title: Comparison of four commercial quantitative HIV-1 assays for viral load monitoring in clinical daily routine.
abstract: BACKGROUND
  Quantification of viral load (VL) is standard for monitoring HIV-1 therapy and is crucial before deciding whether to switch or to continue a current antiretroviral regimen.
  
  
  METHODS
  We compared the performance of the four most widely used commercial viral-load assays, COBAS Amplicor Monitor v1.5, Versant HIV-1 RNA 3.0, Abbott RealTime HIV-1 and Cobas AmpliPrep/Cobas TaqMan HIV-1 (CAP/CTM), in terms of intra- and inter-assay variability, as well as hands-on-time, specificity and ability to quantify group M subtypes.
  
  
  RESULTS
  Although linearity and correlation were confirmed for the assays and comparable sensitivity and specificity were verified for genetically diverse HIV-1 subtypes, demonstrating suitability for monitoring of HIV group M isolates, the viral loads obtained showed variations, with a mean difference of 0.1-0.4 log, depending on the system used.
  
  
  CONCLUSIONS
  Although sensitivity and precision were confirmed for all the systems, differences between them should be taken into account when viral load monitoring of the same person is performed using different systems.
authors.affiliation: PZB Aachen, Aachen, Germany. pab@pzb.de
authors.forename: Patrick
authors.initials: P
authors.lastname: Braun
authors.forename: Robert
authors.initials: R
authors.lastname: Ehret
authors.forename: Frank
authors.initials: F
authors.lastname: Wiesmann
authors.forename: Frauke
authors.initials: F
authors.lastname: Zabbai
authors.forename: Mechthild
authors.initials: M
authors.lastname: Knickmann
authors.forename: Rainer
authors.initials: R
authors.lastname: Kühn
authors.forename: Sven
authors.initials: S
authors.lastname: Thamm
authors.forename: Gerald
authors.initials: G
authors.lastname: Warnat
authors.forename: Heribert
authors.initials: H
authors.lastname: Knechten
mesh_terms: D001681:Biological Assay; D021121:Branched DNA Signal Amplification Assay; D003955:Diagnostic Tests, Routine / Q000706:statistics & numerical data*; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification; D021141:Nucleic Acid Amplification Techniques; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000097:blood*; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D019562:Viral Load
chemical_list: D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic