Antioxidant enzymes activities and plasma levels of oxidative stress markers in B-chronic lymphocytic leukemia patients.

PURPOSE

Overproduction of reactive oxygen species (ROS) intermediates above the functional capability of cellular antioxidants may result in instability of important macromolecules and represents the molecular basis of many diseases including inflammation processes, cardiovascular alterations, cancer etc. The purpose of this study was to determine plasma level of superoxide anion, hydrogen-peroxide and malondialdehyde (MDA) as markers of oxidative stress and activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) as antioxidant enzymes in B-chronic lymphocytic leukemia (B-CLL) patients.

METHODS

The study included 29 untreated B-CLL patients in stage A, and 21 in stages B and C, classified according to the Binet system; 31 healthy volunteers formed the control group. After centrifugation of heparinized peripheral blood, plasma levels of all investigated parameters were determined using spectrophotometric methods.

RESULTS

Plasma CAT activity was increased in B-CLL patients compared with control subjects; also, progression of disease was related with significantly higher plasma activity of CAT. Also, B-CLL patients showed significantly higher plasma concentration of MDA compared with controls. No statistically significant differences of superoxide anion and hydrogen peroxide as well as plasma activity of SOD and GPx between the tested groups were noted.

CONCLUSION

Increase of CAT activity in B-CLL patients indicates that there is stimulation of the antioxidant enzyme system, while the increase of MDA concentration shows increased lipid peroxidation level. According to these results it could be concluded that an imbalance exists between oxidants and antioxidants in the plasma of B-CLL patients.