Does the treatment of renal anaemia with recombinant erythropoetin influence oxidative stress in hemodialysed patients?

Patients with end-stage renal failure (ESRF) undergoing hemodialysis (HD) a re exposed to oxidative stress. Increased levels of malondialdehyde (MDA) w ere demonstrated in plasma of uremic patients indicating accelerated lipid peroxidation (LPO) as a consequence of multiple pathogenetic factors. The a im of our investigation was to examine the role of renal anemia in oxidativ e stress in HD patients. Therefore, MDA and 4-hydroxynonenal (HNE) were mea sured in three groups of patients undergoing HD: group I included eight pat ients with a blood hemoglobin (Hb)< 10 g/dl (mean Hb = 8.1 +/- 1.3 g/dl), a nd group Il were eight patients with a Hb > 10 g/dl (mean Hb = 12.4 +/- 1.9 g/dl); none of these 16 patients had been treated with human recombinant e rythropoietin (rhEpo). Group III included 27 patients with a mean Hb of 10. 5 +/- 1.6 g/dl after long-term rhEpo treatment. Mean plasma concentrations of both MDA and HNE were significantly higher (p < 0.0001) in all 43 HD pat ients than in 20 healthy controls (MDA: 2.85 +/- 0.25 vs. 0.37 +/- 0.03 mu M, HNE: 0.32 +/- 0.03 vs. 0.10 +/- 0.01 mu M). Comparing the three groups, it was shown that HD patients with a Hb < 10 g/dl had significantly higher plasma levels of LPO products (MDA 3.81 +/- 0.86 mu M, HNE 0.45 +/- 0.07 mu M) than HD patients with a Hb > 10 g/dl (MDA 2.77 +/- 0.58 mu M, HNE 0.25 +/- 0.05 mu M), and than HD patients treated with rhEpo (MDA 2.50 +/- 0.12 mu M, HNE 0.29 +/- 0.03 mu M). Furthermore, an inverse correlation between plasma concentration of LPO products and hemoglobin levels was seen (r = 0. 62, p < 0.0001). Therefore we conclude that radical generation in HD patien ts might be caused in part by renal anemia itself. Treatment with rhEpo may effectively decrease radical generation in HD patients due to the increase of the number of red blood cells and blood hemoglobin concentration.