[Role of Th9, Th17, Treg Cells levels and IL-9, IL-17 and TGF-β Expression in Peripheral Blood of Patients with ITP in Pathogenesis of ITP].

OBJECTIVE: To detect the levels of Treg, Th17, Th9 cells and expression of transforming growth factor-β (TGF-β), interleukin-17 (IL-17) and interleukin-9 (IL-9) in peripheral blood of patients with immune thrombocytopenia (ITP) and to explore its role in the pathogenesis of ITP. METHODS: Fifty-four patients with ITP (ITP group) and 40 healthy volunteers (control group) were selected in our hospital. The of Treg, Th17 and Th9 cells in peripheral blood of 2 groups were measured by flow cytometry, and the expression of cytokines, such as TGF-β, IL-17 and IL-9 in the peripheral blood of 2 groups were detected by enzyme linked immunosorbent assay (ELISA). RESULTS: The level of Treg cells in the peripheral blood of the ITP group was significantly decreased in comparison with the control group, while the levels of Th17 and Th9 cells significantly increased in comparison with the control group (all P<0.01). The expression of cytokine such as TGF-β in the peripheral blood of the case group significantly decreased in comparison with the control group, while the expression levels of IL-17 and IL-9 significantly increased in comparison with the control group (P<0.01). The results of Pearson correlation analysis showed that there was a positive correlation between the level of Treg cells and platelet count (PLT) in peripheral blood of the ITP group (r=0.35, P<0.05), and there were negative correlation between the level rate of Th17, Th9 cells and Plt count (r=-0.37, -0.43, P<0.05); there was a positive correlation between the expression of the TGF-β in the ITP group and Plt count (r=0.46, P<0.05), while the expression of IL-17 and IL-9 showed negative correlation with PLT (r=-0.48, -0.54, P<0.05). CONCLUSION: The percentage of Treg, Th17 and Th9 cells in the peripheral blood of patients with ITP is abnormal, and the expression of TGF-β, IL-17 and IL-9 also is abnormal, which may play an important role in the pathogenesis of ITP.