Evaluation of the Aptima^® HIV‐1 Quant Dx assay for HIV‐1 RNA viral load detection and quantitation in plasma of HIV‐1‐infected individuals: A comparison with Abbott RealTime HIV‐1 assay

Abstract

The Hologic Aptima ® HIV‐1 Quant Dx assay (Aptima HIV) is a real‐time transcription‐mediated amplification method CE‐approved for use in diagnosis and monitoring of HIV‐1 infection. The analytical performance of this new assay was compared to the FDA‐approved Abbott RealTi m e HIV‐1 (RealTime). The evaluation was performed using 220 clinical plasma samples, the WHO 3rd HIV‐1 International Standard, and the QCMD HIV‐1 RNA EQA. Concordance on qualitative results, correlation between quantitative results, accuracy, and reproducibility of viral load data were analyzed. The ability to measure HIV‐1 subtypes was assessed on the second WHO International Reference Preparation Panel for HIV‐1 Subtypes. With clinical samples, inter‐assay agreement for qualitative results was high (91.8%) with Cohen's kappa statistic equal to 0.836. For samples with quantitative results in both assays (n = 93), Lin's concordance correlation coefficient was 0.980 ( P < 0.0001) and mean differences of measurement, conducted according to Bland–Altman method, was low (0.115 log 10 copies/ml). The Aptima HIV quantified the WHO 3rd HIV‐1 International Standard diluted from 2000 to 31 cp/ml (5,700–88 IU/ml) at expected values with excellent linearity (R 2 > 0.970) and showed higher sensitivity compared to RealTime being able to detect HIV‐1 RNA in 10 out of 10 replicates containing down to 7 cp/ml (20 IU/ml). Reproducibility was very high, even at low HIV‐1 RNA values. The Aptima HIV was able to detect and accurately quantify all the main HIV‐1 subtypes in both reference panels and clinical samples. Besides excellent performance, Aptima HIV shows full automation, ease of use, and improved workflow compared to RealTime. J. Med. Virol. 88:1535–1544, 2016 . © 2016 Wiley Periodicals, Inc.

Evaluation of Hologic Aptima HIV-1 Quant Dx Assay on the Panther System on HIV Subtypes

“…Thus, differences in quantitation between the three assays can be normalized to nearly equivalent levels if the data are expressed in international units, although quantitation of subtypes C, F, and G and CRF02_AG would still be 0.20 to 0.25 log lower by RealTime assay than by Aptima assay. Overall differences in quantitation among the three assays are relatively small and are comparable across diverse group M subtypes, recombinant circulating forms, and group O samples, and the results are consistent with previous studies (30)(31)(32)(33)(34)(35)(36). Our study demonstrates the excellent linearity and accuracy of the Aptima assay in quantifying viral load measurements on diverse HIV-1 subtypes, groups, and circulating recombinant forms, even at very low RNA levels.…”

“…The modest increase (1.5-to 2-fold) in viral loads observed at concentrations above 10,000 copies/ml of HIV-1 by using the Hologic assay relative to the comparator assays should have a minimal impact on treatment decisions because these concentrations are significantly above the 200-copies/ml medical decision point in the NIH treatment guidelines (2). Studies conducted by various investigators showed that although the Aptima assay detected HIV in more samples, the number of quantified results above 50 copies/ml reported by the Aptima assay was lower than those for the CAP/ CTM and RealTime assays (30)(31)(32)(33). Therefore, the likelihood of a patient categorized as virologically controlled by the CAP/CTM or RealTime assay (below 200 copies/ml) yielding results above the medical decision point (200 copies/ml) in the Aptima assay is low.…”

“…Previous performance evaluations of viral load assays have shown the Aptima assay to be more sensitive than the RealTime assay (30,31) for detection of HIV-1 RNA in serial dilutions of the WHO 3rd international standard and that the assay is capable of detecting lower viral loads in clinical samples (32,33). A more recent study showed the Aptima assay to be more sensitive than the CAP/CTM assay on both standards and clinical samples (34).…”

Evaluation of the Aptima HIV-1 Quant Dx Assay using plasma and dried blood spots

“…While several studies have compared Aptima to a variety of HIV-1 virus load tests (25,26,(32)(33)(34)(35), to date, only the studies from Hopkins et al (25) and Nair et al (26) have compared Aptima with CAP/CTM. Consistent with the evaluation presented here, in those studies linearity was confirmed using commercially available material, similar levels of precision were observed at low virus loads, and there was good agreement between methods for both qualitative and quantitative results.…”

Comparison of the Aptima HIV‐1 Quant Dx assay with the COBAS AmpliPrep/COBAS TaqMan HIV‐1 v2.0 Test for HIV‐1 viral load quantification in plasma samples from HIV‐1–infected patients

“…Yet another study found Aptima‐HIV‐1 to be more sensitive than CAP/CTM2 . Aptima‐HIV‐1 has also been shown to have performance characteristics similar to or better than the RealTime HIV‐1 assay (Abbott Molecular, Des Plaines, Illinois) and superior to the NucliSens EasyQ HIV‐1 v.2 assay (BioMérieux, Marcy l'Etoile, France) and the Artus HIV‐1 QS‐RGQ assay (Qiagen GmbH, Hilden, Germany) …”