Common variable immunodeficiency

A case report navigating CVID and sarcoidosis overlaps in pediatric nephritis

Common variable immunodeficiency (CVID) can be complicated by granulomatous disease, often granulomatous lymphocytic interstitial lung disease (GLILD). Granulomatous interstitial nephritis represents an atypical presentation in pediatrics. Our patient is a previously healthy 13-year-old white male with a recent diagnosis of CVID. He presented with a rash and laboratory findings included pancytopenia (white blood cells 2.6 cells × 103/μl, hemoglobin 11.8 g/dl, platelets 60 × 103/μl), hypercalcemia (14.9 mg/dl), elevated Vit D 1,25 OH level (>200 pg/ml), hyperuricemia (8.8 mg/dl), and acute kidney injury (AKI) (serum creatinine 1.1 mg/dl; baseline 0.64 mg/dl). A broad infectious workup was unremarkable. The rash improved with empiric doxycycline. Hypercalcemia and hyperuricemia were managed with fluid resuscitation, calcitonin, and zoledronic acid. Evaluation for malignancy including a positron emission tomography scan, revealed multiple mediastinal hypermetabolic lymph nodes and pulmonary ground glass opacities, later reported as small pulmonary nodules by computed tomography (CT). Splenomegaly was confirmed by ultrasound and CT. Peripheral smear, bone marrow biopsy, and genetic testing were non-revealing. His angiotensin-converting enzyme level was elevated (359 U/L), raising concerns for sarcoidosis. Given Stage 1 AKI, a renal biopsy was pursued and identified non-caseating granulomatous interstitial nephritis. Treatment with 60 mg of prednisone began for presumed sarcoidosis for 4 months, causing steroid-induced hypertension and mood changes. Zoledronic acid minimally reduced serum creatinine. Pneumocystis jirovecii pneumonia prophylaxis was initiated due to T-cell cytopenia. Chest CT findings showed a suboptimal response to steroids. A bronchoalveolar lavage demonstrated >50% lymphocytes (normal <10%) and the lung biopsy exhibited non-caseating granulomas, indicating GLILD. Rubella was identified by staining. Following a fever, he was found to have elevated liver enzymes and confirmed hepatitis with portal hypertension on CT. A liver biopsy revealed epithelioid non-caseating granuloma and HHV6 was detected by PCR. He was treated with four cycles of rituximab and granulocyte-colony stimulating factor for persistent neutropenia. Subsequent treatment with mycophenolate led to the resolution of the granulomatous lesions and cytopenias. The rare complication of granulomatous interstitial nephritis in CVID illustrates the intricate nature of diagnosis. This case underscores the necessity for a holistic view of the patient's clinical and immune phenotype, including distinctive radiological presentations, for precise diagnoses and tailored management of CVID.

Clinical features and predictors of osteoarticular manifestations in common variable immunodeficiency

INTRODUCTION

This study aimed to assess osteoarticular manifestations in patients with common variable immunodeficiency (CIVD) and to identify the predictive factors.

METHODS

This was a retrospective and prognostic study conducted in the pediatrics: immuno-hematology and stem cell transplantation department, including patients who fit the definition of CVID. A Cox model analysis was used to identify predictive factors.

RESULTS

A total of 36 patients were enrolled. Osteoarticular involvement was noted in 15 patients (42%) with a cumulative incidence of 90% after a median follow-up of 25 years. Non-infectious manifestations were reported in 14 patients (39%). The cumulative risk of inflammatory or autoimmune osteoarticular etiology was 74%. Well-characterized rheumatic diseases were retained in six patients and unlabeled autoimmune or inflammatory mechanism in five cases. Bone mineral density revealed osteoporosis in six cases leading to a cumulative risk of degenerative complications of 72%. The cumulative incidence of infectious complications was 17%. In multivariate analysis, predictors of osteoarticular complications were low body weight (HR = 8.67, CI: 1.496-50.278, p = 0.01) and hepatomegaly at diagnosis (HR = 6.2, CI: 1.537-25.075, p = 0.01). Reduced CD4 cells rate < 600 cells/mm3 and hepatomegaly were predictors of autoimmune or inflammatory complications, while chronic diarrhea and iron deficiency were associated with degenerative manifestations.

CONCLUSIONS

Osteoarticular manifestations have emerged as a real health problem for CVID patients. Risk increases with low body weight, hepatomegaly, chronic diarrhea, iron deficiency, and CD4 cells rate under 600 cell/mm3. Elucidating the mechanisms of these complications in CVID is important for developing preventive strategies. Key Points • This retrospective and prognostic study described the clinical characteristics of osteoarticular manifestations in 36 patients with CVID to ensure better recognition and understanding of this association by clinicians. • Identification of predictive factors of osteoarticular complications according to its etiology is crucial to establish appropriate, optimal and early management of patients at risk.

Clinical Validation of a Primary Antibody Deficiency Screening Algorithm for Primary Care

PURPOSE

The diagnostic delay of primary antibody deficiencies (PADs) is associated with increased morbidity, mortality, and healthcare costs. Therefore, a screening algorithm was previously developed for the early detection of patients at risk of PAD in primary care. We aimed to clinically validate and optimize the PAD screening algorithm by applying it to a primary care database in the Netherlands.

METHODS

The algorithm was applied to a data set of 61,172 electronic health records (EHRs). Four hundred high-scoring EHRs were screened for exclusion criteria, and remaining patients were invited for serum immunoglobulin analysis and referred if clinically necessary.

RESULTS

Of the 104 patients eligible for inclusion, 16 were referred by their general practitioner for suspected PAD, of whom 10 had a PAD diagnosis. In patients selected by the screening algorithm and included for laboratory analysis, prevalence of PAD was ~ 1:10 versus 1:1700-1:25,000 in the general population. To optimize efficiency of the screening process, we refitted the algorithm with the subset of high-risk patients, which improved the area under the curve-receiver operating characteristics curve value to 0.80 (95% confidence interval 0.63-0.97). We propose a two-step screening process, first applying the original algorithm to distinguish high-risk from low-risk patients, then applying the optimized algorithm to select high-risk patients for serum immunoglobulin analysis.

CONCLUSION

Using the screening algorithm, we were able to identify 10 new PAD patients from a primary care population, thus reducing diagnostic delay. Future studies should address further validation in other populations and full cost-effectiveness analyses.

REGISTRATION

Clinicaltrials.gov record number NCT05310604, first submitted 25 March 2022.

