Open AccessEvaluation of the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 Test and Identification of Rare Polymorphisms Potentially Affecting Assay Performance
Author(s) -
Michael T. Pyne,
Katherine L. Brown,
David R. Hillyard
Publication year - 2010
Publication title -
journal of clinical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.349
H-Index - 255
eISSN - 1070-633X
pISSN - 0095-1137
DOI - 10.1128/jcm.00776-10
Subject(s) - bdna test , reproducibility , virology , serial dilution , human immunodeficiency virus (hiv) , coefficient of variation , viral load , roche diagnostics , titer , medicine , chemistry , chromatography , virus , pathology , alternative medicine
We evaluated the FDA-approved Roche Cobas AmpliPrep/Cobas TaqMan (CAP/CTM) HIV-1 viral load assay for sensitivity, reproducibility, linearity, HIV-1 subtype detection, and correlation to the Roche Amplicor HIV-1 monitor test, version 1.5 (Amplicor). The limit of detection calculated by probit analysis was 23.8 copies/ml using the 2nd International WHO Standard and 30.8 copies/ml using Viral Quality Assurance (VQA) standard material. Serial dilutions of six patient samples were used to determine inter- and intra-assay reproducibility and linearity, which were very good (<8% coefficient of variation [CV]; between ∼1.7 and 7.0 log10 copies/ml). Subtype detection was evaluated in the CAP/CTM, Amplicor, and Bayer Versant HIV-1 bDNA 3.0 (Versant) assays using a commercially available panel. Versant averaged 0.829 log10 copies/ml lower than CAP/CTM and Amplicor averaged 0.427 log10 copies/ml lower than CAP/CTM for the subtype panel. Correlation with samples previously tested by Amplicor was excellent (R 2 = 0.884; average difference [Amplicor value minus CAP/CTM value], 0.008 log10 copies/ml). Of the 305 HIV samples tested, 7 samples generated CAP/CTM titers between 1.0 and 2.75 log10 copies/ml lower than those for Amplicor. Three of these samples revealed primer and probe mismatches that could account for the discrepancies. Otherwise, the CAP/CTM assay exhibits excellent sensitivity, dynamic range, reproducibility, and correlation with Amplicor in an automated format.