Influence of epoietinum therapy on the oxidative stress in haemodialysis patients.

Background: The causes of oxidative stress in haemodialysis (HD) patients are still controversial. Beside the uraemic state and dialysis-related factors, adjuvant drug therapies such as epoietinum (rHuEpo) and intravenous iron were involved. Methods: Several parameters related to oxidative stress were assessed by spectrophotometry in stable HD patients, treated for at least 2 months with epoietinum (n = 14; mean dose = 97.7 +/- 19.1 U/kg/ week) or not (n = 15), none of them on iron therapy, and in 13 controls. Plasma thiobarbituric acid-reactive substances (TBARS) were used as markers of reactive species generation. Erythrocyte and plasma antioxidant systems, reflected by non-protein erythrocyte thiols, and erythrocyte enzyme activities - superoxide dismutase (SOD), glutathione peroxidase, catalase and plasma total thiols, respectively - were also investigated. Results: There were no differences between HD subgroups regarding haemoglobin levels. Plasma TBARS was increased in all HD patients as opposed to controls, irrespective of rHuEpo therapy. In addition, no change in antioxidant status parameters between rHuEpo-treated and -untreated patients was observed. Except for SOD, the other antioxidant indices were higher in all HD patients versus controls. Conclusions: These results suggest that (1) chronic HD patients appear to have simultaneously enhanced reactive species generation and antioxidative systems efficiency, and (2) epoietinum therapy did not change their oxidative status, at least in the absence of concomitant iron supplementation and at similar haemoglobin levels. Copyright (C) 2005 S. Karger AG, Basel.