Characterization of infectious and non-infectious gastrointestinal disease in common variable immunodeficiency: analysis of 114 patient cohort

Common Variable Immunodeficiency (CVID), a complex primary immunodeficiency syndrome defined by defective B cell responses to infection and vaccination, has heterogeneous clinical manifestations. Gastrointestinal (GI) complications in CVID, both infectious and non-infectious, can cause significant impairment leading to malabsorption and frank malnutrition. In order to better characterize the spectrum of GI disease associated with CVID, we describe 114 patients with GI disease (15.6%) from our 728 patient single center CVID cohort. Norovirus, Giardia and Cytomegalovirus were the most frequently isolated infectious pathogens. CVID enteropathy was the most encountered GI diagnosis based on endoscopy, with only a minority of patients having Crohn's disease (6.1%) or ulcerative colitis/proctitis (4.5%). Concurrent autoimmunity (30.7%), lung disease (18.4%) and malignancy (8.7%) were also present in significant proportion of subjects. Lastly, 16 of 47 (34%) who underwent whole exome sequencing demonstrated a culprit gene defect associated with CVID.

Unraveling the Role of Toll-like Receptors in the Immunopathogenesis of Selected Primary and Secondary Immunodeficiencies

The human immune system is a complex network of cells, tissues, and molecules that work together to defend the body against pathogens and maintain overall health. However, in some individuals, the immune system fails to function correctly, leading to immunodeficiencies. Immunodeficiencies can be classified into primary (PID) and secondary (SID) types, each with distinct underlying causes and manifestations. Toll-like receptors (TLRs), as key components of the immune system, have been implicated in the pathogenesis of both PID and SID. In this study, we aim to unravel the intricate involvement of TLR2, TLR4, TLR3, TLR7, TLR8, and TLR9 in the immunopathogenesis of common variable immunodeficiency-CVID (as PID)-and chronic lymphocytic leukemia-CLL (as SID). The obtained results indicate a significant increase in the percentage of all tested subpopulations of T lymphocytes and B lymphocytes showing positive expression of all analyzed TLRs in patients with CVID and CLL compared to healthy volunteers, constituting the control group, which is also confirmed by analysis of the concentration of soluble forms of these receptors in the plasma of patients. Furthermore, patients diagnosed with CVID are characterized by the percentage of all lymphocytes showing positive expression of the tested TLR2, TLR4, TLR3, and TLR9 and their plasma concentrations in relation to patients with CLL. By investigating the functions and interactions of TLRs within the immune system, we seek to shed light on their critical role in the development and progression of these immunodeficiencies. Through a comprehensive analysis of the literature and presented experimental data, we hope to deepen our understanding of the complex mechanisms by which TLRs contribute to the pathogenesis of PID and SID. Ultimately, our findings may provide valuable insights into developing targeted therapeutic strategies to mitigate the impact of these disorders on those affected by immunodeficiency.

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.

New-onset Hypogammaglobulinemia and Infectious Complications Associated with Rituximab Use in Childhood-onset Rheumatic Diseases

OBJECTIVE

To investigate the incidence and risk factors for hypogammaglobulinemia and infectious complications associated with rituximab treatment in childhood-onset rheumatic diseases.

METHODS

We performed a single-center retrospective study of patients (n = 85) treated at Boston Children's Hospital (BCH) from 2009 to 2019. Study subjects included patients (ages 6 to 24) who received rituximab for the treatment of a childhood-onset rheumatic disease.

RESULTS

New-onset hypogammaglobulinemia developed in 23 (27.1%) patients within 18 months of rituximab induction treatment. 22 patients (25.9%) developed at least one infectious complication in the 18 months following the first rituximab infusion; of these, 11 (50%) had serious infections requiring inpatient treatment. After adjusting for potential confounders, exposure to pulse corticosteroid therapy in the month prior to rituximab use was a significant predictor of both new-onset hypogammaglobulinemia (OR 3.94; 95% CI 1.07-16.0; p = 0.044) and infectious complications (OR 15.3; 95% CI 3.04-126.8; p = 0.003). Post-rituximab hypogammaglobulinemia was the strongest predictor of serious infectious complications (OR 7.89; 95% CI 1.41-65.6; p = 0.028). Younger age at rituximab use was also a significant predictor of new-onset hypogammaglobulinemia (OR 0.83; 95% CI 0.70-0.97; p = 0.021). Compared with other rheumatic diseases, patients with vasculitis had a higher likelihood of developing infectious complications, including serious infections.

CONCLUSION

Although rituximab was well tolerated in terms of infectious complications in the majority of patients with childhood-onset rheumatic diseases, a substantial proportion developed new-onset hypogammaglobulinemia and infectious complications following treatment. Our study highlights a role for heightened vigilance of rituximab-associated hypogammaglobulinemia and infections in pediatric patients with rheumatic conditions.

Reconstitution of IgG Subclasses Following Immunoglobulin Administration in Adult Patients with Common Variable Immune Deficiency

BACKGROUND

Immunoglobulin (Ig) therapy reduces the frequency and severity of infection among patients with antibody deficiency disorders. However, a subset of patients lacks adequate clinical response.

OBJECTIVE

The purpose of this study was to determine in adult common variable immune deficiency (CVID) patients (A) if lack of clinical response to Ig therapy correlates with lack of reconstitution of IgG subclass (es), (B) correlation between Ig dosing and/or IgG trough levels and IgG subclass reconstitution, (C) and most common impaired Streptococcus pneumoniae (S. pneumoniae) serotype antibody response.

METHODS

Single-institution, retrospective chart review for CVID patients at immunology clinics from 2015 to 2019. Patients were monitored every 3-6 months for IgG dosage, IgG trough levels, IgG subclass reconstitution, infectious episodes (chronic sinusitis, bronchitis, upper respiratory, and lower respiratory tract infections), urinary tract infections, and antibiotic use. Follow-up was calculated in patient years.

RESULTS

Twenty-five of 41 patients achieved complete reconstitution of all IgG subclasses, and 16/41 demonstrated intermittent or lack of reconstitution. There were significantly less (p < 0.001) infections among fully reconstituted patients (0.66 ± 0.19 infections per patient year) as compared to those with intermittent or lack of reconstitution (1.26 ± 0.13 infections per patient year). There was a significant correlation between IgG trough levels and IgG subclass reconstitution. Most common impaired S. pneumoniae serotype included 3, 4, 9n, 10a, 11a, 12f, and 15b.

CONCLUSIONS

Incomplete IgG subclass reconstitution was associated with increased frequency of infections. IgG trough levels correlate with IgG subclass reconstitution. A limited number of S. pneumoniae serotype antibodies are commonly impaired in CVID.

Granulomatous lung disease: clinical aspects

INTRODUCTION

Granulomatous lung diseases (GLD) are heterogeneous group of diseases that can be broadly categorized as infectious or noninfectious. This distinction is extremely important, as the misdiagnosis of a GLD can have serious consequences. In this manuscript, we describe the clinical manifestations, histopathology, and diagnostic approach to GLD. We propose an algorithm to distinguish infectious from noninfectious GLD.

AREAS COVERED

We have searched PubMed and Medline database from 1950 to December 2019, using multiple keywords as described below. Major GLDs covered include those caused by mycobacteria and fungi, sarcoidosis, hypersensitivity pneumonitis, and vasculidities.

EXPERT OPINION

The cause of infectious GLD is usually identified through microbiological culture and molecular techniques. Most noninfectious GLD are diagnosed by clinical and laboratory criteria, often with exclusion of infectious pathogens. Further understanding of the immunopathogenesis of the granulomatous response may allow improved diagnosis and treatment of GLD.

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.

Pulmonary Manifestations of Predominantly Antibody Deficiencies

Predominantly antibody deficiencies (PADs) are the most frequent forms of primary immunodeficiency diseases (PIDs). Commonly accompanied with complications involving several body systems, immunoglobulin substitution therapy along with prophylactic antibiotics remained the cornerstone of treatment for PADs and related complications. Patients with respiratory complications should be prescribed an appropriate therapy as soon as possible and have to be adhering to more and longer medical therapies. Recent studies identified a gap for screening protocols to monitor respiratory manifestations in patients with PADs. In the present chapter, the pulmonary manifestations of different PADs for each have been discussed. The chapter is mainly focused on X-linked agammaglobulinemia, common variable immunodeficiency, activated PI3K-δ syndrome, LRBA deficiency, CD19 complex deficiencies, CD20 deficiency, other monogenic defects associated with hypogammaglobulinemia, immunoglobulin class switch recombination deficiencies affecting B-cells, transient hypogammaglobulinemia of infancy, and selective IgA deficiency.

Common Variable Immunodeficiency-Associated Inflammatory Enteropathy: The New Era of Biological Therapy

Common variable immunodeficiency (CVID) is the most frequent form of immunodeficiency in adults. Clinical manifestations are heterogeneous with an increased susceptibility to infections and inflammatory conditions, namely autoimmune diseases, such as inflammatory bowel disease. We present the clinical case of a Caucasian female patient, 21 years old, with a past medical history of CVID, with multiple visits to the emergency department due to abdominal pain in the lower quadrants and diarrhea. Her biochemical analysis showed elevated inflammatory parameters. Stool cultures and parasitological examination of feces were negative. Ileocolonoscopy revealed lymphoid nodular hyperplasia of the terminal ileum, and the small bowel capsule endoscopy demonstrated edema and multiple pleomorphic ulcers (Lewis score = 1,104). CVID-associated inflammatory enteropathy was suspected. Budesonide 9 mg/day was started, but no positive clinical response was observed. It was decided to initiate biological therapy with infliximab. The patient's condition is currently clinically improved with no complications due to biological therapy.

Acute Rejection of a Kidney Transplant in a Patient With Common Variable Immunodeficiency: A Case Report

Common variable immunodeficiency is a primary immunodeficiency characterized by hypogammaglobulinemia and recurrent bacterial infections. We report a case of a 44-year-old male patient with end-stage renal disease and an established diagnosis of common variable immunodeficiency who underwent a living unrelated kidney transplant. He remained nearly infection free on maintenance immunoglobulin replacement. However, his posttransplant course was complicated by acute rejection that ultimately led to allograft loss. This case illustrates the challenge of transplantation in this patient population because of the delicate balance that must be achieved between maintaining adequate immunosuppression and minimizing the risk of infection.

Treatment with rituximab and brentuximab vedotin in a patient of common variable immune deficiency-associated classic Hodgkin lymphoma

Background

Patients with common variable immunodeficiency (CVID) have an increased risk of developing lymphoproliferative diseases, including non-Hodgkins lymphoma (Blood 116:1228–1234, 2010; Blood 119:1650–7, 2012). The incidence and prognosis of Hodgkin lymphoma in this population is not clear, with only a few case reports in the literature. Conventional cytotoxic chemotherapy, although highly efficacious in treating Hodgkin lymphoma in immune competent patients, is problematic in patients with CVID due to the increased risk of infectious complications (Ther Umsch 69:687–91, 2012; Pediatr Hematol Oncol 24:337–42, 2012). Rituximab and brentuximab vedotin are both targeted agents used to treat lymphomas that express CD20 and CD30, respectively. Compared to cytotoxic chemotherapy typically used in Hodgkin lymphoma, these agents are better tolerated with minimal side effects. This makes them an attractive option for treating lymphoma in patients who have significant co-morbidities, including those with immune deficiencies. Additionally, rituximab has been used safely to treat autoimmune cytopenias in patients with CVID5. However, the role of these targeted therapies in CVID-associated Hodgkin lymphoma has not been reported.

Case Presentation

Here we report the case of a 25 year old female diagnosed with CVID-associated classic Hodgkin lymphoma, who achieved a complete remission following treatment with rituximab followed by brentuximab vedotin.

Conclusions

We demonstrate that rituximab and brentuximab are likely safe and effective in CVID-associated Hodgkin lymphoma, providing a feasible and potentially optimal treatment option for this patient population.

International Consensus Document (ICON): Common Variable Immunodeficiency Disorders

The International Collaboration in Asthma, Allergy and Immunology initiated an international coalition among the American Academy of Allergy, Asthma & Immunology; the European Academy of Allergy and Clinical Immunology; the World Allergy Organization; and the American College of Allergy, Asthma & Immunology on common variable immunodeficiency. An author group was formed and then divided into individual committees. Within the committee, teams of authors were subgrouped to generate content for specific sections of the document. Content was derived from literature searches, relevant published guidelines, and clinical experience. After a draft of the document was assembled, it was collectively reviewed and revised by the authors. Where evidence was lacking or conflicting, the information presented represents the consensus expert opinion of the group. The full document was then independently reviewed by 5 international experts in the field, none of whom was among the authors of the original. The comments of these reviewers were incorporated before submission for publication.

Unbalanced Immune System: Immunodeficiencies and Autoimmunity

Increased risk of developing autoimmune manifestations has been identified in different primary immunodeficiencies (PIDs). In such conditions, autoimmunity and immune deficiency represent intertwined phenomena that reflect inadequate immune function. Autoimmunity in PIDs may be caused by different mechanisms, including defects of tolerance to self-antigens and persistent stimulation as a result of the inability to eradicate antigens. This general immune dysregulation leads to compensatory and exaggerated chronic inflammatory responses that lead to tissue damage and autoimmunity. Each PID may be characterized by distinct, peculiar autoimmune manifestations. Moreover, different pathogenetic mechanisms may underlie autoimmunity in PID. In this review, the main autoimmune manifestations observed in different PID, including humoral immunodeficiencies, combined immunodeficiencies, and syndromes with immunodeficiencies, are summarized. When possible, the pathogenetic mechanism underlying autoimmunity in a specific PID has been explained.

The role of toll-like receptors in B-cell development and immunopathogenesis of common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most frequent symptomatic primary immune deficiency and is characterized by hypogammaglobulinemia, defect in specific antibody response and increased susceptibility to recurrent infections, malignancy and autoimmunity. Patients with CVID often have defects in post-antigenic B-cell differentiation, with fewer memory B cells and impaired isotype switching. Toll-like receptors (TLRs) are expressed on various immune cells as key elements of innate and adaptive immunity. TLR signaling in B cells plays multiple roles in cell differentiation and activation, class-switch recombination and cytokine and antibody production. Moreover, recent studies have shown functional alteration of TLRs responses in CVID patients including poor cell proliferation, impaired upregulation of co-stimulatory molecules and failure in cytokine and immunoglobulin production. The purpose of the present review is to discuss the role of TLRs in B-cell development and function as well as their role in the immunopathogenesis of CVID.

IgH sequences in common variable immune deficiency reveal altered B cell development and selection

Common variable immune deficiency (CVID) is the most common symptomatic primary immune deficiency, affecting ~1 in 25,000 persons. These patients suffer from impaired antibody responses, autoimmunity, and susceptibility to lymphoid cancers. To explore the cellular basis for these clinical phenotypes, we conducted high-throughput DNA sequencing of immunoglobulin heavy chain gene rearrangements from 93 CVID patients and 105 control subjects and sorted naïve and memory B cells from 13 of the CVID patients and 10 of the control subjects. The CVID patients showed abnormal VDJ rearrangement and abnormal formation of complementarity-determining region 3 (CDR3). We observed a decreased selection against antibodies with long CDR3s in memory repertoires and decreased variable gene replacement, offering possible mechanisms for increased patient autoreactivity. Our data indicate that patient immunodeficiency might derive from both decreased diversity of the naïve B cell pool and decreased somatic hypermutation in memory repertoires. The CVID patients also exhibited an abnormal clonal expansion of unmutated B cells relative to the controls. Although impaired B cell germinal center activation is commonly viewed as causative in CVID, these data indicate that CVID B cells diverge from controls as early as the pro-B stage, cell and suggest possible explanations for the increased incidence of autoimmunity, immunodeficiency, and lymphoma CVID patients.

Necrotizing and sarcoidal granulomas in the skin and synovial membrane, associated with common variable immunodeficiency

Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by hypogammaglobulinaemia, T-cell abnormalities and recurrent bacterial infections. Patients with CVID can present granulomatous lesions on both the skin and other organs. When these lesions are the first sign of the disease, the diagnosis can be very challenging. We report the case of a patient with undiagnosed CVID, who presented with necrotizing and sarcoidal granulomas on the skin and synovial membrane as the first appearance of immunodeficiency.

Cervical lymph node diseases in children

The lymph nodes are an essential part of the body’s immune system and as such are affected in many infectious, autoimmune, metabolic and malignant diseases. The cervical lymph nodes are particularly important because they are the first drainage stations for key points of contact with the outside world (mouth/throat/nose/eyes/ears/respiratory system) – a critical aspect especially among children – and can represent an early clinical sign in their exposed position on a child’s slim neck.

Involvement of the lymph nodes in multiple conditions is accompanied by a correspondingly large number of available diagnostic procedures. In the interests of time, patient wellbeing and cost, a careful choice of these must be made to permit appropriate treatment. The basis of diagnostic decisions is a detailed anamnesis and clinical examination. Sonography also plays an important role in differential diagnosis of lymph node swelling in children and is useful in answering one of the critical diagnostic questions: is there a suspicion of malignancy? If so, full dissection of the most conspicuous lymph node may be necessary to obtain histological confirmation.

Diagnosis and treatment of childhood cervical lymph node disorders present the attending pediatric and ENT physicians with some particular challenges. The spectrum of differential diagnoses and the varying degrees of clinical relevance – from banal infections to malignant diseases – demand a clear and considered approach to the child’s individual clinical presentation. Such an approach is described in the following paper.

Laboratory diagnosis of primary immunodeficiencies

Primary immune deficiency disorders represent a highly heterogeneous group of disorders with an increased propensity to infections and other immune complications. A careful history to delineate the pattern of infectious organisms and other complications is important to guide the workup of these patients, but a focused laboratory evaluation is essential to the diagnosis of an underlying primary immunodeficiency. Initial workup of suspected immune deficiencies should include complete blood counts and serologic tests of immunoglobulin levels, vaccine titers, and complement levels, but these tests are often insufficient to make a diagnosis. Recent advancements in the understanding of the immune system have led to the development of novel immunologic assays to aid in the diagnosis of these disorders. Classically utilized to enumerate lymphocyte subsets, flow cytometric-based assays are increasingly utilized to test immune cell function (e.g., neutrophil oxidative burst, NK cytotoxicity), intracellular cytokine production (e.g., TH17 production), cellular signaling pathways (e.g., phosphor-STAT analysis), and protein expression (e.g., BTK, Foxp3). Genetic testing has similarly expanded greatly as more primary immune deficiencies are defined, and the use of mass sequencing technologies is leading to the identification of novel disorders. In order to utilize these complex assays in clinical care, one must have a firm understanding of the immunologic assay, how the results are interpreted, pitfalls in the assays, and how the test affects treatment decisions. This article will provide a systematic approach of the evaluation of a suspected primary immunodeficiency, as well as provide a comprehensive list of testing options and their results in the context of various disease processes.

Diagnostic Immunization with Bacteriophage ΦX 174 in Patients with Common Variable Immunodeficiency/Hypogammaglobulinemia

Purpose: Use of the T cell-dependent neoantigen bacteriophage ΦX 174 has been described since the 1960s as a method to assess specific antibody response in patients with primary immunodeficiencies. We reviewed a cohort of patients at Duke University Medical Center who received immunization with bacteriophage and report the clinical utility and safety of the immunization, as well as patient characteristics.

Methods: A retrospective chart review was performed of all Duke Immunology Clinic patients (pediatric and adult) who received immunizations with bacteriophage, from 1976 to 2012. Subjects were selected for inclusion if their diagnosis at the time of bacteriophage was either presumed or confirmed common variable immunodeficiency (CVID), hypogammaglobulinemia, transient hypogammaglobulinemia, or antibody deficiency unspecified. Follow up post-immunization was also recorded.

Results: One hundred twenty-six patients were identified, 36 adults and 90 pediatric patients. Diagnoses prior to bacteriophage were CVID (n = 100), hypogammaglobulinemia (n = 23), and antibody deficiency (n = 3). Post-immunization diagnoses were CVID (n = 65), hypogammaglobulinemia (n = 19), unknown (n = 23), no primary immune deficiency (n = 10), and other primary immunodeficiency (n = 9). Seventy-five patients had abnormal bacteriophage results, 37 were normal, and 14 were borderline. There were 257 recorded administrations of the immunization. Information was available on adverse reactions for 171 administrations. Fourteen immunizations were associated with minor adverse events. Nineteen patients stopped their immunoglobulin replacement therapy based on reported normal responses to immunization.

Conclusion: Bacteriophage ΦX 174 immunization is a safe, well-tolerated, and clinically useful method to assess antibody response in patients with suspected antibody-mediated immunodeficiencies, particularly those who are on immunoglobulin replacement therapy at the time of immunization.

Complex regional pain syndrome treated with intravenous immunoglobulin in a patient with common variable immune deficiency

INTRODUCTION

Common variable immunodeficiency (CVID) represents a large heterogeneous group of antibody-deficiency syndromes associated with a wide range of clinical features and a lack of defined causes in the realm of primary immunodeficiencies. Here, we present a case of CVID in a 62-year-old white male patient with a history of longstanding complex regional pain syndrome (CRPS).

CASE PRESENTATION

His medical history included multiple sinus infections per year and several pneumonias requiring antibiotics. He has had various back surgeries, including a laminectomy at the L4 level 1 year prior to his diagnosis. Thereafter, he underwent four sympathetic nerve blocks with minimal pain relief. Blood chemistries showed a normal white blood cell count with a normal differential, but increased erythrocyte sedimentation rate and C-reactive protein levels. Total Ig (Immunoglobulin)G was 611 mg/dL (normal 700-1,600), IgG1 was 425 mg/dL (341-894), IgG2 was 114 mg/dL (171-632), IgG3 was 14.4 mg/dL (18.4-106), and IgG4 was 7.4 mg/dL (2.4-121). IgA was 47 mg/dL (normal 70-400), IgM was 131 mg/dL (40-230), and IgE was 4.5 kU/L (<4.0). He only had 10 of 23 pneumococcal titers in the protective range post-vaccination. Upon treatment of the CVID with intravenous immunoglobulin, the patient's pain levels were significantly decreased and have been maintained for more than 2 years.

CONCLUSION

Therefore, immunoglobulin therapy appears to have been beneficial in the treatment of the patient's symptoms of CRPS, including pain. Additional studies investigating the mechanism by which immunoglobulin therapy may reduce the inflammation and pain of CRPS are needed.

Cytokines in common variable immunodeficiency as signs of immune dysregulation and potential therapeutic targets - a review of the current knowledge

Common variable immunodeficiency (CVID) is characterized by low levels of circulating immunoglobulins and compromised specific antibody response leading to frequent infections. Cytokines play an important role in the orchestration of the antibody response. Several previous studies have attempted to identify distinct cytokines responsible for the inflammatory changes and different manifestations of CVID, but there are conflicting results regarding the cytokine profiles in CVID patients. In light of this, an extensive review regarding the level of various cytokines and their potential therapeutic role in CVID patients was performed. This review delineates the contribution of interleukin (IL)-1, IL-2, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12, IL-21, interferons, tumor necrosis factor (TNF)-α, IL-17, APRIL (a proliferation inducing ligand) and BAFF (B cell activating factor) in CVID disease and outline their potential therapeutic implications in these patients.

A rare case report of chronic variable immunodeficiency divulged by ABO discrepancy

ABO discrepancy refers to incongruence between the results of red cell and serum groupings. One such case is described here; the discrepant results of whose routine ABO grouping led to the diagnosis of common variable immunodeficiency. There was no reaction in the reverse grouping of a young patient presenting with recurrent bacterial infections, pointing towards an absence of antibodies in the serum. Diagnosis was made on the basis of markedly decreased serum immunoglobulin levels and by serum protein electrophoresis showing scanty gamma regions.

Autoimmune haematological disorders in two Italian children with Kabuki syndrome

Kabuki syndrome (also called Niikawa-Kuroki syndrome) is a rare genetic disease described for the first time in Japan, characterised by anomalies in multiple organ systems and often associated with autoimmune disorders and impaired immune response. We herein report the clinical history, the therapeutic approach and the outcome of two children with Kabuki syndrome who developed autoimmune haematological disorders (haemolytic anaemia and immune thrombocytopenia). Factors regarding differential diagnosis and interventions in better management of this syndrome and its complications are discussed. This is the first report of Italian children with autoimmune haematological disorders complicating Kabuki syndrome.

Genetic defects and the role of helper T-cells in the pathogenesis of common variable immunodeficiency

Common variable immunodeficfiiency (CVID) is a primary immunodeficiency syndrome representing a heterogeneous set of disorders resulting mostly in antibody deficiency and recurrent infections. However, inflammatory and autoimmune disorders and some kinds of malignancies are frequently reported as a part of the syndrome. Although it is one of the most widespread primary immunodeficiency, only recently some genetic defects in CVID have been identified. Mutations have been detected in inducible T-cell costimulator (ICOS), transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), B-cell activating factor-receptor (BAFF-R), B-cell receptor complex (CD19, CD21 and CD81) and CD20. On the other hand, recent studies have shown a decrease in T-helper-17 cells frequency and their characteristic cytokines in CVID patients and this emphasis on the vital role of the T-cells in immunopathogenesis of the CVID. Furthermore, in the context of autoimmune diseases accompanying CVID, interleukin 9 has recently attracted a plenty of considerations. However, the list of defects is expanding as exact immunologic pathways and genetic disorders in CVID are not yet defined. In this review, we have a special focus on the immunopathogenesis of CVID, recent advances in understanding the underlying etiology and genetics for patients.

A review on guidelines for management and treatment of common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency in adults. As symptoms of CVID are usually heterogeneous and unspecific, diagnosis and follow-up of CVID can be challenging. In light of this, a broad review of advances in management and treatment of CVID is performed here in order to reach a distinct protocol. However, it should be noted that owing to the nature of the disease, it can only be treated symptomatically but not cured. There is little evidence to guide appropriate or universal guidelines to improve the current status of management of the disease. The most satisfactory treatments of CVID could be achieved by the use of immunoglobulin replacement, antibiotics, immunosuppressants and hematopoietic stem cell transplantation. This review is written based on the importance of clinical surveillance of asymptomatic CVID cases and early recognition of different clinical complications. Moreover, for each complication, appropriate interventions for improving outcomes are mentioned.

Interferon signature in the blood in inflammatory common variable immune deficiency

About half of all subjects with common variable immune deficiency (CVID) are afflicted with inflammatory complications including hematologic autoimmunity, granulomatous infiltrations, interstitial lung disease, lymphoid hyperplasia and/or gastrointestinal inflammatory disease. The pathogenesis of these conditions is poorly understood but singly and in aggregate, these lead to significantly increased (11 fold) morbidity and mortality, not experienced by CVID subjects without these complications. To explore the dysregulated networks in these subjects, we applied whole blood transcriptional profiling to 91 CVID subjects, 47 with inflammatory conditions and 44 without, in comparison to subjects with XLA and healthy controls. As compared to other CVID subjects, males with XLA or healthy controls, the signature of CVID subjects with inflammatory complications was distinguished by a marked up-regulation of IFN responsive genes. Chronic up-regulation of IFN pathways is known to occur in autoimmune disease due to activation of TLRs and other still unclarified cytoplasmic sensors. As subjects with inflammatory complications were also more likely to be lymphopenic, have reduced B cell numbers, and a greater reduction of B, T and plasma cell networks, we suggest that more impaired adaptive immunity in these subjects may lead to chronic activation of innate IFN pathways in response to environmental antigens. The unbiased use of whole blood transcriptome analysis may provides a tool for distinguishing CVID subjects who are at risk for increased morbidity and earlier mortality. As more effective therapeutic options are developed, whole blood transcriptome analyses could also provide an efficient means of monitoring the effects of treatment of the inflammatory phenotype.

