Oxidative stress and erythrocyte integrity in end-stage renal failure patients hemodialysed using a vitamin E-modified membrane.
Oxidative stress has been implicated in a range of disease states, including end-stage renal failure treated with hemodialysis. Hemodialysis with vitamin E-modified membranes reduces lipid peroxidation, but the effect on erythrocyte integrity has not been determined. This study compared antioxidant defense parameters and the resistance of erythrocytes to free radical-mediated hemolysis in patients dialysed with cellulose acetate membranes at baseline and with a vitamin E-modified membrane (Excebrane Clirans; Terumo Corporation) for 13 wk. Resistance of erythrocytes to free radical attack was assessed in vitro using the peroxyl hemolysis test. The time to 50% hemolysis (T50%) increased significantly during the first 6 wk of Excebrane use (p < 0.05), but this parameter returned to baseline by 13 wk. Glutathione concentration and erythrocyte superoxide dismutase activity were unchanged during the study, but glutathione peroxidase activity increased from low levels at baseline and became significantly higher at 6 and 13 wk (p < 0.001). Total erythrocyte polyunsaturated fatty acid content and C18:2 level increased (p < 0.001) and saturated fatty acids (total, C16:0, C18:0, C22:0 and C24:0) decreased (p < 0.03). Total monounsaturated fatty acid content was unchanged. The increased resistance of erythrocytes to hemolysis, the increased glutathione peroxidase activity, and the increased degree of unsaturation of fatty acids in the erythrocyte membrane are compatible with a reduction of oxidative stress during hemodialysis with vitamin E-modified membranes.