IL17A and autoimmune thrombocytopenic purpura: In ITP patients, there would be significantly increased proportions of Th1, Th2, Th17, Th22 and Tfh cells in the bone marrow, simultaneously increased levels of plasma IL-22, IL-17A and interferon-γ (IFN-γ), as well as decreased proportions of Tregs in both the bone marrow and peripheral blood [57].