Common variable immunodeficiency and isosporiasis: first report case

We report a severe case of diarrhea in a 62-year-old female HIV-negative patient from whom Giardia lamblia and Isospora belli were isolated. Because unusual and opportunistic infections should be considered as criteria for further analysis of immunological status, laboratory investigations led to a diagnosis of common variable immunodeficiency (CVID). This is the first reported case of isosporiasis in a patient with CVID and illustrates the importance of being aware of a possible link, particularly in relation to primary immunodeficiency.

Evaluation of CD4+CD25+FOXP3+ regulatory T cells function in patients with common variable immunodeficiency

Common variable immunodeficiency (CVID) is one of the predominant antibody disorders where abnormalities in regulatory T cells (Tregs) may result in autoimmunity and chronic inflammation. To evaluate Tegs frequency and function, 13 CVID patients and 10 age- and sex-matched healthy volunteer were enrolled. The percentages of Tregs were calculated using flow cytomety method. For assessment of Treg function, Tregs were isolated and their suppressive functions were determined using Tregs suppression assay. The levels of immunoregulatory cytokines IL-10 and TGF-β produced by Tregs were also measured. Our results revealed that Tregs frequency (P<0.001) and their suppressive functions (P<0.001) were impaired in CVID patients. The level of TGF-β did not differ between CVID patients and controls (p=0.09); while the amount of IL-10 was remarkably decreased in CVID patients (P=0.007). Our findings suggest that disturbed Tregs frequency and their functional characteristics might account for aberrant immune responses observed in CVID patients.

TACI mutations and impaired B-cell function in subjects with CVID and healthy heterozygotes

BACKGROUND

Mutations in the gene coding for the transmembrane activator and calcium-modulating cyclophilin ligand interactor (TACI) are found in 8% to 10% of subjects with common variable immunodeficiency (CVID). Although heterozygous mutations may coincide with immunodeficiency in a few families, most mutation-bearing relatives are not hypogammaglobulinemic. Thus, the role of TACI mutations in producing the immune defect remains unclear.

OBJECTIVE

This study examined the expression and function of TACI mutations in healthy heterozygous relatives.

METHODS

We examined the surface and intracellular expression of TACI protein in EBV-transformed B cells of patients and relatives with mutations in 7 families, binding of a proliferation-inducing ligand, and secretion of IgG and IgA by ligand-activated B cells. We tested whether Toll-like receptor 9 agonists increased TACI expression and whether an agonistic anti-TACI antibody could induce activation-induced cytidine deaminase mRNA in those with mutations.

RESULTS

Intracellular and extracellular TACI expression was defective for B cells of all subjects with mutations, including subjects with CVID and relatives. Although Toll-like receptor 9 triggering normally up-regulates B-cell TACI expression, this was defective for all subjects with mutations. Triggering TACI by an agonistic antibody showed loss of activation-induced cytidine deaminase mRNA induction in all mutation-bearing B cells. However, ligand-induced IgG and IgA production was normal for healthy relatives but not for subjects with CVID.

CONCLUSION

Thus, B cells of relatives of subjects with CVID who have mutations in TACI but normal immune globulin levels still have detectable in vitro B-cell defects.

Use of combination chemotherapy for treatment of granulomatous and lymphocytic interstitial lung disease (GLILD) in patients with common variable immunodeficiency (CVID)

PURPOSE

A subset of patients with common variable immunodeficiency (CVID) develops granulomatous and lymphocytic interstitial lung disease (GLILD), a restrictive lung disease associated with early mortality. The optimal therapy for GLILD is unknown. This study was undertaken to see if rituximab and azathioprine (combination chemotherapy) would improve pulmonary function and/or radiographic abnormalities in patients with CVID and GLILD.

METHODS

A retrospective chart review of patients with CVID and GLILD who were treated with combination chemotherapy was performed. Complete pulmonary function tests (PFTs) and high-resolution computed tomography (HRCT) scans of the chest were done prior to therapy and >6 months later. HRCT scans of the chest were blinded, randomized, and scored independently (in pairs) by two radiologists. The differences between pre- and post-treatment HRCT scores and PFT parameters were analyzed.

RESULTS

Seven patients with CVID and GLILD met inclusion criteria. Post-treatment increases were noted in both FEV1 (p=0.034) and FVC (p=0.043). HRCT scans of the chest demonstrated improvement in total score (p=0.018), pulmonary consolidations (p=0.041), ground-glass opacities (p=0.020) nodular opacities (p=0.024), and both the presence and extent of bronchial wall thickening (p=0.014, 0.026 respectively). No significant chemotherapy-related complications occurred.

CONCLUSIONS

Combination chemotherapy improved pulmonary function and decreased radiographic abnormalities in patients with CVID and GLILD.

Combined immunodeficiency with life-threatening EBV-associated lymphoproliferative disorder in patients lacking functional CD27

CD27, a tumor necrosis factor receptor family member, interacts with CD70 and influences T-, B- and NK-cell functions. Disturbance of this axis impairs immunity and memory generation against viruses including Epstein Barr virus (EBV), influenza, and others. CD27 is commonly used as marker of memory B cells for the classification of B-cell deficiencies including common variable immune deficiency. Flow cytometric immunophenotyping including expression analysis of CD27 on lymphoid cells was followed by capillary sequencing of CD27 in index patients, their parents, and non-affected siblings. More comprehensive genetic analysis employed single nucleotide polymorphism-based homozygosity mapping and whole exome sequencing. Analysis of exome sequencing data was performed at two centers using slightly different data analysis pipelines, each based on the Genome Analysis ToolKit Best Practice version 3 recommendations. A comprehensive clinical characterization was correlated to genotype. We report the simultaneous confirmation of human CD27 deficiency in 3 independent families (8 patients) due to a homozygous mutation (p. Cys53Tyr) revealed by whole exome sequencing, leading to disruption of an evolutionarily conserved cystein knot motif of the transmembrane receptor. Phenotypes varied from asymptomatic memory B-cell deficiency (n=3) to EBV-associated hemophagocytosis and lymphoproliferative disorder (LPD; n=3) and malignant lymphoma (n=2; +1 after LPD). Following EBV infection, hypogammaglobulinemia developed in at least 3 of the affected individuals, while specific anti-viral and anti-polysaccharide antibodies and EBV-specific T-cell responses were detectable. In severely affected patients, numbers of iNKT cells and NK-cell function were reduced. Two of 8 patients died, 2 others underwent allogeneic hematopoietic stem cell transplantation successfully, and one received anti-CD20 (rituximab) therapy repeatedly. Since homozygosity mapping and exome sequencing did not reveal additional modifying factors, our findings suggest that lack of functional CD27 predisposes towards a combined immunodeficiency associated with potentially fatal EBV-driven hemo-phagocytosis, lymphoproliferation, and lymphoma development.

