RESUMO
BACKGROUND: Psoriasis is a chronic inflammatory skin disease characterized by pathological skin lesions because of various exogenous and endogenous factors and associated with a number of biochemical and immunological disturbances. OBJECTIVE: The aim of the present study was to determine the level of adenosine deaminase activity, serum trypsin inhibitory capacity and total antioxidant capacity of plasma in psoriatic patients. SUBJECTS AND METHODS: The study was performed in controls (n = 46) and in psoriatic patients (n = 40). The patients were scored with PASI (psoriasis area and severity index). The serum ADA activity was determined using Aguisti and Galanti method and serum trypsin inhibitory capacity (sTIC) were measured by enzymatic assay. Besides, serum total antioxidant capacity was measured using ferric reducing ability of plasma. RESULTS: The serum ADA activity of the psoriatic patients was found to be significantly higher (P < 0.001) than that of the healthy control. We also found that the trypsin inhibitory capacity was significantly higher in patients than in control group (P < 0.001). Total antioxidant capacity of plasma was significantly lower in psoriatic patients than in healthy controls (P = 0.025). There were no significant correlations among ADA, TAC and TIC. CONCLUSION: Serum ADA activity and sTIC were increased in psoriatic patients. In parallel, serum total anti-oxidant activity was decreased in these patients.