Comparison of the Percentage of Regulatory T cells and their p-STAT5 Expression in Allergic and Non-Allergic Common Variable Immunodeficiency Patients

Common Variable Immunodeficiency (CVID) is a primary immunodeficiency characterized by an immunologic deficiency in immunoglobulin production. Regulatory T cells (Tregs) play a key role in preventing the development allergic disorders. p-STAT5 is a known factor for the function and survival of Tregs. This study aimed to investigate the number of Tregs and their p-STAT5 expression in allergic and non-allergic CVID patients.Peripheral blood mononuclear cells (PBMCs) were isolated from 10 healthy volunteers, 10 allergic patients, and 16 CVID patients (allergic and non-allergic) using Ficoll density centrifugation. The percentage of Tregs in PBMCs was analyzed by flow cytometry. Tregs were also isolated from participants using an immunomagnetic separation method and p-STAT5 expression was evaluated in Tregs using flow cytometry.The results revealed that Treg percentage was significantly lower in the CVID patients than the control groups (healthy and allergic individuals) (p0.001). There was a significant reduction in Treg percentage in allergic patients compared to healthy subjects (p0.05). No significant difference in Treg percentage between allergic and non-allergic CVID patients was observed. The expression of p-STAT5 in Tregs was significantly lower in CVID patients than the control groups (p0.001). In addition, the expression of p-STAT5 in Tregs of allergic patients was significantly decreased compared to healthy subjects (p0.001). However, the deference of p-STAT5 level was not statistically significant between allergic and non-allergic CVID patients.These findings suggest that p-STAT5 signaling defect and decreased Treg number may not participate in the development of allergy in CVID patients.