Elevated interleukin-27 enhances the polarization of Th1/Tc1 cells and the production of proinflammatory cytokines in primary immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is an acquired, organ-specific, autoimmune disease with many immune dysfunctions. Interleukin-27 (IL-27) can regulate T cell differentiation. However, it is unclear whether IL-27 correlates with the dysfunctions of T cell differentiation in ITP patients. Thus, to determine the roles of IL-27 in ITP, we studied the expression of IL-27/IL-27 receptor in ITP patients. The results indicated that the levels of IL-27 in the plasma of untreated active ITP patients were higher than in normal controls. We next evaluated the contribution of IL-27 to T cell differentiation. Our results indicated that IL-27 increased T-bet expression, inhibited GATA-3 and ROR-γt expression, and promoted the secretion of tumor necrosis factor-α, interferon-γ, and granzyme B of peripheral blood mononuclear cells from ITP patients. Also, we confirmed that IL-27 induced the differentiation of T helper (Th)-1 and Tc1 cells. In conclusion, IL-27 might play an important role in the pathogenesis of ITP by inducing the polarization of Th1/Tc1 cells and the production of proinflammatory cytokines.