Investigations of Immune Response and Interleukin-2 Level in Iranian Patients with Common Variable Immunodeficiency

Abstract

Common variable immunodeficiency (CVID) is the primary immunodeficiency disease with unknown etiology, characterized by impaired antibody responses. In addition to the defect in humoral immunity, the number and function of T cells may be impared in patients with CVID. Regarding interleukin-2 (IL-2) is a fundamental role in survival, proliferation, and development of T cells as the effector arm of cell-mediated immunity, the aim of this study was whether the situation of the cellualr immune system and level of IL-2 in CVID patients differ from healthy subjects. Peripheral blood mononuclear cells were isolated from whole blood of 20 CVID and 10 healthy subjects. The cells were cultured in the presence or absence of phytohemagglutinin (2.5 µl/ml) at 37˚C. The culture supernatant was collected after 72 hours and the IL-2 level was measured by Enzyme-linked immunoabsorbant assay (ELISA).The clinical and laboratory characteristics of the patients were also studied. CVID patients showed the reduction in the levels of IgG, IgA, and IgM compared to healthy individuals ( P < 0.0001). The CD4+ cell, CD8+ cell, and CD19+ cell frequencies and CD4/CD8+ cell ratio in patients were significantly reduced (P < 0.001-0.05). Stimulated PBMCs of patients significantly produced lower level of IL-2 than healthy controls ( P < 0.0001). IL-2 level in CVID patients was positively associated with Igm level, CD4 cell frequency, CD4/CD8 cell ratio (P < 0.05, R = 0.464), while this association was negative for CD8+ cell precentage. Based on these findings, IL-2 may be considered as a useful drug supplement to treatment of infectious and non-infectious complications in CVID patient through enhancing cellular immunity.