Background: T-helper (Th) 22 and Th17 cells are implicated in the pathogenesis of autoimmune diseases. The roles of Th22 cells in the pathophysiology of rheumatoid arthritis (RA) remain unsettled.
Materials and methods: CD4(+)IFNγ(-)IL17(-)IL-22(+) T cells (Th22 cells), CD4(+)IFNγ(-)IL-22(-)IL17(+) T cells (pure Th17 cells), CD4(+)IL17(+) T cells (Th17 cells), and CD4(+)IFNγ(+) T cells (Th1 cells) in RA, osteoarthritis patients, and healthy controls were examined by flow cytometry. Plasma IL-22 and IL-17 levels were examined by enzyme-linked immunosorbent assay.
Results: Th22 cells, pure Th17 cells, Th17 cells, and interleukin-22 were significantly elevated in RA patients compared with osteoarthritis and healthy controls, but there were no significant differences regarding Th1 cells and interleukin-17. Th22 cells showed a positive correlation with interleukin-22 as well as pure Th17 cells or Th17 cells in RA patients. Additionally, the percentages of Th22 cells, pure Th17 cells as well as Th17 cells correlated positively with both C-reactive protein levels and 28-joints disease activity score.
Conclusion: Together, our results indicated a possible role of Th22 pure Th17 cells and Th17 cells in RA, and blockade of the interleukin-22 may be a reasonable therapeutic strategy for RA.