFF levels can be utilized in patients with humoral PID, once more extensive studies confirm this exploratory investigation.

The Etiologic Landscape of Lymphoproliferation in Childhood: Proposal for a Diagnostic Approach Exploring from Infections to Inborn Errors of Immunity and Metabolic Diseases

Lymphoproliferation is defined by lymphadenopathy, splenomegaly, hepatomegaly, or lymphocytic organ and tissue infiltration. The most common etiologies of lymphoproliferation are represented by infectious diseases and lymphoid malignancies. However, it is increasingly recognized that lymphoproliferative features can be the presenting sign of rare conditions, including inborn errors of immunity (IEI) and inborn errors of metabolism (IEM). Among IEI, lymphoproliferation is frequently observed in autoimmune lymphoproliferative syndrome (ALPS) and related disorders, common variable immunodeficiency (CVID), activated phosphoinositide 3-kinase δ syndrome, and Epstein-Barr virus (EBV)-related disorders. Gaucher disease and Niemann-Pick disease are the most common IEMs that can present with isolated lymphoproliferative features. Notably, other rare conditions, such as sarcoidosis, Castleman disease, systemic autoimmune diseases, and autoinflammatory disorders, should be considered in the differential diagnosis of patients with persistent lymphoproliferation when infectious and malignant diseases have been reasonably ruled out. The clinical features of lymphoproliferative diseases, as well as the associated clinical findings and data deriving from imaging and first-level laboratory investigations, could significantly help in providing the correct diagnostic suspicion for the underlying etiology. This paper reviews the most relevant diseases associated with lymphoproliferation, including infectious diseases, hematological malignancies, IEI, and IEM. Moreover, some practical indications to orient the initial diagnostic process are provided, and two diagnostic algorithms are proposed for the first-level assessment and the approach to persistent lymphoproliferation, respectively.

Interstitial lung diseases in inborn errors of immunity

PURPOSE OF REVIEW

Our goal is to review current understanding of interstitial lung disease (ILD) affecting patients with inborn errors of immunity (IEI). This includes understanding how IEI might predispose to and promote development or progression of ILD as well as how our growing understanding of IEI can help shape treatment of ILD in these patients. Additionally, by examining current knowledge of ILD in IEI, we hope to identify key knowledge gaps that can become focus of future investigative efforts.

RECENT FINDINGS

Recent identification of novel IEI associated with ILD and the latest reports examining treatment of ILD in IEI are included. Of noted interest, are recent clinical studies of immunomodulatory therapy for ILD in common variable immunodeficiency.

SUMMARY

ILD is a frequent complication found in many IEI. This article provides a guide to identifying manifestations of ILD in IEI. We review a broad spectrum of IEI that develop ILD, including antibody deficiency and immune dysregulation disorders that promote autoimmunity and autoinflammation. This work integrates clinical information with molecular mechanisms of disease and diagnostic assessments to provide an expedient overview of a clinically relevant and expanding topic.

Cytokine dysregulation despite immunoglobulin replacement therapy in common variable immunodeficiency (CVID)

Introduction

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency. CVID is a heterogeneous disorder with a presumed multifactorial etiology. Intravenous or subcutaneous immunoglobulin replacement therapy (IgRT) can prevent severe infections but not underlying immune dysregulation.

Methods

In this study, we evaluated the serum concentrations of proinflammatory (TNF-α, IL-1β, IL-6) and immunoregulatory cytokines (IL-10), as well as lipopolysaccharide (LPS) and soluble CD14 (sCD14) in CVID individuals with infectious only (INF-CVID), and those with additional systemic autoimmune and inflammatory disorders (NIC-CVID), and healthy donors (HD).

Results

Our results showed increased serum concentrations of TNF-α, IL-1β, IL-6, and IL-10 in both INF-CVID and NIC-CVID subjects compared to HD. However, elevations of TNF-α, IL-1β, IL-6, and IL-10 were significantly more marked in NIC-CVID than INF-CVID. Additionally, LPS concentrations were increased only in NIC-CVID but not in INF-CVID compared to HD. Circulating levels of sCD14 were significantly increased in NIC-CVID compared to both INF-CVID and HD.

Discussion

These findings indicate persistent cytokine dysregulation despite IgRT in individuals with CVID. Moreover, the circulating cytokine profile reveals the heterogeneity of immune dysregulation in different subgroups of CVID subjects.

The efficacy and safety of systemic corticosteroids as first line treatment for granulomatous lymphocytic interstitial lung disease

BACKGROUND

Granulomatous and lymphocytic interstitial lung disease (gl-ILD) is a major cause of morbidity and mortality among patients with common variable immunodeficiency. Corticosteroids are recommended as first-line treatment for gl-ILD, but evidence for their efficacy is lacking.

OBJECTIVES

This study analyzed the effect of high-dose corticosteroids (≥0.3 mg/kg prednisone equivalent) on gl-ILD, measured by high-resolution computed tomography (HRCT) scans, and pulmonary function test (PFT) results.

METHODS

Patients who had received high-dose corticosteroids but no other immunosuppressive therapy at the time (n = 56) and who underwent repeated HRCT scanning or PFT (n = 39) during the retrospective and/or prospective phase of the Study of Interstitial Lung Disease in Primary Antibody Deficiency (STILPAD) were included in the analysis. Patients without any immunosuppressive treatment were selected as controls (n = 23). HRCT scans were blinded, randomized, and scored using the Hartman score. Differences between the baseline and follow-up HRCT scans and PFT were analyzed.

RESULTS

Treatment with high-dose corticosteroids significantly improved HRCT scores and forced vital capacity. Carbon monoxide diffusion capacity significantly improved in both groups. Of 18 patients, for whom extended follow-up data was available, 13 achieved a long-term, maintenance therapy independent remission. All patients with relapse were retreated with corticosteroids, but only one-fifth of them responded. Two opportunistic infections were found in the corticosteroid treatment group, while overall infection rate was similar between cohorts.

CONCLUSIONS

Induction therapy with high-dose corticosteroids improved HRCT scans and PFT results of patients with gl-ILD and achieved long-term remission in 42% of patients. It was not associated with major side effects. Low-dose maintenance therapy provided no benefit and efficacy was poor in relapsing disease.

Allergic Diseases as a Clinical Phenotype Marker in Patients with Common Variable <bold>Immunodeficiency</bold>

INTRODUCTION

Patients with common variable immunodeficiency (CVID) have been shown to be more predisposed to develop allergic diseases because of mucosal immune defects and immune dysregulation. The aim of this study was to determine the prevalence, and clinical and laboratory characteristics of various allergic diseases in patients with CVID.

METHODS

The study included patients aged ≥18 years who were followed up for a diagnosis of CVID. Patients were separated into 5 groups according to the clinical phenotypic characteristics of lymphoproliferation, autoimmunity, gastrointestinal diseases, allergic diseases, and malignancy. Atopic dermatitis (AD), drug hypersensitivity reaction (DHR), allergic rhinitis (AR), and asthma were accepted as allergic diseases.

