Synovial and circulating profiles of immunomodulatory cytokines displaying an early increase in their joint levels during antigen-induced arthritis. Expression of protein was assessed before the induction of antigen-induced arthritis (day 0) or afterwards (at 7 hours and on days 1, 2, 3, 7, and 14) in both arthritic (mBSA-sensitized) and contralateral (saline-injected) knees and in sera. Results are expressed as concentrations (in picograms per milliliter) in serum and as quantity by knee (in picograms per knee) of the immunomodulatory cytokines interleukin-17 (IL-17) (a), IL-2 (b), and interferon-gamma (IFNγ) (c) and IL-9 (d). Values are the mean ± standard error of the mean of five independent samples. *P < 0.05 in comparison with day 0. D, day; h, hour; mBSA, methylated bovine serum albumin.