RESUMO
OBJECTIVES: To evaluate the oxidative status and antioxidant defense in patients with acute lymphoblastic leukemia (ALL). DESIGN AND METHODS: We measured concentrations of plasmatic thiobarbituric acid reactive substances (TBARS), serum protein carbonylation, whole blood catalase (CAT) and superoxide dismutase (SOD) activities, as well as the plasmatic and erythrocyte thiol levels and serum vitamin E concentration. This study was performed on 80 children with ALL divided into 4 groups: just diagnosed, remission induction, remission maintenance and out-of-treatment. RESULTS: TBARS levels and serum protein carbonylation were higher in ALL patients than in controls and reduced levels of antioxidants were found in these patients. CONCLUSION: These findings may indicate a possible link between decreased antioxidants and increased levels of cells alterations due to oxidative damage, supporting the idea that there is a persistence of oxidative stress in acute lymphoblastic leukemia.