Oxidative status in rheumatoid arthritis

The insufficiency of antioxidant defense systems and the acceleration of the oxidative reactions can be results of the pro-oxidant/antioxidant imbalance in rheumatoid arthritis (RA). The aim of our study was to investigate the changes in oxidant status by measuring two different parameters; one was the level of malondialdehyde (MDA) as an index of lipid peroxidation and the other was total oxidative status; we could then compare our results with the antioxidant status, superoxide dismutase (SOD) enyzme activities. All were assessed in 22 patients with active RA and 18 age- and gender-matched control subjects. While serum MDA levels were significantly increased in patients with RA compared to the control group (p < 0.03), the total oxidative status levels were decreased in patients with RA compared to the control group (p < 0.008), and serum SOD activities did not show any statistical difference between the two groups. In conclusion, the increased MDA levels in our study may be important as a marker but are not sufficient to conclude that there was an increase in oxidative stress in RA patients because supporting results were not obtained from SOD and oxidative status measurements. These results give further support to the concept of oxygen free radicals playing a role in the pathogenesis of chronic inflammatory disorders, but we also consider that there is a more complex relationship than has been assumed. We think that further studies are needed to clarify these conflicting results.