RESULTS

The most commonly seen clinical phenotypes were lymphoproliferation in 41 (48.8%) patients and allergic diseases in 31 (37%). AD was determined in 2 (2.4%) patient, DHR in 5 (6%), AR in 7 (8.3%), and asthma in 21 (25%). The delay in diagnosis of patients with allergic disease was determined to be shorter compared to those without allergic disease (p = 0.042). Serum total immunoglobulin E level, CD19+ B cell, switched memory B cell, and natural killer cell counts were determined to be higher in the CVID patients with allergic disease compared to those without (p = 0.007, p = 0.022, p = 0.023, p = 0.017, respectively).

CONCLUSION

Allergic diseases should be considered as a marker of clinical phenotype in CVID because of the clinical and immunological differences. Early diagnosis and treatment of allergic diseases in patients with CVID can improve quality of life.

Skin Manifestations in Patients with Selective Immunoglobulin E Deficiency

Selective immunoglobulin E deficiency (SIgED) is still an unrecognised primary immunodeficiency despite several observations supporting its existence. This study aimed to describe the skin manifestations associated with SIgED. We retrospectively assessed medical records of patients with SIgED, the diagnosis being based on serum IgE levels ≤2 Uk/L associated with normal serum levels of immunoglobulins G, M, and A. A total of 25 patients (24 female) with SIgED were included in the study. Eleven patients (44%) presented chronic spontaneous urticaria (CSU), five (20%) angioedema always associated with CSU, five erythema (20%), and six eczema (24%). Other, less frequent manifestations were lichen planus, anaphylactoid purpura, thrombocytopenic purpura, bullous pemphigoid, bullous pyoderma gangrenosum, and atypical skin lymphoproliferative infiltrate associated with reactive lymphadenopathy, chronic cholestasis, arthritis, and fibrosing mediastinitis. Fifteen patients (60%) had different types of associated autoimmune diseases, Hashimoto's thyroiditis being the most frequent (n = 5, 20%), followed by arthritis (n = 4, 16%), autoimmune hepatitis, neutropenia, vitiligo, and Sjögren's syndrome (n = 2, 8% each). Five malignancies were diagnosed in four patients (16%). An ultralow IgE serum level may be the only biomarker that reveals the presence of a dysregulated immune system in patients with a broad spectrum of skin manifestations.

Convergence of cytokine dysregulation and antibody deficiency in common variable immunodeficiency with inflammatory complications

BACKGROUND

Noninfectious complications are the greatest cause of morbidity and mortality in common variable immunodeficiency (CVID), but their pathogenesis remains poorly defined.

OBJECTIVE

Using high-throughput approaches, we aimed to identify, correlate, and determine the significance of immunologic features of CVID with noninfectious complications (CVIDc).

METHODS

We simultaneously applied proteomics, RNA sequencing, and mass cytometry to a large cohort with primary antibody deficiency.

RESULTS

CVIDc is differentiated from uncomplicated CVID, other forms of primary antibody deficiency, and healthy controls by a distinct plasma proteomic profile. In addition to confirming previously reported elevations of 4-1BB, IL-6, IL-18, and IFN-γ, we found elevations of colony-stimulating factor 1, IL-12p40, IL-18R, oncostatin M, TNF, and vascular endothelial growth factor A to differentiate CVIDc. This cytokine dysregulation correlated with deficiency of LPS-specific antibodies and increased soluble CD14, suggesting microbial translocation. Indicating potential significance of reduced LPS-specific antibodies and resultant microbial-induced inflammation, CVIDc had altered LPS-induced gene expression matching plasma proteomics and corresponding with increased CD14⁺CD16^- monocytes, memory T cells, and tissue inflammation ameliorated by T-cell-targeted therapy. Unsupervised machine learning accurately differentiated subjects with CVIDc and supported cytokine dysregulation, antibody deficit, and T-cell activation as defining and convergent features.

CONCLUSIONS

Our data expand understanding of CVIDc proteomics, establish its link with deficiency of IgA and LPS-specific antibodies, and implicate altered LPS-induced gene expression and elevated monocytes and T cells in this cytokine dysregulation. This work indicates that CVIDc results when insufficient antibody neutralization of pathogen-associated molecular patterns, like LPS, occurs in those with a heightened response to these inflammatory mediators, suggesting a 2-hit model of pathogenesis requiring further exploration.

Case report: Effectiveness of sirolimus in a de novo FAS mutation leading to autoimmune lymphoproliferative syndrome-FAS and elevated DNT/Treg ratio

BACKGROUND

The autoimmune lymphoproliferative syndrome (ALPS) is a rare disease characterized by defective function of the FAS death receptor, which results in chronic, non-malignant lymphoproliferation and autoimmunity accompanied by elevated numbers of double-negative (DN) T cells (T-cell receptor α/β + CD4-CD8-) and an increased risk of developing malignancies later in life.

CASE DESCRIPTION

Here, we report a patient with a de novo FAS mutation with a severe phenotype of ALPS-FAS. The FAS gene identified as a novel spontaneous germline heterozygous missense mutation (c.857G > A, p.G286E) in exon 9, causing an amino acid exchange and difference in hydrogen bond formation. Consequently, the treatment with sirolimus was initiated. Subsequently, the patient's clinical condition improved rapidly. Moreover, DNT ratio continuously decreased during sirolimus application.

CONCLUSION

We described a novel germline FAS mutation (c.857G > A, p.G286E) associated with a severe clinical phenotype of ALPS-FAS. Sirolimus effectively improved the patient clinical manifestations with obvious reduction of the DNT ratio.

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.

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.

Autoimmunity in Primary Immunodeficiency Disorders: An Updated Review on Pathogenic and Clinical Implications

During the last years, studies investigating the intriguing association between immunodeficiency and autoimmunity led to the discovery of new monogenic disorders, the improvement in the knowledge of the pathogenesis of autoimmunity, and the introduction of targeted treatments. Autoimmunity is observed with particular frequency in patients with primary antibody deficiencies, such as common variable immunodeficiency (CVID) and selective IgA deficiency, but combined immunodeficiency disorders (CIDs) and disorders of innate immunity have also been associated with autoimmunity. Among CIDs, the highest incidence of autoimmunity is described in patients with autoimmune polyendocrine syndrome 1, LRBA, and CTLA-4 deficiency, and in patients with STAT-related disorders. The pathogenesis of autoimmunity in patients with immunodeficiency is far to be fully elucidated. However, altered germ center reactions, impaired central and peripheral lymphocyte negative selection, uncontrolled lymphocyte proliferation, ineffective cytoskeletal function, innate immune defects, and defective clearance of the infectious agents play an important role. In this paper, we review the main immunodeficiencies associated with autoimmunity, focusing on the pathogenic mechanisms responsible for autoimmunity in each condition and on the therapeutic strategies. Moreover, we provide a diagnostic algorithm for the diagnosis of PIDs in patients with autoimmunity.