Three different classifications, B lymphocyte subpopulations, TNFRSF13B (TACI), TNFRSF13C (BAFF-R), TNFSF13 (APRIL) gene mutations, CTLA-4 and ICOS gene polymorphisms in Turkish patients with common variable immunodeficiency

B lymphocyte subpopulations, previously defined classification schemes (Freiburg, Paris, EuroClass), TNFRSF13B (TACI), TNFRSF13C (BAFF-R), TNFSF13 (APRIL) gene mutations, CTLA-4 and ICOS gene polymorphisms were analyzed in 25 common variable immunodeficiency (CVID) patients and 25 healthy controls. Patients were also divided into two subgroups due to some disease severity criteria. SG (severe disease group) (n:11) included patients who have splenomegaly and/or granulomatous diseases and/or bronchiectasis and/or lower baseline IgG values (<270 mg/dl). MG (moderate disease group) (n:14) patients diagnosed as having ESID/PAGID criteria but does not fulfill SG inclusion criteria. The onset of infectious symptoms and age at diagnosis were 50.0 ± 45.7 and 78.5 ± 54.5 months, respectively. Parental consanguinity rate was 54.5% in SG and 7.1% in MG. Switched-memory B cells (CD19 + 27 + IgD-IgM-) showed significant decrease in CVID patients and these cells were also significantly lower in SG compared to MG. CVID patients had significantly higher percentages of CD19 + κ + B cells and CD19 + λ + B cells than healthy controls. Freiburg classification: 87.5% of patients (n:21) were in group I and 12.5% were in Group II. Eighteen (75%) CVID patients with a low percentage of CD21(low) B cells were in Group Ib while three patients classified as Group Ia. The significantly lower levels of IgG and IgA in Group Ia is a novel finding. The percentages of patients for Paris Classification groups MB0, MB1, MB2 were 88%, 4% and 8%, respectively. There was a significant increase of splenomegaly, lymphadenopathy and autoimmune cytopenia in Group MB0. EuroClass: 45.8% of patients were smB+ and 54.2% were smB-. Splenomegaly and lymphadenopathy were significantly higher in smB- group. TACI: One patient carried heterozygous C104R mutation which was known as disease causing. APRIL: G67R and N96S SNPs were detected in most of the patients and healthy controls. BAFF-R: P21R/H159Y compound heterozygous mutation (n:1) and P21R heterozygous mutations (n:3) were detected. +49 A > G changes in exon 1 of CTLA-4 gene: GG and AG genotypes increase the risk of CVID development 1.32 and 2.18 fold, respectively. 1564 T > C polymorphisms on 3'UTR region in exon 2 of ICOS gene was not found to be significantly different in CVID patients. CVID classifications were not helpful in determining the genetic etiology of CVID.

Toll-like receptor function in primary B cell defects

Primary immunodeficiency diseases include more than 150 different genetic defects, classified on the basis of the mutations or physiological defects involved. The first immune defects to be well recognized were those of adaptive immunity affecting B cell function and resulting in hypogammaglobulinemia and defects of specific antibody production; more recently, novel defects of innate immunity have been described, some involving Toll-like receptors (TLRs) and their signaling pathways. Furthermore, it is increasingly evident that the innate and adaptive pathways intersect and reinforce each other. B cells express a number of TLRs, which when activated lead to cell activation, up-regulation of co-stimulatory molecules, secretion of cytokines, up-regulation of recombination enzymes, isotype switch and immune globulin production. TLR activation of antigen presenting cells leads to heightened cytokine production, providing additional stimuli for B cell development and maturation. Recent studies have demonstrated that patients with common variable immunodeficiency (CVID) and X-linked agammaglobulinemia (XLA) have altered TLR responsiveness. We review TLR defects in these disorders of B cell development, and discuss how B cell gene defects may modulate TLR signaling.

Morbidity and mortality in common variable immune deficiency over 4 decades

The demographics, immunologic parameters, medical complications, and mortality statistics from 473 subjects with common variable immune deficiency followed over 4 decades in New York were analyzed. Median immunoglobulin levels were IgG, 246 mg/dL; IgA, 8 mg/dL; and IgM, 21 mg/dL; 22.6% had an IgG less than 100 mg/dL. Males were diagnosed earlier (median age, 30 years) than females (median age, 33.5 years; P = .004). Ninety-four percent of patients had a history of infections; 68% also had noninfectious complications: hematologic or organ-specific autoimmunity, 28.6%; chronic lung disease, 28.5%; bronchiectasis, 11.2%; gastrointestinal inflammatory disease, 15.4%; malabsorption, 5.9%; granulomatous disease, 9.7%; liver diseases and hepatitis, 9.1%; lymphoma, 8.2%; or other cancers, 7.0%. Females had higher baseline serum IgM (P = .009) and were more likely to develop lymphoma (P = .04); 19.6% of patients died, a significantly shorter survival than age- and sex-matched population controls (P < .0001). Reduced survival was associated with age at diagnosis, lower baseline IgG, higher IgM, and fewer peripheral B cells. The risk of death was 11 times higher for patients with noninfectious complications (hazard ratio = 10.95; P < .0001). Mortality was associated with lymphoma, any form of hepatitis, functional or structural lung impairment, and gastrointestinal disease with or without malabsorption, but not with bronchiectasis, autoimmunity, other cancers, granulomatous disease, or previous splenectomy.

Perspectives on common variable immune deficiency

Common variable immunodeficiency (CVID) is considered to be a collection of genetic immune defects with complex inheritance patterns. While the main phenotype is loss of B cell function, the majority of the genetic mechanisms leading to CVID remain elusive. In the past two decades there have been increasing efforts to unravel the genetic defects in CVID. Here, we provide an overview of our current understanding of the genetic basis of these defects, as revealed over time by earlier linkage studies in large cohorts, analysis of families with recessive inheritance, targeted gene approaches, and genome-wide association studies using single nucleotide polymorphism arrays and copy number variation, and whole genome studies.

