Aim: To investigate the levels of interleukin (IL)-21 in CD4(+);T cells of peripheral blood from the different types of patients infected with hepatitis B virus (HBV) and elucidate its role in the hepatitis B pathogenesis.
Methods: Peripheral blood mononuclear cells (PBMCs) from the patients infected with HBV and healthy individuals were stimulated with or without PMA coupled with ionomycin. The levels of IL-21 in CD4(+) T cells and Th17 cells were analyzed by flow cytometry.
Results: PMA and ionomycin induced the expression of IL-21, and IL-21 was mainly produced by CD4(+); T cells, but IL-17A(+) IL-21(+) CD4(+) T cells were not detected. The frequencies of IL-21(+) CD4(+) T cells in the patients of acute hepatitis B and chronic asymptomatic HBV carriers were higher than in healthy controls and severe chronic hepatitis B patients; there were no remarkable differences in the proportion of Th17 cells among the different groups of patients. Furthermore, the proportion of IL-21(+) CD4(+) T cells correlated with Th17 cells in all groups except for the acute hepatitis B patients.
Conclusion: IL-21 levels, which correlated with Th17 cells, were different in CD4(+);T cells from the different types of patients infected with hepatitis B virus (HBV). The results showed that IL-21 may play a role in the hepatitis B pathogenesis.