Nitric oxide and superoxide dismutase in rheumatoid arthritis: Correlation with disease activity

Abstract

Aim: To analyse serum and synovial fluid nitric oxide (NO) concentrations and erythrocyte CuZn superoxide dismutase (SOD) activity in rheumatoid arthritis (RA) patients and to determine the importance of imflammatory markers in reflect disease activity. Methods: 20 RA patients and 15 healthy controls were included. NO level was determined spectrophotometrically by the Griess reaction and CuZn SOD activity by the method of Sun et al. Results: Erythrocyte sedimentation rate (ESR), C-reactive protein and leukocyte levels were determined as inflammatory markers. Significantly higher ESR (p<0.001) and leukocyte levels (p<0.01) and serum and synovial fluid NO levels (p<0.01, p<0.05) and lower CuZn SOD activity (p<0.05) were observed in RA patients. Classification of RA patients according to disease activity score (DAS) revealed significantly higher synovial fluid NO level (p<0.05) and lower CuZn SOD activity (p<0.05) in RA patients with DAS≥2.7. Conclusions: Increased serum and synovial fluid NO levels and decreased CuZn SOD activity up-regulated inflammatory response are observed in RA patients.