New perspectives in the diagnosis of hepatitis C

Since the identification and molecular characterization of the non-A, non-B hepatitis virus (HCV) in 1989, a variety of diagnostic tests based on the detection of hepatitis virus antibodies or HCV RNA in the serum have been d eveloped and refined. The enzyme-linked immunosorbent assays (ELISAs) and t he recombinant immunoblot assays (RIBAs) exhibit improved sensitivity and s pecificity for HCV antibodies compared with their predecessors, and the ELI SA-3 is at the forefront of HCV screening. Furthermore, the advent of molec ular assays that employ quantitative reverse-transcriptase polymerase chain reaction to detect HCV RNA has allowed clinicians to track the natural his tory of HCV and to monitor the progress of therapy. A role for further refi nement of an HCV diagnosis using tests to determine genotype, subtype, and quasispecies is explored. In addition, the role of liver biopsy and noninva sive markers of histologic status are placed into the context of patient pr ognosis. This article reviews the state-of-the-art tests and assays develop ed for the diagnosis and management of HCV infection.