title: Comparison of two human immunodeficiency virus (HIV) RNA surrogate assays to the standard HIV RNA assay.
abstract: Human immunodeficiency virus (HIV) RNA testing is the gold standard for monitoring antiretroviral therapy in HIV-infected patients. However, equipment and reagent costs preclude widespread use of the assay in resource-limited settings. The Perkin-Elmer Ultrasensitive p24 assay and the Cavidi Exavir Load assay both offer potentially simpler, less costly technologies for monitoring viral load. These assays were compared to the Roche Amplicor HIV-1 Monitor Test, v1.5, using panels of clinical samples (subtype B) from HIV-positive subjects and HIV-spiked samples (subtypes A, C, D, CRF_01AE, CRF_02AG, and F). The Ultrasensitive p24 assay detected 100% of the spiked samples with virus loads of >250,000 copies/ml and 61% of the clinical samples with virus loads of 219 to 288,850 copies/ml. Detection rates were improved substantially if an external lysis buffer was added to the procedure. The Cavidi assay detected 54 to 100% of spiked samples with virus loads >10,000 copies/ml and 68% of the clinical samples. These detection rates were also greatly improved with a newly implemented version of this kit. Coefficients of variation demonstrate good reproducibility for each of these kits. The results from the Cavidi v1.0, Cavidi v2.0, and Perkin-Elmer, and the Perkin-Elmer Plus external buffers all correlated well with the results from the Roche Monitor Test (r = 0.83 to 0.96, r = 0.84 to 0.99, r = 0.58 to 0.67, and r = 0.59 to 0.95, respectively). Thus, the use of these two assays for monitoring patients, together with less-frequent confirmation testing, offers a feasible alternative to frequent HIV RNA testing in resource-limited settings.
authors.affiliation: Rush Medical College, Department of Immunology/Microbiology, 1653 W. Congress Parkway, Chicago, IL 60612, USA. cjenning@rush.edu
authors.forename: Cheryl
authors.initials: C
authors.lastname: Jennings
authors.forename: Susan A
authors.initials: SA
authors.lastname: Fiscus
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Crowe
authors.forename: Aleksandra D
authors.initials: AD
authors.lastname: Danilovic
authors.forename: Ralph J
authors.initials: RJ
authors.lastname: Morack
authors.forename: Salvatore
authors.initials: S
authors.lastname: Scianna
authors.forename: Ada
authors.initials: A
authors.lastname: Cachafeiro
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Brambilla
authors.forename: Jorg
authors.initials: J
authors.lastname: Schupbach
authors.forename: Wendy
authors.initials: W
authors.lastname: Stevens
authors.forename: Richard
authors.initials: R
authors.lastname: Respess
authors.forename: Oliviero E
authors.initials: OE
authors.lastname: Varnier
authors.forename: Gary E
authors.initials: GE
authors.lastname: Corrigan
authors.forename: J Simon
authors.initials: JS
authors.lastname: Gronowitz
authors.forename: Michael A
authors.initials: MA
authors.lastname: Ussery
authors.forename: James W
authors.initials: JW
authors.lastname: Bremer
mesh_terms: D016655:HIV Core Protein p24 / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis* / Q000821:virology; D054303:HIV Reverse Transcriptase / Q000378:metabolism; D015497:HIV-1 / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D006801:Humans; D012367:RNA, Viral / Q000097:blood*; D011933:Reagent Kits, Diagnostic / Q000191:economics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019562:Viral Load
chemical_list: D016655:HIV Core Protein p24; D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic; D054303:HIV Reverse Transcriptase