DIAGNOSIS OF CHRONIC HEPATITIS-C - COMPARISON OF IMMUNOASSAYS AND THEPOLYMERASE CHAIN-REACTION

We evaluated a series of first- and second-generation enzyme-linked im munoassays for anti-HCV and compared the findings to those with two co nfirmatory assays, the recombinant immunoblot assay and serum HCV RNA, in patients with chronic hepatitis C, primary biliary cirrhosis, and chronic hepatitis B. All second-generation immunoassays had good sensi tivities (98-100%). Interestingly, detection of HCV RNA had a sensitiv ity of only 93%, although it was 100% specific. The recombinant immuno blot assay and a peptide-based immunoassay also had good specificity ( 97% and 100%, respectively), whereas the second-generation immunoassay based on recombinant proteins had a high rate of false positivity, pa rticularly among patients with primary biliary cirrhosis and hyperglob ulinemia (specificity 68%). Thus, the diagnosis of HCV infection appea rs to require the use of more than one test. Whereas a second-generati on enzyme-linked immunoassay can be used as an initial test, a confirm atory test (such as recombinant immunoblot assay or determination of h epatitis C viral RNA) may be required if the diagnosis remains uncerta in.