RESUMO
Psoriasis is a common, chronic inflammatory skin disease with unknown etiology. Recently it has been suggested that increased ROS production and deficient function of antioxidant systems activities may be involved in the pathogenesis of the disease. Although there are several studies investigating oxidant/antioxidant systems in psoriatic patients, the data obtained from these studies is not concordant. In this study, superoxide dismutase (SOD) enzyme activity, and malondialdehyde (MDA) and antioxidant potential (AOP) levels in thirty-five patients with psoriasis were investigated and compared with those of twenty-four control subjects. Clinical severity of the disease was determined according to the Psoriasis Area and Severity Index (PASI) scores in the patients. Plasma SOD activity and MDA levels were significantly higher (p=0.012 and p=0.005 respectively), whereas AOP levels were lower, in patients than controls (p=0.001). There was no correlation between PASI scores and plasma SOD, MDA, and AOP levels. Our findings may provide some evidence for a potential role of increased ROS production and decreased antioxidant activity in psoriasis.