title: Prevalence of CXCR4 tropism among antiretroviral-treated HIV-1-infected patients with detectable viremia.
abstract: Although CXCR4-tropic viruses are relatively uncommon among untreated human immunodeficiency virus (HIV)-infected individuals except during advanced immunodeficiency, the prevalence of CXCR4-tropic viruses among treated patients with detectable viremia is unknown. To address this issue, viral coreceptor usage was measured with a single-cycle recombinant-virus phenotypic entry assay in treatment-naive and treated HIV-infected participants with detectable viremia sampled from 2 clinic-based cohorts. Of 182 treated participants, 75 (41%) harbored dual/mixed or X4-tropic viruses, compared with 178 (18%) of the 976 treatment-naive participants (P<.001). This difference remained significant after adjustment for CD4+ T cell count and CCR5 Delta 32 genotype. Enrichment for dual/mixed/X4-tropic viruses among treated participants was largely but incompletely explained by lower pretreatment nadir CD4 + T cell counts. CCR5 inhibitors may thus be best strategically used before salvage therapy and before significant CD4 + T cell depletion.
authors.affiliation: Positive Health Program, San Francisco General Hospital, San Francisco, CA 94110, USA. phunt@php.ucsf.edu
authors.forename: Peter W
authors.initials: PW
authors.lastname: Hunt
authors.forename: P Richard
authors.initials: PR
authors.lastname: Harrigan
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Michael
authors.initials: M
authors.lastname: Bates
authors.forename: David W
authors.initials: DW
authors.lastname: Williamson
authors.forename: Joseph M
authors.initials: JM
authors.lastname: McCune
authors.forename: Richard W
authors.initials: RW
authors.lastname: Price
authors.forename: Serena S
authors.initials: SS
authors.lastname: Spudich
authors.forename: Harry
authors.initials: H
authors.lastname: Lampiris
authors.forename: Rebecca
authors.initials: R
authors.lastname: Hoh
authors.forename: Teri
authors.initials: T
authors.lastname: Leigler
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Martin
authors.forename: Steven G
authors.initials: SG
authors.lastname: Deeks
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D024882:Drug Resistance, Viral; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012367:RNA, Viral / Q000097:blood; D019718:Receptors, CXCR4 / Q000378:metabolism*; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*; D016896:Treatment Outcome; D014766:Viremia / Q000188:drug therapy* / Q000821:virology
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral; D019718:Receptors, CXCR4; D018894:Reverse Transcriptase Inhibitors