Free radicals, antioxidant enzymes and lipid peroxidation profile in untreated leukaemias

We have determined superoxide anion, hydrogen peroxide and superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities, in erythrocytes, and malondialdehyde products in plasma, from 15 patients with different types of leukaemias prior to therapy. In all cases, superoxide anion levels, and Cu-Zn SOD and GSH-PX activities, in the erythrocytes were significantly raised in leukaemia patients. Although hydrogen peroxide levels were higher too, the rises were not statistically significant. However, the levels of lipid peroxidation products were comparable to control values. The increases in SOD and GSH-PX activities were not related to the anaemic condition. There were no differences in any of the parameters among the types of leukaemias. These results suggest that the antioxidant defence system may not be affected in red cells and that there could be an abnormality in the regulation of the expression of SOD and GSH-PX genes in pleuripotent stem cells in leukaemic conditions. (C) 1998 Lippincott-Raven Publishers.