Estimation of measurement error in plasma HIV-1 RNA assays near their limit of quantification.

<h4>Background</h4>Plasma HIV-1 RNA levels (pVLs), routinely used for clinical management, are influenced by measurement error (ME) due to physiologic and assay variation.<h4>Objective</h4>To assess the ME of the COBAS HIV-1 Ampliprep AMPLICOR MONITOR ultrasensitive assay ver...

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Main Authors: Viviane D Lima, Lu Wang, Chanson Brumme, Lang Wu, Julio S G Montaner, P Richard Harrigan
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2017-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0171155&type=printable
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author Viviane D Lima
Lu Wang
Chanson Brumme
Lang Wu
Julio S G Montaner
P Richard Harrigan
author_facet Viviane D Lima
Lu Wang
Chanson Brumme
Lang Wu
Julio S G Montaner
P Richard Harrigan
author_sort Viviane D Lima
collection DOAJ
description <h4>Background</h4>Plasma HIV-1 RNA levels (pVLs), routinely used for clinical management, are influenced by measurement error (ME) due to physiologic and assay variation.<h4>Objective</h4>To assess the ME of the COBAS HIV-1 Ampliprep AMPLICOR MONITOR ultrasensitive assay version 1.5 and the COBAS Ampliprep Taqman HIV-1 assay versions 1.0 and 2.0 close to their lower limit of detection. Secondly to examine whether there was any evidence that pVL measurements closest to the lower limit of quantification, where clinical decisions are made, were susceptible to a higher degree of random noise than the remaining range.<h4>Methods</h4>We analysed longitudinal pVL of treatment-naïve patients from British Columbia, Canada, during their first six months on treatment, for time periods when each assay was uniquely available: Period 1 (Amplicor): 08/03/2000-01/02/2008; Period 2 (Taqman v1.0): 07/01/2010-07/03/2012; Period 3 (Taqman v2.0): 08/03/2012-30/06/2014. ME was estimated via generalized additive mixed effects models, adjusting for several clinical and demographic variables and follow-up time.<h4>Results</h4>The ME associated with each assay was approximately 0.5 log10 copies/mL. The number of pVL measurements, at a given pVL value, was not randomly distributed; values ≤250 copies/mL were strongly systematically overrepresented in all assays, with the prevalence decreasing monotonically as the pVL increased. Model residuals for pVL ≤250 copies/mL were approximately three times higher than that for the higher range, and pVL measurements in this range could not be modelled effectively due to considerable random noise of the data.<h4>Conclusions</h4>Although the ME was stable across assays, there is substantial increase in random noise in measuring pVL close to the lower level of detection. These findings have important clinical significance, especially in the range where key clinical decisions are made. Thus, pVL values ≤250 copies/mL should not be taken as the "truth" and repeat pVL measurement is encouraged to confirm viral suppression.
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spelling doaj-art-6859292ce8104346baf4ddbf4c81a8172025-08-20T02:03:54ZengPublic Library of Science (PLoS)PLoS ONE1932-62032017-01-01122e017115510.1371/journal.pone.0171155Estimation of measurement error in plasma HIV-1 RNA assays near their limit of quantification.Viviane D LimaLu WangChanson BrummeLang WuJulio S G MontanerP Richard Harrigan<h4>Background</h4>Plasma HIV-1 RNA levels (pVLs), routinely used for clinical management, are influenced by measurement error (ME) due to physiologic and assay variation.<h4>Objective</h4>To assess the ME of the COBAS HIV-1 Ampliprep AMPLICOR MONITOR ultrasensitive assay version 1.5 and the COBAS Ampliprep Taqman HIV-1 assay versions 1.0 and 2.0 close to their lower limit of detection. Secondly to examine whether there was any evidence that pVL measurements closest to the lower limit of quantification, where clinical decisions are made, were susceptible to a higher degree of random noise than the remaining range.<h4>Methods</h4>We analysed longitudinal pVL of treatment-naïve patients from British Columbia, Canada, during their first six months on treatment, for time periods when each assay was uniquely available: Period 1 (Amplicor): 08/03/2000-01/02/2008; Period 2 (Taqman v1.0): 07/01/2010-07/03/2012; Period 3 (Taqman v2.0): 08/03/2012-30/06/2014. ME was estimated via generalized additive mixed effects models, adjusting for several clinical and demographic variables and follow-up time.<h4>Results</h4>The ME associated with each assay was approximately 0.5 log10 copies/mL. The number of pVL measurements, at a given pVL value, was not randomly distributed; values ≤250 copies/mL were strongly systematically overrepresented in all assays, with the prevalence decreasing monotonically as the pVL increased. Model residuals for pVL ≤250 copies/mL were approximately three times higher than that for the higher range, and pVL measurements in this range could not be modelled effectively due to considerable random noise of the data.<h4>Conclusions</h4>Although the ME was stable across assays, there is substantial increase in random noise in measuring pVL close to the lower level of detection. These findings have important clinical significance, especially in the range where key clinical decisions are made. Thus, pVL values ≤250 copies/mL should not be taken as the "truth" and repeat pVL measurement is encouraged to confirm viral suppression.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0171155&type=printable
spellingShingle Viviane D Lima
Lu Wang
Chanson Brumme
Lang Wu
Julio S G Montaner
P Richard Harrigan
Estimation of measurement error in plasma HIV-1 RNA assays near their limit of quantification.
PLoS ONE
title Estimation of measurement error in plasma HIV-1 RNA assays near their limit of quantification.
title_full Estimation of measurement error in plasma HIV-1 RNA assays near their limit of quantification.
title_fullStr Estimation of measurement error in plasma HIV-1 RNA assays near their limit of quantification.
title_full_unstemmed Estimation of measurement error in plasma HIV-1 RNA assays near their limit of quantification.
title_short Estimation of measurement error in plasma HIV-1 RNA assays near their limit of quantification.
title_sort estimation of measurement error in plasma hiv 1 rna assays near their limit of quantification
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0171155&type=printable
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