DETECTION OF HEPATITIS-C VIRUS-INFECTION WITH RECOMBINANT IMMUNOBLOT ASSAY, SYNTHETIC IMMUNOBLOT ASSAY, AND POLYMERASE CHAIN-REACTION

The newly developed immunoblot assay, RIBA SIA (recombinant and synthe tic polypeptide immunoblot assay), Chiron, Calif., was compared with t he commercially available second generation recombinant immunoblot ass ay (RIBA-2) for the detection of antibody to hepatitis C virus (anti-H CV). The two immunoblot tests were also compared with the polymerase c hain reaction (PCR) for the detection of HCV RNA. Ninety-one percent o f samples reactive by RIBA-2 were positive for anti-HCV by RIBA SIA. A total of 31% of RIBA-2 indeterminate samples became reactive by RIBA SIA, 24% became non-reactive, and 45% remained the same. Samples react ive by RIBA-2 or SIA from different risk groups, were mostly positive (67-100%) by PCR for HCV RNA. All indeterminate samples from hemophili acs and intravenous drug users were PCR positive. RIBA SIA is more sen sitive and specific than RIBA-2 and correlates well with PCR results.