Comparative evaluation of the Cobas Amplicor HIV-1 Monitor Ultrasensitive Test, the new Cobas AmpliPrep/Cobas Amplicor HIV-1 Monitor Ultrasensitive Test and the Versant HIV RNA 3.0 assays for quantitation of HIV-1 RNA in plasma samples.
BACKGROUND
There are several commercially available assays for the quantitation of HIV RNA. A new automated specimen preparation system, the Cobas AmpliPrep, was developed to automate this last part of the PCR.


OBJECTIVE
We compared the results obtained by the Roche Cobas Amplicor HIV-1 Monitor Ultrasensitive Test (MCA, manual sample preparation) with those by the Versant HIV-1 RNA 3.0 assay (bDNA). Secondly we compared the MCA with the new Cobas AmpliPrep/Cobas Amplicor HIV Monitor Ultrasensitive Test (CAP/CA, automated specimen preparation) by investigating clinical patient samples and a panel of HIV-1 non-B subtypes. Furthermore, we assessed the assay throughput and workflow (especially hands-on time) for all three assays.


RESULTS
Seventy-two percent of the 140 investigated patient samples gave concordant results in the bDNA and MCA assays. The MCA values were regularly higher than the bDNA values. One sample was detected only by the MCA within the linear range of quantification. In contrast, 38 samples with results <50 copies/ml in the MCA showed in the bDNA results between 51 and 1644 copies/ml (mean value 74 copies/ml); 21 of these specimens were shown to have detectable HIV RNA < 50 copies/ml in the MCA assay. The overall agreement between the MCA and the CAP/CA was 94.3% (551/584). The quantification results showed significant correlation, although the CAP/CA generated values slightly lower than those generated by the manual procedure. We found that the CAP/CA produced comparable results with the MCA test in a panel of HIV-1 non-B subtypes.


CONCLUSIONS
All three assays showed comparable results. The bDNA provides a high sample throughput without the need of full automation. The new CAP/CA provides reliable test results with no HIV-subtype specific influence and releases time for other works in the laboratory; thus it is suitable for routine diagnostic PCR.
Berger
Annemarie
A
Institute for Medical Virology, J.W. Goethe University Hospital, Paul Ehrlich-Street 40, D-60596 Frankfurt am Main, Germany. annemarie.berger@em.uni-frankfurt.de
Scherzed
Lina
L
Stürmer
Martin
M
Preiser
Wolfgang
W
Doerr
Hans Wilhelm
HW
Rabenau
Holger Felix
HF
D001331:Automation; D021121:Branched DNA Signal Amplification Assay / Q000379:methods*; D015658:HIV Infections / Q000175:diagnosis* / Q000821:virology; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods; D012367:RNA, Viral / Q000097:blood*; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019562:Viral Load
D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic