Background: An improved test version of the Abbott ARCHITECT anti-hepatitis C virus (HCV) test became available at the end of 2005.
Study design: We compared the new test version with the Ortho Vitros anti-HCV test by evaluating 2034 serum samples in parallel on both systems under routine laboratory conditions. Discordant samples were tested in the Inno-LIA HCV Score assay as well as in the RIBA HCV 3.0.
Results: Of the 2034 samples 140 (6.9%) yielded positive and 1856 (91.2%) negative results in both assays. We observed discordant results in 38 samples (1.9%). All discrepant samples showed a low S/CO ratio of 1.0-6.9 (mean 2.8) in the Ortho assay and of 1.3-3.0 (mean 1.96) in the ARCHITECT assay. As expected, most of them could not be confirmed by immunoblot testing. Comparison of the results of the two immunoblots (Inno-LIA and RIBA) revealed a great variability in test results.
Conclusions: This study represents the first comparative evaluation of the modified version of the Abbott ARCHITECT anti-HCV assay in comparison with the Ortho Vitros anti-HCV test. Under routine laboratory testing, we observed good overall concordance between the two assays and no evidence that one assay shows more false-reactive or negative results than the other.