[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.

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

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

Common Variable Immunodeficiency and Autoimmune Diseases: A Retrospective Study of 95 Adult Patients in a Single Tertiary Care Center

Common variable immunodeficiency (CVID) is the most common clinically significant primary immunodeficiency in adulthood, which presents a broad spectrum of clinical manifestations, often including non-infectious complications in addition to heightened susceptibility to infections. These protean manifestations may significantly complicate the differential diagnosis resulting in diagnostic delay and under-treatment with increased mortality and morbidity. Autoimmunity occurs in up to 30% of CVID patients, and it is an emerging cause of morbidity and mortality in this type of patients. 95 patients (42 males and 53 females) diagnosed with CVID, basing on ESID diagnostic criteria, were enrolled in this retrospective cohort study. Clinical phenotypes were established according to Chapel 2012: i) no other disease-related complications, ii) cytopenias (thrombocytopenia/autoimmune hemolytic anemia/neutropenia), iii) polyclonal lymphoproliferation (granuloma/lymphoid interstitial pneumonitis/persistent unexplained lymphadenopathy), and iv) unexplained persistent enteropathy. Clinical items in the analysis were age, gender, and clinical features. Laboratory data included immunoglobulin (Ig)G, IgM and IgA levels at diagnosis, flow-cytometric analysis of peripheral lymphocytes (CD3+, CD3+CD4+, CD3+CD8+, CD19+, CD4+CD25highCD127low, CD19hiCD21loCD38lo, and follicular T helper cell counts). Comparisons of continuous variables between groups were performed with unpaired t-test, when applicable. 39 patients (41%) showed autoimmune complications. Among them, there were 21 females (53.8%) and 18 males (46.2%). The most prevalent autoimmune manifestations were cytopenias (17.8%), followed by arthritis (11.5%), psoriasis (9.4%), and vitiligo (6.3%). The most common cytopenia was immune thrombocytopenia, reported in 10 out of 95 patients (10.5%), followed by autoimmune hemolytic anemia (n=3, 3.1%) and autoimmune neutropenia (n=3, 3.1%). Other autoimmune complications included thyroiditis, coeliac disease, erythema nodosum, Raynaud’s phenomenon, alopecia, recurring oral ulcers, autoimmune gastritis, and primary biliary cholangitis. There were no statistically significant differences comparing immunoglobulin levels between CVID patients with or without autoimmune manifestations. There was no statistical difference in CD3+, CD8+, CD4+CD25highCD127low T, CD19, CD19hiCD21loCD38lo, and follicular T helper cell counts in CVID patients with or without autoimmune disorders. In conclusion, autoimmune manifestations often affect patients with CVID. Early recognition and tailored treatment of these conditions are pivotal to ensure a better quality of life and the reduction of CVID associated complications.

Lymphadenopathy at the crossroad between immunodeficiency and autoinflammation: An intriguing challenge

Lymphadenopathies can be part of the clinical spectrum of several primary immunodeficiencies, including diseases with immune dysregulation and autoinflammatory disorders, as the clinical expression of benign polyclonal lymphoproliferation, granulomatous disease or lymphoid malignancy. Lymphadenopathy poses a significant diagnostic dilemma when it represents the first sign of a disorder of the immune system, leading to a consequently delayed diagnosis. Additionally, the finding of lymphadenopathy in a patient with diagnosed immunodeficiency raises the question of the differential diagnosis between benign lymphoproliferation and malignancies. Lymphadenopathies are evidenced in 15–20% of the patients with common variable immunodeficiency, while in other antibody deficiencies the prevalence is lower. They are also evidenced in different combined immunodeficiency disorders, including Omenn syndrome, which presents in the first months of life. Interestingly, in the activated phosphoinositide 3‐kinase delta syndrome, autoimmune lymphoproliferative syndrome, Epstein–Barr virus (EBV)‐related lymphoproliferative disorders and regulatory T cell disorders, lymphadenopathy is one of the leading signs of the entire clinical picture. Among autoinflammatory diseases, the highest prevalence of lymphadenopathies is observed in patients with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) and hyper‐immunoglobulin (Ig)D syndrome. The mechanisms underlying lymphoproliferation in the different disorders of the immune system are multiple and not completely elucidated. The advances in genetic techniques provide the opportunity of identifying new monogenic disorders, allowing genotype–phenotype correlations to be made and to provide adequate follow‐up and treatment in the single diseases. In this work, we provide an overview of the most relevant immune disorders associated with lymphadenopathy, focusing on their diagnostic and prognostic implications.

State-of-the-art diagnostic evaluation of common variable immunodeficiency

OBJECTIVE

To summarize the current understanding of diagnostic and postdiagnostic evaluation of common variable immunodeficiency (CVID).

DATA SOURCES

PubMed Central database.

STUDY SELECTIONS

Original research articles and review articles from 2015 to 2020 including seminal articles that shaped the diagnostic and postdiagnostic evaluation of CVID were incorporated. This work focuses on initial diagnosis of CVID, genetic evaluations, and postdiagnostic assessment of respiratory, gastrointestinal, and hepatobiliary diseases including spleen and lymph node enlargement.

RESULTS

CVID presents not only with frequent infections but also with noninfectious complications such as autoimmunity, gastrointestinal disease, chronic lung disease, granulomas, liver disease, lymphoid hyperplasia, splenomegaly, or malignancy. The risk of morbidity and mortality is higher in patients with CVID and noninfectious complications. Detailed diagnostic approaches, which may incorporate genetic testing, can aid characterization of individual CVID cases and shape treatment in some instances. Moreover, continued evaluation after CVID diagnosis is key to optimal management of this complex disorder. These postdiagnostic evaluations include pulmonary function testing, radiologic studies, and laboratory evaluations that may be conducted at frequencies determined by disease activity.

CONCLUSION

Although the diagnosis can be achieved similarly in all patients with CVID, those with noninfectious complications have distinct concerns during clinical evaluation. State-of-the-art workup of CVID with noninfectious complications typically includes genetic analysis, which may shape precision therapy, and thoughtful application of postdiagnostic tests that monitor the presence and progression of disease in the myriad of tissues that may be affected. Even with recent advancements, knowledge gaps in diagnosis, prognosis, and treatment of CVID persist, and continued research efforts are needed.

B Cell Dysregulation in Common Variable Immunodeficiency Interstitial Lung Disease

Common variable immunodeficiency (CVID) is the most frequently diagnosed primary antibody deficiency. About half of CVID patients develop chronic non-infectious complications thought to be due to intrinsic immune dysregulation, including autoimmunity, gastrointestinal disease, and interstitial lung disease (ILD). Multiple studies have found ILD to be a significant cause of morbidity and mortality in CVID. Yet, the precise mechanisms underlying this complication in CVID are poorly understood. CVID ILD is marked by profound pulmonary infiltration of both T and B cells as well as granulomatous inflammation in many cases. B cell depletive therapy, whether done as a monotherapy or in combination with another immunosuppressive agent, has become a standard of therapy for CVID ILD. However, CVID is a heterogeneous disorder, as is its lung pathology, and the precise patients that would benefit from B cell depletive therapy, when it should administered, and how long it should be repeated all remain gaps in our knowledge. Moreover, some have ILD recurrence after B cell depletive therapy and the relative importance of B cell biology remains incompletely defined. Developmental and functional abnormalities of B cell compartments observed in CVID ILD and related conditions suggest that imbalance of B cell signaling networks may promote lung disease. Included within these potential mechanisms of disease is B cell activating factor (BAFF), a cytokine that is upregulated by the interferon gamma (IFN-γ):STAT1 signaling axis to potently influence B cell activation and survival. B cell responses to BAFF are shaped by the divergent effects and expression patterns of its three receptors: BAFF receptor (BAFF-R), transmembrane activator and CAML interactor (TACI), and B cell maturation antigen (BCMA). Moreover, soluble forms of BAFF-R, TACI, and BCMA exist and may further influence the pathogenesis of ILD. Continued efforts to understand how dysregulated B cell biology promotes ILD development and progression will help close the gap in our understanding of how to best diagnose, define, and manage ILD in CVID.

Chronic Lung Disease in Primary Antibody Deficiency: Diagnosis and Management

Chronic lung disease is a complication of primary antibody deficiency (PAD) associated with significant morbidity and mortality. Manifestations of lung disease in PAD are numerous. Thoughtful application of diagnostic approaches is imperative to accurately identify the form of disease. Much of the treatment used is adapted from immunocompetent populations. Recent genomic and translational medicine advances have led to specific treatments. As chronic lung disease has continued to affect patients with PAD, we hope that continued advancements in our understanding of pulmonary pathology will ultimately lead to effective methods that alleviate impact on quality of life and survival.

Shorter Diagnostic Delay in Polish Adult Patients With Common Variable Immunodeficiency and Symptom Onset After 1999

Common variable immunodeficiency (CVID) is the most clinically significant primary antibody immunodeficiency recognized in adulthood. Previously published data have shown an average diagnostic delay of 10 years for Polish adult patients with CVID. In the current study, we aimed to analyze the current diagnostic delay of adult patients with CVID in Poland. To this end, we identified patients from four immunological centers specialized in the care of adult patients with primary immunodeficiencies (PID). Demographic and clinical data of patients were collected using an internet database. We identified 103 adult patients (F:M 44.7%:55.3%) in Poland with CVID. The median age at onset of symptoms was 24 (0–66), 33 (4–70) at diagnosis, and 37 (18–73) years at the time of analysis. The median diagnostic delay for the entire study population was 6 (0–57) years. However, this delay was higher in patients with symptom onset before the year 2000 than after the year 1999 [15 (0–57) vs. 3 (0–19) years; p < 0.001]. Comparing patients (median ≤ 6 years, N = 53) with short diagnostic delay (SDD) and those (median > 6 years, N = 50) with long diagnostic delay (LDD), the LDD group had a statistically significant higher incidence of infections of the lower respiratory tract before diagnosis (90.0 vs. 71.70%). During the entire observation period, cytopenias (44.00 vs. 22.64%), granulomatous lesions (28.00 vs. 11.32%), and solid tumors (14.00 vs. 1.89%) were significantly more frequent in the LDD group. In conclusion, we found a significant reduction in the median diagnostic delay in Polish CVID patients with disease onset in the last two decades.

Serum B-Cell Maturation Antigen (BCMA) Levels Differentiate Primary Antibody Deficiencies

BACKGROUND

Primary antibody deficiencies (PADs) are the most prevalent primary immunodeficiencies. More severe forms of PADs-common variable immunodeficiency (CVID) and X-linked agammaglobulinemia (XLA)-require immunoglobulin replacement therapy (IRT) and may have serious complications. Differentiating severe PAD from milder hypogammaglobulinemia not requiring IRT can involve prolonged evaluations and treatment discontinuation. Severe PAD is defined by plasma cell deficiency, but this requires a biopsy to establish. Serum B-cell maturation antigen (sBCMA) is elevated in multiple myeloma, but levels are reduced among patients with myeloma in remission who have hypogammaglobulinemia.

OBJECTIVE

To measure the sBCMA level in 165 subjects to determine whether it differentiates severe PAD-CVID and XLA-from less severe forms not requiring IRT and those without PAD.

METHODS

sBCMA, B cells, and tissue plasma cells were measured among subjects with and without PAD, and correlated to clinical and laboratory data.

RESULTS

Subjects with an IgG level of less than 600 mg/dL had reduced sBCMA levels compared with subjects with PAD with IgG levels of greater than or equal to 600 mg/dL and controls without PAD. sBCMA level was lower in patients with CVID and XLA compared with patients with IgA or IgG deficiency and controls. sBCMA level correlated with gastrointestinal plasma cells. sBCMA level of less than 15 ng/mL had 97% positive predictive value for CVID or XLA, whereas 25 ng/mL or more had an 88% negative predictive value.

CONCLUSIONS

sBCMA level is profoundly reduced in patients with severe PAD, including those with CVID and XLA and those with IgG levels of less than 600 mg/dL. sBCMA level measurement has potential to augment clinical evaluation of PAD. Prospective studies are needed to evaluate sBCMA for new PAD diagnosis and determine the necessity of IRT.

Current Understanding and Recent Developments in Common Variable Immunodeficiency Associated Autoimmunity

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency and comprises a group of disorders with similar antibody deficiency but a myriad of different etiologies, most of which remain undefined. The variable aspect of CVID refers to the approximately half of patients who develop non-infectious complications in addition to heightened susceptibility to infection. The pathogenesis of these complications is poorly understood and somewhat counterintuitive because these patients that are defined by their immune futility simultaneously have elevated propensity for autoimmune disease. There are numerous aspects of immune dysregulation associated with autoimmunity in CVID that have only begun to be studied. These findings include elevations of T helper type 1 and follicular helper T cells and B cells expressing low levels of CD21 as well as reciprocal decreases in regulatory T cells and isotype-switched memory B cells. Recently, advances in genomics have furthered our understanding of the fundamental biology underlying autoimmunity in CVID and led to precision therapeutic approaches. However, these genetic etiologies are also associated with clinical heterogeneity and incomplete penetrance, highlighting the fact that continued research efforts remain necessary to optimize treatment. Additional factors, such as commensal microbial dysbiosis, remain to be better elucidated. Thus, while recent advances in our understanding of CVID-associated autoimmunity have been exciting and substantial, these current scientific advances must now serve as building blocks for the next stages of discovery.

