Complement activation is influenced by the membrane material, design of the dialyser, sterilizing method, and type of dialysate

The complement system becomes activated during blood-membranecontact in the dialyser. This study was designed to evaluateto what extent the dialyser design, the sterilization method,and the type of dialysate influence complement as measured byC3d. Twelve patients were dialysed three times on each of fourdifferent dialysers. Two hollow-fibre dialysers made of cuprophane(Hf-CuE ethylene-oxidesterilized, Hf-CuS steam-sterilized) werecompared with two plate dialysers made of cuprophane (P-Cu)or polycarbonate (P-Pc). Five patients were dialysed with acetateand seven with bicarbonate. Differences in C3d between at startof dialysis and after 180 mm were calculated. C3d was increasedmore by P-Cu than by the other dialysers (P<0.012, n=12).In the bicarbonate group, C3d was increased more by P-Cu thanby Hf-CuS or P-Pc (P<0.022, n=7) and more by Hf-CuE thanHf-CuS (P<0.013). In the acetate group, C3d was increasedmore by Hf-CuS and P-Cu than by P-Pc (P<0.006, n=5). In conclusion, complement activation during dialysis varieddue to membrane material, membrane design, sterilization method,and dialysate composition.