A clinical study on different cellulosic dialysis membranes.

A controlled clinical study was performed over a period of 8 weeks in two dialysis centres (Rostock, GDR, and Munich, FRG). The aim was to compare a dialysis membrane made of modified cellulose (Hemophan) with classical regenerated cellulose (Cuprophan). Dialysers containing these membranes, together with a cellulose acetate dialyser, were therefore incorporated in a cross-over programme and clinical and biochemical investigations undertaken. The efficacy of the modified cellulosic membrane with respect to urea and creatinine clearance was shown to be comparable to that of regenerated cellulose and cellulose acetate. However, modified cellulose showed an increased clearance for inorganic phosphate, significantly different from that demonstrated by both regenerated cellulose and cellulose acetate. Blood compatibility studies, which included the assessment of C3a activation and the reduction of white blood cell (WBC) and platelet count, clearly demonstrated that in comparison to regenerated cellulose, modified cellulose resulted in significantly less complement activation and WBC reduction. Similarly in comparison to cellulose acetate, modified cellulose showed reduced complement-activating and WBC-reducing properties. The reason for the improved blood compatibility of modified cellulose is not, as was originally assumed, related to binding of complement-inhibiting heparin, but appears instead to be due to the substitution of hydroxyl groups of regenerated cellulose.