RESUMO
Superoxde dismutase is dimeric antioxidant enzyme responsible for quenching of superoxide radicals which are released during the chemical reactions of the various metabolic pathways .The enzyme levels of SOD are altered to a considerable extent in various diseased states exhibiting either elevation or depletion in their enzymatic activity.As this phenomenon was found to be more evident in leukaemias, we have estimated the Cu-Zn SOD levels in the red cells of the leukaemic patients in order to evaluate the efficiency of anti oxidant system and its relation to leukaemiogenesis. The overall mean SOD levels in the leukaemic patients (AML, ALL and CML) were significantly low (124.97±6.46) as compared to that of the normal controls (287.08±6.79). In respect to the age, the mean SOD levels were found to be elevated indicating the extent of the free radicals might have stimulated the production of the antioxidants.In response to chemotherapy, the mean SOD levels were observed to be elevated but not the extent of the normal levels among the treated groups in AML(127.40±8.67) and CML (174.73±53.59) types of leukaemias as compared to that of the untreated groups. In general the stage of leukaemia did not cause any variation in the SOD levels. However, the L2 in ALL (107.49±4.88), blast crisis in CML (154.00±19.86) showed reduced levels of SOD.