Peonim Vichan, Worasuwannarak Wisarn, Sujirachato Kanchana, Teerakamchai Somsri, Srisont Smith, Udnoon Jitta, Chudoung Ubon
Division of Forensic Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Ratchathewi, Bangkok 10400, Thailand.
J Forensic Leg Med. 2013 Aug;20(6):578-81. doi: 10.1016/j.jflm.2013.06.009. Epub 2013 Jul 10.
To compare the effectiveness of the prostate specific antigen (PSA) test and the acid phosphatase (AP) test for semen detection in human vaginal samples.
The source materials were vaginal swabs that were tested at Ramathibodi Hospital between 2008 and 2010 from 2450 cases of raped women. Each swab was tested for semen by three methods: sperm detection by light microscopy, the AP enzymatic reaction, and the presence of PSA by using an immuno-chromatographic rapid kit test. The efficiencies of the AP and PSA tests were compared using the light microscopy result for the presence of sperm as the gold standard.
The specificities of the AP, the PSA and the combined AP-PSA tests were 96.4%, 92.3% and 91.9%, respectively, and the sensitivities were 65.5%, 80.4% and 84.5%, respectively. The receiver operating characteristic (ROC) area of the AP, PSA and combined AP-PSA tests were 0.8091, 0.8639 and 0.8823, respectively. The ROC area of the PSA test was significantly greater than that of the AP test (p < 0.0001), and the ROC area of the combined AP-PSA test was significantly greater than both the tests individually (p < 0.0001).
Based on the ROC area, the PSA test was better than the AP test for semen detection in the vaginal swabs, and the combined results (AP + PSA) were better than the individual tests. The specificity of the AP test was higher than the PSA test in this study because a positive detection was made within only 15 s. While the PSA test was more convenient as it was available in a rapid test kit format, our recommendation is PSA detection should be done together with AP test and spermatozoa examination to identify evidence of rape.
Using these three tests together (AP, PSA, and spermatozoa detection) was recommended as a forensic tool for investigations of vaginal swabs of the rape victims.
比较前列腺特异性抗原（PSA）检测和酸性磷酸酶（AP）检测在人阴道样本精液检测中的有效性。
源材料为2008年至2010年期间在拉玛蒂博迪医院对2450例强奸案女性进行检测的阴道拭子。每个拭子通过三种方法检测精液：光学显微镜下精子检测、AP酶促反应以及使用免疫层析快速检测试剂盒检测PSA的存在。以光学显微镜下精子存在情况的检测结果作为金标准，比较AP和PSA检测的效率。
AP检测、PSA检测以及联合AP - PSA检测的特异性分别为96.4%、92.3%和91.9%，敏感性分别为65.5%、80.4%和84.5%。AP检测、PSA检测以及联合AP - PSA检测的受试者工作特征（ROC）曲线下面积分别为0.8091、0.8639和0.8823。PSA检测的ROC曲线下面积显著大于AP检测（p < 0.0001），联合AP - PSA检测的ROC曲线下面积显著大于单独的两种检测（p < 0.0001）。
基于ROC曲线下面积，在阴道拭子精液检测中，PSA检测优于AP检测，联合检测结果（AP + PSA）优于单独检测。本研究中AP检测的特异性高于PSA检测，因为AP检测仅在15秒内就能得出阳性结果。虽然PSA检测以快速检测试剂盒形式提供更方便，但我们建议PSA检测应与AP检测及精子检查一起进行，以确定强奸证据。
建议将这三种检测（AP、PSA和精子检测）一起用作法医工具，用于对强奸受害者阴道拭子的调查。
