A Comparative Evaluation of the Sensitivity of Five Anti-Hepatitis C Virus Immunoblot Assays

Background and Objectives: In order to compare sensitivity, five anti‐hepatitis C virus (HCV) immunoblot assays were tested (Deciscan plus, Inno‐Lia III, Matrix, Murex Western blot and RIBA‐3). Materials and Methods: The test panel (50 samples for each assay) included 6 anti‐HCV‐negative samples and 44 samples from 36 HCV‐infected subjects. Results: There were minor differences in core reactivity among the assays. The smallest number of NS3‐reactive results occurred with the Murex and Matrix assays, and the smallest number of NS4 reactives with RIBA‐3 and Matrix. Among the 20 discrepant results for NS5 there was one clear false‐negative with Inno‐Lia. Only 28 of the 50 samples of the panel gave the same results in all the assays: 5 negatives and 23 positives. One of the 6 negative samples was indeterminate in 3 assays. Eighteen of the 21 other divergent results were interpreted as either indeterminate or positive, a common reactivity being exhibited by all 5 assays. The most important discrepancies occurred on 3 HCV‐RNA‐positive samples which came up negative in some assays: 2 samples with isolated NS3 reactivity were negative by Matrix and Murex Western blot, 1 of them being also negative by Inno‐Lia III; another sample was negative by RIBA‐3 and Matrix due to weak signals (