Due to the link between IL-1 and IL-1ra, and taking into account the recent data shown by our group that revealed that both erythrocyte sedimentation rate (ESR) and disease activity scores were significantly related to higher serum levels of IL-1ra in patients with RA [13], in the present study we analyzed the possible correlation between IL-1ra and IL-6 in patients with RA, and how both are related to the inflammatory activity of the disease. Here, IL6 is linked to rheumatoid arthritis.