title: Improved HIV-1 RNA quantitation by COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, v2.0 using a novel dual-target approach.
abstract: 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.
authors.affiliation: Roche Diagnostics Ltd., Forrenstrasse, CH-6343 Rotkreuz, Switzerland. dorothea.sizmann@roche.com
authors.forename: Dorothea
authors.initials: D
authors.lastname: Sizmann
authors.forename: Joachim
authors.initials: J
authors.lastname: Glaubitz
authors.forename: Christian O
authors.initials: CO
authors.lastname: Simon
authors.forename: Sebastian
authors.initials: S
authors.lastname: Goedel
authors.forename: Philippe
authors.initials: P
authors.lastname: Buergisser
authors.forename: Daniel
authors.initials: D
authors.lastname: Drogan
authors.forename: Martin
authors.initials: M
authors.lastname: Hesse
authors.forename: Michael
authors.initials: M
authors.lastname: Kröh
authors.forename: Pascale
authors.initials: P
authors.lastname: Simmler
authors.forename: Manuela
authors.initials: M
authors.lastname: Dewald
authors.forename: Marion
authors.initials: M
authors.lastname: Gilsdorf
authors.forename: Marion
authors.initials: M
authors.lastname: Fuerst
authors.forename: Ralph
authors.initials: R
authors.lastname: Ineichen
authors.forename: Anette
authors.initials: A
authors.lastname: Kirn
authors.forename: Paul
authors.initials: P
authors.lastname: Pasche
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Wang
authors.forename: Sabrina
authors.initials: S
authors.lastname: Weisshaar
authors.forename: Karen
authors.initials: K
authors.lastname: Young
authors.forename: Gerd
authors.initials: G
authors.lastname: Haberhausen
authors.forename: Reiner
authors.initials: R
authors.lastname: Babiel
mesh_terms: 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
chemical_list: D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic