Effects of High-Dose Dexamethasone on Regulating Interleukin-22 Production and Correcting Th1 and Th22 Polarization in Immune Thrombocytopenia

Background T-cell dysregulation and T-cell-related cytokine abnormalities are involved in the pathogenesis of immune thrombocytopenia (ITP). One of our previous studies showed that elevated IL-22 correlated to Th1 and Th22 cells plays an important role in the immunopathogenesis of ITP. In this study, we aimed to investigate the effects of high-dose dexamethasone (HD-DXM) on IL-22 production and on the IL-22-producing T-cell subsets in ITP patients. Methods IL-22 plasma levels and the percentages of Th1, Th17, and Th22 cells were determined by enzyme-linked immunosorbent assay and flow cytometry in 25 ITP patients receiving DXM 40 mg/day for 4 consecutive days. Results Plasma IL-22 concentrations and the percentages of Th1 and Th22 cells were significantly increased in pretherapy patients relative to controls (P<0.05), but the percentage of Th17 cells was not. HD-DXM administration reduced IL-22 production and corrected the imbalance between Th1 and Th22 subsets. IL-22 levels were positively correlated with Th1 and Th22 cells in ITP patients before and after HD-DXM treatment. Conclusion These results suggest that HD-DXM may regulate the production of IL-22 in ITP, possibly by correcting Th1 and Th22 polarization.