title: Human immunodeficiency virus (HIV) reverse transcriptase activity correlates with HIV RNA load: implications for resource-limited settings.
abstract: Measurement of human immunodeficiency virus type 1 (HIV-1) plasma RNA levels using Roche AMPLICOR version 1.5 (HIV RNA) is an integral part of monitoring HIV-infected patients in industrialized countries. These assays are currently unaffordable in resource-limited settings. We investigated a reverse transcriptase (RT) assay as a less expensive alternative for measuring viral burden that quantifies RT enzyme activity in clinical plasma samples. A comparison of RT and HIV RNA assays was performed on 29 paired plasma samples from patients living in the United States and 21 paired plasma samples from patients living in Cameroon. RT levels correlated significantly with plasma HIV RNA viral loads in plasma from U.S. patients (r = 0.898; P < 0.001) and Cameroonian patients, a majority of whom were infected with HIV-1 clade type CRF02_AG (r = 0.669; P < 0.01). Among 32 samples with HIV viral load of >2,000 copies/ml, 97% had detectable RT activity. One Cameroon sample had undetectable RNA viral load but detectable RT activity of 3 fg/ml. The RT assay is a simple and less expensive alternative to the HIV RNA assay. Field studies comparing these assays in resource-limited settings are warranted to assess the practicality and usefulness of this assay for monitoring HIV-infected patients on antiretroviral therapy.
authors.affiliation: Department of Medicine, New York University School of Medicine, New York, New York 10016, USA. sumathi.sivapalasingam@med.nyu.edu
authors.forename: Sumathi
authors.initials: S
authors.lastname: Sivapalasingam
authors.forename: Shaffiq
authors.initials: S
authors.lastname: Essajee
authors.forename: Phillipe N
authors.initials: PN
authors.lastname: Nyambi
authors.forename: Vincenza
authors.initials: V
authors.lastname: Itri
authors.forename: Bruce
authors.initials: B
authors.lastname: Hanna
authors.forename: Robert
authors.initials: R
authors.lastname: Holzman
authors.forename: Fred
authors.initials: F
authors.lastname: Valentine
mesh_terms: D015331:Cohort Studies; D015658:HIV Infections / Q000821:virology*; D054303:HIV Reverse Transcriptase / Q000097:blood*; D006801:Humans; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000097:blood*; D019562:Viral Load
chemical_list: D012367:RNA, Viral; D054303:HIV Reverse Transcriptase