ROCKVILLE, MarylandNew screening systems expected to further lower the threat of HIV and hepatitis C virus (HCV) contamination in the nation’s blood supply have received FDA approval. The agency has licensed two nucleic acid test (NAT) systems, which can significantly reduce the infection window, ie, the time in which a blood donor can be infected but the infection may not be detected. For HIV, the window with NAT is 12 days, compared with 22 days for antibody tests and 16 days for antigen tests. For HCV, the window is reduced from 82 days to 25 days.
The NAT systems were developed by the National Genetics Institute (NGI) for screening plasma used in manufacturing products such as clotting factors and immune globulins, and by Alpha Therapeutic Corp., for use in its plasma collection centers.
NAT enables the detection of minute amounts of DNA or RNA by amplifying a gene fragment. The newly approved tests are extremely sensitive for the RNA of HIV-1, the dominant AIDS-virus variant in the United States, and HCV.
Approval of the tests was based on clinical trials involving test pools of 512 plasma samples. These samples represented a total of 342,729 donations from about 48,000 individuals, which were collected at 33 plasmapheresis centers.