Changes in Th17 and CD4+CD25+ Treg cells and their significance among children with hand, foot and mouth disease

Abstract:

Objective To investigate the changes in peripheral blood Th17 and CD4⁺CD25⁺ regulatory T (Treg) cells and their significance among children with hand, foot and mouth disease (HFMD). Methods Eighty-nine children with HFMD, including 55 cases of common HFMD and 34 cases of severe HFMD, were included in the study; and 30 healthy children were selected as the control group. The percentages of Th17 and CD4⁺CD25⁺ Treg cells in CD4+ T cells in peripheral blood were determined by flow cytometry. The expression levels of interleukin (IL)-10, transforming growth factor-β (TGF-β), and IL-17 were measured by enzyme-linked immunosorbent assay. Results Compared with the control group, the cases of common HFMD and severe HFMD had significantly increased levels of Th17 cells and IL-17 (P<0.05) but significantly decreased levels of CD4⁺CD25⁺ Treg cells, IL-10, and TGF-β (P<0.05). The severity of the HFMD was positively correlated with the levels of Th17 cells and IL-17 in peripheral blood but negatively correlated with the levels of CD4⁺CD25⁺ Treg cells, IL-10, and TGF-β. Conclusions Children with HFMD have increased response of Th17 cells but decreased response of CD4⁺CD25⁺ Treg cells in peripheral blood. Th17/CD4⁺CD25⁺ Treg cell imbalance may play an important role in the pathogenesis of HFMD.