Reschly-Krasowski Justine M, Krasowski Matthew D
City High School, Iowa City, IA, USA.
Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
Acad Pathol. 2018 Nov 21;5:2374289518811797. doi: 10.1177/2374289518811797. eCollection 2018 Jan-Dec.
Urine drug testing by immunoassay is widely used to detect nonmedical drug use and to monitor patients prescribed controlled substances. A key attribute of urine drug testing immunoassays is cross-reactivity, namely the response of various compounds compared to the target of the assay. In this report, we analyzed the variability in how manufacturer cross-reactivity data are summarized in package inserts for commercially available amphetamines, benzodiazepines, and opiates immunoassays, 3 broad drug classes commonly included in routine drug testing panels. Specifically, we determined the number of compounds tested for cross-reactivity, manner in which cross-reactivity is measured, concentration units used, how often compounds known to be cross-reactive with marketed urine drug testing immunoassays prior to 2010 were tested, availability of the package insert online, and how often cross-reactivity on "designer drugs" was found in the package inserts. There was wide variability in the number of compounds tested (both positive and negative), with the highest number of tested compounds generally found in point-of-care urine drug testing applications. Most package inserts used ng/mL as the concentration units and expressed cross-reactivity in terms of equivalent concentrations to the assay calibrator. Approximately 50% of package inserts were directly available online. Cross-reactivity data were sparse with respect to "off-target" drugs known to be cross-reactive prior to 2010 (an example being quinolone antibiotics and opiates immunoassays) and designer drugs. The present study indicates lack of consistency in cross-reactivity information in package inserts, complicating the interpretation of urine drug testing results. We use 3 example clinical cases to illustrate practical challenges accessing and interpreting cross-reactivity data.
免疫分析法进行尿液药物检测被广泛用于检测非医疗目的的药物使用情况以及监测使用管制药物的患者。尿液药物检测免疫分析法的一个关键特性是交叉反应性，即各种化合物与检测目标相比的反应情况。在本报告中，我们分析了市售苯丙胺类、苯二氮䓬类和阿片类免疫分析法包装说明书中制造商交叉反应性数据汇总方式的差异，这三类药物是常规药物检测面板中常见的广泛药物类别。具体而言，我们确定了进行交叉反应性测试的化合物数量、测量交叉反应性的方式、使用的浓度单位、2010年之前已知与市售尿液药物检测免疫分析法有交叉反应的化合物的测试频率、包装说明书在线获取情况以及包装说明书中发现“设计药物”交叉反应性的频率。所测试的化合物数量（包括阳性和阴性）存在很大差异，检测化合物数量最多的情况通常出现在即时检验尿液药物检测应用中。大多数包装说明书使用ng/mL作为浓度单位，并以与检测校准物等效的浓度来表示交叉反应性。约50%的包装说明书可直接在线获取。关于2010年之前已知有交叉反应的“非目标”药物（例如喹诺酮类抗生素与阿片类免疫分析法）和设计药物，交叉反应性数据很少。本研究表明包装说明书中交叉反应性信息缺乏一致性，这使得尿液药物检测结果的解读变得复杂。我们用3个临床案例来说明获取和解读交叉反应性数据时面临的实际挑战。
