Ethyl glucuronide - a marker of alcohol consumption and a relapse marker with clinical and forensic implications

Abstract

Ethyl glucuronide (EtG) is a non-volatile, water-soluble, direct metabolite of ethanol that can be detected in body fluids and hair. We investigated urine and serum samples from three patient groups: (1) 33 in-patients in acute alcohol withdrawal; (2) 30 detoxified in-patients (treated for at least 4 weeks) from a 'motivation station'; and (3) 43 neuro-rehabilitation patients (non-alcoholics; most of them suffering from stroke, traumatic brain injury, Parkinson's disease etc.) using gas chromatography/mass spectrometry (GC/MS) with deuterium-labelled EtG as the internal standard and additionally in the second group of patients using liquid chromatography (LC/MS-MS). We found no correlation between the concentration of EtG in urine at hospitalization and the blood-ethanol concentration (r = 0.17), the time frame of detection (r = 0.5) or the total amount of clomethiazole required for the treatment of withdrawal symptoms (r = 0.28). In four out of 30 in-patients from the 'motivation station'--where neither clinical impression nor routine laboratory findings gave indications of relapse--concentrations of EtG in urine ranged between 4.2 and 196.6 mg/l. EtG concentrations in urine of between 2.89 and 23.49 mg/l were found in seven out of 43 neuro-rehabilitation patients using GC/MS. The GC/MS and the LC/MS-MS results showed a correlation of 0.98 with Pearson's correlation test and 1.0 with Spearman's correlation test. We suggest that EtG is a marker of alcohol consumption that can be detected for an extended time period after the complete elimination of alcohol from the body. When used as a relapse marker with a specific time frame of detection intermediate between short- and long-term markers, EtG fills a clinically as well as forensically important gap. Its specificity and sensitivity exceed those of all other known ethanol markers.

Involvement of UDP-Glucuronosyltransferases UGT1A9 and UGT2B7 in Ethanol Glucuronidation, and Interactions with Common Drugs of Abuse

“…Ethyl glucuronide [ethyl-b-D-6-glucuronic acid (ethyl glucuronide); EtG] can be detected in various body fluids, tissues, and hair. It is eliminated with a terminal half-life of 2 to 3 hours (Schmitt et al, 1997) and presents a particularly interesting detection window in body fluids (up to 8 hours and 5 days after complete ethanol elimination, in serum and urine, respectively (Schmitt et al, 1997;Wurst et al, 1999). EtG determination is also much more sensitive and specific than conventional markers (e.g., g-glutamyl transferase, alanine aminotransferase, aspartate aminotransferase, mean corpuscular volume, and carbohydrate-deficient transferrin).…”

Confirmatory analysis of ethylglucuronide in urine by liquid-chromatography/electrospray ionization/tandem mass spectrometry according to forensic guidelines

“…Since EtG is a very polar substance, precipitation or dilution prior to analysis by GC-MS and LC-MS have been used for sample clean-up in most published papers. LC-MS or LC-MS/MS methods are advantageous in comparison with GC-MS methods because of the reduced need for derivatization and shorter analysis times (10 min per chromatographic run) [4,12]. In our experience, GC-MS with derivatization requires much more system maintenance than does LC-MS, because of the high load of polar matrix which is present in urine samples.…”

“…In urine, it can be detected longer than ethanol. Therefore, EtG meets the need for a sensitive and specific marker to elucidate alcohol use not detected by standard testing [5][6][7][8][9][10][11][12][13]. Furthermore, EtG has been detected in hair samples [14 -16] and post-mortem tissues (liver, brain, fat tissue [17]) of alcohol addicts.…”

Ethyl glucuronide

“…54 Similarly, four out of 30 patients, in whom neither clinical assessment nor routine laboratory testing suggested relapse, tested positive for EtG in urine with concentrations ranging from 4200 to 196600 mg/L. 55 However, only the subject with the highest urine EtG concentrations had detectable EtG in serum. In a double-blind placebo-controlled study of oral acamprosate, 56 alcoholdependent subjects (30 men) gave urine samples at baseline and at weekly intervals for measurement of EtG and EtS.…”