Comparison of clinical characteristics in primary immunodeficiency patients based on the presence of autoimmunity or autoinflammation.

Background: Autoimmunity and autoinflammation are increasingly recognized manifestations of immune dysregulation in patients with primary immunodeficiency (PID), alongside recurrent infections. Objective: The objectives were to determine the prevalence of autoimmune and autoinflammatory findings in patients with PID and to compare their clinical, laboratory, and immunologic characteristics. Methods: This retrospective study included 130 adult patients with PID who were followed up at a tertiary university immunology clinic. The patients were divided into three groups: those without immune dysregulation (group 1), those with predominant autoimmune features (group 2), and those with predominant autoinflammatory features (group 3). Demographic data, laboratory parameters, immunoglobulin levels, lymphocyte subsets, switched memory B cells, and genetic mutation data were analyzed. Results: Autoimmune manifestations were predominant in 32.3% and autoinflammatory findings were predominant in 9.2% of the patients. The patients in group 3 showed significantly elevated C-reactive protein, erythrocyte sedimentation rate (ESR), and fibrinogen levels (p < 0.05). Of the patients in group 2, the platelet count, serum immunoglobulin E (IgE) level, and switched memory B cells were significantly lower compared with other groups (p = 0.001, p = 0.007, p = 0.005, respectively). There were no significant differences in genetic mutation frequency or mortality among groups. Conclusion: Autoimmunity and autoinflammation are frequent in PID and associated with distinct immunologic profiles. Elevated acute phase reactants may indicate autoinflammation, whereas low IgE levels and decreased switched memory B cells may serve as early markers of autoimmunity. Routine evaluation for immune dysregulation in patients with PID is recommended.