title: Y chromosome and HIV DNA detection in vaginal swabs as biomarkers of semen and HIV exposure in women.
abstract: BACKGROUND
  The inability to quantify sexual exposure to HIV limits the power of HIV prevention trials of vaccines, microbicides, and preexposure prophylaxis in women. We investigated the detection of HIV-1 and Y chromosomal (Yc) DNA in vaginal swabs from 83 participants in the HPTN 035 microbicide trial as biomarkers of HIV exposure and unprotected sexual activity.
  
  
  METHODS
  One hundred forty-three vaginal swabs from 85 women were evaluated for the presence of Yc DNA (Quantifiler Duo DNA quantification kit; Applied Biosystems) and total HIV-1 DNA (single-copy in-house quantitative polymerase chain reaction assay). Y DNA detection was paired with self-reported behavioral data with regard to recent coitus (≤1 week before collection) and condom usage (100% vs. <100% compliance).
  
  
  RESULTS
  Yc DNA was detected in 62 (43%) of 143 swabs. For the 126 visits at which both behavioral data and swabs were collected, Yc DNA was significantly more frequent in women reporting less than 100% condom usage (odds ratio, 10.69; 95% confidence interval, 2.27-50.32; P = 0.003). Notably, 27 (33%) of 83 swabs from women reporting 100% condom usage were positive for Yc DNA. HIV DNA was only detected in swabs collected postseroconversion.
  
  
  CONCLUSIONS
  The use of Yc DNA in HIV prevention trials could reliably identify subgroups of women who have unprotected sexual activity and could provide valuable exposure-based estimates of efficacy.
authors.affiliation: From the *University of Pittsburgh, Pittsburgh, PA; †University of Washington, Seattle, WA; ‡Magee-Womens Research Institute, Pittsburgh, PA; §Albert Einstein College of Medicine, New York, NY; and ¶Centre for the AIDS Programme of Research in South Africa, Durban, South Africa.
authors.forename: Kerri J
authors.initials: KJ
authors.lastname: Penrose
authors.forename: Barbra A
authors.initials: BA
authors.lastname: Richardson
authors.forename: Guillaume
authors.initials: G
authors.lastname: Besson
authors.forename: Charlene S
authors.initials: CS
authors.lastname: Dezzutti
authors.forename: Betsy C
authors.initials: BC
authors.lastname: Herold
authors.forename: Salim S
authors.initials: SS
authors.lastname: Abdool Karim
authors.forename: John W
authors.initials: JW
authors.lastname: Mellors
authors.forename: Urvi M
authors.initials: UM
authors.lastname: Parikh
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000737:chemistry; D016022:Case-Control Studies; D041322:Chromosomes, Human, Y / Q000737:chemistry* / Q000235:genetics; D003075:Coitus; D017280:Condoms / Q000706:statistics & numerical data; D017931:DNA Primers; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification*; D005260:Female; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D057566:Self Report; D012661:Semen / Q000737:chemistry* / Q000821:virology; D012680:Sensitivity and Specificity; D013019:South Africa; D014621:Vagina / Q000737:chemistry* / Q000821:virology; D014626:Vaginal Smears
chemical_list: D015415:Biomarkers; D017931:DNA Primers; D004279:DNA, Viral