[Expression of regulatory T cells and Th17 cells in idiopathic thrombocytopenic purpura and its significance].

OBJECTIVE: To investigate the expression of regulatory T cells and Th17 cells in idiopathic thrombocytopenic purpura (ITP) and its significance. METHODS: The quantity of CD4(+)CD25(+)T cells, CD4(+)CD25(high) T cells and CD4(+) IL-17(+)T cells in peripheral blood were measured with flow cytometry (FCM), the plasma level of IL-10 and IL-17 with ELISA and the expression of Foxp3 mRNA and RORc mRNA with RT-PCR in 29 newly diagnosed ITP patients and 28 healthy controls. RESULTS: The ratio of CD4(+)CD25(+)T cells/CD4(+) T cells in the peripheral blood of ITP patients was significantly higher than that of the normal controls (P < 0.05). And the ratio of CD4(+)CD25(high) T/CD4(+) T cells in the patients was remarkably lower (P < 0.05). There was no difference in the percentage of CD4(+) IL-17(+)T/CD4(+) T cells between ITP patients and controls (P > 0.05). The ratio of Treg/Th17 was lower in ITP patients (P < 0.05). The plasma level of IL-10 in ITP patients was significantly decreased (P < 0.05), whereas no statistical difference was observed in the level of IL-17 (P > 0.05). The Foxp3 mRNA expression levels were largely reduced (P < 0.05), but the RORc mRNA expression was increased compared with that in controls (P < 0.05). CONCLUSION: The imbalance of Treg/Th17 plays an important role in the pathogenesis of ITP.