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.
Eggleton et al. Arthritis Research & Therapy 2011 13:R208 doi:10.1186/ar3541