Leucopenia, hypoxia and complement activation in haemodialysis. Three unrelated phenomena.

Acute, transient leucopenia occurs in uraemic patients during the first minutes of haemodialysis, haemofiltration and ultrafiltration, and this leucopenia depends on the membrane used: maximal with cuprophan, less marked using cellulose acetate in haemofiltration and minimal with polyacrylonitrile. Complement activation was noted in all dialysis procedures except ultrafiltration. However, no correlation was found between the intensity of the complement activation and the degree of leucopenia. Significant hypoxia only appeared in haemodialysis using an acetate bath even with the polyacrylonitrile membrane. Sequential ultrafiltration-dialysis studies clearly demonstrate that leucopenia and hypoxia are unrelated effects of haemodialysis. Leucopenia depends on the membrane used and hypoxia may be related to the use of an acetate dialysate. In addition, the presence of dialysis fluid was necessary for membrane-induced complement activation suggesting an important influence of the dialysate on membrane biocompatibility.