Appropriate lung management in patients with primary antibody deficiencies

Introduction: Human primary immunodeficiency diseases (PIDs) include a broad spectrum of more than 350 disorders, involving different branches of the immune system and classified as 'rare diseases.' Predominantly antibody deficiencies (PADs) represent more than half of the PIDs diagnosed in Europe and are often diagnosed in the adulthood. Areas covered: Although PAD could first present with autoimmune or neoplastic features, respiratory infections are frequent and respiratory disease represents a relevant cause of morbidity and mortality. Pulmonary complications may be classified as infection-related (acute and chronic), immune-mediated, and neoplastic. Expert opinion: At present, no consensus guidelines are available on how to monitor and manage lung complications in PAD patients. In this review, we will discuss the available diagnostic, prognostic and therapeutic instruments and we will suggest an appropriate and evidence-based approach to lung diseases in primary antibody deficiencies. We will also highlight the possible role of promising new tools and strategies in the management of pulmonary complications. However, future studies are needed to reduce of diagnostic delay of PAD and to better understand lung diseases mechanisms, with the final aim to ameliorate therapeutic options that will have a strong impact on Quality of Life and long-term prognosis of PAD patients.

Autoimmunity in common variable immunodeficiency

OBJECTIVE

Common variable immunodeficiency (CVID) is a primary immunodeficiency that is clinically heterogeneous, characterized by both infectious and noninfectious complications. Although the hallmark of disease presentation is commonly a history of recurrent sinopulmonary infections, autoimmunity and noninfectious inflammatory conditions are increasingly associated with CVID.

DATA SOURCES

A comprehensive literature search using PubMed of basic science and clinical articles was performed.

STUDY SELECTIONS

Articles discussing the association of autoimmunity with primary immunodeficiency, specifically CVID, were selected.

RESULTS

The most common autoimmune conditions are cytopenias, including immune thrombocytopenia purpura and hemolytic anemia, but organ-specific autoimmune/inflammatory complications involving the gastrointestinal, skin, joints, connective tissue, and respiratory tract. In most cases, immunoglobulin replacement therapy does not ameliorate or treat these inflammatory complications, and additional immunomodulatory treatments are needed.

CONCLUSION

Mechanisms producing these conditions are poorly understood but include cytokine and cellular inflammatory pathways, and loss of tolerance to self-antigens through the multiple signaling molecules and pathways common to tolerance and immune deficiency.

Common Variable Immune Deficiency and Associated Complications

Common variable immunodeficiency disorders refer to a relatively common primary immune deficiency group of diseases that present with infectious and inflammatory complications secondary to defects in antibody production and sometimes in cellular immunity. The disorder often presents in middle age or later with recurrent sinopulmonary infections, bronchiectasis, or a plethora of noninfectious complications such as autoimmune disorders, granulomatous interstitial lung disease, GI diseases, malignancies (including lymphoma), and multisystem granulomatous disease resembling sarcoidosis. Infusion of immunoglobulin by IV or subcutaneous is the mainstay of therapy. Management of complications is often difficult as immune suppression may be necessary in these conditions and entails the use of medications and biologicals which may further increase the risk for infections. Specifically, bronchiectasis, granulomatous lymphocytic interstitial lung disease, repeated sinopulmonary infections, and malignancies are sequelae of antibody deficiency that may present to the pulmonologist. This review will provide an updated understanding of the molecular aspects, differential diagnosis, presentations, and the management of common variable immunodeficiency disorders.

Factors Beyond Lack of Antibody Govern Pulmonary Complications in Primary Antibody Deficiency

PURPOSE

Pulmonary complications occur frequently in primary antibody deficiency (PAD). While the impact of antibody deficiency may appear implicit for certain respiratory infections, immunoglobulin replacement therapy does not completely ameliorate pulmonary complications in PAD. Thus, there may be antibody-independent factors influencing susceptibility to respiratory disease in PAD, but these remain incompletely defined.

METHODS

We harnessed the multicenter US Immunodeficiency Network primary immunodeficiency registry to compare prevalence of asthma, bronchiectasis, interstitial lung disease (ILD), and respiratory infections between two forms of PAD: common variable immunodeficiency (CVID) and x-linked agammaglobulinemia (XLA). We also defined the clinical and immunological characteristics associated with ILD and asthma in CVID.

RESULTS

Asthma, bronchiectasis, ILD, pneumonia, and upper respiratory infections were more prevalent in CVID than XLA. ILD was associated with autoimmunity, bronchiectasis, and pneumonia as well as fewer B and T cells in CVID. Asthma was the most common chronic pulmonary complication and associated with lower IgA and IgM in CVID. Age of symptom onset or CVID diagnosis was unrelated with ILD or asthma.

CONCLUSION

Despite having less severe immunoglobulin deficiency than XLA, respiratory infections, ILD, and asthma were more common in CVID. Among CVID patients, ILD was associated with autoimmunity and reduced lymphocytes and asthma with lower immunoglobulins. Though our results are tempered by registry limitations, they provide evidence that factors beyond lack of antibody promote pulmonary complications in PAD. Efforts to understand how genetic etiology, nature of concurrent T cell deficiency, and propensity for autoimmunity shape pulmonary disease may improve treatment of PAD.

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.

Soluble Markers of Antibody Secreting Cell Function as Predictors of Infection Risk in Rheumatoid Arthritis

Background

Rheumatoid arthritis (RA) is a systemic autoimmune disease associated with immune dysregulation and increased risk of infections. The presence of autoantibodies and immunoglobulin abnormalities indicates B-cell and antibody-secreting cell (ASC) dysfunction. We hypothesize that soluble factors associated with B-cell and ASC activity are decreased in RA patients and that this is linked to higher susceptibility to infections.

Methods

Using the Johns Hopkins Arthritis Cohort and Biorepository, we contrasted serum protein levels of soluble factors involved in B-cell activation (CD40, CD40L) and B-cell/ASC homing (CXCL10, CXCL11, and CXCL13) or survival (BAFF, APRIL, TACI, and BCMA) in 10 healthy subjects and 23 adult RA patients (aged 24-65 years). We subdivided RA patients into those with (n = 17) and those without infections (n = 6) within a 2-year period. In order to reduce the effect of RA treatment, we only included patients receiving methotrexate monotherapy or no RA treatments at baseline. Soluble serum protein levels of B-cell/ASC factors were quantified by multiplex immunoassays.

Results

We identified that (1) serum levels of soluble BCMA, APRIL, CD40, and CD40L were significantly decreased in RA patients relative to healthy individuals; (2) serum soluble BCMA, predominantly released by ASC, correlated with serum concentrations of class-switched immunoglobulins, IgG and IgA; and (3) RA patients with a history of infections had significantly lower soluble BCMA levels compared with healthy donors and with RA patients without infections.

