[Plasma donor screening and product safety]

In addition to the specific virus reduction and inactivation procedures during the manufacturing process, the thorough selection of the source material is an essential factor for the product safety of plasmaderivatives. Screening of donors, inventory hold, and plasma pool testing by PCR are important aspects in raising the safety margin. Between January 1, 1994 and June 30, 1996, 576,673 plasma donations were collected in the German and Austrian plasmapheresis centers of IMMUNO. Incidence rates for viral markers (confirmatory tests) as antibodies against HIV, HCV, and HB surface antigen (HBsAg) were calculated as 0.35, 0.87, and 0.87 per 10(5) donations, respectively. Due to look-back, 1.33% of the donations were eliminated between January and October 1995. In 32% of the donations being rejected in the time of inventory hold in case of elevated alaninamino-transferase (ALT) of the donors, HCV genomes were shown which emphasizes the importance of this surrogate marker. Out of 1,240 pilot pools tested by quality assured PCR (IQ-PCR) being performed by IMMUNO since October 1995, in 4% of cases HCV and in 0.2% HBV genomic equivalents were shown. However, genomes of HIV were not found. The measures aiming at a safe plasma pool are part of IMMUNO's safety concept which is confirmed by the fact that there was no transmission of hepatitis or AIDS viruses by IMMUNO products, since virus inactivation procedures have been established.