title: Evaluation of the Aptima HIV-1 Quant Dx Assay Using Plasma and Dried Blood Spots.
abstract: HIV-1 RNA quantitation in plasma, or virus load testing, is the primary method by which the response to antiretroviral therapy is monitored. Here we describe evaluation of the Aptima HIV-1 Quant Dx assay (Aptima) performed on the automated Panther system. The clinical performance of Aptima was compared to that of the Cobas AmpliPrep/Cobas TaqMan HIV-1 Test v2.0 (CAP/CTM) using 162 EDTA plasma samples collected from patients undergoing HIV-1 monitoring. Overall agreement was 84.0% (136/162), with a kappa statistic of 0.723 (standard error, 0.047; 95% confidence interval [CI], 0.630 to 0.815), indicating substantial agreement. Using the 86 clinical samples quantifiable by both methods, Passing-Bablok regression revealed a regression line of Y = (1.069 × X) - 0.346 (95% CI of the slope [1.003 to 1.139] and intercept [-0.666 to -0.074]), and Bland-Altman analysis demonstrated a mean difference (Aptima-CAP/CTM) of -0.075 log10 copies/ml (95% limits of agreement of -0.624 to 0.475), consistent with negative bias. Comparison of Aptima results for paired dried blood spot (DBS) and plasma specimens archived from participants in the Peninsula AIDS Research Cohort Study (PARC) demonstrated an overall agreement of 94.7% (90/95) when 1,000 copies/ml was used as the threshold. In conclusion, the Aptima HIV-1 Quant Dx assay provides a suitable alternative for HIV-1 monitoring in plasma and DBS.
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Malaya K
authors.initials: MK
authors.lastname: Sahoo
authors.affiliation: Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Vici
authors.initials: V
authors.lastname: Varghese
authors.affiliation: Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: White
authors.affiliation: Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Meg
authors.initials: M
authors.lastname: Winslow
authors.affiliation: Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Katzenstein
authors.affiliation: Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Shafer
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, California, USA Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA bpinsky@stanford.edu.
authors.forename: Benjamin A
authors.identifier: 0000-0001-8751-4810
authors.initials: BA
authors.lastname: Pinsky
mesh_terms: D001769:Blood / Q000821:virology*; D016903:Drug Monitoring / Q000379:methods; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D019562:Viral Load / Q000379:methods*
chemical_list: D012367:RNA, Viral