Antioxidant enzyme activities and the production of mda and 8-oxo-dG in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a neoplastic disease susceptible to a ntioxidant enzyme alterations and oxidative stress. We have examined the ac tivities of superoxide dismutase (SOD), catalase (CAT), and glutathione per oxidase (GPx), and the oxidized/reduced glutathione (GSSG/GSH) ratio togeth er with the levels of malondialdehyde (MDA) and 8-oxo-2'-deoxyguanosine (8- oxo-dG) in lymphocytes of CLL patients and compared them with those of norm al subjects of the same age. SOD and CAT activity decreased in CLL lymphocy tes while GPx activity increased. GSH content of CLL lymphocytes also incre ased, and GSSG concentration remained constant. Thus, a reduced GSSG/GSH ra tio was obtained. The oxidation product MDA, and the damaged DNA base 8-oxo -dG were also increased in CLL. The observed changes in enzyme activities, GSSG/GSH ratio, and MDA were significantly enhanced as the duration of the disease increased in years. The results support a predominant oxidative str ess status in CLL lymphocytes and emphasize the role of the examined parame ters as markers of the disease evolution. (C) 2001 Elsevier Science Inc.