Detection of two biological markers of intercourse: prostate-specific antigen and Y-chromosomal DNA

Abstract

Background 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. Study Design 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). Results 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). Conclusions 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.

Comparison of Visual and Ultraviolet Light Inspection Versus DNA/Protein Biomarkers to Assess Product Adherence With Vaginal Microbicide Applicators

“…14 However, seminal proteins such as semenogelin and prostate-specific antigen degrade in the vagina approximately 24 to 72 hours after exposure. [15][16][17] Our preliminary data support that DNA-based semen biomarkers, including SRYand TSPY, are present in the vagina for up to 7 to 15 days after exposure.…”

Y chromosome DNA in cervicovaginal self-collected samples of childbearing age women: Implications for epitheliotropic sexually transmitted infections?

“…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].…”

Semen says: assessing the accuracy of adolescents' self-reported sexual abstinence using a semen Y-chromosome biomarker

“…These results are not explained by non-coital sexual behaviour. This study provides a minimum for the under-report of sexual abstinence because the sensitivity of Yc-PCR decreases quickly with time-women whose most recent coitus was 24 h ago are four times as likely to test positive as women whose most recent coitus was 7 days ago 6 -which suggests that biomarkers should be used together with self-reported sexual behaviour in HIV prevention research. These findings may generalise to sexually active urban African-American adolescent females attending family planning and STI clinics.…”

“…Studies using inoculation with 1 mL of semen estimated the sensitivity to be respectively 49% and 12%, 24 h and 7 days after exposure. 6 The estimated specificity is 92% (95% CI (80% to 98%)): 92% of women in the calibration trial who had protected sex tested negative for Yc-PCR, and the remaining 8% had digital or oral genital contact with their male partner; so, false positives could be explained by epithelial cells. 5 Follow-up interviews were administered at 6 and 12 months using similar methods; as a proportion of wave 1 participants, follow-up proportion was 84.8% at wave 2 and 84.5% at wave 3.…”