Understanding the natural history of selective IgA deficiency

Patients with selective IgA deficiency (SIgAD) present elevated morbidity associated with infections, allergic conditions, autoimmune disorders, and neoplasms. This study aims to characterize clinical manifestations, disease progression, and laboratory findings in a cohort of pediatric patients with SIgAD.

The study included patients with confirmed SIgAD and a clinical history of at least 5 years. Data encompassed clinical manifestations of the disease, patient outcomes, and laboratory findings, including IgA, IgG, IgM, IgE levels and complete blood count.

A total of 51 patients (1.2:1 female-to-male ratio) were included, with a median age at diagnosis of 6 years. Infections were the most common clinical manifestations of SIgAD (98 %), with pneumonia being the most frequent (94 %), followed by sinusitis (70 %). Additionally, 47 patients (92.1 %) exhibited allergic manifestations, including rhinitis or asthma. Autoimmune conditions were identified in 10 patients, predominantly thyroiditis (60 %), while neoplasms were observed in 3 patients. The sequence of disease onset revealed a natural progression, beginning with infectious diseases, followed significantly by allergic and autoimmune conditions. Elevated immunoglobulin levels (IgM or IgG) were observed in 25 patients, with hypergammaglobulinemia significantly associated with autoimmune conditions or the presence of autoantibodies (p < 0.05).

SIgAD is a clinically significant condition. Understanding its natural history deepens our knowledge of the disease and helps early detection and diagnosis of comorbidities that may arise at various stages of a patient's life. Monitoring other immunoglobulin levels may offer potential biomarkers for predicting autoimmune conditions; however, larger studies are needed to validate these biomarkers.