Polymerase Chain Reaction Detection of Y Chromosome Sequences in Vaginal Fluid: Preliminary Studies of a Potential Biomarker for Sexual Behavior

Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, USA.
Sex Transm Dis (Impact Factor: 2.84). 03/2005; 32(2):90-4. DOI: 10.1097/01.olq.0000149668.08740.91
Source: PubMed


Self-reported measures of sexual behavior are subject to nontrivial reporting biases.
The objective of this study was to develop a behavioral biomarker of recent sexual activity among females that is inexpensive, easily administered, and can be used in low sexually transmitted disease prevalence populations.
We developed a polymerase chain reaction (PCR) assay to detect Y chromosome (Yc) fragments. The Yc primers were developed against a 200-basepair (bp) microsatellite repeat sequence, which is unique to the male genome. A standard PCR technique was used. Assay sensitivity was determined quantitatively using donated semen samples. To assess longevity of detectability, we recruited female subjects in monogamous relationships. Seventeen subjects had unprotected intercourse followed by 3 weeks of abstinence from vaginal intercourse. Self-administered vaginal swabs (SAVS) were collected every other day. In addition to the swabs, subjects kept daily sexual diaries. Swabs were processed by semiquantitative PCR, and Yc decay curves were determined for each subject. The half-life of Yc in vaginal fluid was calculated on the collection of individual decay curves by a random-effects regression model approach.
The sensitivity of our Yc-PCR assay was determined to be 5 copies of Yc. In the longevity studies, Yc was detectable in SAVS up to 15 postcoital days (PCD). Mean Yc DNA concentration in SAVS eluate followed an exponential decay pattern for each subject. Mean concentrations were 66.7 ng/mL at PCD-1, 20.6 ng/mL at PCD-7, and 4.5 ng/mL at PCD-15. The estimated half-life for Yc clearance was 3.83 days.
The swab-based Yc-DNA PCR assay can detect coitus in women for a 2-week retrospective period. This can be used to validate sexual behavior-reporting and condom use in women and promises to be a useful tool in sexual behavior research.

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Available from: Jonathan M Zenilman, Jul 17, 2014
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    • "Semen residues may be detected in the lower female genital tract up to 5 days after sexual intercourse [5]. Yc is a predictor of recent unprotected sexual activity [1] [2] [3] [4] [5] [6] [7] [8] and CV samples from women at high risk of STIs have frequently been found to contain traces of semen [33]. To the best of our knowledge, this study is the first to describe the Yc detection and its correlation with HPV, CT and HSV-2 in Portuguese women at childbearing age. "
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    ABSTRACT: Assuming a possible association between Y chromosome (Yc)-DNA and sexually transmitted infections (STIs) transmission rate, could Yc-DNA be related to an increased prevalence of human Papillomavirus (HPV), Herpes Simplex Virus (HSV-1/2) and Chlamydia trachomatis (CT)? Could Yc-DNA be used to validate self-reported condom use and sexual behaviours? Cervicovaginal (CV) self-collected samples of 612 Portuguese women at childbearing age were tested for Yc, HPV, HSV-1/2 and CT by polymerase chain reaction (PCR). The prevalence of Yc, HPV, CT and HSV-2 was 4.9%, 17.6%, 11.6% and 2.8%, respectively. There was a statistically significant trend for increased Yc-DNA prevalence in HPV positive samples [odds ratio (OR) 2.35 95% confidence interval (CI) 1.03-5.31] and oral contraceptives (OC) use (OR 4.73 95% CI 1.09-20.44). A protective effect of condom use was observed in Yc-DNA detection (OR 0.40 95% CI 0.18-0.89). No statistically significant deference was found between Yc-DNA, CT and HSV-2 infection. HPV infection risk increased with age (>20 years), young age at first sexual intercourse (FSI) (≤18 years), >1 lifetime sexual partner (LSP) and OC use. Risk factors for CT infection were young age (≤20 years) and young age at FSI (≤18 years). HSV-2 infection risk increased with age (>20 years) and >1 LSP. Considering the prevalence of HPV and CT in Yc positive samples, we hypothesize a current infection due to recent sexual activity. The study of Yc PCR may add information as (i) predictor of STIs transmission and (ii) indicative biomarker to validate self-reported condom use. Copyright © 2015. Published by Elsevier Inc.
    Full-text · Article · Aug 2015 · Life sciences
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    • "A second biomarker involves detecting Y-chromosome DNA (Yc DNA) fragments from spermatozoa in vaginal fluid. Using a polymerase chain reaction (PCR) assay, Yc DNA has been found in vaginal swabs collected up to 15 days after unprotected intercourse, with a half-life for clearance of 3.8 days [11] [12]. "
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    ABSTRACT: Although biological markers of women's exposure to semen from vaginal intercourse have been developed as surrogates for risk of infection or probability of pregnancy, data on their persistence time and clearance are limited. During 2006-2008, 52 couples were enrolled for three 14-day cycles of abstinence from vaginal sex during which women were exposed in the clinic to a specific quantity (10, 100 or 1000 μL) of their partner's semen. Vaginal swabs were collected before and at 1, 6, 12, 24, 48, 72 and 144 h after exposure for testing for prostate-specific antigen (PSA) and Y-chromosome DNA (Yc DNA). Immediately after exposure to 1000 μL of semen, the predicted sensitivity of being PSA positive was 0.96; this decreased to 0.65, 0.44, 0.21 and 0.07 at 6, 12, 24 and 48 h, respectively. Corresponding predicted sensitivity of being Yc DNA positive was 0.72 immediately postexposure; this increased to 0.76 at 1 h postexposure and then decreased to 0.60 (at 6 h), 0.63 (at 12 h), 0.49 (at 24 h), 0.21 (at 48 h), 0.17 (at 72 h) and 0.12 (at 144 h). Overall findings suggest that PSA may be more consistent as a marker of very recent exposure and that Yc DNA is more likely to be detected in the vagina after 12 h postexposure compared to PSA.
    Full-text · Article · Aug 2013 · Contraception
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    • "Furthermore, self-sampling has been shown to be acceptable to women [5]. However, it has been shown previously that male DNA was detectable in vaginal swabs up to 15 days after intercourse, with an estimated half-life of male DNA of 3.8 days [6]. We undertook to investigate whether a female vaginal swab may reflect a male active HPV infection. "
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    ABSTRACT: Vaginal self-sampling for human papillomavirus (HPV) detection is the focus of recent research. However, it has been shown previously that male DNA can be detected in vaginal swabs. The aim of this study was to investigate whether a female vaginal swab may reflect a male active HPV infection. Eleven women volunteered to take vaginal samples. The first sample was taken within hours after unprotected intercourse, the others each following morning for five consecutive days. On these samples, a Y-chromosomal locus, as a surrogate marker for HPV, was amplified by PCR. To investigate the prevalence of male DNA in self-obtained vaginal swabs, 282 swabs from 16 women enrolled in an ongoing HPV follow-up study were tested. All baseline samples from the 11 women were positive for male DNA. In the follow-up samples, positivity ranged from day 1 till day 5, with a sharp drop from day 2 (91%) to day 3 (36%). Of 282 swabs, 23 (8.2%) were positive for male DNA. However, 10 of these 23 swabs were provided by one single woman. Since HPV can be deposited by the male in the vagina, either through semen, or through exfoliated epithelial cells, our results are of some importance when testing for HPV in vaginal swabs. It is conceivable that women with acquired immunity to HPV, but with an HPV positive partner, are found to be HPV positive in the swab. However, larger studies on more diverse populations are warranted.
    Full-text · Article · Feb 2011
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