False-Positive Phosphatidylethanol Results Due to Blood Transfusion and Implications in the Process of Liver Transplantation Selection.

Phosphatidylethanol (PEth) testing is becoming increasingly common as a tool to assess for alcohol consumption in the practice of addiction medicine. Its potential to be an objective measure of ethanol exposure is appealing; however, the field has yet to develop a complete understanding of the factors that can influence a PEth level. Here we describe 3 patient cases in which blood transfusion within the preceding 28 days was the reason that PEth studies were positive in patients undergoing liver transplant evaluation. These patients all had in-depth evaluations by physicians on an addiction medicine consult service and were believed abstinent from alcohol. In the field of liver transplant, even a mildly elevated PEth level can result in listing delay or even liver transplant candidacy denial. Further study is needed to understand how PEth is impacted by medical procedures and events such as blood transfusion if we are to maintain a just and ethical practice in the setting of addiction and transplant medicine.