Is heparin responsible for enhanced platelet aggregation after haemodialysis?

The platelet aggregation--enhancing action of heparin with adenosine diphosphate and epinephrine was tested in vitro in a group of volunteers. This action of heparin can be eliminated by protamine sulphate which has no effect on platelet aggregation. In dialyzed patients the aggregation effect of heparin manifested itself after haemodialysis and could also be abolished by protamine sulphate. We therefore assumed that the heparin used during dialysis was one of the factors accounting for the increased platelet aggregation after dialysis.