Clinical utility of HCV core antigen detection and quantification in the diagnosis and management of patients with chronic hepatitis C receiving an all-oral, interferon-free regimen.
The introduction of highly potent direct-acting combination therapies for HCV have negated the role of response-guided therapy and reduced the role of treatment monitoring. However, there remains a need to identify patients who are actively infected with HCV and discriminate those who have achieved sustained virological response (SVR) from those who fail to achieve SVR.



A total of 1,678 plasma samples from the 631 subjects enrolled in AbbVie's SAPPHIRE I trial (NCT01716585) were tested in a blinded fashion with Abbott HCV core antigen (cAg) assay and results were compared with Roche High-Pure system/COBAS®TaqMan HCV RNA 2.0 assay.



Using 10 fmol/l as the clinical cutoff for cAg, the HCV RNA and cAg tests were in 100% agreement for true negative samples and 99.6% agreement for truly positive samples. One discordant (screening) sample was identified. This sample was target not detected by HCV RNA method but positive by anti-HCV and highly positive by ARCHITECT core antigen (7,912 fmol/l). Seventeen samples had cAg levels in the 'grey zone' >3 but <10 fmol/l at initial testing and were re-tested per package insert. All of these samples gave a result of <3 fmol/l upon retest. These results were in alignment with target not detected HCV RNA result. One sample had a cAg >3 but <10 fmol/l when tested on three consecutive occasions (5.8, 5.5 and 4.4) but had a target not detected RNA result.



In this study cAg, with a 10 fmol/l cutoff, accurately identified 99.6% of patients with active viraemia and discriminated all subjects who achieved SVR from those who failed therapy.
Hopital Henri Mondor, Université Paris-Est, Créteil, France.
Stéphane
S
Chevaliez
Toronto Centre for Liver Disease, McLaughlin-Rotman Centre for Global Health, University of Toronto, Toronto, ON, Canada.
Jordan
J
Feld
Abbott Laboratories, Abbott Park, IL, USA.
Kevin
K
Cheng
Klinik für Gastroenterologie, Hepatologie und Endokrinologie, Medizinische Hochschule Hannover, Hannover, Germany.
Heiner
H
Wedemeyer
Medizinische Klinik 1, Universitätsklinikum Frankfurt, Frankfurt am Main, Germany.
Christoph
C
Sarrazin
Klinik für Gastroenterologie, Hepatologie und Endokrinologie, Medizinische Hochschule Hannover, Hannover, Germany.
Benjamin
B
Maasoumy
Abbott Laboratories, Abbott Park, IL, USA.
Christine
C
Herman
Abbott Laboratories, Abbott Park, IL, USA.
John
J
Hackett
AbbVie, North Chicago, IL, USA.
Daniel
D
Cohen
Abbott Laboratories, Abbott Park, IL, USA.
George
G
Dawson
Hopital Henri Mondor, Université Paris-Est, Créteil, France.
Jean-Michel
JM
Pawlotsky
Abbott Laboratories, Abbott Park, IL, USA.
Gavin
G
Cloherty
D000956:Antigens, Viral / Q000276:immunology; D000998:Antiviral Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D019468:Disease Management; D004359:Drug Therapy, Combination; D016174:Hepacivirus / Q000276:immunology; D019698:Hepatitis C, Chronic / Q000175:diagnosis* / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D006801:Humans; D007118:Immunoassay; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D019562:Viral Load
D000956:Antigens, Viral; D000998:Antiviral Agents