A new technique for the collection of plasma: machine plasmapheresis

The Haemonetics Model 50 permits the collection of 500 ml of plasma within an average of 30 minutes, and the donor is never disconnected from his cells. In a detailed assessment of 28 donors, we found no detrimental effect of the procedure. There was no evidence of fibrin split products or complement activation. The plasma showed good recovery of protein with slightly elevated factor VIII levels; citrate levels are only two-thirds of manual plasmapheresis values. While there was a relatively large number of platelets collected into this plasma, the platelets were small, with a mean diameter of 1.8 mu and poor response to aggregation. Therefore it would appear that this plasma should not be used to make a platelet preparation. Nonetheless, evaluation of this machine indicated that the performance parameters are acceptable and that donor acceptance is exceptional, with widespread enthusiasm for this "new" method of blood donation.