Multicentre evaluation of the Versant HIV1 RNA 1.0 Assay (kPCR) with the Versant kPCR molecular system

Abstract number: P541

Taylor P., Mistry H., Nutter P., Yao J., Schmidt D., Kathrotiya J., Turczyn J., Fisher L., Maghakian D.

Objectives: The Siemens VERSANT^®a HIV-1 RNA 1.0 Assay (kPCR)^b is a reverse transcription kinetic polymerase chain reaction (kPCR) method for quantifying human immunodeficiency virus type 1 (HIV-1) RNA in human plasma, using the VERSANT kPCR Molecular System – a semi-automated system combining a fully automated sample preparation module and a fully automated amplification and detection module. This study examined the performance characteristics of the assay, and a method comparison was conducted between the VERSANT HIV-1 RNA 1.0 Assay (kPCR) and the Abbott RealTime^® HIV-1 assay.

Methods: Assay performance characteristics were evaluated at three laboratory sites, with each site using two VERSANT HIV-1 RNA 1.0 Assay (kPCR) kit lots and two instrument systems. Plasma samples from 1,055 HIV-1 seronegative individuals were tested to assess assay specificity. A 13-member dilution panel prepared from high titer HIV-1 8E5/LAV viral stock was used to determine precision, linearity, accuracy, quantification range and analytical sensitivity: panel members had HIV-1 RNA concentrations ranging from 10 to >11,000,000 copies/mL. The method comparison between the VERSANT HIV-1 RNA 1.0 Assay (kPCR) and the Abbott RealTime HIV-1 assay was conducted using 189 HIV-1 RNA-positive plasma samples that included HIV-1 Group M subtypes A, B, C, D, F, G, H; circulating recombinant forms AE and AG; and Group O variants. All samples possessed HIV-1 viral loads within the common assay range of 75 to 10,000,000 copies/mL.

Results: The overall assay specificity was 99.7%. The limit of detection (LoD) was 37 copies/mL: the lower limit of quantitation (LLoQ) was 37 copies/mL and the upper limit of quantitation (ULoQ) was 11,000,000 copies/mL. On average the VERSANT HIV-1 RNA 1.0 Assay (kPCR) generated values that were 0.21 log copies/mL lower than the Abbott RealTime HIV-1 assay. The Deming regression slope (fitting VERSANT log quantitation versus Abbott log quantitation) was 1.07.

Conclusions: The VERSANT HIV-1 RNA 1.0 Assay (kPCR) using the VERSANT kPCR Molecular System is a reliable and accurate assay for the quantification of HIV-1 RNA in plasma from HIV-1 infected individuals.

^aVERSANT is a registered trademark of Siemens and all other trademarks are the property of their respective owners.

^bCE marked in Europe; not available in the US.