CD4 and rheumatoid arthritis: In this study, to further characterize the significance of IL-22+CD4+T cells in the pathogenesis of RA, we treated RA patients with MTX plus LEF, and monitored circulating levels of IL-22+CD4+T subsets (including Th22, IL-22+Th17, and IL-22+Th1 cells) and plasma IL-22 in response to treatment.