title: Performance and clinical utility of a novel fully automated quantitative HCV-core antigen assay.
abstract: BACKGROUND
  Recently, a novel quantitative HCVcoreAg immunoassay developed for commercialisation by Abbott has become available in Europe and Asia.
  
  
  OBJECTIVE
  We evaluated the correlation of HCV-RNA and HCVcoreAg and investigated the stability of HCVcoreAg and HCV-RNA.
  
  
  METHODS
  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.
authors.affiliation: Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany. wedemeyer.heiner@mh-hannover.de
authors.forename: Ingmar
authors.initials: I
authors.lastname: Mederacke
authors.forename: Heiner
authors.initials: H
authors.lastname: Wedemeyer
authors.forename: Sandra
authors.initials: S
authors.lastname: Ciesek
authors.forename: Eike
authors.initials: E
authors.lastname: Steinmann
authors.forename: Regina
authors.initials: R
authors.lastname: Raupach
authors.forename: Karsten
authors.initials: K
authors.lastname: Wursthorn
authors.forename: Michael P
authors.initials: MP
authors.lastname: Manns
authors.forename: Hans Ludger
authors.initials: HL
authors.lastname: Tillmann
mesh_terms: D000465:Algorithms; D057205:Automation, Laboratory; D003430:Cross-Sectional Studies; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification*; D018936:Hepatitis C Antigens / Q000097:blood*; D019698:Hepatitis C, Chronic / Q000097:blood / Q000175:diagnosis / Q000821:virology*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008137:Longitudinal Studies; D055550:Protein Stability; D020871:RNA Stability; D012367:RNA, Viral / Q000097:blood; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D014758:Viral Core Proteins / Q000097:blood*
chemical_list: D018936:Hepatitis C Antigens; D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic; D014758:Viral Core Proteins