IL-10KO mice have enhanced and prolonged antigen-induced arthritis (AIA). Disease activity in AIA challenged WT (closed circles) and IL-10KO (open circles) mice. (A) Joint swelling, (B) arthritic index scores and (C) synovial inflammation are shown. Swelling data reflects the mean ± SEM of knee diameters (in mm; n = 7-28, *P <0.05). Arthritic index and synovial inflammation values post AIA are presented for individual joints taken at days 3, 14, 28 and 35 (data is presented as the mean ± SEM, n = 5-7 per time point from a single experiment, *P <0.05, **P <0.01 between WT and IL-10KO groups). IL-10KO, interleukin-10-deficient; WT, wild-type.