Our results indicated that significantly higher percentages of circulating IL-22+CD4+ and IL-17+CD4+ T cells were detected in the HT patients than in the HC, and the percentages of Th22 cells, Th17 cells and IL-17A+IL-22+CD4+ T cells were negatively correlated with the levels of serum TSH in the HT patients. The gene discussed is IL17A; the disease is hematocrit.