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HelpTest Code PETH Phosphatidylethanol Confirmation, Blood
Specimen Required
Container/Tube: Lavender top (EDTA)
Specimen Volume: 1 mL
Collection Instructions:
1. Do not use alcohol to clean arm. Use alternatives such as Betadine or ChloraPrep to cleanse arm before collecting any specimen.
2. Do not centrifuge.
3. Send whole blood specimen in original tube. Do not aliquot.
Useful For
Verifying abstinence or use of ethanol, especially in liver transplant candidates/patients
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Phosphatidylethanol Confirmation, BSpecimen Type
Whole Blood EDTASpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood EDTA | Frozen (preferred) | 28 days | |
| Refrigerated | 14 days |
Reject Due To
| Gross lipemia | OK |
| Gross icterus | OK |
Clinical Information
Phosphatidylethanol (PEth) is a direct biomarker for alcohol (ethanol) intake. In presence of ethanol, phosphatidylcholine is converted to PEth on the red blood cell membrane by the phospholipase D enzyme. PEth homologues (16:0/18:1 [POPEth: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanol] and 16:0/18:2 [PLPEth: 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphoethanol]) levels correlate with the amount of alcohol consumed within the previous 2 weeks and may be detected in the blood up to 2 to 4 weeks after excessive alcohol consumption. POPEth and PLPEth comprise approximately 60% of all observed PEth homologues in the blood.(1)
Reference Values
Negative (<10 ng/mL)
PEth 16:0/18:1 (POPEth): Lower limit of quantification =10 ng/mL
PEth 16:0/18:2 (PLPEth): Lower limit of quantification =10 ng/mL
Interpretation
POPEth (1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanol):
A result of 20 ng/mL to 200 ng/mL is considered evidence of moderate ethanol consumption, while results over 200 ng/mL indicate heavy ethanol consumption. However, the Center for Substance Abuse Treatment advises caution in interpretation and use of biomarkers alone to assess alcohol use. Results should be interpreted in the context of all available clinical and behavioral information.(2)
PLPEth (1-Palmitoyl-2-linoleoyl-sn-glycero-3-phosphoethanol):
There are no current clinical reference limits for this phosphatidylethanol (PEth) homologue.
PEth 16:0/18:1 (POPEth)
Less than 10 ng/mL: Not detected
10-19 ng/mL: Abstinence or light alcohol consumption (<2 drinks per day for several days a week)
20-200 ng/mL: Moderate alcohol consumption (up to 4 drinks per day for several days a week)
Greater than 200 ng/mL: Heavy alcohol consumption or chronic alcohol use (at least 4 drinks per day several days a week)
PEth 16:0/18:2 (PLPEth): Reference ranges are not well established.
Cautions
No significant cautionary statements
Day(s) Performed
Monday through Sunday
Report Available
2 to 5 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
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
80321
G0480 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PETH | Phosphatidylethanol Confirmation, B | 101506-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 617481 | PEth 16:0/18:1 (POPEth) by LC-MS/MS | 97607-6 |
| 617482 | PEth 16:0/18:2 (PLPEth) by LC-MS/MS | 97606-8 |
| 617483 | PEth Interpretation | 69050-3 |
Forms
If not ordering electronically, complete, print, and send 1 of the following with the specimen:
-Therapeutics Test Request (T831)
-General Test Request (T239)
-Renal Diagnostics Test Request (T830)