Department of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
Department of Clinical Biostatistics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
Leg Med (Tokyo). 2023 May;62:102243. doi: 10.1016/j.legalmed.2023.102243. Epub 2023 Mar 21.
Prostate-specific antigen (PSA) tests are used in forensics to conduct rapid screening for semen in vaginal swab samples from alleged victims of sexual abuse. Although PSA membrane tests have been applied to autopsy specimens, no study has evaluated predictors of false-positive test results in relation to factors such as age, cause of death, postmortem interval, drugs, and alcohol. This study describes the results obtained with the Seratec® PSA SemiQuant Kit test in 283 deceased women, with or without a history of sexual assault. Overall, 18.4% (52/283) of the vaginal swab samples tested positive for PSA. However, 63.5% (33/52) of the PSA-positive vaginal swab samples had no sperm detected. The proportion of false-positives in positive PSA results was 94.4% in those aged over 60 years. Multivariate logistic regression for PSA-positive samples showed that the proportion of false-positives in positive PSA results increased with the age of the deceased. However, the cause of death, postmortem interval, and presence of drugs or alcohol in the blood or urine of the deceased did not affect the PSA determination. These results show that PSA membrane tests are relatively unreliable and can be misleading, especially when derived from vaginal swab samples of older women, obtained at autopsy. In forensic cases, positive PSA screening test results may have an impact on subsequent legal actions and criminal charges brought against the accused. These findings are important for both forensic pathologists and the police to ensure accurate screening of older women in cases of suspected sex crimes.
前列腺特异性抗原 (PSA) 检测法被用于法医领域，通过对疑似遭受性虐待的受害者的阴道拭子样本进行快速精液筛查。尽管 PSA 膜检测法已应用于尸检标本，但尚无研究评估与年龄、死因、死后间隔时间、药物和酒精等因素相关的假阳性检测结果的预测因素。本研究描述了 Seratec® PSA SemiQuant 试剂盒检测法在 283 名有或没有性侵犯史的已故女性中的检测结果。总体而言，283 份阴道拭子样本中 18.4%（52/283）检测出 PSA 呈阳性。然而，52 份 PSA 阳性的阴道拭子样本中，有 63.5%（33/52）未检测到精子。在年龄超过 60 岁的 PSA 阳性结果中，假阳性的比例为 94.4%。对 PSA 阳性样本进行多变量逻辑回归分析表明，随着死者年龄的增加，PSA 阳性结果中假阳性的比例增加。然而，死者的死因、死后间隔时间以及死者血液或尿液中是否存在药物或酒精，均不会影响 PSA 检测。这些结果表明，PSA 膜检测法相对不可靠，可能会产生误导，尤其是当它们源自尸检时从老年女性的阴道拭子样本中获得时。在法医案例中，阳性 PSA 筛选检测结果可能会对随后对被告提起的法律诉讼和刑事指控产生影响。这些发现对于法医病理学家和警方都很重要，有助于确保在涉嫌性犯罪案件中对老年女性进行准确筛查。
