Effect of blockade of endogenous IL-17 on synovium and bone destruction. (a) Synovium (n = 5) and (b) bone explants (n = 3) from RA patients were incubated for 7 days with and without blocking anti-IL-17 mAb (10 μg/ml) or sIL-17R (1 μg/ml), which was added at the onset of the culture. CTX levels after 7 days of culture were measured by ELISA. Results are expressed as mean ± SEM of culture triplicates. Differences between IL-17 inhibitor treated groups and control groups were analyzed with the nonparametric Wilcoxon paired t test.*P < 0.05.