Abstract: 【Abstract】Objective A growing body of evidence suggests that oxidative stress is enhanced in patients with end stage renal diseases (ESRD) and is involved in pathogenesis of related chronic complications. Reactive oxygen species (ROS) may cause DNA damage and increase of cancer mortality in ESRD patients. But the detailed mechanism still remains unclear, and the degree of DNA oxidative damage in ESRD patients has not been well examined. We measured serum 8-hydroxy-2'-deoxyguanosine (8-OHdG), a product derived from interaction of oxygen radicals with deoxyguanosine, as well as nitric oxide (NO) and malondialdehyde (MDA) in patients with ESRD to investigate the degree of DNA oxidative damage and its related factors in ESRD. Methods Forty subjects were enrolled in this study, in which 15 subjects were non-dialysis ESRD patients (CRF group), 15 were ESRD patients undergoing regular hemodialysis (HD group), and 10 age- and sex-matched health people were selected as controls. Patients in this study had no inflammatory or malignant diseases, and no supplement with vitamin C, E and iron ion. Smokers and patients with positive hepatitis C virus antibody or hepatitis B surface antigen were excluded. Serum 8-OHdG was measured by an enzyme-linked immunosorbent assay (ELISA) kit, NO was measured by a modified cadmium particle reduction method, and MDA was measured by a thiobarbital product chromatometry method. Results Serum 8-OHdG was significantly higher in CRF group and HD group before and after hemodialysis than in normal subjects (P< 0.01). In HD patients, serum 8-OHdG was increased after hemodialysis, as compared with that before hemodialysis (P<0.05). In addition, serum NO and MDA were also significantly higher in CRF group and HD group before and after hemodialysis than in normal subjects (P<0.05). Serum 8-OHdG had a significant positive correlation with serum creatinine (r = 0.368, P＜0.05) and NO (r =0.453, P＜0.01), but had an insignificant correlation with age, sex, blood urea nitrogen, hemoglobin and hematocrit (P>0.05). Conclusion Serum 8-OHdG was increased in ESRD patients, indicating that DNA oxidative damage is enhanced in those patients. Serum 8-OHdG is a good and reliable parameter for the evaluation of oxidative stress degree in ESRD.

Key words: Hemodialysis, DNA oxidative damage