RESUMO
Rheumatoid arthritis [RA] is an autoimmune disorder with unknown etiology. In recent years, a great number of studies have investigated the possible role of reactive oxygen species in the etiology and pathogenesis of Rheumatoid Arthritis. The aim of this study was to analyze the level of activities of catalase, glutathione peroxidas [GSH-Px], Super oxide dismotase [SOD] in patients with RA compared with the healthy subjects. In a case-control study sixty rheumatoid arthritis patients 18-75 years old and 60 healthy sex and age-matched controls were selected, Catalase activity was measured by determining the constant rate [k] of hydrogen peroxide decomposition. GSH-Px activity of plasma was measured with spectrophotometer by Glutathione oxide generation due to GSH-Px. SOD activity is measured by degree of inhibition effect of SOD in generating super oxide radicals by xanthine and xanthine oxidase. C-reactive protein and rheumatoid factor values were determined by agglutination and latex tests. The plasma activity of catalase [p<0.001], GSH-Px [p<0.01], plasma level of hemoglobin and hematocrit [p<0.05] were significantly lower in patients with RA comparing with controls. The reduction in SOD activity was not significant [p>0.05]. There was a negative significant relation between C reactive protein and Rheumatoid factor values with the erythrocyte activity of catalase and GSH-Px [p<0.01]. These results suggested that oxidative stress plays a very important role in the inflammation and pathogenesis of RA