Oxidant/antioxidant status of the erythrocytes from patients with rheumatoid arthritis

It has been suggested that enzymatic and/or non-enzymatic antioxidant syste ms are impaired in rheumatoid arthritis (RA) and hence patients are exposed to oxidant stress. This study aimed to establish whether this is really th e case. Fasting blood samples were obtained from 24 patients with rheumatoi d arthritis and 20 controls. The activities of erythrocyte superoxide dismu tase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and xanthine ox idase (XO) enzymes and malondialdehyde (MDA), oxidant resistant (OR) and no n-enzymatic superoxide radical scavenger activity (NSSA) values were measur ed in both groups. Patients with RA had higher SOD and XO activities and MD A levels than did the controls. However, NSSA and OR levels were found to b e decreased, and CAT and GSH-Px activities unchanged in the study group. Re sults suggest that excessive free radical production through the xanthine-x anthine oxidase system is the primary factor in rheumatoid arthritis, rathe r than an impaired antioxidant system. The therapeutic use of XO enzyme inh ibitors and some antioxidants can be beneficial in this regard.