EVALUATION OF LABORATORY ASSAYS FOR SCREENING ANTIBODY TO HEPATITIS-C VIRUS

An evaluation study, involving 11 screening methods for the detection of antibody to hepatitis C virus (anti-HCV) and a panel of 500 serum samples, was performed. Samples were tested by all 11 methods, and those showing reactivity in at least one method were studied by a combination of supplemental assays (recombinant immunoblot assay, first and second generation; neutralization test for anti-c100; synthetic peptide immunoblot assay; recombinant multi-dot immunoassay) and classified as positive (110 samples), indeterminate (4 samples), or negative (386 samples) on the basis of the results obtained. Second-generation recombinant methods performed better on positive samples than first-generation assays or synthetic peptide-based methods (99.1-100% correlation vs. 64.5-85.5% and 93.6-99.1%, respectively), whereas the latter showed higher correlations on negative samples than recombinant assays (97.4-99.7% vs. 82.4-93%). Further investigations, using broad panels of indeterminate samples from blood donors, should be done, however, before synthetic peptide-based methods are recommended for blood bank screening. Reactivity of samples must be confirmed by one supplemental test in all cases before the donor is informed. In some cases, it may require the use of two or more different tests to obtain definite conclusions.