Changes of antioxidative homeostasis in patients on chronic haemodialysis.

The balance between reactive oxygen species (ROS) generated during metabolism and their scavengers and trappers is changed in patients on chronic haemodialysis. Recently we found an increased superoxide anion-trapping capacity of uraemic serum before haemodialysis which was decreased during the treatment, probably because of loss of antioxidants into the dialysate. In this study the generation of superoxide anions by polymorphonuclear leukocytes (PMN) was examined. There was a tendency for decreased ROS generation during transient leukopenia regarding all conditions of PMN incubation and stimulation. The changed antioxidative homeostasis is thought to be one factor of decreased red blood cell (RBC) survival and thereby of renal anaemia in patients on chronic haemodialysis. Our results support this hypothesis, indicating an increased haemolysis ratio of RBC after haemodialysis in a strongly artificial singlet oxygen stress.