A CASE CONTROL STUDY OF ANTIOXIDANT AND OXIDANT STATUS IN TUNISIAN RHEUMATOID ARTHRITIS PATIENTS

Rheumatoid arthritis is a chronic inflammatory disease with several triggers such as oxidative stress. The aim of this study was to assess the antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase), the total antioxidant status, lipid peroxidation (malondialdehyde) and homocysteine levels in patients with rheumatoid arthritis. The study population consists of 172 patients with rheumatoid arthritis and 147 healthy controls. The glutathione peroxidase and the glutathione reductase erythrocyte activities were determined at 340 nm. The catalase activity was measured by colorimetric assay (Goth). The superoxide dismutase activity and the total antioxidant status levels were calculated using the colorimetric method at 505 nm and 600 nm respectively. Plasma malondialdehyde was determined by the spectrofluorometric method of Yagi. Serum homocysteine was measured by fluorescence polarization immunoassay. Glutathione peroxidase, glutathione reductase and catalase activities and total antioxidant status levels were significantly lower in patients compared to controls. However, malondialdehyde and homocysteine levels in patients were significantly higher than in healthy subjects. No significant difference in superoxide dismutase activity between patients and healthy subjects was noticed. Decreased antioxidant system and increased malondialdehyde and homocysteine in Tunisian rheumatoid arthritis patients confirm the implication of the oxidative stress in rheumatoid arthritis and suggest the role of homocysteine as a pro-oxidant factor.