Available tests to detect hepatitis C virus miss certain infectedindividuals and cannot fully protect the blood supply, accordingto a report Saturday in The Lancet.

Scientists from the New York Blood Center, the NationalInstitutes of Health and Japanese researchers wrote that if theresults are confirmed, at least 30 percent of high-risk donorswith HCV are seronegative by available screening assays.

Moreover, the researchers added, "it seems unlikely that futureimmunoassays will show greatly improved sensitivity." Thescientists found that analysis by polymerase chain reaction(PCR) outperformed even the most sensitive of availableassays. Of 19 blood samples found to contain HCV by PCR, only13 were detected by other assays.

The tests evaluated by the scientists included Abbott's second-generation ELISA, which uses Chiron Corp. antigens; Ortho'srecombinant immunoblot assay; and United Biomedical Inc.'santi-HCV peptide-based assay. A test developed by the NewYork researchers that detects the internal core antigen of thehepatitis C virus was also assessed.

If this preliminary report is confirmed "in much largernumbers," New York investigator Alfred Prince told BioWorld,"the industry will have to mount an effort" to make PCRworkable in the blood bank setting.

United Biomedical was awarded a patent last week for itssynthetic peptide-based test that detects antibodies to thevirus, which causes non-A, non-B hepatitis. UBI is negotiatingwith Organon for U.S. marketing rights. Ortho markets Chiron'ssecond-generation HCV diagnostic, which was approved lastmonth.

-- Roberta Friedman, Ph.D. Special to BioWorld

(c) 1997 American Health Consultants. All rights reserved.