Fig. 1

Serum and synovial fluid levels of IL-18 and IL-18BP in patients with rheumatoid arthritis (RA). A Serum levels of IL-18 and IL-18BP was measured by ELISA in active, inactive RA and OA patients. B IL-18 and IL-18BP levels was also measured in synovial fluid obtained from active RA and OA patients. C Correlations between the serum levels of IL-18 and IL-18BP in active and inactive RA. ^*P < 0.05, ^**P < 0.001, ^***P < 0.001