What is Phosphatidylethanol (PEth)?

From the Guidelines

Phosphatidylethanol (PEth) is a highly specific and sensitive biomarker for detecting alcohol consumption, capable of detecting a single drinking episode for up to 12 days and a semi-quantitative measure of chronic heavy use for up to 6 weeks, as supported by recent studies 1.

Key Points

• PEth testing requires a blood sample and is particularly valuable for monitoring abstinence in treatment programs, detecting relapse, assessing chronic alcohol use, and in legal contexts such as child custody cases or workplace testing.
• The test can detect moderate to heavy drinking patterns but may not reliably identify light or occasional drinking.
• Levels above 20-30 ng/mL generally indicate alcohol consumption, while levels exceeding 200-300 ng/mL suggest heavy drinking.
• PEth is not significantly affected by liver disease, medication use, or other medical conditions, providing a more accurate assessment of alcohol consumption patterns over the preceding month.

Clinical Application

• PEth testing can be used to monitor alcohol use in liver transplant centers, as well as in other clinical settings where accurate assessment of alcohol consumption is necessary.
• The use of PEth testing can help to identify patients who are at risk of developing alcohol-related liver disease (ALD) or metabolic dysfunction-associated steatotic liver disease (MASLD).
• PEth testing can also be used to assess the effectiveness of treatment programs for alcohol use disorder.

Limitations

• PEth testing may not be widely available due to its cost and the need for specialized equipment.
• The test may not be able to detect light or occasional drinking, and may not be suitable for all patients.
• Further studies are needed to fully understand the clinical utility and diagnostic performance of PEth testing in different patient populations.

Recommendations

• PEth testing should be considered as a valuable tool for monitoring alcohol use and assessing the risk of developing ALD or MASLD, particularly in patients with a history of heavy drinking or those who are at risk of developing these conditions 1.
• Clinicians should be aware of the limitations of PEth testing and use it in conjunction with other assessment tools, such as standardized questionnaires and collateral information, to obtain a comprehensive understanding of a patient's alcohol use.
• Further research is needed to fully understand the clinical utility and diagnostic performance of PEth testing and to develop guidelines for its use in clinical practice.

From the Research

Phosphatidylethanol Overview

• Phosphatidylethanol (PEth) is a biomarker used for detecting and quantifying alcohol use in various environments, including security, medical, and legal settings 2.
• The basic chemistry of PEth makes it a suitable biomarker for alcohol use due to its ability to accurately reflect alcohol consumption levels.

Interpretation Guidelines for PEth Values

• A study published in the Journal of Forensic Sciences proposes three guidelines for evaluating PEth values:
  • Light or no consumption: <20 ng/mL
  • Significant consumption: 20-199 ng/mL
  • Heavy consumption: >200 ng/mL 2.
• These guidelines are essential in employment and security environments, as well as in activities such as alcohol treatment programs, organ transplant decisions, and monitoring impaired medical professionals.

Comparison with Other Screening Methods

• A study published in Alcoholism, Clinical and Experimental Research compared PEth with the Alcohol Use Disorders Identification Test (AUDIT) and the Timeline Follow-back (TLFB) as screening methods for hazardous alcohol use in the Emergency Department 3.
• The results showed a moderate correlation between PEth values and AUDIT scores, as well as a high correlation between PEth values and TLFB scores.
• PEth identified patients with problematic alcohol use who were missed by the AUDIT questionnaire, suggesting its potential as an additional screening method for hazardous alcohol use.

Relationship with Alcohol Use Disorder Treatment

• While PEth is used as a biomarker for alcohol use, other studies have focused on the treatment of alcohol use disorder, including the use of medications such as disulfiram, naltrexone, and acamprosate 4, 5, 6.
• These studies highlight the importance of evidence-based pharmacotherapies for treating alcohol use disorder, but do not directly relate to the use of PEth as a biomarker.