title: Prostate-specific antigen as a biomarker of condom failure: comparison of three laboratory assays and self-reported condom use problems in a randomized trial of female condom performance.
abstract: BACKGROUND
  Prostate-specific antigen (PSA), a biomarker for semen exposure, may provide a more objective measure of condom failure than subject self-reports. Methods for measuring PSA vary and their comparability with respect to assessing condom performance has not been adequately evaluated. This study compared results from three different PSA assays of vaginal samples collected by subjects in a randomized clinical trial which compared the performance of female condoms.
  
  
  METHODS
  We selected 30 pairs of pre- and post-coital vaginal samples from subjects who reported condom functionality problems or whose original PSA assay was positive. Samples were retested using three different PSA assays [quantitative enzyme-linked immunoassay (EIA), rocket immune-electrophoresis (RIE) and chromatographic immunoassay (CIA)]. We compared the proportion of condom uses where the post-coital PSA result indicated semen exposure for each of the three assays.
  
  
  RESULTS
  Despite varying levels of sensitivity, the results from all three assays were remarkably consistent. Self-reported condom failures did not correlate well with positive PSA results, suggesting that exclusive reliance on either PSA or user self-report may be inadequate for assessing condom functionality.
  
  
  CONCLUSIONS
  In combination with user self-report of condom failure, PSA testing provides a reliable, objective marker of condom functionality. Studies based on PSA testing may improve on conventional contraceptive clinical trials by offering a more direct assessment of a condom product's ability to prevent semen exposure.
authors.affiliation: California Family Health Council, Los Angeles, CA 90010, USA.
authors.forename: Terri
authors.initials: T
authors.lastname: Walsh
authors.forename: Lee
authors.initials: L
authors.lastname: Warner
authors.forename: Maurizio
authors.initials: M
authors.lastname: Macaluso
authors.forename: Ron
authors.initials: R
authors.lastname: Frezieres
authors.forename: Margaret
authors.initials: M
authors.lastname: Snead
authors.forename: Brian
authors.initials: B
authors.lastname: Wraxall
mesh_terms: D015415:Biomarkers / Q000032:analysis; D019111:Single-Use Internal Condom / Q000592:standards*; D059026:Diagnostic Self Evaluation; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000032:analysis*
chemical_list: D015415:Biomarkers; D017430:Prostate-Specific Antigen