RESUMO
ObjectiveTo investigate the effects of different laboratory test reagents for hepatitis C virus (HCV) antibody through a comparative analysis. MethodsA total of 207 samples which tested positive by four anti-HCV screening reagents commonly used in the laboratories in China (Kehua, Xinchuang, Wantai, and Abbott) were included. HCV RNA nucleic acid amplification (NAT) was performed, and if NAT results were negative, recombinant immunoblot assay (RIBA) was performed for further confirmation. The test results of these four screening reagents were compared, and their S/CO values and true positive rates were analyzed. ResultsOf all the 205 samples testing positive by any one reagent, 191 (93.2%) tested positive by the four reagents, and 14 (6.8%) were tested inconsistently by the four reagents. The positive predictive values of Xinchuang, Kehua, Wantai, and Abbott reagents were 88.2% (180/204), 93.8% (180/192), 91.4% (180/197), and 90.0% (180/200), respectively. The S/CO thresholds with a positive predictive value of ≥95% for Xinchuang, Kehua, Wantai, and Abbott reagents were 9.0, 4.0, 5.0, and 7.0, respectively. ConclusionXinchuang, Kehua, Wantai, and Abbott reagents have significantly different S/CO thresholds with a positive predictive value of ≥95%, which are significantly different from those in other domestic laboratories. Each laboratory should establish an applicable S/CO threshold with a positive predictive value of ≥95%, in order to reduce the sample size for confirmatory test.