title: Evaluation of a hepatitis C virus (HCV) antigen assay for routine HCV screening among men who have sex with men infected with HIV.
abstract: BACKGROUND
  For detection of early HCV infection and reinfection, commercial HCV-RNA tests are available. However, these tests are relatively time-consuming and expensive. A commercially available test that may supplement current screening methods, targets the HCV core protein.
  
  
  METHODS
  During five waves of anonymous surveys at the Amsterdam STI clinic between 2009-2012, all HIV-infected MSM (N=439) were tested for HCV-antibodies (AxSYM HCV 3.0, Abbott), and HCV-RNA (TMA Versant, Siemens). To evaluate the potential value of the ARCHITECT HCV antigen (HCV-Ag) assay (Abbott), all HCV-RNA-positive sera (N=31) were tested with this assay, as well as two HIV-infected HCV-RNA-negative controls. In addition, all included samples were tested for alanine aminotransferase (ALT).
  
  
  RESULTS
  Among 439 HIV-infected MSM, 31 (7.1%) tested positive for HCV-RNA; the HCV-Ag assay showed concordant positive results for 31/31 (100%). A substantial number of MSM, i.e., 5/31 (16.1%), had detectable HCV-RNA but were HCV-seronegative at the time of screening and were presumed to have been recently infected. Concordant HCV-RNA-negative results were obtained in 57/60 control-samples. Specificity was 95.0% (95% CI: 86.1-99.0). The detection limit was between 3.0 and 3.7 Log10 IU/mL, irrespective of HCV genotype/subtype. ALT concentrations were elevated (i.e.,>40 U/L) in 9/31 (29.0%) HCV-RNA positive MSM, including 1/5 (20.0%) MSM with recent HCV-infection.
  
  
  CONCLUSIONS
  The HCV-Ag assay proved a valuable screening tool for detection of active HCV infection among HIV-infected MSM with and without anti-HCV. Adding ALT to current screening methods would improve case finding marginally. We therefore recommend implementation of routine HCV-Ag screening for populations at risk for HCV-(re)infection.
authors.affiliation: Cluster of Infectious Diseases, Department of Research, Public Health Service, Amsterdam, The Netherlands; Department of Medical Microbiology, Section of Clinical Virology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Joost W
authors.initials: JW
authors.lastname: Vanhommerig
authors.affiliation: Department of Blood-borne Infections, Sanquin Blood Supply Foundation, Amsterdam, The Netherlands.
authors.forename: Thijs J W
authors.initials: TJ
authors.lastname: van de Laar
authors.affiliation: Department of Blood-borne Infections, Sanquin Blood Supply Foundation, Amsterdam, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: Koot
authors.affiliation: Cluster of Infectious Diseases, Department of Research, Public Health Service, Amsterdam, The Netherlands.
authors.forename: Martijn S
authors.initials: MS
authors.lastname: van Rooijen
authors.affiliation: Department of Medical Microbiology, Section of Clinical Virology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Janke
authors.initials: J
authors.lastname: Schinkel
authors.affiliation: Cluster of Infectious Diseases, Department of Research, Public Health Service, Amsterdam, The Netherlands.
authors.forename: Arjen G C L
authors.initials: AG
authors.lastname: Speksnijder
authors.affiliation: Cluster of Infectious Diseases, Department of Research, Public Health Service, Amsterdam, The Netherlands; Department of Internal Medicine, Center of Infectious diseases and Immunology Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Maria
authors.initials: M
authors.lastname: Prins
authors.affiliation: Cluster of Infectious Diseases, Department of Research, Public Health Service, Amsterdam, The Netherlands; Department of Internal Medicine, Center of Infectious diseases and Immunology Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Henry J
authors.initials: HJ
authors.lastname: de Vries
authors.affiliation: Cluster of Infectious Diseases, Department of Research, Public Health Service, Amsterdam, The Netherlands. Electronic address: sbruisten@ggd.amsterdam.nl.
authors.forename: Sylvia M
authors.initials: SM
authors.lastname: Bruisten
mesh_terms: D019411:Clinical Laboratory Techniques / Q000379:methods*; D003430:Cross-Sectional Studies; D015658:HIV Infections / Q000150:complications*; D016174:Hepacivirus / Q000302:isolation & purification*; D006526:Hepatitis C / Q000175:diagnosis*; D018936:Hepatitis C Antigens / Q000097:blood*; D018451:Homosexuality, Male; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D008403:Mass Screening / Q000379:methods*; D009426:Netherlands; D012680:Sensitivity and Specificity
chemical_list: D018936:Hepatitis C Antigens
keywords: Acute HCV infection; HCV core antigen; HIV coinfection; Hepatitis C Virus; Men who have sex with men