Ethyl glucuronide: a marker of recent alcohol consumption with clinical and forensic implications

A marker with a specific time spectrum of detection and both high sensitivity and specificity is required to diminish the clinically as well as forensically important gap on the time axis between short- and long-term markers of alcohol consumption like ethanol and CDT, GGT or MCV, respectively. Ethyl glucuronide (EtG) is a non-volatile, water-soluble, stable upon storage, direct metabolite of ethanol with a molecular weight of 222 g/mol that can be detected in body fluids for an extended time period after the complete elimination of alcohol from the body. We investigated 107 urine and 78 serum samples of a total of 107 inpatients in 4 groups: (1) 33 inpatients in acute alcohol withdrawal and long term treatment; (2/3) 29 and 15 addicted forensic psychiatric inpatients (#64 StGB, penal code); (4) 30 recently detoxified inpatients of a station for long term treatment by LC/MS-MS with the internal standard d5-EtG and additionally in the fourth group of patients also by gas chromatography/mass spectrometry (GC/MS). In 2 out of 33 inpatients of the first group, EtG could be determined 3 days after hospitalization; in an other subject, a relapse could be detected. In 2 out of 29 and in 1 out of 15 forensic inpatients of group 2 and 3, respectively--where neither clinical impression nor routine laboratory findings gave an indication for relapse--concentrations of EtG ranged between 0.1 and 18 mg/l in urine. For the serum samples of the 30 inpatients of group 4, we could demonstrate a total agreement for the results of the GC/MS and the LC/MS-MS method as to whether a sample was found to be positive or negative for EtG. We suggest that these results strengthen our earlier findings that ethyl glucuronide is a marker of alcohol consumption in general that can be detected for an extended time period after the complete elimination of alcohol from the body and a marker for relapse control with a specific time frame of detection intermediate between short- and long-term markers.