ROUTINE LABORATORY DIAGNOSIS OF HEPATITIS-C VIRUS-INFECTION

Hepatitis C virus (HCV) is the major cause of parenterally transmitted non-A, non-B hepatitis. The analysis of the genomic sequence of HCV h as facilitated the development of a number of diagnostic assays for te sting circulating antibodies in serum from patients with HCV infection . Besides the first-generation ELISA and RIBA, which employed the C100 -3 non-structural polypeptide, second-generation tests employing both structural and non-structural polypeptides are being rapidly introduce d. Several coded panels were employed in a comparative study of HCV-SP ELISA (utilizing a new synthetic peptide whose sequence was derived f rom the structural region) along with first- and second-generation tes ts. On the basis of the results, evidently antigens corresponding to t he structural components of the virus are more sensitive and specific for the early detection of HCV antibodies than tests using non-structu ral epitopes. Additionally epitopes of the structural region elicit a very strong antibody response in laboratory animals. An example of one such application is the detection of HCV specific antigens in semen f rom patients diagnosed with non-A, non-B (NANB) hepatitis. Semen sampl es from 9 patients clinically diagnosed as having NANB hepatitis were tested by an ELISA using antibodies against HCV-specific structural an tigens. The semen from all 9 patients had HCV-specific structural anti gens in comparison to semen from 5 healthy donors. Semen from 5 of the 9 patients had significant levels of the HCV-specific antigen. This a pproach to detecting HCV antigens could, if rigorously tested, evolve into promising new assays for detecting HCV.