PREDICTIVE VALUE OF SCREENING-TESTS FOR PERSISTENT HEPATITIS-C VIRUS-INFECTION EVIDENCED BY VIREMIA - JAPANESE EXPERIENCE

In November 1989, Japanese Red Cross Blood Centres started screening f or heaptitis C virus (HCV) with enzyme-linked immunosorbent assay (Eli sa) for the C100-3 viral peptide as the first such nationwide programm e in the world. Thereafter post-transfusion non-A non-B hepatitis (PTN ANBH) was reduced by 61-80%, but this was not as complete a success as our programme to prevent post-transfusion hepatitis B by screening fo r high titer hepatitis B core antibody, which we began in the same per iod. In order to acquire more effective control of PTNANBH, the HCV co re-related antigen (GOR, N14) and second-generation Elisa (Ortho2, Abb ott2)and second-generation antigen agglutination (PA, PHA) tests have been employed. Among 16,500 donors in 11 blood centers, 365 were serol ogically positive by at least one of these tests. Among these, HCV RNA was detected in 138 units and the remaining 227 were HCV RNA negative s. The effectiveness of these serological tests to detect HCV RNA-posi tive status were analyzed. Passive haemagglutination and particle aggl utination (PHA and PA) tests were highly effective to predict HCV vira emia among blood donors. Also, these tests can easily determine antibo dy titre. By either PHA or PA, all units with greater-than-or-equal-to 2(12) agglutination titre (120 and 122 units) were HCV RNA positive a nd all agglutination-positive units with serum alanine aminotransferas e level higher than 35 Karmen units were HCV RNA positive. These resul ts have formed the basis for implementing a more effective screening f or HCV viraemia in blood donors, where effectiveness is defined as enh ancing the protection of patients from post-transfusion hepatitis C an d providing higher quality information to achieve more effective donor counselling.