title: False I50V resistance readings of HIV isolates: co-amplification of NASBA HIV-1 RNA QT internal calibrators and HIV-1 patient isolates may lead to a false I50V mutation resistance reading in genotypic tests.
abstract: The I50V protease inhibitor (PI) resistance mutation was found in 87.4% of protease gene fragments sequenced from 199 nucleic acid isolates extracted using an NASBA virus load assay, performed between 1997 and 2001 in Brazil. This mutation is an amprenavir-related mutation, and at that particular time this PI was seldom used in Brazil. This mutation was found both in patients with and without therapeutic success. Q calibrators showed the PI resistance mutation I50V when directly amplified and sequenced from the 423-bp PCR product targeting protease gene. The majority of the patients' samples had a mixture of I50I and I50V; however, this artifact was nor seen when a 989-bp PCR product was used. These results show that RNA extracted using virus load kits need to be critically evaluated before being used in home-brew genotypic tests.
authors.affiliation: Laboratório de Imunologia e Biologia Molecular, Infectious Diseases Service and School of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Waléria-Aleixo
authors.forename: D B
authors.initials: DB
authors.lastname: Greco
authors.forename: R
authors.initials: R
authors.lastname: Brindeiro
authors.forename: A
authors.initials: A
authors.lastname: Tanuri
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology / Q000627:therapeutic use; D024882:Drug Resistance, Viral / Q000235:genetics; D005189:False Positive Reactions; D015658:HIV Infections / Q000235:genetics / Q000821:virology; D016333:HIV Protease / Q000235:genetics / Q000378:metabolism; D017320:HIV Protease Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D009154:Mutation; D012367:RNA, Viral / Q000032:analysis; D011933:Reagent Kits, Diagnostic / Q000592:standards* / Q000706:statistics & numerical data; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic; D016333:HIV Protease