title: Performance characteristics of an ELISA screening assay for urinary synthetic cannabinoids.
abstract: Synthetic cannabinoids are marketed as legal alternatives to cannabis, as routine urine cannabinoid immunoassays do not detect synthetic cannabinoids. Laboratories are challenged to identify these new designer drugs that are widely available and represent a major public health and safety problem. Immunoassay testing offers rapid separation of presumptive positive and negative specimens, prior to more costly and time-consuming chromatographic confirmation. The Neogen SPICE ELISA kit targets JWH-018 N-pentanoic acid as a marker for urinary synthetic cannabinoids. Assay performance was evaluated by analyzing 2469 authentic urine samples with the Neogen immunoassay and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two immunoassay cut-off concentrations, 5 and 10 µg/L, classified samples as presumptive positive or negative, followed by qualitative LC-MS/MS confirmation for 29 synthetic cannabinoids markers with limits of detection of 0.5-10 µg/L to determine the assay's sensitivity, specificity and efficacy. Challenges at ±25% of each cut-off also were investigated to determine performance around the cut-off and intra- and inter-plate imprecision. The immunoassay was linear from 1 to 250 µg/L (r(2)  = 0.992) with intra- and inter-plate imprecision of ≤5.3% and <9%, respectively. Sensitivity, specificity, and efficiency results with the 5 µg/L cut-off were 79.9%, 99.7%, and 97.4% and with the 10 µg/L cut-off 69.3%, 99.8%, and 96.3%, respectively. Cross-reactivity was shown for 18 of 73 synthetic cannabinoids markers evaluated. Good sensitivity, specificity, and efficiency, lack of sample preparation requirements, and rapid semi-automation documented that the Neogen SPICE ELISA kit is a viable method for screening synthetic cannabinoids in urine targeting JWH-018 N-pentanoic acid.
authors.affiliation: Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA.|School of Pharmacy, Fluminense Federal University (CAPES Foundation - BEX 1534/12-2), Rio de Janeiro, Brazil.
authors.forename: Eliani
authors.initials: E
authors.lastname: Spinelli
authors.affiliation: Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA.
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Barnes
authors.affiliation: Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA.
authors.forename: Sheena
authors.initials: S
authors.lastname: Young
authors.affiliation: Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA.
authors.forename: Marisol S
authors.initials: MS
authors.lastname: Castaneto
authors.affiliation: Drug Testing and Program Policy, Office of the Under Secretary of Defense (Personnel & Readiness), Personel Risk Reduction, Washington, DC, USA.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Martin
authors.affiliation: Drug Testing and Program Policy, Office of the Under Secretary of Defense (Personnel & Readiness), Personel Risk Reduction, Washington, DC, USA.
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Klette
authors.affiliation: Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA.
authors.forename: Marilyn A
authors.initials: MA
authors.lastname: Huestis
mesh_terms: D002186:Cannabinoids / Q000652:urine*; D002853:Chromatography, Liquid; D015198:Designer Drugs / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D057230:Limit of Detection; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D002186:Cannabinoids; D015198:Designer Drugs
keywords: ELISA; immunoassay; synthetic cannabinoids