title: Clinical evaluation of the signal-to-cutoff ratios of hepatitis C virus antibody screening tests used in China.
abstract: The clinical diagnosis of hepatitis C virus (HCV) infection is important to direct an accurate course of therapy. Previous studies have reported a correlation between the signal-to-cutoff (S/CO) ratios of the anti-HCV screening test and confirm HCV infections for American anti-HCV screening kits as well as for those in China. It is currently unknown whether clinical laboratories use the same threshold S/CO ratios under routine conditions and if these values are acceptable for the analysis of Chinese samples. A total of 336 anti-HCV screening-test-positive serum samples were tested in duplicate using different lots of three most commonly used enzyme immunoassay (EIA) kits available in China. Samples were also tested using the Architect Anti-HCV chemiluminescent microparticle immunoassay (CMIA) kit and measured for HCV RNA. Recombinant immunoblot assays (RIBA) were additionally performed on samples with HCV RNA-negative results with RIBA HCV 3.0. The relationship between S/CO ratios and confirmed HCV infection rates were analyzed. The threshold S/CO ratio for each screening kit correlated with the ≥ 95% positive predictive value was InTec 12.0, KHB 4.0, Wantai 5.0, and Abbott Architect 5.0. Therefore, the same threshold S/CO ratios for manufactured domestically EIA kits was difficult to attain. A multi-center study with a large sample size is required to identify a uniform threshold S/CO ratio for use in different diagnostic laboratories. Alternatively, individual laboratories may be required to establish threshold S/CO ratios in their own laboratories to obtain consistent diagnostic results.
authors.affiliation: Department of Clinical Laboratory, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Shiji
authors.initials: S
authors.lastname: Wu
authors.forename: Yanling
authors.initials: Y
authors.lastname: Liu
authors.forename: Liming
authors.initials: L
authors.lastname: Cheng
authors.forename: Botao
authors.initials: B
authors.lastname: Yin
authors.forename: Jing
authors.initials: J
authors.lastname: Peng
authors.forename: Ziyong
authors.initials: Z
authors.lastname: Sun
mesh_terms: D002681:China; D019411:Clinical Laboratory Techniques / Q000379:methods*; D016174:Hepacivirus / Q000276:immunology*; D006526:Hepatitis C / Q000175:diagnosis* / Q000276:immunology; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008403:Mass Screening / Q000379:methods*; D011237:Predictive Value of Tests
chemical_list: D018937:Hepatitis C Antibodies