Department of Pathology, UC San Diego Health, San Diego, CA, United States.
Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego Health, La Jolla, CA, United States.
J Appl Lab Med. 2024 Nov 4;9(6):964-976. doi: 10.1093/jalm/jfae083.
Benzodiazepines are commonly prescribed medications frequently linked to instances of abuse and overdose. Historically, FDA-cleared benzodiazepine urine immunoassays cross-react poorly with glucuronidated benzodiazepine metabolites, leading to false negatives. Clinical laboratories have addressed this deficiency by creating laboratory-developed tests (LDTs) that incorporate a beta-glucuronidase hydrolysis step to increase the clinical sensitivity of these assays.
Performance characteristics of 2 FDA-cleared benzodiazepine urine immunoassays (Benzodiazepines Plus, no glucuronidase and Benzodiazepines II, with glucuronidase; Roche Diagnostics) and a previously described benzodiazepine immunoassay LDT (with glucuronidase) were evaluated using 258 clinical urine specimens. The positive immunoassay cutoff was set at 200 ng/mL of nordiazepam and results were compared to an LC-MS/MS benzodiazepine LDT. Clinical sensitivity, specificity, precision, and immunoassay cross-reactivity were determined for all 3 immunoassays.
The Benzodiazepines II and LDT immunoassays exhibited greater clinical sensitivity (100% and 95.2%) compared to the Benzodiazepines Plus assay (66.7%). Clinical specificity of 100% was observed for all 3 assays. Immunoassay response of the Benzodiazepines II assay was greater across the range of concentrations tested (100-1000 ng/mL) relative to the other immunoassays and was the most sensitive immunoassay for the detection of lorazepam glucuronide.
The Benzodiazepines II immunoassay demonstrated the greatest clinical and analytical sensitivity compared to the Benzodiazepines Plus and LDT immunoassays. The incorporation of beta-glucuronidase was crucial, as the Benzodiazepines II and LDT immunoassays demonstrated superior clinical sensitivity when compared to the Benzodiazepines Plus immunoassay that does not incorporate a beta-glucuronidase hydrolysis step.
苯二氮䓬类药物是常用的处方药物，常与滥用和过量用药有关。历史上，FDA 批准的苯二氮䓬尿液免疫分析法与葡萄糖醛酸结合的苯二氮䓬代谢物交叉反应不佳，导致假阴性。临床实验室通过创建包含β-葡萄糖醛酸酶水解步骤的实验室开发的测试（LDT）来解决这一缺陷，以提高这些测定的临床灵敏度。
使用 258 份临床尿液标本评估了 2 种 FDA 批准的苯二氮䓬尿液免疫分析法（Benzodiazepines Plus，无葡萄糖醛酸酶和 Benzodiazepines II，含葡萄糖醛酸酶；罗氏诊断）和之前描述的苯二氮䓬免疫分析 LDT（含葡萄糖醛酸酶）的性能特征。阳性免疫分析截止值设定为诺达唑仑 200ng/mL，结果与 LC-MS/MS 苯二氮䓬 LDT 进行比较。确定了所有 3 种免疫分析法的临床灵敏度、特异性、精密度和免疫分析交叉反应性。
与 Benzodiazepines Plus 测定法（66.7%）相比，Benzodiazepines II 和 LDT 免疫分析法的临床灵敏度（100%和 95.2%）更高。所有 3 种测定法的临床特异性均为 100%。在测试浓度范围内（100-1000ng/mL），Benzodiazepines II 测定法的免疫分析反应大于其他免疫分析法，并且是检测氯硝西泮葡萄糖醛酸的最敏感免疫分析法。
与 Benzodiazepines Plus 和 LDT 免疫分析法相比，Benzodiazepines II 免疫分析法具有最大的临床和分析灵敏度。β-葡萄糖醛酸酶的加入至关重要，因为与不包含β-葡萄糖醛酸酶水解步骤的 Benzodiazepines Plus 免疫分析法相比，Benzodiazepines II 和 LDT 免疫分析法的临床灵敏度更高。
