Performance and clinical utility of a novel fully automated quantitative HCV-core antigen assay

Background: Recently, a novel quantitative HCVcoreAg immunoassay developed for commercialisation by Abbott has become available in Europe and Asia. Objectives: We evaluated the correlation of HCV-RNA and HCVcoreAg and investigated the stability of HCVcoreAg and HCV-RNA. Study design: HCVcoreAg was quantified by a novel fully automated immunoassay (Architect HCVAg, Abbott, Germany). HCV-RNA quantification was performed either using the Cobas-TaqMan assay or Amplicor-HCV-Monitor (Roche-Diagnostics, Germany). Correlation of HCVcoreAg with HCV-RNA was studied cross-sectionally and longitudinally in untreated patients followed for up to 8 years. Stability of HCVcoreAg and HCV-RNA was evaluated in plasma and whole blood stored for up to 96 h at different conditions. Results: HCVcoreAg showed good correlation with HCV-RNA in all 118 cross-sectional tested samples irrespective of the HCV genotype (r = 0.75). In the majority but not all of the 10 longitudinally studied patients HCVcoreAg also demonstrated a good correlation with HCV-RNA. HCVcoreAg was stable in plasma at 4, 20, and 37 degrees C for up to 96 h, whereas HCV-RNA significantly declined at 37 degrees C. In whole blood, HCVcoreAg and HCV-RNA levels declined at all conditions with exception of HCVcoreAg at 37 degrees C. HCVcoreAg was stable after 1-5 freezing/thawing cycles and not light-sensitive. Conclusions: HCVcoreAg represents a stable and reliable marker of viral replication showing a good correlation with HCV-RNA irrespective of the HCV genotype. HCVcoreAg determination can be used to confirm viral replication and monitor viral load or acquisition of HCV over time. (C) 2009 Elsevier B.V. All rights reserved.