Validation of an ELISA Synthetic Cannabinoids Urine Assay

Abstract

Background Synthetic cannabinoids are touted as legal alternatives to cannabis, at least when first released, and routine urine cannabinoid screening methods do not detect these novel psychoactive substances. Synthetic cannabinoids are widely available, are a major public health and safety problem, and a difficult challenge for drug testing laboratories. We evaluated performance of the NMS JWH-018 direct ELISA kit to sensitively, selectively, and rapidly screen urinary synthetic cannabinoids. Materials/ Methods The NMS ELISA kit targeting the JWH-018 N-(5-hydroxypentyl) metabolite was utilized to screen 2492 urine samples with 5 and 10µg/L cutoffs. A fully validated LC-MS/MS method for 29 synthetic cannabinoids markers confirmed all presumptive positive and negative results. Performance challenges at ±25 and ±50% of cutoffs determined intra- and inter-plate imprecision around proposed cutoffs. Result The immunoassay was linear from 1–500µg/L with intra- and inter-plate imprecision of ≤8.2% and <14.0%, respectively. No interferences were present from 93 common drugs of abuse, metabolites, co-administered drugs, over-the-counter medications or structurally similar compounds, and 19 of 73 individual, synthetic cannabinoids (26%) exhibited moderate to high cross-reactivity to JWH-018 N-(5-hydroxypentyl) metabolite. Sensitivity, specificity, and efficiency results were 83.7%, 99.4% and 97.6% and 71.6%, 99.7% and 96.4%, with the 5 and 10µg/L urine cutoffs, respectively. Conclusion This high throughput immunoassay exhibited good diagnostic efficiency and documented that the NMS JWH-018 direct ELISA is a viable method for screening synthetic cannabinoids in urine targeting the JWH-018 N-(5-hydroxypentyl) and related analytes. Optimal performance was achieved with a matrix-matched 5µg/L urine cutoff.

In vivo detection of the new psychoactive substance AM-694 and its metabolites

“…For this reason, several fast and simple procedures have been recently described in literature and their applications to real cases in various analytical fields have been discussed[35][36][37][38][39]. The major limitation is due to the increasing variety of structures and compounds should be detected; however, the high versatility androbustness of the LC-MS(/MS) may be helpful to plain open methods for future upgrades.…”

A Case of Acute Life-Threatening Pulmonary Hemorrhage from Synthetic Cannabinoid Abuse

“…What was uniquely important in our patient's case was that the initial urine drug screen for cannabinoids was negative, and yet a serum metabolite of UR-144, UR-144 N (4/5-hydroxypentyl), was identified. Therefore, a negative urine drug screen for THC does not exclude the possibility of SC toxicity and a dedicated urine or serum study is necessary [8, 9].…”

Bad Weed

“…A few immunoassays have been developed to test for major metabolites of JWH-018. 10,11 However, testing in the urine is difficult due to the constantly changing composition of SC. Clinicians may consider urine testing for SC in patients presenting with psychosis though these tests are not routinely available at most medical centers.…”