Influence of Haemodialysis on Susceptibility of Red Blood Cells to Peroxidation

Keywords: Background: Uremic anaemia has been the subject of several studies, since it causes serious problems. Decreased RBC production and survival seem to be due to erythropoietin deficiency combined with cell damage. Aims and Objectives: During haemodialysis, complement and leukocyte activation by contact with artificial surfaces promotes the formation of free radicals. However, the cell membrane is protected from this damaging effect by the presence of very efficient antioxidant enzyme defence mechanism. When this protective system is overwhelmed, it leads to cellular damage in the form of decreased RBC survival. It is postulated that antioxidant capacity in uremic patients is reduced, yet the exact mechanism remains unclear. In view of this data a study was undertaken to determine the activities of antioxidant enzymes to assess the oxidant damage to RBC in terms of TBARS (Thiobarbituric Acid Reactive Substances). Materials and Methods: Blood samples were collected from patients (n=40), before and after dialysis. They were compared with age and sex matched normals (n=45), who served as controls. The activities of enzymes glutathione peroxidase (GSH-Px) and Catalase (CAT) along with glutathione reduced (GSH) and malondialdehyde (MDA) expressed as TBARS in the RBC of patients on haemodialysis were determined. Results: The results indicated a marginal to moderate decrease in the antioxidant enzyme activities , such as CAT and GSH-Px, and increased TBARS levels before and after dialysis. Conclusion: Our results are suggestive of an increased susceptibility of the RBC to peroxidation on haemodialysis.