Urinary ethyl glucuronide (uEtG) as a marker for alcohol consumption in liver transplant candidates: A real-world cohort

Background In order to reduce alcohol relapse after liver transplantation (LT), the German national guidelines for waiting-list maintenance and organ allocation demand a minimum 6-month period of alcohol abstinence pre-LT, confirmed by measuring urinary ethyl glucuronide (uEtG). Methods Between January 2015 and June 2016, uEtG was measured at least once in 339 cirrhotic patients with an indication for LT at the University Medical Center Mainz. uEtG was measured with an enzyme-linked immunosorbent assay (ELISA) screening test (cutoff value: 500μg/L). For uEtG values ≥500μg/L, liquid chromatography-mass spectrometry (LC-MS/MS) was performed as a confirmatory assay. Data were collected prospectively in a transplant database. Results Of the 339 potential liver transplant candidates, uEtG was negative in 86.4%. Most patients were male (64.3%), with an average age of 56.42±10.1 years. In the multivariate analysis, mean corpuscular volume (p=0.001), urinary creatinine (p=0.001), gamma-glutamyl transferase (p=0.001), and hemoglobin (p=0.003) were significantly associated with a positive uEtG test result. The sensitivity of the ELISA screening test was 100% for uEtG values >2000μg/L, as confirmed by LC-MS/MS. Conclusion uEtG is an effective parameter to reveal alcohol consumption by patients on the waiting list for LT. The sensitivity of the ELISA is excellent for uEtG values >2000μg/L, for which LC-MS/MS confirmation could be omitted.