EFFECTS OF DIALYSIS MEMBRANES ON THE KINETICS OF TUMOR-NECROSIS-FACTOR-ALPHA PRODUCTION BY PERIPHERAL MONONUCLEAR-CELLS IN CHRONIC-HEMODIALYSIS PATIENTS

To evaluate the biocompatibility of dialysis membranes, blood samples were collected from 10 hemodialysis patients immediately before dialys is and peripheral blood mononuclear cells were isolated The 3.0 x 10(5 ) cells/ml were then passed 30 times through modules made of a polyeth ylene glycol-grafted cellulose membrane, a polyacrylonitrile membrane, and a polysulfone membrane. Expression of messenger RNA for tumor nec rosi factor-alpha (TNF-alpha) was determined. Cells were also cultured for 2 h with and without lipopolysaccharide and TNF-alpha levels in t he supernatant were measured. TNF-alpha messenger RNA expression was s ignificantly higher immediately after passage through the polyacryloni trile membrane compared with the other membranes. Cells cultured witho ut lipopolysaccharide, produced significantly less TNF-alpha after pas sage through the polysulfone membrane, while lipopolysaccharide signif icantly increased TNF-alpha production by cells passed through the pol yacrylonitrile membrane. These results suggest that biocompatibility d iffers even among dialysis membranes believed to cause no complement a ctivation.