IL17A and autoimmune thrombocytopenic purpura: The frequency of CD3+CD4+IL-17+ (Th17) cells, a proinflammatory T cell subset, was also significantly elevated in ITP patients (NC, (0.83 ± 0.40)%; ITP, (2.46 ± 1.09)%, P < 0.001) (Figure 4(a)), which was reminiscent of the enriched IL-10+CD19+ B cells in ITP.