title: Clinical usefulness of HCV core antigen assay for the management of patients with chronic hepatitis C.
abstract: OBJECTIVE
  The study aimed to evaluate the clinical utility of the chemiluminescent HCV core Ag test compared to viral load assessment in the management of patients with chronic hepatitis C.
  
  
  METHODS
  A retrospective study was performed at a tertiary-care infectious diseases hospital on samples collected from anti-HCV positive patients. Seventy-six samples were tested with the Architect HCV core Antigen kit and Cobas AmpliPrep/Cobas Taqman HCV kit. The HCV Ag test accuracy was estimated using data from all the HCV RNA tested samples received between January 2011 and December 2012.
  
  
  RESULTS
  The HCV Ag test showed a good correlation between the logarithmic values of HCV RNA and HCV Ag (R=0.98), with a 100% specificity and PPV, but with reduced sensitivity for viral loads lower than 1,000 UI/mL. In a model using data from 2,478 HCV RNA tested samples and a cut-off of the Ag assay corresponding to 1,000 UI/mL HCV RNA, the Ag test would have a sensitivity of 82.4%, a NPV of 80.9% and a high specificity and PPV (100%) compared to the viral load. The sensitivity would be higher for baseline evaluation compared to on-treatment samples (98.5 vs. 50%). The highest NPV (98%) would be obtained at 48 and 72 weeks after the initiation of treatment, with a sensitivity of 88.2% and 96.1%, respectively.
  
  
  CONCLUSIONS
  The Architect HCV core Ag assay might be an alternative for the diagnosis of active HCV infection if molecular tests are not available, and a useful method for the evaluation of sustained virological response in treated patients.
authors.affiliation: Prof Dr Matei Bals National Institute for Infectious Diseases;Carol Davila University of Medicine and Pharmacy, Bucharest, Romania. dragos.florea@mateibals.ro.
authors.forename: Dragos
authors.initials: D
authors.lastname: Florea
authors.affiliation: Prof Dr Matei Bals National Institute for Infectious Diseases, Bucharest, Romania.
authors.forename: Emil
authors.initials: E
authors.lastname: Neaga
authors.affiliation: Prof Dr Matei Bals National Institute for Infectious Diseases, Bucharest, Romania.
authors.forename: Ionelia
authors.initials: I
authors.lastname: Nicolae
authors.affiliation: Prof Dr Matei Bals National Institute for Infectious Diseases, Bucharest, Romania.
authors.forename: Daniela
authors.initials: D
authors.lastname: Maxim
authors.affiliation: Prof Dr Matei Bals National Institute for Infectious Diseases, Bucharest, Romania.
authors.forename: Madalina
authors.initials: M
authors.lastname: Popa
authors.affiliation: Prof Dr Matei Bals National Institute for Infectious Diseases, Bucharest, Romania.
authors.forename: Dan
authors.initials: D
authors.lastname: Otelea
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D016174:Hepacivirus / Q000187:drug effects / Q000235:genetics / Q000276:immunology*; D018936:Hepatitis C Antigens / Q000097:blood*; D019698:Hepatitis C, Chronic / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D062606:Tertiary Care Centers; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers; D018936:Hepatitis C Antigens