Conclusions

Our study using soluble factors linked to B-cell/ASC activation and survival suggests that there is a paucity of ASC in a subset of RA patients and that this may be linked to altered antibody production and increased risk of infections. Further delineating the link between ASC and infection susceptibility in RA may optimize disease management and provide novel insights into disease pathogenesis that are susceptible to intervention.

Humoral immunodeficiencies: conferred risk of infections and benefits of immunoglobulin replacement therapy

Primary immunodeficiency (PID) diseases result from genetic defects of the immune system that increase a patient's susceptibility to infections. The types of infections that occur in patients with PID diseases are dictated largely by the nature of the immunodeficiency, which can be defined by dysfunction of cellular or humoral defenses. An increasing number of PID diseases, including those with both cellular and humoral defects, have antibody deficiency as a major feature, and as a result can benefit from immunoglobulin replacement therapy. In fact, the most common PID diseases worldwide are antibody deficiencies and include common variable immunodeficiency, congenital agammaglobulinemia, hyper‐IgM syndrome, specific antibody deficiency, and Good syndrome. Although immunoglobulin replacement therapy is the cornerstone of treatment for the majority of these conditions, a thorough understanding of the specific infections for which these patients are at increased risk can hasten diagnosis and guide additional therapies. Moreover, the infection trends in some patients with PID disease who have profound defects of cellular immunity, such as autosomal‐dominant hyper‐IgE syndrome (Job/Buckley syndrome) or dedicator of cytokinesis 8 (DOCK8) deficiency, suggest that select patients might benefit from immunoglobulin replacement therapy even if their immunodeficiency is not limited to antibody defects. In this review, we provide an overview of the predisposition to infections seen in PID disease that may benefit from immunoglobulin replacement therapy.

BAFF-driven B cell hyperplasia underlies lung disease in common variable immunodeficiency

BACKGROUND

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency and is frequently complicated by interstitial lung disease (ILD) for which etiology is unknown and therapy inadequate.

METHODS

Medical record review implicated B cell dysregulation in CVID ILD progression. This was further studied in blood and lung samples using culture, cytometry, ELISA, and histology. Eleven CVID ILD patients were treated with rituximab and followed for 18 months.

RESULTS

Serum IgM increased in conjunction with ILD progression, a finding that reflected the extent of IgM production within B cell follicles in lung parenchyma. Targeting these pulmonary B cell follicles with rituximab ameliorated CVID ILD, but disease recurred in association with IgM elevation. Searching for a stimulus of this pulmonary B cell hyperplasia, we found B cell-activating factor (BAFF) increased in blood and lungs of progressive and post-rituximab CVID ILD patients and detected elevation of BAFF-producing monocytes in progressive ILD. This elevated BAFF interacts with naive B cells, as they are the predominant subset in progressive CVID ILD, expressing BAFF receptor (BAFF-R) within pulmonary B cell follicles and blood to promote Bcl-2 expression. Antiapoptotic Bcl-2 was linked with exclusion of apoptosis from B cell follicles in CVID ILD and increased survival of naive CVID B cells cultured with BAFF.

CONCLUSION

CVID ILD is driven by pulmonary B cell hyperplasia that is reflected by serum IgM elevation, ameliorated by rituximab, and bolstered by elevated BAFF-mediated apoptosis resistance via BAFF-R.

FUNDING

NIH, Primary Immune Deficiency Treatment Consortium, and Rare Disease Foundation.

Central Nervous System Involvement in Common Variable Immunodeficiency: A Case of Acute Unilateral Optic Neuritis in a 26-Year-Old Italian Patient

Common Variable Immunodeficiency (CVID) is a group of heterogeneous primary immunodeficiencies sharing defective B lymphocytes maturation and dysregulated immune response and resulting in impaired immunoglobulin production. Clinical picture encompasses increased susceptibility to infections, hematologic malignancies, inflammatory, and autoimmune diseases. Neurological manifestations are uncommon and optic neuritis has been previously reported only in one case with bilateral involvement. We hereby report a case of a 26-year-old man affected by CVID undergoing regular immunoglobulin supplementation, who presented with acute unilateral demyelinating optic neuritis and lymphocytic pleocytosis in the cerebrospinal fluid. A variety of infectious, inflammatory, and neoplastic conditions were excluded and a diagnosis of clinically isolated optic neuritis was made. The patient was treated with a short course of intravenous steroids with complete recovery. Overall, this case expands our current knowledge about clinical spectrum of complications in CVID and highlights the need for further research about this complex disease.

The burden of common variable immunodeficiency disorders: a retrospective analysis of the European Society for Immunodeficiency (ESID) registry data

Background

Common variable immunodeficiency disorders (CVID) are a group of rare innate disorders characterized by specific antibody deficiency and increased rates of infections, comorbidities and mortality. The burden of CVID in Europe has not been previously estimated. We performed a retrospective analysis of the European Society for Immunodeficiencies (ESID) registry data on the subset of patients classified by their immunologist as CVID and treated between 2004 and 2014. The registered deaths and comorbidities were used to calculate the annual average age-standardized rates of Years of Life Lost to premature death (YLL), Years Lost to Disability (YLD) and Disability Adjusted Life Years (DALY=YLL + YLD). These outcomes were expressed as a rate per 10⁵ of the CVID cohort (the individual disease burden), and of the general population (the societal disease burden).

Results

Data of 2700 patients from 23 countries were analysed. Annual comorbidity rates: bronchiectasis, 21.9%; autoimmunity, 23.2%; digestive disorders, 15.6%; solid cancers, 5.5%; lymphoma, 3.8%, exceeded the prevalence in the general population by a factor of 34.0, 7.6, 8.1, 2.4 and 32.6, respectively. The comorbidities of CVID caused 8722 (6069; 12,363) YLD/10⁵ in this cohort, whereas 44% of disability burden was attributable to infections and bronchiectasis. The total individual burden of CVID was 36,785 (33,078, 41,380) DALY/10⁵. With estimated CVID prevalence of ~ 1/ 25,000, the societal burden of CVID ensued 1.5 (1.3, 1.7) DALY/10⁵ of the general population.

In exploratory analysis, increased mortality was associated with solid tumor, HR (95% CI): 2.69 (1.10; 6.57) p = 0.030, lymphoma: 5.48 (2.36; 12.71) p < .0001 and granulomatous-lymphocytic interstitial lung disease: 4.85 (1.63; 14.39) p = 0.005. Diagnostic delay (median: 4 years) was associated with a higher risk of death: 1.04 (1.02; 1.06) p = .0003, bronchiectasis: 1.03 (1.01; 1.04) p = .0001, solid tumor: 1.08 (1.04; 1.11) p < .0001 and enteropathy: 1.02 (1.00; 1.05) p = .0447 and stayed unchanged over four decades (p = .228).

Conclusions

While the societal burden of CVID may seem moderate, it is severe to the individual patient. Delay in CVID diagnosis may constitute a modifiable risk factor of serious comorbidities and death but showed no improvement. Tools supporting timely CVID diagnosis should be developed with high priority.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0941-0) contains supplementary material, which is available to authorized users.

Mild Hypogammaglobulinemia Can Be a Serious Condition

Background: Most patients with primary antibody deficiency (PAD) suffer from less well-described and understood forms of hypogammaglobulinemia (unclassified primary antibody deficiency, unPAD). Because of the moderately decreased immunoglobulin levels compared to CVID, unPAD is generally considered to be clinically mild and not very relevant.

Objective: To describe our cohort of—mainly—unPAD patients, and to analyze whether subgroups can be identified.

Methods: Data were prospectively collected (February-2012 to June-2016) as part of a standardized, 1-day Care Pathway for suspected primary immunodeficiency. The TNO-AZL Questionnaire for Health-Related Quality of Life (HRQoL) was part of the pre-first-visit intake procedure.

Results: Three hundred and twenty patients were referred to the Care Pathway. Data from 23/27 children and 99/113 adults who were diagnosed with PAD and gave informed consent were available for analysis. 89/99 adults had unPAD, the majority (74%) were female and 44% already showed bronchiectasis. HRQoL was significantly decreased in all domains, meaning that a lot of unPAD patients had to cope simultaneously with pain, negative feelings and impairments in cognition, home management tasks, sleep, social interaction, and work. The most prominently impaired HRQoL domain was vitality, indicating these patients feel extremely tired and worn out.

Conclusion: These results highlight the need for more attention to the potential patient burden of unPADs. A larger cohort is needed to increase our understanding of unPADs and to analyze whether distinct subgroups can be identified. For now, it is important for the clinician to acknowledge the existence of unPAD and be aware of its potential consequences, in order to timely and appropriately manage its effects and complications.

Common Variable Immunodeficiency with Genetic Defects Identified by Whole Exome Sequencing

Common variable immunodeficiency (CVID) belongs to the primary immunodeficiency disorders (PIDs), presenting a profound heterogeneity in phenotype and genotype, with monogenic or complex causes. Recurrent respiratory infections are the most common clinical manifestations. CVID patients can also develop various autoimmune and lymphoproliferative complications. Genetic testing such as whole exome sequencing (WES) can be utilized to investigate likely genetic defects, helping for better clinical management. We described the clinical phenotypes of three sporadic cases of CVID, who developed recurrent respiratory infections with different autoimmune and lymphoproliferative complications. WES was applied to screen disease-causing or disease-associated mutations. Two patients were identified to have monogenic disorders, with compound heterozygous mutations in LRBA for one patient and a frameshift insertion in NFKB1 for another. The third patient was identified to be a complex form of CVID. Two novel mutations were identified, respectively, in LRBA and NFKB1. A combination of clinical and genetic diagnosis can be more extensively utilized in the clinical practice due to the complexity and heterogeneity of CVID.

The broad spectrum of lung diseases in primary antibody deficiencies

Human primary immunodeficiency diseases (PIDs) represent a heterogeneous group of more than 350 disorders. They are rare diseases, but their global incidence is more relevant than generally thought. The underlying defect may involve different branches of the innate and/or adaptive immune response. Thus, the clinical picture may range from severe phenotypes characterised by a broad spectrum of infections to milder infectious phenotypes due to more selective (and frequent) immune defects. Moreover, infections may not be the main clinical features in some PIDs that might present with autoimmunity, auto-inflammation and/or cancer. Primary antibody deficiencies (PADs) represent a small percentage of the known PIDs but they are the most frequently diagnosed, particularly in adulthood. Common variable immunodeficiency (CVID) is the most prevalent symptomatic PAD.

PAD patients share a significant susceptibility to respiratory diseases that represent a relevant cause of morbidity and mortality. Pulmonary complications include acute and chronic infection-related diseases, such as pneumonia and bronchiectasis. They also include immune-mediated interstitial lung diseases, such as granulomatous-lymphocytic interstitial lung disease (GLILD) and cancer. Herein we will discuss the main pulmonary manifestations of PADs, the associated functional and imaging findings, and the relevant role of pulmonologists and chest radiologists in diagnosis and surveillance.

The spectrum of lung complications in primary antibody deficiency ranges from asthma or COPD to extremely rare and specific ILDs. Early diagnosis of the underlying immune defect might significantly improve patients' lung disease, QoL and long-term prognosis.http://ow.ly/5cP230kZvOB

Phenotypic characterization of patients with rheumatologic manifestations of common variable immunodeficiency

Patients with common variable immunodeficiency (CVID) have a higher incidence of rheumatologic disorders. To delineate this clinical association, we investigated the phenotypic features of patients with CVID affected by these conditions.

METHODS

We conducted a retrospective analysis of 870 pediatric and adult patients with CVID included in the United States Immunodeficiency Network (USIDNET) registry. Outcomes included clinical characteristics (age, gender, ethnicity, rheumatologic diagnosis, and comorbidities), infectious history and basic immunophenotype (serum immunoglobulin levels, CD19+ B cells, and CD4/CD8 ratio) in patients with CVID and rheumatologic disorders compared to those with non-inflammatory CVID. Demographic and clinical data were compared using chi-square, Fisher's exact or Wilcoxon-Mann-Whitney tests. Non-parametric tests, single and multiple logistic regression models were used to evaluate the relationship between CVID-associated rheumatologic disorders and basic immunophenotypic parameters (IgA, IgM, CD19+ B-cell counts, and CD4/CD8 ratios).

RESULTS

Physician-reported rheumatic diseases were present in 5.9% of patients with CVID (n = 51) included in the registry. Although CVID affects both sexes equally, and patients are of predominantly White-Caucasian ethnicity, there were more females (3.3:1 female to male ratio) and increased proportion of non-white patients in the rheumatologic disease group (p < 0.05). Specific disorders included: inflammatory arthritis (n = 18), Sjogren's syndrome (n = 11), SLE (n = 8), Raynaud's syndrome (n = 8), vasculitis (n = 9), MCTD (n = 3), and other (n = 5). In about one-third of patients, a rheumatologic condition was associated with an additional inflammatory complication or malignancy. In regards to the immunophenotype parameters compared (CD19+ B-cell counts, CD4/CD8 ratio, IgA, and IgM), no significant differences were demonstrated between the two groups.

