Evaluation of clinical usefulness of second-generation HCV core antigen assay: Comparison with COBAS AMPLICOR HCV MONITOR assay version 2.0

Background: Hepatitis C virus (HCV) is an important etiologic agent for chronic liver diseases. Methods: The aim of this study was to evaluate the clinical usefulness of second-generation HCV core antigen assay by comparing the results of the assay with those of the COBAS AMPLICOR HCV MONITOR version 2.0 (COBAS v2.0). Results: HCV core antigen was detectable by this assay in 142/149 (95.3 %) of serotype 1 (3821 ±322 fmol/1; mean ± SD), in 56/58 (96.6%) of serotype 2 (2589 ± 449 fmol/1), and in 6/6 (100%) of serotypes 1+2 (1240 ± 548 fmol/1). The HCV core antigen levels measured by this assay correlated well with the HCV RNA levels by COBAS v2.0 (r = 0. 848, P < 0.0001). In relation to the outcome of interferon monotherapy, the pretreatment HCV core antigen levels of sustained and non-sustained virological responders were 659 ± 189 and 4904 ± 376 fmol/1 in serotype 1, 1993 ± 740 and 3145 ± 519 fmol/1 in serotype 2. The cutoff values with the best accuracy for HCV core Ag levels to discriminate between sustained and non-sustained virological response were 699 frnol/1 for serotype 1 and 292 fmol/1 for serotype 2, respectively, by receiver operating characteristic curve analysis. Conclusion: This new assay was considered to be useful in evaluating the HCV levels in patients with chronic hepatitis C.