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A Simple Phosphate-Buffered-Saline-Based Extraction Method Improves Specificity of HIV Viral Load Monitoring Using Dried Blood Spots

Although Roche COBAS Ampliprep/COBAS TaqMan (CAP/CTM) systems are widely used in sub-Saharan Africa for early infant diagnosis of HIV from dried blood spots (DBS), viral load monitoring with this system is not practical due to nonspecific extraction of both cell-free and cell-associated viral nuclei...

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Autores principales: Makadzange, A. Tariro, Boyd, F. Kathryn, Chimukangara, Benjamin, Masimirembwa, Collen, Katzenstein, David, Ndhlovu, Chiratidzo E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Microbiology 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5483919/
https://www.ncbi.nlm.nih.gov/pubmed/28468852
http://dx.doi.org/10.1128/JCM.00176-17
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author Makadzange, A. Tariro
Boyd, F. Kathryn
Chimukangara, Benjamin
Masimirembwa, Collen
Katzenstein, David
Ndhlovu, Chiratidzo E.
author_facet Makadzange, A. Tariro
Boyd, F. Kathryn
Chimukangara, Benjamin
Masimirembwa, Collen
Katzenstein, David
Ndhlovu, Chiratidzo E.
author_sort Makadzange, A. Tariro
collection PubMed
description Although Roche COBAS Ampliprep/COBAS TaqMan (CAP/CTM) systems are widely used in sub-Saharan Africa for early infant diagnosis of HIV from dried blood spots (DBS), viral load monitoring with this system is not practical due to nonspecific extraction of both cell-free and cell-associated viral nucleic acids. A simplified DBS extraction technique for cell-free virus elution using phosphate-buffered saline (PBS) may provide an alternative analyte for lower-cost quantitative HIV virus load (VL) testing to monitor antiretroviral therapy (ART). We evaluated the CAP/CTM v2.0 assay in 272 paired plasma and DBS specimens using the cell-free virus elution method and determined the level of agreement, sensitivity, and specificity at thresholds of target not detected (TND), target below the limit of quantification (BLQ) (<20 copies/ml in plasma or <400 copies/ml in DBS), and VL of <1,000 copies/ml, and VL of <5,000 copies/ml. Reported plasma VL ranged from TND, or <20, to 5,781,592 copies/ml, and DBS VL ranged from TND, or <400, to 467,600 copies/ml. At <1000 copies/ml, agreement between DBS and plasma was 96.7% (kappa coefficient, 0.93; P < 0.0001). The mean difference between DBS and plasma VL values was −1.06 log(10) copies/ml (95% confidence interval [CI], −1.17, −0.97; P < 0.0001). At a treatment failure threshold of >1,000 copies/ml, the sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV) were 92.7%, 100%, 100%, and 94.3%, respectively. PBS elution of DBS offers a sensitive and specific method for monitoring plasma viremia among adults and children on ART at the WHO-recommended threshold of >1,000 copies/ml on the Roche CAP/CTM system.
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spelling pubmed-54839192017-06-27 A Simple Phosphate-Buffered-Saline-Based Extraction Method Improves Specificity of HIV Viral Load Monitoring Using Dried Blood Spots Makadzange, A. Tariro Boyd, F. Kathryn Chimukangara, Benjamin Masimirembwa, Collen Katzenstein, David Ndhlovu, Chiratidzo E. J Clin Microbiol Virology Although Roche COBAS Ampliprep/COBAS TaqMan (CAP/CTM) systems are widely used in sub-Saharan Africa for early infant diagnosis of HIV from dried blood spots (DBS), viral load monitoring with this system is not practical due to nonspecific extraction of both cell-free and cell-associated viral nucleic acids. A simplified DBS extraction technique for cell-free virus elution using phosphate-buffered saline (PBS) may provide an alternative analyte for lower-cost quantitative HIV virus load (VL) testing to monitor antiretroviral therapy (ART). We evaluated the CAP/CTM v2.0 assay in 272 paired plasma and DBS specimens using the cell-free virus elution method and determined the level of agreement, sensitivity, and specificity at thresholds of target not detected (TND), target below the limit of quantification (BLQ) (<20 copies/ml in plasma or <400 copies/ml in DBS), and VL of <1,000 copies/ml, and VL of <5,000 copies/ml. Reported plasma VL ranged from TND, or <20, to 5,781,592 copies/ml, and DBS VL ranged from TND, or <400, to 467,600 copies/ml. At <1000 copies/ml, agreement between DBS and plasma was 96.7% (kappa coefficient, 0.93; P < 0.0001). The mean difference between DBS and plasma VL values was −1.06 log(10) copies/ml (95% confidence interval [CI], −1.17, −0.97; P < 0.0001). At a treatment failure threshold of >1,000 copies/ml, the sensitivities, specificities, positive predictive values (PPV), and negative predictive values (NPV) were 92.7%, 100%, 100%, and 94.3%, respectively. PBS elution of DBS offers a sensitive and specific method for monitoring plasma viremia among adults and children on ART at the WHO-recommended threshold of >1,000 copies/ml on the Roche CAP/CTM system. American Society for Microbiology 2017-06-23 2017-07 /pmc/articles/PMC5483919/ /pubmed/28468852 http://dx.doi.org/10.1128/JCM.00176-17 Text en Copyright © 2017 Makadzange et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license (http://creativecommons.org/licenses/by/4.0/) .
spellingShingle Virology
Makadzange, A. Tariro
Boyd, F. Kathryn
Chimukangara, Benjamin
Masimirembwa, Collen
Katzenstein, David
Ndhlovu, Chiratidzo E.
A Simple Phosphate-Buffered-Saline-Based Extraction Method Improves Specificity of HIV Viral Load Monitoring Using Dried Blood Spots
title A Simple Phosphate-Buffered-Saline-Based Extraction Method Improves Specificity of HIV Viral Load Monitoring Using Dried Blood Spots
title_full A Simple Phosphate-Buffered-Saline-Based Extraction Method Improves Specificity of HIV Viral Load Monitoring Using Dried Blood Spots
title_fullStr A Simple Phosphate-Buffered-Saline-Based Extraction Method Improves Specificity of HIV Viral Load Monitoring Using Dried Blood Spots
title_full_unstemmed A Simple Phosphate-Buffered-Saline-Based Extraction Method Improves Specificity of HIV Viral Load Monitoring Using Dried Blood Spots
title_short A Simple Phosphate-Buffered-Saline-Based Extraction Method Improves Specificity of HIV Viral Load Monitoring Using Dried Blood Spots
title_sort simple phosphate-buffered-saline-based extraction method improves specificity of hiv viral load monitoring using dried blood spots
topic Virology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5483919/
https://www.ncbi.nlm.nih.gov/pubmed/28468852
http://dx.doi.org/10.1128/JCM.00176-17
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