CONCLUSION

Our findings highlight the coexistence of primary antibody immunodeficiencies and systemic rheumatologic disorders, describe the spectrum of rheumatologic manifestations, and contrast differences in relevant demographic, clinical and immunophenotype parameters in the largest registry of CVID patients in the U.S. In spite of its limitations, our study details the intersection of systemic autoimmunity and CVID and provides valuable insights into these two groups of disorders. Further delineating the link between systemic autoimmunity and humoral immunodeficiencies can provide novel insights into the immune abnormalities underlying these related conditions.

Dysregulation of Innate Lymphoid Cells in Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immune deficiency. With widespread use of immunoglobulin replacement therapy, non-infectious complications, such as autoimmunity, chronic intestinal inflammation, and lung disease, have replaced infections as the major cause of morbidity and mortality in this immune deficiency. The pathogenic mechanisms that underlie the development of these complications in CVID are not known; however, there have been numerous associated laboratory findings. Among the most intriguing of these associations is elevation of interferon signature genes in CVID patients with inflammatory/autoimmune complications, as a similar gene expression profile is found in systemic lupus erythematosus and other chronic inflammatory diseases. Linked with this heightened interferon signature in CVID is an expansion of circulating IFN-γ-producing innate lymphoid cells. Innate lymphoid cells are key regulators of both protective and pathogenic immune responses that have been extensively studied in recent years. Further exploration of innate lymphoid cell biology in CVID may uncover key mechanisms underlying the development of inflammatory complications in these patients and may inspire much needed novel therapeutic approaches.

Evans Syndrome as First Manifestation of Primary Immunodeficiency in Clinical Practice

BACKGROUND

Evans syndrome (ES) is a rare immune disorder in children, manifested by simultaneous or sequential autoimmune cytopenias (ACs) of unknown cause and having a chronic course with periods of exacerbation and remission. Some primary immunodeficiencies (PIDs) may present with autoimmune manifestations without infections, masking suspicion of them. The PIDs that can typically manifest as ES are autoimmune lymphoproliferative syndrome and common variable immunodeficiency (CVID).

MATERIALS AND METHODS

Review of clinical charts and laboratory results of pediatric patients followed-up in the outpatient clinic of PID with a diagnosis of ES and humoral immunodeficiency.

RESULTS

Three pediatric patients, a boy and 2 girls, presented with corticosteroid-dependent ES. In the diagnostic approach, autoimmune lymphoproliferative syndrome was ruled out, and during follow-up, patients showed laboratory signs of humoral immune deficiency and were diagnosed with CVID. After initiating the recommended treatment for CVID with AC, patients improved without new exacerbations.

CONCLUSIONS

These cases highlight the importance of detection of possible PID in the context of ES and the establishment of CVID treatment to control AC.

The Lung in Dysregulated States of Humoral Immunity

In common variable immunodeficiency, lung manifestations are related to different mechanisms: recurrent pneumonias due to encapsulated bacteria responsible for diffuse bronchiectasis, diffuse infiltrative pneumonia with various patterns, and lymphomas, mostly B cell extranodal non-Hodgkin type. The diagnosis relies on significant serum Ig deficiency and the exclusion of any primary or secondary cause. Histopathology may be needed. Immunoglobulin (IgG) replacement is crucial to prevent infections and bronchiectasis. IgG4-related respiratory disease, often associated with extrapulmonary localizations, presents with solitary nodules or masses, diffuse interstitial lung diseases, bronchiolitis, lymphadenopathy, and pleural or pericardial involvement. Diagnosis relies on international criteria including serum IgG4 dosage and significantly increased IgG4/IgG plasma cells ratio in pathologically suggestive biopsy. Respiratory amyloidosis presents with tracheobronchial, nodular, and cystic or diffuse interstitial lung infiltration. Usually of AL (amyloid light chain) subtype, it may be localized or systemic, primary or secondary to a lymphoproliferative process. Very rare other diseases due to nonamyloid IgG deposits are described. Among the various lung manifestations of dysregulated states of humoral immunity, this article covers only those associated with the common variable immunodeficiency, IgG4-related disease, amyloidosis, and pulmonary light-chain deposition disease. Autoimmune connective-vascular tissue diseases or lymphoproliferative disorders are addressed in other chapters of this issue.

Considerations for dosing immunoglobulin in obese patients

Obesity is a very common condition; however, the effect of excess body weight on the appropriate dose of immunoglobulin has not been defined empirically. The proposed pharmacokinetic differences between lean and obese patients and the opportunity to reduce costs has led to the proposition that obese patients should receive proportionally lower doses of immunoglobulin once a certain threshold is reached. Here the theoretical factors which could affect dosing in obese patients are considered alongside the available empirical evidence. The available evidence indicates that obesity may affect the pharmacokinetics of immunoglobulin; however, the effect is likely to be too small to have a clinically important effect on dosing. Wide interpatient individuality and highly variable clinical need mean that obesity should not play a major factor in dosing considerations. However, patients who are obese are more likely to have multiple cardiovascular risk factors and their weight indicates a large dose. This puts these patients at a higher risk of adverse reactions, and therefore caution is advised.

Approach to the Management of Autoimmunity in Primary Immunodeficiency

Primary immunodeficiency diseases (PIDs) consist of a genetically heterogeneous group of immune disorders that affect distinct elements of the immune system. PID patients are more prone to infections and non-infectious complications, particularly autoimmunity. The concomitance of immunodeficiency and autoimmunity appears to be paradoxical and leads to difficulty in the management of autoimmune complications in PID patients. Therefore, management of autoimmunity in patients with PID requires special considerations because dysregulations and dysfunctions of the immune system along with persistent inflammation impair the process of diagnosis and treatment.

Lung Disease in Primary Antibody Deficiencies

Primary antibody deficiencies (PADs) are the most common form of primary immunodeficiency and predispose to severe and recurrent pulmonary infections, which can result in chronic lung disease including bronchiectasis. Chronic lung disease is among the most common complications of PAD and a significant source of morbidity and mortality for these patients. However, the development of lung disease in PAD may not be solely the result of recurrent bacterial infection or a consequence of bronchiectasis. Recent characterization of monogenic immune dysregulation disorders and more extensive study of common variable immunodeficiency have demonstrated that interstitial lung disease (ILD) in PAD can result from generalized immune dysregulation and frequently occurs in the absence of pneumonia history or bronchiectasis. This distinction between bronchiectasis and ILD has important consequences in the evaluation and management of lung disease in PAD. For example, treatment of ILD in PAD typically uses immunomodulatory approaches in addition to immunoglobulin replacement and antibiotic prophylaxis, which are the stalwarts of bronchiectasis management in these patients. Although all antibody-deficient patients are at risk of developing bronchiectasis, ILD occurs in some forms of PAD much more commonly than in others, suggesting that distinct but poorly understood immunological factors underlie the development of this complication. Importantly, ILD can have earlier onset and may worsen survival more than bronchiectasis. Further efforts to understand the pathogenesis of lung disease in PAD will provide vital information for the most effective methods of diagnosis, surveillance, and treatment of these patients.