Detection of phosphatidylethanol after ethanol intake with targeted blood alcohol concentrations of 0.6 g/kg and 0.75 g/kg

Alcohol consumption is widespread in most western countries such as Germany and a relevant risk factor for morbidity and mortality. Sensitive detection of alcohol consumption using suitable markers is therefore of central importance for clinical and forensic diagnostics. Direct alcohol markers are non-oxidative products of ethanol, which are produced in the body during the degradation of ethanol and provide high sensitivity and specificity. Phosphatidylethanol (PEth) is a promising marker for detecting alcohol consumption in the past days to weeks. The aim of this study was to determine the minimum amount of ethanol for a single alcohol consumption that leads to a detectable increase in blood PEth concentration. Therefore, 12 participants were recruited and, after four weeks of abstinence, drinking tests were carried out with target blood alcohol concentrations (BAC) of 0.6 g/kg and 0.75 g/kg. The PEth samples were obtained as dried-blood spots on the test day and the three following days and analyzed using LC-MS/MS. The result of the study were a detectable increase of PEth in the blood above limit of detection after both drinking events in all participants and an increase in PEth above the cutoff concentration for abstinence of 20 ng/mL in 9/12 (75%) and 7/12 (58%) participants, respectively, from a minimum BAC of 0.48 g/kg. These results make PEth appear promising as a marker for controlled moderate alcohol consumption.