Israel Medical Association Journal

Inborn errors of immunity (IEI), formerly referred to as primary immunodeficiencies, is a growing spectrum of over 550 genetically defined disorders of the immune system. As our understanding of the mechanisms of these disorders grows, immune dysregulation syndromes, autoimmunity, malignancy, bone marrow failure with immunodeficiency, and phenocopies are recognized as part of the clinical spectrum of IEI. Early recognition and accurate classification are critical as many IEI conditions have specific therapeutic implications, including targeted immune modulation, immunoglobulin replacement therapy, hematopoietic stem cell transplantation, and gene therapy. In this review, we present recent changes in classification, updated laboratory workup strategies, and therapeutic advances.

Background: Common variable immunodeficiency (CVID) is the most common clinically significant primary immunodeficiency disorder, typically presenting with hypogammaglobulinemia and recurrent infections. Mechanistically, CVID is caused by abnormal B-cell maturation or function. These abnormalities lead to an impaired ability to generate a normal quantity or diversity of antibodies and an impaired response to neo-antigens. In addition to the resulted immunodeficiency, CVID can also involve immune dysregulation affecting different organ systems, with the lungs being one of the more commonly involved organs. Granulomatous lymphocytic interstitial lung disease (GLILD) is a challenging and well known CVID-related complication. It is associated with high morbidity and increased risk of mortality.

Objectives: To describe the clinical and immunological features of five CVID patients with radiologic and/or pathologic features consistent with granulomatous lymphocytic interstitial lung disease.

Methods: We conducted a review of clinical, laboratory, imaging, and pathology data, as well as B-cell and T-cell immunophenotyping of patient PBMCs, focusing on unique characteristics of CVID GLILD patients.

Results: CVID GLILD patients showed several clinical characteristics, including multiorgan involvement with cytopenias and lymphoproliferation but without significant gastrointestinal involvement. B-cell phenotyping showed abnormal B-cell maturation and development with severely impaired class switching. In addition, unique T-cell phenotype with low to near-absent naive CD4⁺ T cells was observed.

Conclusions: Lung involvement in the form of GLILD is associated with significant co-morbidity and typical B-cell and T-cell immunophenotyping. Patients should be actively screened for the possibility of GLILD, especially when regularly performed lymphocyte immunophenotyping suggests similar patterns.

Obesity is a growing global health concern, with its prevalence contributing to the rise of multiple chronic conditions, including autoimmune diseases. In this review I explore the intricate relationship between obesity and autoimmunity, focusing on how excess adiposity can affect immune responses and promote the development of autoimmune disorders. Obesity alters adipose tissue architecture, promoting chronic low-grade inflammation and triggering the release of pro-inflammatory cytokines, which contribute to immune system dysregulation. Adipose tissue is no longer seen as merely an energy store but as an active endocrine organ that interacts with the immune system. The review delves into mechanisms such as the role of adipokines, altered T cell function, and the recruitment of immune cells to inflamed adipose tissue, which together exacerbate autoimmune risk in obese individuals. Genetic and environmental factors also play a critical role in these processes, as polymorphisms and high-fat diets have been shown to influence both obesity and autoimmune susceptibility. Last, the review explores potential therapeutic strategies, such as lifestyle interventions and targeting obesity-driven inflammatory pathways, which could mitigate autoimmunity. Understanding the connection between obesity and autoimmunity offers insights into more effective interventions for patients suffering from these intertwined conditions.

Background: Approximately 80% of patients with myelodysplastic syndromes (MDS) receive multiple red blood cells (RBC), often multiple transfusions, and are therefore prone to develop alloantibodies against RBC. Because of increasing evidence for the role of immune dysregulation in the pathobiology of MDS, we hypothesized that in patients with MDS there is an increase in alloantibody formation beyond that expected by multiple transfusions.

Objectives: To determine the prevalence rates of alloantibodies in patients with MDS who are transfusion dependent and compare them to those of non-MDS patients matched for number of RBC units they received. 

Methods: The blood bank database was screened to identify non-MDS patients matched for age and number of units transfused. Logistic regression analysis was applied to determine factors affecting alloantibody formation. 

Results: Of 60 patients with MDS, 18 (30%) developed alloantibodies against RBC. Transfusion-dependent MDS and non-MDS patients (N=56 each), matched for number of RBC units and age, were compared. Fifteen MDS patients (27%) but only 12 non-MDS patients (12%) developed alloantibodies (P = 0.057). The relative risk for developing antibodies in MDS patients was 2.14, and MDS was the strongest predictor for formation of alloantibodies during transfusion therapy (odds ratio 3.66, confidence interval 1.4–9.3). 

Conclusions: Patients with MDS are at increased risk to develop RBC alloantibodies, partly because these patients receive multiple RBC transfusions. Whether matching for RH and KEL would lead to lower rates of RBC alloantibodies remains to be determined.