Validity testing of the accuPINCH THC test.
Self-contained drug-testing kits are currently being marketed for a variety of drugs of abuse. These tests are designed to provide rapid access to test results without the need for laboratory facilities. This report describes a validity study of the accuPINCH THC test, a self-contained test for cannabinoids in urine. Three healthy male volunteers with a history of marijuana use participated in the clinical study. Each subject smoked one, two, or four marijuana cigarettes (2.6% THC) on each test day. Urine samples were collected and incorporated into a specimen set consisting of 178 clinical samples, 72 urine samples containing known amounts of drug, and 50 drug-free urine samples. The specimen set was randomized and analyzed under blind conditions by the accuPINCH test and by gas chromatography-mass spectrometry (GC-MS) for 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (THCCOOH). AccuPINCH results were interpreted independently by three readers as positive at either two calibration points (positive A < 100 ng/mL THCCOOH; positive B > or = 100 ng/mL THCCOOH) or negative. Concordance analysis was performed by comparison of the accuPINCH results with GC-MS. In addition, the effects of changes in sample turbidity, temperature, and assay reading time on test outcome were assessed. For the clinical samples, positive B results were associated exclusively with THCCOOH concentrations greater than or equal to 15 ng/mL, whereas positive A and negative results were obtained at all concentrations. All drug-free urine samples were interpreted as either negative or positive A. The test demonstrated relatively low cross-reactivity with THC and other cannabinoids.(ABSTRACT TRUNCATED AT 250 WORDS)
Jenkins
A J
AJ
Addiction Research Center, NIDA/NIH, Baltimore, MD 21224.
Darwin
W D
WD
Huestis
M A
MA
Cone
E J
EJ
Mitchell
J M
JM
D000328:Adult; D002186:Cannabinoids / Q000652:urine*; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D002189:Marijuana Abuse / Q000175:diagnosis*; D008385:Marijuana Smoking / Q000652:urine*; D008875:Middle Aged; D011897:Random Allocation; D011933:Reagent Kits, Diagnostic / Q000592:standards; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013696:Temperature
D002186:Cannabinoids; D011933:Reagent Kits, Diagnostic; C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol