Performance characteristics of the Cavidi ExaVir viral load assay and the ultra-sensitive P24 assay relative to the Roche Monitor HIV-1 RNA assay.

TitlePerformance characteristics of the Cavidi ExaVir viral load assay and the ultra-sensitive P24 assay relative to the Roche Monitor HIV-1 RNA assay.
Publication TypeJournal Article
Year of Publication2010
AuthorsStewart P, Cachafeiro A, Napravnik S, Eron JJ, Frank I, van der Horst C, Bosch RJ, Bettendorf D, Bohlin P, Fiscus SA
JournalJ Clin Virol
Volume49
Issue3
Pagination198-204
Date Published2010 Nov
ISSN1873-5967
KeywordsHIV Core Protein p24, HIV Infections, HIV-1, Humans, Predictive Value of Tests, Reagent Kits, Diagnostic, RNA, Viral, Sensitivity and Specificity, Viral Load
Abstract

BACKGROUND: The Cavidi viral load assay and the ultra-sensitive p24 antigen assay (Up24 Ag) have been suggested as more feasible alternatives to PCR-based HIV viral load assays for use in monitoring patients infected with HIV-1 in resource-limited settings.

OBJECTIVES: To describe the performance of the Cavidi ExaVir Load™ assay (version 2.0) and two versions of the Up24 antigen assay and to characterize their agreement with the Roche Monitor HIV-1 RNA assay (version 1.5).

STUDY DESIGN: Observational study using a convenience sample of 342 plasma specimens from 108 patients enrolled in two ACTG clinical trials to evaluate the performance characteristics of the Up24 Ag assay using two different lysis buffers and the Cavidi ExaVir Load™ assay.

RESULTS: In analysis of agreement with the Roche assay, the Cavidi assay demonstrated superiority to the Up24 Ag assays in accuracy and precision, as well as sensitivity, specificity, and positive and negative predictive values for HIV-1 RNA ≥ 400, ≥ 1000 and ≥ 5000 copies/mL. Logistic performance curves indicated that the Cavidi assay was superior to the Up24 assays for viral loads greater than 650 copies/mL.

CONCLUSIONS: The results suggest that the Cavidi ExaVir Load assay could be used for monitoring HIV-1 viral load in resource-limited settings.

DOI10.1016/j.jcv.2010.07.022
Alternate JournalJ. Clin. Virol.
PubMed ID20832356
PubMed Central IDPMC3025774
Grant List1U54RR024383 / RR / NCRR NIH HHS / United States
AI068634 / AI / NIAID NIH HHS / United States
AI068636 / AI / NIAID NIH HHS / United States
AI069423 / AI / NIAID NIH HHS / United States
AI069467 / AI / NIAID NIH HHS / United States
P30 AI045008 / AI / NIAID NIH HHS / United States
P30 AI045008 / AI / NIAID NIH HHS / United States
P30 AI050410 / AI / NIAID NIH HHS / United States
P30 AI50410 / AI / NIAID NIH HHS / United States
U01 AI068634 / AI / NIAID NIH HHS / United States
U01 AI069423 / AI / NIAID NIH HHS / United States
U01 AI069467 / AI / NIAID NIH HHS / United States