THC in Hair Presentation.
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Transcript of THC in Hair Presentation.
THCA in Head Hair: A Comparison with
Fingernail
Conflict of InterestEmployees of USDTL
• Privately held company• Commercial laboratory• Sells hair testing services• Internally funded• No role in:
• Study design• Data collection• Analysis• publication
Marijuana usage trendsTHCA in hair and nailValidation w 10 fg/mg LODComparison hair and nailConclusions
OBJECTIVES
Most common illicit drug2010-17.4 M past month users2009 factor 376k ED visits
Trends of Marijuana Use
Trends of Marijuana Use23 States and DC
LegalizedMedical use Decriminalized Both
Trends of Marijuana Use
Daily use 12th
graders 6.5% from
5.1% in 2007
12th graders negative
perception of regular use
44.1%, lowest since
1979
What Do We Look For?
THC THCA
Detection Windows
#1 ENVIRONMENTAL EXPOSURE
SMOKE
TRANSFERANCE CONTACT
FUMES
HOW DO DRUGS GET INTO THE HAIR?
HOW DO DRUGS GET INTO THE HAIR?
#2 SWEAT AND OIL
THESE DRUG AND METABOLITE CONTAINING FLUIDS BATHE THE HAIR
SHAFT
HOW DO DRUGS GET INTO THE HAIR?
#3 THE BLOOD
Specimen Type: Why Fingernail?
Anatomy of Fingernail
NAILMATRIX
NAIL PLATE
NAIL BED
Fingernails Are Made of Keratin
o Keratin: fibrous structural protein of hair, nails, horn, hoofs, wool, feathers, and of the epithelial cells in the outermost layers of the skin. The polypeptide chains of keratin are arranged in parallel sheets held together by hydrogen bonding.
~Encyclopedia Britannica
Fingernails Are Made of Keratin
o These keratin sheets stack on top of each other, giving the nail thickness and length, making adulteration of the specimen difficult.
Incorporation of Drug
Biomarker: a measurable substance whose presence is indicative of ingestion or exposure to substances of abuse (SOA).
o Biomarkers can be found in nails as early as 1-2 weeks after substances of abuse are ingested.
o The time period during which drug ingestion can be detected depends on the substance used, the amount used, and personal metabolism.
Biomarker Absorption
Single point Calibrator – 50 fg/mgLOQ – 20 fg/mg LOD – 10 fg/mgULOL – 1000 fg/mgControls 20, 62.5, and 400 fg/mgRobust – minimum 22 consecutive days
THCA Validation Specs
LOD 10 fg/mgLOQ 20 fg/mgULOL 500 fg/mgImprecision < 13.5%Bias < 13.8%Stable
THCA Validation Results
1000 fg = 1 pg1000 pg = 1 ng
What is a Femtogram
THCA Low
Control
The Collection of Specimen
NIAAA – 1 R44 AA016463-02 (Phase II)
UW- Milwaukee- CABHRDe-identified Remnants
POSITIVITY RATETHCA HAIR/NAIL
MEAN CONCENTRATIONSTHCA HAIR/NAIL
Paired Sample t-TestDifference 1449.2 +/- 745.3t = 1.944, df = 59, P < 0.05
60 Matched Pairs of Hair and Nail
0
2000
4000
6000
8000
10000
12000
14000
0 500 1000 1500 2000 2500
Nail T
HC
A (
fg/m
g)
Hair THCA (fg/mg)
r = 0.974
LIMITATIONS
Accurate self-report
Verified dose administration
Demographics
Prevalence not generalizable
Personal hygiene
Cosmetic treatment
Published Results
CONCLUSION
Method is very sensitive & robust
Nail is a suitable alternative
[THCA] hair/nail strongly associated
Slightly higher positivity rate in nail
[THCA] up to 5x higher
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