Alcohol Use Biomarkers Testing

  • Preferred method for ruling out ethanol exposure
  • Identify recent ethanol exposure within 1-5 days after ingestion
  • Results do not accurately correlate with amount or frequency of ethanol use
  • May be useful in the assessment of ethanol exposure in the contexts of compliance and/or abuse
  • Identify recent ethanol exposure within 1-5 days after ingestion
  • Results do not accurately correlate with amount or frequency of ethanol use
  • Identify alcohol abuse or abuse relapse
  • Will detect chronic ethanol use (≥40 g/day for 2 weeks)
Tests for Acute Ethanol Use
Tests for Chronic Ethanol Use or Abuse Relapse

Test for chronic ethanol use

Identify chronic heavy ethanol use for up to 28 days

Alcohol use biomarkers (eg, ethyl glucuronide, ethyl sulfate, carbohydrate deficient transferrin) can help determine acute or chronic alcohol use. Screening tests may be useful in ruling out recent alcohol use, for general screening in the assessment of ethanol exposure in the contexts of compliance and/or abuse, and as aid for monitoring alcohol abstinence.

Disease Overview

Clinical Issues

Acute ethanol intoxication beyond the first 6-8 hours is not reliably predicted by serum testing, so other biomarkers are often used to detect alcohol use.  

Ethyl glucuronide (EIG) and ethyl sulfate (EIS)

  • Direct metabolites of ethanol
    • Detected up to 80 hours in urine after ethanol ingestion
    • Good biomarkers of recent alcohol ingestion
    • Useful in short-term monitoring for abstinence

Carbohydrate deficient transferrin (CDT)

  • Negative charged glycoprotein proteins with incomplete glycan chain(s)
    • Markedly increased by moderate to heavy alcohol use
    • Most useful for long-term abstinence monitoring (up to 2 weeks)

Phosphatidylethanol (PEth)

  • Phospholipid formed only in the presence of ethanol
    • PEth may be a more sensitive marker of chronic use than CDT
    • Identifies chronic heavy ethanol use for up to 28 days

Test Interpretation

Analytical Sensitivity

Analytical Sensitivity
Test Results

Ethyl Glucuronide Screen with Reflex to Confirmation, Urine

Cutoff for positive screen is set at 500 ng/mL

Ethyl Glucuronide and Ethyl Sulfate Confirmation, Urine

  • Reported as a concentration
  • Analytical range is 100-10,000 ng/mL
  • Lower limit of quantification is 100 ng/mL

Carbohydrate Deficient Transferrin

Reported as percent:

  • ≥1.7%: supports alcohol use >40g/day
  • <1.4%: does not support alcohol use >40g/day over the prior 2 weeks
  • 1.4-1.6%: reported as inconclusive

Phosphatidylethanol (PEth)

  • Concentration > 20 ng/mL is considered evidence of moderate to heavy ethanol use
  • Results should be interpreted within clinical, environmental, and behavioral contexts

Limitations (by Test)

Ethyl Glucuronide and Ethyl Sulfate Confirmation, Urine

Incidental exposure from ethanol-containing products may be detected.

Ethyl Glucuronide Screen with Reflex to Confirmation, Urine

  • False positive results may be caused by microbial formation or fermentation, ethanol-containing products (eg, hand sanitizer, mouthwash).
  • False negative results may be caused by bacterial degradation, >4 days since ethanol ingestion.

Carbohydrate Deficient Transferrin

  • Cannot be used in individuals suspected of having congenital glycosylation disorders.
  • Advanced liver damage (including severe chronic viral hepatitis) and antiepileptic drug therapy can increase CDT levels.
  • Interference in quantitation may be caused by:
    • Severe icterus
    • Genetic variants of transferrin
    • Excess monoclonal or polyclonal immunoglobulins

Phosphatidylethanol (PEth)

Elevated PEth may result from incidental or unintentional ethanol exposure

    References