Automated platelet production during plasmapheresis.

Manual plasmapheresis is widely used to permit collection of fresh-frozen plasma with return of the red cells to the donor. However, this method is time-consuming and carries the inherent risk of returning the wrong cells to any individual donor. Automated plasmapheresis, using a specially designed discontinuous cell separator, permits the collection of 500 ml of plasma within 30 minutes without disconnecting the donor from the bag containing the donor's red cells. However, this plasma contains a small number of platelets which are not suitable for transfusion. We now report the modification of this machine to permit simultaneous collection of 3 units of platelet concentrate as well as 500 ml of plasma in less than 50 minutes. Reduction of the g force of the separator from 1200 to 650 g permits the simultaneous collection of plasma and a platelet concentrate with an average yield of 2.21 X 10(11) platelets. Platelet size distribution, in-vitro function. 51Cr survival, posttransfusion increment, and bleeding time correction are all normal. This modification has increased the flexibility of the separator and provides an instrument which can be used with a random volunteer blood donor population to generate both plasma and cells in less than 50 minutes and with increased cost-effectiveness over plasmapheresis alone.