Donor safety and plasma quality in automated plasmapheresis. Comparison of two filter materials.

The level of blood cells and differential counts as well as of selected clotting and complement system components and breakdown products were measured in donor plasma of 42 polycarbonate filter (group I) and 7 nylon filter (group II) plasmapheresis procedures. Three different sampling time points were considered: (1) 1 min prior to connecting the donor to the machine (sample A); (2) 1 min after donation by a repeat venipuncture (sample B), and (3) in collected plasma (sample C). The better biocompatibility of the newly introduced nylon filters became evident on the basis of blood cell counts with significant drops of total white blood cell counts, monocytes, lymphocytes and platelets in sample B of group I, but not of group II. Similarly, complement studies revealed significant decrease of CH 50, C4 and C3 in samples B and C of group I, but only in samples C of group II. Coagulation studies showed significant increases of fibrinopeptide A and beta-thromboglobulin in samples B and C of group I; in group II beta-thromboglobulin was significantly increased in sample C compared to sample A. Plasminogen levels were decreased in samples B and C of group I but not of group II. Nonactivated partial thromboplastin time remained normal in group I. Factor VIII:C determinations in group II revealed a recovery of 86% in sample C.