Improved HIV-1 RNA quantitation by COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, v2.0 using a novel dual-target approach.
BACKGROUND
HIV-1 RNA viral load is a key parameter for reliable treatment monitoring of HIV-1 infection. Accurate HIV-1 RNA quantitation can be impaired by primer and probe sequence polymorphisms as a result of tremendous genetic diversity and ongoing evolution of HIV-1. A novel dual HIV-1 target amplification approach was realized in the quantitative COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, v2.0 (HIV-1 TaqMan test v2.0) to cope with the high genetic diversity of the virus.


OBJECTIVE
The performance of the new assay was evaluated for sensitivity, dynamic range, precision, subtype inclusivity, diagnostic and analytical specificity, interfering substances, and correlation with the COBAS AmpliPrep/COBAS TaqMan HIV-1 (HIV-1 TaqMan test v1.0) predecessor test in patients specimens.


RESULTS
The new assay demonstrated a sensitivity of 20 copies/mL, a linear measuring range of 20-10,000,000 copies/mL, with a lower limit of quantitation of 20 copies/mL. HIV-1 Group M subtypes and HIV-1 Group O were quantified within +/-0.3 log(10) of the assigned titers. Specificity was 100% in 660 tested specimens, no cross reactivity was found for 15 pathogens nor any interference for endogenous substances or 29 drugs. Good comparability with the predecessor assay was demonstrated in 82 positive patient samples. In selected clinical samples 35/66 specimens were found underquantitated in the predecessor assay; all were quantitated correctly in the new assay.


CONCLUSIONS
The dual-target approach for the HIV-1 TaqMan test v2.0 enables superior HIV-1 Group M subtype coverage including HIV-1 Group O detection. Correct quantitation of specimens underquantitated in the HIV-1 TaqMan test v1.0 test was demonstrated.
Sizmann
Dorothea
D
Roche Diagnostics Ltd., Forrenstrasse, CH-6343 Rotkreuz, Switzerland. dorothea.sizmann@roche.com
Glaubitz
Joachim
J
Simon
Christian O
CO
Goedel
Sebastian
S
Buergisser
Philippe
P
Drogan
Daniel
D
Hesse
Martin
M
Kröh
Michael
M
Simmler
Pascale
P
Dewald
Manuela
M
Gilsdorf
Marion
M
Fuerst
Marion
M
Ineichen
Ralph
R
Kirn
Anette
A
Pasche
Paul
P
Wang
Zhijun
Z
Weisshaar
Sabrina
S
Young
Karen
K
Haberhausen
Gerd
G
Babiel
Reiner
R
D015658:HIV Infections / Q000175:diagnosis* / Q000821:virology*; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D012367:RNA, Viral / Q000032:analysis*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D019562:Viral Load
D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic