Chen MP, Macaluso M, Blackwell R, Galvao L, Kulczycki A, Diaz J, et al. Self-reported mechanical problems during condom use and semen exposure. Comparison of two randomized trials in the United States of America and Brazil
To compare self-reported condom use problems and objectively determined semen exposure in 2 populations.
Two randomized crossover trials in the United States and Brazil compared the failure rates of the female condom (FC) and male condom (MC). Participants used both condom types, completed condom-specific questionnaires to report problems, and collected precoital and postcoital samples of vaginal fluid. Prostate-specific antigen (PSA) was detected by immunoassay.
Problems with condom use were reported less frequently in the Brazilian study (rate difference: FC = 24%, P <0.0001, MC = 5%, P = 0.003). By contrast, the PSA detection rates were similar for both the FC and the MC (rate difference: FC = 2%, MC = 1%, not significant). These results suggest that the PSA detection rate was similar in the 2 study groups and that self-reported problems may be a less reliable measure of condom failure.
Use of biomarkers of condom failure like PSA may help to strengthen the validity of studies promoting behavior change for the prevention of sexually transmitted diseases.
"For instance, investigators have used these markers to evaluate condom integrity or to validate self reporting of sexual activity/protocol compliance   . Furthermore, PSA has been proposed as a surrogate of female condom efficacy  . However, these proteins have certain limitations. "
[Show abstract][Hide abstract] ABSTRACT: Background:
Developing an objective, reliable method to determine semen exposure in cervicovaginal fluids is important for accurately studying the efficacy of vaginal microbicides and contraceptives. Y-chromosome biomarkers offer better stability, sensitivity, and specificity than protein biomarkers. TSPY4 belongs to the TSPY (testis-specific protein Y-encoded) family of homologous genes on the Y-chromosome. Using a multiplex PCR amplifying TSPY4, amelogenin, and Sex-determining region in the Y chromosome (SRY), our objective was to determine whether a gene in the TSPY family was a more sensitive marker of semen exposure in cervicovaginal fluids than SRY.
The multiplex polymerase chain reaction (PCR) was developed using sperm and vaginal epithelial (female) DNA. Diluted sperm DNA and mixed male/female DNA was used to determine the sensitivity of the multiplex PCR. Potential interference of TSPY4 amplification by components in cervicovaginal and seminal fluids was determined. TSPY4 and SRY amplification was also investigated in women participating in a separate IRB-approved clinical study in which cervicovaginal swab DNA was collected before semen exposure and at various time points after exposure.
TSPY4, SRY, and amelogenin were amplified in sperm DNA, but only amelogenin in female DNA. The limit of sperm DNA from which TSPY4 could be amplified was lower than SRY (4 pg vs 80 pg). TSPY4 could also be amplified from mixed male/female DNA. Amplification was not affected by cervicovaginal and seminal components. Using cervicovaginal swab DNA from three women before and after semen exposure, TSPY4 was detected up to 72 h post exposure while SRY detection was observed up to 24-48 h. TSPY4 was detected up to 7 days post exposure in one out of three women.
We have demonstrated that TSPY4 is a new sensitive, and sperm-specific biomarker. The multiplex PCR incorporating this new biomarker has potential to be an objective measure for determining semen exposure in clinical trials of vaginal products such as contraceptives and HIV pre/post-exposure prophylaxis agents.
[Show abstract][Hide abstract] ABSTRACT: Prostate-specific antigen (PSA) in vaginal fluid indicates exposure to semen, and was used to assess condom effectiveness, although validity and reliability have not been fully evaluated. Our objective was to compare PSA in self-collected samples with samples collected by a nurse.
We conducted two studies, each with 100 women aged 18-48 years. In the first, a nurse exposed each participant to her partner's semen (10, 100 and 1000 microl), and nurse and participant collected samples. In the second, each participant sampled before and after using two male condoms (MC) and two female condoms (FC); a nurse collected another sample afterwards.
PSA concentration increased with semen exposure, but was lower in nurse-collected samples. Both procedures were sensitive, almost 100% after exposure to 100-1000 microl of semen. PSA detection rates with MC and FC were 13% and 28% in self-collected samples, 8% and 9% in nurse-collected samples. Concordance between sample types was 93% with the MC (95% CI: 89%; 96%), 78% with the FC (95% CI: 72%; 84%). PSA decay between sampling times may explain higher values in self-collected samples.
PSA is a highly sensitive surrogate endpoint for condom effectiveness studies. Self-collected and nurse-collected samples are equivalent, but sample collection timing is critical.
Human Reproduction 08/2008; 23(11):2444-51. DOI:10.1093/humrep/den283 · 4.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Prostate-specific antigen (PSA) is a valid biomarker of semen exposure in women and has been used to assess reliability of self-reported sexual behavior as well as serve as a proxy measure for condom efficacy. Quantitative PSA tests are expensive and require specialized equipment. A simple, rapid, and inexpensive test for PSA would facilitate semen biomarker evaluation in a variety of research settings. This study evaluated the performance of a rapid PSA test compared with a quantitative assay to identify semen in vaginal swab specimens.
We tested 581 vaginal swabs collected from 492 women participating in 2 separate research studies in Bangladesh and Zimbabwe. PSA in vaginal secretions was detected using the quantitative IMx (Abbott Laboratories) assay and the ABAcard p30 (Abacus Diagnostics) rapid immunochromatographic strip test.
The ABAcard test was 100% sensitive (95% confidence interval [CI], 98%-100%) and 96% specific (95% CI, 93%-97%) compared with the quantitative test in detecting >1.0 ng PSA/mL vaginal swab eluate. Rapid PSA results were semiquantitative and correlated well with PSA concentrations (kappa = 0.88; 95% CI, 0.85-0.90).
Rapid PSA detection requires no instrumentation and can be performed easily and economically. Having rapid PSA results available immediately following interview provides opportunities to explore discrepancies between the objective marker of recent semen exposure and self-reported behaviors.
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