Clinical Utility and Impact of Phosphatidylethanol Testing in Liver Transplantation Evaluations

Background: Phosphatidylethanol (PEth) is a serum biomarker that can detect alcohol use within the last 28 days with excellent sensitivity and specificity. Urinary ethyl glucuronide (uEtG) is commonly used in transplant settings to screen for alcohol use; however, it has several limitations relevant to liver transplantation. Transplant centers are beginning to regularly utilize PEth as part of the screening process for high-risk liver transplantation candidates although the clinical utility of uniform pre- transplant PEth testing is unclear. Methods: This was a retrospective chart review of all patients evaluated for liver transplantation from December 1, 2019, through May 31, 2022, at a large academic tertiary referral center utilizing uniform serum PEth and uEtG screening. Information regarding the patients' transplantation status, age, sex, race, Model for End-Stage Liver Disease score, and PEth levels was obtained. In those with a positive PEth, we examined if the result would have been detected with uEtG, identified a discrepancy from the documented patient report of last use, led to a change in the Psychosocial Assessment of Candidate for Transplantation score, or influenced fluenced the transplant selection committee's decision. Results: Our sample included 865 individuals (mean age = 55.20, 61.27% male and 82.54% white) with calculated Model for End- Stage Liver Disease-Sodium scores ranging from 6.43 to 50.65 (mean: 18.09; median: 16.46). Forty-eight patients were found to have a positive PEth (PEth range 20-1833); 75% of the sample had alcohol-associated liver disease. In 23 of 48 (47.91%) cases, the positive PEth identifed alcohol use missed by a concomitant uEtG screen. A positive PEth test identifed a discrepancy from patients' self-report in 29 (60.42%) cases and influenced fluenced the selection committee's decision in 28 cases (58.33%). Conclusion: Uniform pretransplant PEth screening of liver transplant candidates at the time of initial evaluation identified alcohol use that would have been missed by uEtG testing, identified discrepancies from the patient's self-report, and influenced fluenced clinical decision-making in a significant number of cases. These findings support the use of uniform PEth screening in liver transplantation evaluations.