Correlation between blood antioxidant levels and lipid peroxidation in rheumatoid arthritis

Objectives: To investigate the relationship between lipid peroxidation and certain antioxidant parameters in the blood of rheumatoid arthritis patients. Methods and Results: In the present study, significantly increased lipid peroxidation, measured as malondialdehyde (MDA), was demonstrated in the plasma of rheumatoid arthritis patients (p < 0.01). The activities of erythrocyte antioxidant enzymes, superoxide dismutase and catalase remained unaltered. However, erythrocyte glutathione and plasma ceruloplasmin levels were significantly higher in patients (p < 0.001). Moreover, a positive correlation was also observed between these two parameters and MDA levels in the patient group but not in controls. Interestingly, a significant positive correlation also existed between red cell glutathione and plasma ceruloplasmin levels. Conclusion: These results suggest that increased oxidant stress present in rheumatoid arthritis may lead to compensatory changes in the levels of some antioxidants, viz. glutathione and ceruloplasmin. These changes, in turn, may provide additional protection against lipid peroxidation in rheumatoid arthritis.