Figure 6

Frequency of Th17 cells, and plasma IL-17, IL-21, and IL-23 concentrations. (A) Schematic summarizing the proportions of CD20⁺ and Th17/CD20⁺ cell subsets in healthy subjects (HS) and rheumatoid arthritis (RA) patients. (B) Plasma and synovial fluid (SF) concentrations of IL-17, IL-21, and IL-23 as measured by enzyme-linked immunosorbent assay in RA subjects. The same cytokine concentrations were evaluated in the plasma of HS for comparison. IL, interleukin; Th, T helper cell.