Urinary ethyl glucuronide testing detects alcohol consumption in alcoholic liver disease patients awaiting liver transplantation

This study compared measurement of urinary ethyl glucuronide (EtG), a conjugated minor ethanol metabolite with a longer detection window than ethanol itself, with breath alcohol testing and self-report as ways to disclose recent drinking by 18 liver transplant candidates with an alcoholic liver disease diagnosis that underwent an addiction group therapy program. At each therapy session, patients were questioned about any alcohol consumption in the intervening time, and they also performed a mandatory breath alcohol test, while observed urine samples for measurement of EtG were delivered on a voluntary basis. None of the patients ever admitted to intake of alcohol, and only 1 of 127 breath alcohol tests turned out positive. However, 9 patients showed positive EtG results in 24 (49%) of 49 urine samples. The individual frequency of urine samples being positive for EtG ranged from 22% to 100% with a mean value of 57%. Because 6 patients refused to provide urine on a total of 18 occasions, alcohol use might have been even more common. These results underscore the uncertainty of self-report data and the low sensitivity of breath alcohol testing as ways to disclose recent drinking, and underline the necessity of introducing sensitive and specific objective measures of recent alcohol consumption, such as EtG, in the transplantation setting.