[Lipid peroxidation and the antioxidant system in bicarbonate hemodialysis and acetate-free biofiltration]

Acetate-free biofiltration (AFB) is a modern haemodiafiltration method used at present as a variant in treatment of chronic renal failure. In AFB and standard bicarbonate haemodialysis (BHD), performed under equal conditions in 20 patients with chronic renal failure the authors investigated the degree of lipid peroxidation and the antioxidant defence system. As a marker of lipid peroxidation they used malondialdehyde (MDA); as to antioxidant factors they investigated the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSHP) in red blood cells and the selenium (Se) concentration in blood. The MDA values were elevated in both dialyzation methods, as compared with 30 healthy controls (p < 0.001). The SOD value before AFB did not differ from controls, before BHD it was higher than in controls (p < 0.01). In the course of AFB or BHD the SOD values did not change. The GSHPx activity at the end of AFB rose significantly as compared with the initial value (p < 0.05) and the value during the 30th minute of AFB (p < 0.02). In BHD the GSHPx activity was lower than in controls and did not change during the procedure (p < 0.01). The selenium blood levels were before both AFB and comparative BHD lower than in controls (p < 0.001). The authors found a positive correlation between the GSHPx activity and the Se level. The rise of GSHPx activity at the end of AFB may imply improved antioxidant defence during AFB and contribute to reduced tissue damage by free radicals.