Interleukin 7: A Proposed Role in Primary Immune Thrombocytopenia

Abstract

Immune thrombocytopenic purpra (ITP) is a common immune-mediated bleeding disorder in which platelets are opsonized by autoantibodies and prematurely destroyed by RES. Impaired platelet production and T cell–mediated effects also play a role in the pathogenesis of the disease. Dysfunctional cellular immunity is evaluated by the level of the cytokines at the site of immune activation. IL-7 is critical for T-cell development, survival, proliferation, differentiation and inhibition of apoptosis. In addition, IL-7 could significantly promote the production of Th1 cytokines like IL-2, interferon-g (IFN-g), tumor necrosis factor-a (TNF-a), while slightly induce the Th2 cytokines, IL-4 and IL-5. Besides cytokine secretion, IL-7 also could stimulate the cytotoxic activity mediated by CD8+ T cells and therefore gained much attention in ITP. The aim of the study was to evaluate the serum level of IL7 as an immunological marker in children with ITP and correlate their levels with different disease stages. We applied measuring level of IL7 in both plasma and BM by ELISA technique. The study was conducted on 35 patients (25 active ITP, 10 in remittent phase) and 10 age and sex matched apparently healthy control subjects.