The cytokines (IFN-γ, IL-2, IL-4, IL-10, IL-17) and Treg cytokine (TGF-β1) levels in adults with immune thrombocytopenia

Previous studies have indicated that autoimmune diseases might be caused by an imbalance of T helper cells (Th), cytokines, and regulatory T cells(Treg) cytokines. We measured the plasma concentrations of Th1-associated cytokines (IFN-γ, IL-2), Th2-associated cytokines (IL-4, IL-10), Th17-associated cytokine (IL-17) and Treg -associated cytokine (TGF-β1) in adult patients with immune thrombocytopenia (ITP) and evaluated their clinical relevance. Plasma IFN-γ, IL-2, IL-4, IL-10, IL-17 and TGF-β1 concentrations of 52 ITP patients and 30 age- and sex-matched healthy controls were measured by enzyme-linked immunosorbent assay method (ELISA). Concentration of Th2 cytokines (IL-4 and IL-10) were significantly higher in ITP patients compared to controls (P < 0.05). However, concentrations of Th1 cytokines (IFN-γ, IL-2), Th17 cytokine (IL-17) and Treg cytokine (TGF-β1) were lower in ITP patients (P < 0.05). Concentration of IL-17 was significantly higher in chronic ITP patients compared to severe ITP patients (P < 0.05), and no significant difference of cytokine concentration among the other subgroups in ITP patients was found. Among the ITP patients, concentration of IFN-γ correlated positively and significantly with PAIgG (r = 0.48, P = 0.02). A significant correlation was neither found between other cytokine levels and platelet count, nor between cytokine levels and megakaryocytes number, nor between cytokines levels and PAIgG or GPIIb/IIIa and/or GPIb/IX autoantibodies. The present study demonstrates that an imbalance of Th and Treg cytokines may mediate the pathogenesis of ITP.