Kemp Philip, Sneed Gary, Kupiec Tom, Spiehler Vina
Office of the Medical Examiner, Oklahoma City, Oklahoma, USA.
J Anal Toxicol. 2002 Oct;26(7):504-12. doi: 10.1093/jat/26.7.504.
The object of this study was to evaluate the suitability of the Neogen Corp. microtiter plate enzyme-linked immunoassays (ELISA) for opiates and benzodiazepines for screening of postmortem blood. Ninety postmortem whole blood specimens were obtained from drug-involved deaths which had been screened and confirmed positive for opiates and/or benzodiazepines. Forty negative specimens were obtained from non-opiate-involved deaths. Specimens were tested using the Neogen Opiates Group and Neogen Benzodiazepines Group microtiter plate ELISA assays. No matrix effects were found for whole blood in these assays and a dilution of 1:5 was chosen to facilitate pipetting and to bring the IC50 of the microtiter plate ELISA assay within the range of opiates and benzodiazepines encountered in medical examiner specimens. True positive, true negatives, false positives, and false negatives were determined and graphed for the ELISA results against gas chromatography-mass spectrometry (GC-MS), gas chromatography-nitrogen-phosphorus detection and case histories. From these graphs and the ROC curves, the optimal cut-off for the Neogen Opiates Group ELISA was found to be between 20 and 50 ng/mL morphine equivalents and the optimum cut-off for the Neogen Benzodiazepines Group ELISA was between 20 and 50 ng/mL temazepam equivalents. The Neogen Opiates Group ELISA had a sensitivity of 95.2% +/- 2.7% and a specificity of 92.2% +/- 3.4% versus GC-MS at a cut-off of 20-ng/mL cut-off and a sensitivity of 88.8% +/- 3.9% and specificity of 96.8% +/- 2.1% versus GC-MS at a 50-ng/mL morphine equivalents cut-off. The Neogen Benzodizepines Group ELISA had a sensitivity of 100% +/- 1.3% and a specificity of 94.6% +/- 2.9% versus GC-MS (20-ng/mL temazepam equivalents cut-off) and a sensitivity of 95.8% +/- 2.5% and specificity of 98.2% +/- 1.8% versus GC-MS at a 50-ng/mL cut-off.
本研究的目的是评估Neogen公司用于检测阿片类药物和苯二氮䓬类药物的微量滴定板酶联免疫吸附测定法（ELISA）对死后血液筛查的适用性。从因药物相关死亡且已筛查并确认阿片类药物和/或苯二氮䓬类药物呈阳性的案例中获取了90份死后全血标本。从与阿片类药物无关的死亡案例中获取了40份阴性标本。使用Neogen阿片类药物检测组和Neogen苯二氮䓬类药物检测组微量滴定板ELISA检测法对标本进行检测。在这些检测中未发现全血的基质效应，选择1:5的稀释度以方便移液，并使微量滴定板ELISA检测法的半数抑制浓度（IC50）处于法医标本中常见的阿片类药物和苯二氮䓬类药物浓度范围内。针对ELISA结果与气相色谱 - 质谱联用（GC - MS）、气相色谱 - 氮磷检测以及病例史确定并绘制了真阳性、真阴性、假阳性和假阴性结果。从这些图表和ROC曲线中发现，Neogen阿片类药物检测组ELISA的最佳临界值在20至50纳克/毫升吗啡当量之间，Neogen苯二氮䓬类药物检测组ELISA的最佳临界值在20至50纳克/毫升替马西泮当量之间。在20纳克/毫升临界值时，Neogen阿片类药物检测组ELISA相对于GC - MS的灵敏度为95.2%±2.7%，特异性为92.2%±3.4%；在50纳克/毫升吗啡当量临界值时，相对于GC - MS的灵敏度为88.8%±3.9%，特异性为96.8%±2.1%。Neogen苯二氮䓬类药物检测组ELISA在20纳克/毫升替马西泮当量临界值时相对于GC - MS的灵敏度为100%±1.3%，特异性为94.6%±2.9%；在每毫升50纳克临界值时相对于GC - MS的灵敏度为95.8%±2.5%，特异性为98.2%±1.8%。
