Preferred Sample Type
Suitable Specimen Types
- Plain Spot Urine
Specimen Transport
First class post from external laboratories.Sample Processing in Laboratory
Only primary urine tubes accepted.Sample Preparation
NoneTurnaround Time
7 daysSample Stability
Stable for 28 days at room temperature and 4°C.Ethyl Glucuronide (EtG) and Ethyl Sulphate (EtS)
General Information
Ethyl glucuronide (EtG) and ethyl sulphate (EtS) are the end products of the non-oxidative metabolism of alcohol and account for <0.1% of overall alcohol metabolism. EtG and EtS appear in the urine at approximately 90-130 hours post elimination of alcohol and are deemed intermediate biomarkers of alcohol metabolism. EtG and EtS have high clinical sensitivity and can detect as little as a single drink enabling early detection of alcohol relapse in individuals who have previously abstained. Moreover, the concentration of EtG and EtS directly correlates with the degree of alcohol exposure and can indicate when binge drinking has occurred. EtG and EtS are non-volatile and water soluble improving their analytical stability compared to direct ethanol measurement.
This assay will be used primarily by the Hepatology department at UHB as part of a clinical decision tool to assess the suitability of patients for liver transplant. The utility of these markers as early indicators of relapse may therefore be used as a motivational tool to encourage patients to abstain from alcohol. The assay may also be used by external hospitals for similar purposes.
It is important to recognise the clinical limitations of EtG and EtS. These biomarkers will also reflect extraneous alcohol exposure e.g. from hygiene products and hand sanitisers etc. It has also been shown that EtS may be increased in patients taking Rifaximin, a broad-spectrum antibiotic used in the treatment of hepatic encephalopathy (Webzell et al 2020). This drug is used frequently amongst the cohort of patients in whom EtG and EtS will most likely be measured.
Patient Preparation
None
Notes
Additional references: Substance Abuse and Mental Health Services Administration (SAMSHA) Advisory: The role of biomarkers in the treatment of alcohol use disorders, 2012 Revision. HHS; 2012;11(2):1-7. doi: 10.1037/e558582006-001
Reference Range
Internal Interpretation Guidance for Hepatologists
EtG <250 ng/mL - Negative result. No further action required.
EtG = 250-500 ng/mL (&EtS >100 ng/mL) - Low positive result. Result may indicate previous heavy drinking (i.e. 1-3 days), previous light drinking (i.e. 12-36 hours) or recent extraneous exposure e.g. hand-sanitisers, mouthwash.
EtG = 500-1000 ng/mL (& EtS >100 ng/mL) - Positive result. Result may indicate previous heavy drinking (i.e. previous 1-3 days) or recent light drinking (i.e. past 24 hours).
EtG >1000 ng/mL (&EtS >100 ng/mL) - High positive result. Results may indicate heavy drinking on the same day or previously (i.e. previous day or two) or light drinking on the same day.
Due to Rifaximin interference on EtS, only EtG will be used to confirm positive cases of alcohol consumption at UHB.
Please refer to links below for further sources of information for interpretation and sources of positive interference.
Source of Reference Range
US SAMHSA Guidance 2012 and Mayo Clinic Laboratories (adapted for use at UHB)Specifications
- EQA Scheme?: Yes
- EQA Status: LGC Drugs of abuse in urine