Autoimmunity in primary immune deficiency: taking lessons from our patients

The elucidation of the genes leading to selected immune defects has accelerated our understanding of the molecular basis of tolerance in autoimmunity disorders. Mutations in genes of the immune system are known to lead to a catalogue of functional deficits, including loss of activation-induced Fas-mediated apoptosis, an inability to remove self-reactive T and/or B cells and insufficient numbers or functions of regulatory T cells. In most cases, microbial antigen stimulation occurs simultaneously, leading to further inflammatory responses. In each case, probing the molecular pathways involved in these primary immune defects has led to a better understanding of autoimmune diseases in general. While subjects with X-linked agammaglobulinaemia are almost devoid of autoimmune diseases, B cells which are present, but dysfunctional in other defects, lead to a significant incidence of autoimmune disease. Autoimmunity is also particularly common in the antibody deficiency states. Although organ-based autoimmunity also occurs, for unclear reasons the main conditions are immune thrombocytopenia purpura and autoimmune haemolytic anaemia. The common variable immune deficiency subjects most afflicted by these cytopenias are those with specific peripheral blood memory B cell phenotypes. B cells of these subjects have a retained autoimmune potential, lack of somatic hypermutation, profound loss of proliferative potential, accelerated apoptosis and loss of normal Toll-like receptor signalling. Treatment with high-dose immunoglobulin and/or steroids can be helpful, while rituximab provides benefits in the treatment of refractory cytopenias with apparently little risk, even with repeated use, due to ongoing immune globulin therapy.

How I treat common variable immune deficiency

Common variable immunodeficiency is a rare immune deficiency, characterized by low levels of serum immunoglobulin G, A, and/or M with loss of antibody production. The diagnosis is most commonly made in adults between the ages of 20 and 40 years, but both children and older adults can be found to have this immune defect. The range of clinical manifestations is broad, including acute and chronic infections, inflammatory and autoimmune disease, and an increased incidence of cancer and lymphoma. For all these reasons, the disease phenotype is both heterogeneous and complex. Contributing to the complexity is that patient cohorts are generally small, criteria used for diagnosis vary, and the doses of replacement immune globulin differ. In addition, routines for monitoring patients over the years and protocols for the use of other biologic agents for complications have not been clarified or standardized. In the past few years, data from large patient registries have revealed that both selected laboratory markers and clinical phenotyping may aid in dissecting groups of subjects into biologically relevant categories. This review presents my approach to the diagnosis and treatment of patients with common variable immunodeficiency, with suggestions for the use of laboratory biomarkers and means of monitoring patients.

Thoracic manifestations of primary humoral immunodeficiency: a comprehensive review

Humoral immunodeficiencies, which are characterized by defective production of antibodies, are the most common types of primary immunodeficiency. Pulmonary changes are present in as many as 60% of patients with humoral immunodeficiency. Chronic changes and recurrent infections in the respiratory airways are the main causes of morbidity and mortality in those affected by a humoral immunodeficiency. Medical imaging, especially computed tomography (CT), plays a crucial role in the initial detection and characterization of changes and in monitoring the response to therapy. The spectrum of abnormalities seen at thoracic imaging includes noninfectious airway disorders, infections, chronic lung diseases, chronic inflammatory conditions (granulomatosis, interstitial pneumonias), and benign and malignant neoplasms. Recognition of characteristic CT and radiographic features, and correlation of those features with clinical and laboratory findings, are necessary to differentiate between the many possible causes of parenchymal and mediastinal disease seen in patients with primary humoral immunodeficiencies.

Evaluation of immunoglobulin levels and infection rate in patients with common variable immunodeficiency after immunoglobulin replacement therapy

BACKGROUND/PURPOSE

Common variable immunodeficiency (CVID) is characterized by decreased serum levels of IgG and increased susceptibility to recurrent infections. The aim of this study was to evaluate the IgG subclass levels of CVID patients.

METHODS

Twenty-four CVID patients who had been under regular intravenous immunoglobulin replacement therapy for 96.13 +/- 54.83 months were enrolled in this study. Serum IgG and IgG subclass levels, and clinical outcomes for these patients were evaluated after this period of treatment.

RESULTS

Mean serum IgG levels were significantly increased from 272.91 +/- 185.58 mg/dL at the time of diagnosis to 455.29 +/- 200.23 mg/dL after treatment, while there was no significant difference in the serum levels of IgM and IgA. Decreased serum levels of IgG1 were detected in 75% of the patients studied. Decreased serum levels of IgG2, IgG3 and IgG4 were also detected in 6, 11, and 11 patients, respectively. All patients experienced recurrent infectious diseases either before, or after, diagnosis.

CONCLUSION

Although serum IgG levels in the patients significantly increased after regular intravenous immunoglobulin replacement therapy, serum IgM and IgA levels remained diminished over time. Furthermore, a number of cases had low levels of IgG subclasses, in spite of normal total IgG levels, which could explain why some patients had continued infections, even after immunoglobulin replacement therapy.

Immunodeficiencies

Primary immunodeficiencies (PIDs) are uncommon, chronic and severe disorders of the immune system in which patients cannot mount a sufficiently protective immune response, leading to an increased susceptibility to infections. The treatment of choice for PID patients with predominant antibody deficiency is intravenous immunoglobulin (Ig) replacement therapy. Despite major advances over the last 20 years in the molecular characterization of PIDs, many patients remain undiagnosed or are diagnosed too late, with severe consequences. Various strategies to ensure timely diagnosis of PIDs are in place, and novel approaches are being developed. In recent years, several patient registries have been established. Such registries shed light on the pathology and natural history of these varied disorders. Analyses of the registry data may also reveal which patients are likely to respond well to higher Ig infusion rates and may help to determine the optimal dosing of Ig products. Faster infusion rates may lead to improved convenience for patients and thus increase patient compliance, and may reduce nursing time and the need for hospital resources. Data from two recent studies suggest that Gamunex and Privigen are well tolerated at high infusion rates. Nevertheless, careful selection of patients for high infusion rates, based on co-morbid conditions and tolerance of the current infusion rate, is advisable. Based on the available data, intravenous Ig offers broad protection against encapsulated organisms. As vaccine trends change, careful monitoring of specific antibody levels in the general population, such as those against pneumococcal and meningococcal bacteria, should be implemented.

Autoimmunity in common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most common clinically significant primary immune defect. Although the hallmark of CVID is hypogammaglobulinemia, the intrinsic dysregulation of the immune system leads to defective T-cell activation and proliferation, as well as dendritic cell and cytokine defects. Although 70% to 80% of patients have had recurrent sinopulmonary infections, autoimmunity and inflammatory complications are also common. The most common autoimmune conditions are immune thrombocytopenic purpura and hemolytic anemia, but other autoimmune complications arise, including rheumatoid arthritis, pernicious anemia, primary biliary cirrhosis, thyroiditis, sicca syndrome, systemic lupus, and inflammatory bowel disease. Treatment of autoimmunity includes high-dose immunoglobulins, corticosteroids, selected immunosuppressants, and other immune modulators. This review focuses on autoimmune conditions associated with CVID, potential mechanisms of immune dysregulation, and therapeutic strategies.