title: Determination of HIV-1 coreceptor tropism using proviral DNA in women before and after viral suppression.
abstract: BACKGROUND
  An HIV-1 tropism test is recommended prior to CCR5 antagonist administration to exclude patients harboring non-R5 virus from treatment with this class of antiretrovirals. HIV-1 tropism determination based on proviral DNA (pvDNA) may be useful in individuals with plasma viral RNA suppression. We developed a genotypic tropism assay for pvDNA and assessed its performance in a retrospective analysis of samples collected longitudinally.
  
  
  RESULTS
  We randomly selected paired plasma/PBMC samples from the Women's Interagency HIV Study with plasma viral load ≥5,000 cp/mL at time 1 (T1), undetectable viral load maintained for ≥1 year and CD4+ >200 cells/μL at time 2 (T2). pvDNA was isolated from cryopreserved PBMCs. Sequences were analyzed in triplicate from 49/50 women, with tropism assigned using the geno2pheno (g2p) algorithm. The median time between T1 and T2 was 4.1 years. CXCR4-using virus was detected in 24% of the RNA samples and 33% of the pvDNA samples at T1, compared to 37% of the pvDNA samples at T2. Concordance between plasma RNA and pvDNA tropism was 88% at T1 and 80% at T2. The g2p scores for RNA (T1) vs DNA (T1, T2) were strongly correlated (Spearman rho: 0.85 (T1); 0.78 (T2)). In women with evidence of tropism switch at T2 (either R5 to non-R5 or non-R5 to R5), there was a correlation between change in tropism and time. Mean pvDNA viral load decreased by 0.4 log10 copies/106 cells between T1 and T2 (p < 0.0001), but this decrease was not significantly associated with tropism status.
  
  
  CONCLUSIONS
  We demonstrated that pvDNA tropism in women with HIV-1 suppression is concordant with prior RNA tropism results, even after a median time of >4 years. pvDNA tropism testing may be useful to determine eligibility of patients with viral suppression to switch to a CCR5-antagonist based regimen as well as for research purposes.
authors.affiliation: Focus Diagnostics, a Subsidary of Quest Diagnostics, San Juan Capistrano, CA USA.
authors.forename: Russell E
authors.initials: RE
authors.lastname: Baumann
authors.affiliation: Focus Diagnostics, a Subsidary of Quest Diagnostics, San Juan Capistrano, CA USA.
authors.forename: Amy A
authors.initials: AA
authors.lastname: Rogers
authors.affiliation: Focus Diagnostics, a Subsidary of Quest Diagnostics, San Juan Capistrano, CA USA.
authors.forename: Hasnah B
authors.initials: HB
authors.lastname: Hamdan
authors.affiliation: University of California, Davis School of Medicine, and Sacramento VA Medical Center, Sacramento, CA USA.
authors.forename: Harold
authors.initials: H
authors.lastname: Burger
authors.affiliation: University of California, Davis School of Medicine, and Sacramento VA Medical Center, Sacramento, CA USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Weiser
authors.affiliation: Albert Einstein College of Medicine, and Montefiore Medical Center, Bronx, NY USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.affiliation: Albert Einstein College of Medicine, and Montefiore Medical Center, Bronx, NY USA.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Anastos
authors.affiliation: Georgetown University, Washington, DC USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Young
authors.affiliation: Quest Diagnostics, Baltimore, MD USA.
authors.forename: William A
authors.initials: WA
authors.lastname: Meyer
authors.affiliation: Focus Diagnostics, a Subsidary of Quest Diagnostics, San Juan Capistrano, CA USA.
authors.forename: Rick L
authors.initials: RL
authors.lastname: Pesano
authors.affiliation: Focus Diagnostics, a Subsidary of Quest Diagnostics, San Juan Capistrano, CA USA.
authors.forename: Ron M
authors.initials: RM
authors.lastname: Kagan
keywords: HIV; Tropism; pvDNA