Stimulation of neutrophil functions by C5a(desArg): an in vitro model of haemodialysis

Cuprophane membranes during haemodialysis significantly increase the plasma levels of C5a(desArg) (maximal 55 mug C5a(adesArg)/1 blood after 30 min) whereas Hemophane or Polysulphonemembranes induce only low plasma levels of C5a(desArg). C5a(desArg) generated in vitro by yeast incubation of autologous plasma stimulates PMN chemotaxis and oxidative metabolism but has no effect on enzyme release. Preincubation of whole blood with C5a(desArg) causes aggregation and changed oxidative burst activity of the isolated PMN. These changes are similar to those found in cells from patients after haemodialysis with cuprophane membranes. So the elevated plasma levels of C5a(desArg) after haemodialysis explain some of the changes in PMN functions, but additional mechanisms have to be assumed.