Test Code MISC2MAYOASNA Arsenic, Nails
Reporting Name
Arsenic, NailsUseful For
Detection of nonacute arsenic exposure in nail specimens
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
NailNecessary Information
Indicate source of nails (fingernails or toenails), if known.
Specimen Required
Supplies: Hair and Nails Collection Kit (T565)
Specimen Volume: 0.2 g
Collection Instructions:
1. Prepare and transport specimen per the instructions in the kit or see Collecting Hair and Nails for Metals Testing.
2. Clippings should be taken from all 10 fingernails or toenails.
Specimen Minimum Volume
0.05 g
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Nail | Ambient (preferred) | ||
Frozen | |||
Refrigerated |
Special Instructions
Reference Values
0-15 years: Not established
≥16 years: <1.0 mcg/g of nails
Day(s) Performed
Tuesday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82175
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
ASNA | Arsenic, Nails | 8157-0 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
2535 | Arsenic, Nails | 8157-0 |
ASNSC | Specimen Source | 31208-2 |
Clinical Information
Arsenic circulating in the blood will bind to protein by formation of a covalent complex with sulfhydryl groups of the amino acid cysteine. Keratin, the major structural protein in hair and nails, contains many cysteine residues and, therefore, is one of the major sites for accumulation of arsenic. Since arsenic has a high affinity for keratin, the concentration of arsenic in nails is higher than in other tissues.
Several weeks after exposure, transverse white striae, called Mees' lines, may appear in the fingernails.
Interpretation
Nails grow at a rate of approximately 0.1 inch/month. Nail keratin synthesized today will grow to the distal end in approximately 6 months. Thus, a nail specimen collected at the distal end represents exposure of 6 months ago.
Nail arsenic above 1.0 mcg/g dry weight may indicate excessive exposure. It is normal for some arsenic to be present in nails, as everybody is exposed to trace amounts of arsenic from the normal diet.
The highest hair or nail arsenic observed at Mayo Clinic was 210 mcg/g dry weight in a case of chronic exposure that was the cause of death.
Method Description
The metal of interest is analyzed by inductively coupled plasma mass spectrometry.(Unpublished Mayo method)
Report Available
2 to 8 daysReject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Method Name
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)