title: Improved Sensitivity of a Dual-Target HIV-1 Qualitative Test for Plasma and Dried Blood Spots.
abstract: The use of nucleic acid detection for HIV type 1 (HIV-1) detection is strongly recommended in infants <18 months of age, in whom serology is unreliable. This study evaluated the Cobas AmpliPrep/Cobas TaqMan HIV-1 Qualitative Test v2.0 (TaqMan HIV-1 Qual Test, v2.0), a dual-target total nucleic acid real-time PCR assay. The limit of detection (LOD) of the new test in plasma and dried blood spots (DBS) was determined with the 2nd International HIV-1 RNA WHO standard. The specificity of the assay was tested with EDTA plasma (n = 1,301) and DBS from HIV-negative adults (n = 1,000). The sensitivity was determined using HIV-1-positive samples (n = 169 adult EDTA plasma, n = 172 adult DBS, and n = 100 infant DBS) that included group M, subtypes A to H, CRF01_AE, CRF02_AG, and groups O and N. All positive specimens and a subset of the negative specimens were also tested with the Abbott RealTime HIV-1 Qual assay (RealTime). The LOD of the TaqMan assay was 20 copies/ml in plasma and 300 copies/ml in DBS, with specificities of 99.8% in plasma and 99.9% in DBS. The TaqMan assay results were 100% concordant with RealTime results in EDTA plasma samples and in 100 HIV-1-negative adult DBS. Among 172 HIV-1-positive DBS from adults, the TaqMan assay showed positive results for all DBS while RealTime missed five DBS with low target concentrations. Infant DBS results were 100% concordant. The improved sensitivity of the Cobas AmpliPrep/Cobas TaqMan HIV-1 Qualitative Test, v2.0, compared to current commercially available assays may enable earlier diagnosis and treatment in adults and infants. The dual-target test may ensure HIV-1 detection even if a mutation is present in one of the two target regions. The DBS sample matrix facilitates virological testing in remote areas.
authors.affiliation: Roche Diagnostics International AG, Rotkreuz, Switzerland.
authors.forename: Stefanie P
authors.initials: SP
authors.lastname: Templer
authors.affiliation: Roche Diagnostics International AG, Rotkreuz, Switzerland.
authors.forename: Britta
authors.initials: B
authors.lastname: Seiverth
authors.affiliation: Roche Molecular Systems, Inc., Pleasanton, California, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Baum
authors.affiliation: University of the Witwatersrand, Faculty of Health Sciences, School of Pathology, Department of Molecular Medicine and Haematology, Johannesburg, South Africa.|National Health Laboratory Service, Johannesburg, South Africa.
authors.forename: Wendy
authors.initials: W
authors.lastname: Stevens
authors.affiliation: Luxembourg Institute of Health, Department of Infection and Immunity, Luxembourg, Luxembourg.
authors.forename: Carole
authors.initials: C
authors.lastname: Seguin-Devaux
authors.affiliation: University of the Witwatersrand, Faculty of Health Sciences, School of Pathology, Department of Molecular Medicine and Haematology, Johannesburg, South Africa Sergio.carmona@wits.ac.za.|National Health Laboratory Service, Johannesburg, South Africa.
authors.forename: Sergio
authors.initials: S
authors.lastname: Carmona
mesh_terms: D000328:Adult; D001769:Blood / Q000821:virology*; D015658:HIV Infections / Q000175:diagnosis*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity