Lyons T P, Okano C K, Kuhnle J A, Bruins M R, Darwin W D, Moolchan E T, Huestis M A
Forensic Toxicology Drug Testing Laboratory, Tripler Army Medical Center, Honolulu, Hawaii 96859, USA.
J Anal Toxicol. 2001 Oct;25(7):559-64. doi: 10.1093/jat/25.7.559.
In this study, we investigated the effectiveness of the Roche Kinetic Interaction of Microparticles in Solution (KIMS) screening assay for cannabinoid metabolites. Urine specimens (N = 1689) were collected during elimination of cannabinoids from 25 subjects with a history of marijuana use. Specimens were analyzed concurrently for cannabinoid metabolites by a customized Department of Defense (DOD) cannabinoid KIMS kit (50-ng/mL cutoff) and for 11-nor-9-carboxy-delta9-tetrahydrocannabinol (THC-COOH) by GC-MS (15-ng/mL cutoff). As compared to GC-MS results, the sensitivity, specificity, and efficiency of the KIMS assay were 69.7%, 99.8%, and 88.6%, respectively. Many of the false-negative results had GC-MS concentrations between 15 and 26 ng/mL (N = 151). The cannabinoid screening results for the DOD samples tested by the laboratory during the same 8-month period were also evaluated. The linear regression analyses of GC-MS results in the 15-50 ng/mL range and KIMS data resulted in regression coefficients of 0.689 for the research specimens and 0.546 for DOD specimens. The results suggest that the KIMS cannabinoid screening assay is deficient in detecting positives around the cutoff (15-25 ng/mL THC-COOH). This limitation of the KIMS cannabinoid screening method compromises the identification of true positive specimens, therefore reducing the effectiveness of the assay. The success of the DOD program is dependent on sensitive and specific screening assays; the high prevalence of false-negative cannabinoid results compromises the program's primary objective of drug deterrence.
在本研究中，我们调查了罗氏微粒在溶液中的动力学相互作用（KIMS）筛查试验对大麻素代谢物的有效性。在25名有大麻使用史的受试者消除大麻素期间收集尿液标本（N = 1689）。通过定制的国防部（DOD）大麻素KIMS试剂盒（临界值为50 ng/mL）同时分析标本中的大麻素代谢物，并通过气相色谱 - 质谱联用仪（GC-MS）（临界值为15 ng/mL）分析11-去甲-9-羧基-Δ9-四氢大麻酚（THC-COOH）。与GC-MS结果相比，KIMS试验的灵敏度、特异性和效率分别为69.7%、99.8%和88.6%。许多假阴性结果的GC-MS浓度在15至26 ng/mL之间（N = 151）。还评估了实验室在同一8个月期间检测的DOD样本的大麻素筛查结果。在15 - 50 ng/mL范围内，GC-MS结果与KIMS数据的线性回归分析得出，研究标本的回归系数为0.689，DOD标本的回归系数为0.546。结果表明，KIMS大麻素筛查试验在检测临界值（15 - 25 ng/mL THC-COOH）附近的阳性结果方面存在不足。KIMS大麻素筛查方法的这一局限性影响了真阳性标本的识别，从而降低了该试验的有效性。DOD项目的成功取决于灵敏且特异的筛查试验；大麻素假阴性结果的高发生率影响了该项目药物威慑的主要目标。
