Kupiec Tom, DeCicco Lacinda, Spiehler Vina, Sneed Gary, Kemp Philip
Analytical Research Laboratories, Oklahoma City, Oklahoma, USA.
J Anal Toxicol. 2002 Oct;26(7):513-8. doi: 10.1093/jat/26.7.513.
The object of this study was to evaluate the suitability of the Neogen Corp. microtiter plate enzyme-linked immunoassays (ELISA) for the screening of postmortem blood for amphetamine and methamphetamine and to choose the more appropriate assay for screening. Forty-seven postmortem whole blood specimens were obtained from drug-involved deaths, which had been screened and confirmed positive for methamphetamine and/or amphetamine. Eighty-five negative specimens were obtained from non-amphetamines-involved deaths, 17 of which involved decomposition. Specimens were tested using the Neogen Amphetamine Ultra and Neogen Methamphetamine/MDMA 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 amphetamines concentrations encountered in medical examiner specimens. True positives, true negatives, false positives, and false negatives were determined relative to gas chromatography-mass spectrometry (GC-MS) and graphed for the ELISA. From these graphs and the receiver operating curves (ROC), the optimal cut-off for the Neogen Methamphetamine/MDMA ELISA was 50 ng/mL methamphetamine equivalents and the optimum cut-off for the Neogen Amphetamine Ultra ELISA was 100 ng/mL amphetamine equivalents. The Neogen Methamphetamine ELISA had a sensitivity of 93.6% +/- 3.5% and a specificity of 77.6% +/- 4.5% versus GC-MS at the cut-off of 50-ng/mL methamphetamine equivalents. The Neogen Amphetamine Ultra ELISA had a sensitivity of 95.7% +/- 3.0% and a specificity of 72.9% +/- 5.2% versus GC-MS at the 100-ng/mL amphetamine equivalents cut-off. The areas under the ROCs were equivalent for the two ELISA assays.
本研究的目的是评估Neogen公司的微量滴定板酶联免疫吸附测定法（ELISA）用于筛查死后血液中苯丙胺和甲基苯丙胺的适用性，并选择更合适的检测方法进行筛查。从涉及毒品死亡的案例中获取了47份死后全血标本，这些标本经筛查和确认对甲基苯丙胺和/或苯丙胺呈阳性。从与苯丙胺无关的死亡案例中获取了85份阴性标本，其中17份涉及尸体分解。使用Neogen苯丙胺超微量滴定板ELISA检测法和Neogen甲基苯丙胺/摇头丸微量滴定板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）处于法医标本中苯丙胺类药物浓度范围内。相对于气相色谱-质谱联用仪（GC-MS）确定真阳性、真阴性、假阳性和假阴性，并针对ELISA绘制图表。根据这些图表和受试者工作特征曲线（ROC），Neogen甲基苯丙胺/摇头丸ELISA的最佳截断值为50 ng/mL甲基苯丙胺当量，Neogen苯丙胺超微量滴定板ELISA的最佳截断值为100 ng/mL苯丙胺当量。在50 ng/mL甲基苯丙胺当量的截断值下，与GC-MS相比，Neogen甲基苯丙胺ELISA的灵敏度为93.6%±3.5%，特异性为77.6%±4.5%。在100 ng/mL苯丙胺当量的截断值下，与GC-MS相比，Neogen苯丙胺超微量滴定板ELISA的灵敏度为95.7%±3.0%，特异性为72.9%±5.2%。两种ELISA检测法的ROC曲线下面积相当。
