Blood Phosphatidylethanol Offers Limited Utility as an Alcohol Biomarker in Patients with Chronic Liver Disease

Blood phosphatidylethanol (PEth) is a product of ethanol metabolism that may be a useful biomarker of alcohol consumption. For this study, researchers recruited 222 participants with chronic liver disease (median age 52 years; 56% male; 54% with cirrhosis) and measured their PEth levels by mass spectroscopy and their alcohol consumption by a validated calendar method of self-report. Sensitivity and specificity of PEth cutoffs were calculated for detecting any alcohol consumption and an average consumption of ≥4 drinks in a day.

• In the last 30 days, 42% of the participants reported no alcohol consumption; 42% reported consuming an average of <4 drinks in a day; and 16% reported consuming an average of ≥4 drinks in a day.
• For an outcome of any drinking, a PEth cutoff of 8 ng/ml had sensitivity of 79% and specificity of 90%, whereas a cutoff of 20 ng/ml had sensitivity of 73% and specificity of 96%.
• For an outcome of consuming ≥4 drinks in a day, a PEth cutoff of 20 ng/ml had sensitivity of 97% and specificity of 66%, whereas a cutoff of 80 ng/ml had sensitivity of 91% and specificity of 77%.

Comments:

PEth performed reasonably well in detecting any alcohol consumption and average consumption of ≥4 drinks in a day among people with chronic liver disease. However, the lower cutoffs will misclassify some people with alcohol consumption as abstinent, and the upper cutoffs will misclassify some people who consume an average of <4 drinks in a day as having heavier consumption. PEth’s clinical role beyond potential relapse detection in patients with chronic liver disease remains uncertain.

Kevin L. Kraemer, MD, MSc

Reference:

Stewart SH, Koch DG, Willner IR, et al. Validation of blood phosphatidylethanol as an alcohol consumption biomarker in patients with chronic liver disease. Alcohol Clin Exp Res. 2014;38(6):1706–1711.