Biomarkers to disclose recent intake of alcohol: potential of 5-hydroxytryptophol glucuronide testing using new direct UPLC-tandem MS and ELISA methods.
OBJECTIVE
This study compared two new methods for direct determination of 5-hydroxytryptophol glucuronide (GTOL) in urine, a biomarker for detection of recent alcohol consumption.


METHODS
Urine samples were collected from ten alcoholic patients during recovery from intoxication. A direct injection ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for measurement of the urinary GTOL to 5-hydroxyindoleacetic acid (5-HIAA) ratio, and an ELISA assay for direct measurement of GTOL, were used. Comparison was made with the urinary ethanol and ethyl glucuronide (EtG) concentrations.


RESULTS
The breath ethanol concentration on admission ranged between 1.0-3.1 g/l. The UPLC-MS/MS method showed a median detection time of 39 h for an elevated urinary GTOL/5-HIAA ratio, while EtG was detected for a median of 65 h. Determination of GTOL by the ELISA assay showed 87% sensitivity in detecting positive samples at a 44% specificity, as compared with the UPLC-MS/MS method.


CONCLUSIONS
The lower sensitivity of the urinary GTOL/5-HIAA ratio compared with EtG for recent drinking may be clinically useful, in cases where the EtG test provides an unwanted high sensitivity for intake of only small amounts of alcohol or unintentional ethanol exposure.
Beck
Olof
O
Department of Medicine, Karolinska Institute and Karolinska University Hospital, Stockholm, Sweden. olof.beck@karolinska.se
Stephanson
Nikolai
N
Böttcher
Michael
M
Dahmen
Norbert
N
Fehr
Christoph
C
Helander
Anders
A
D000428:Alcohol Drinking / Q000652:urine*; D000437:Alcoholism / Q000652:urine; D015415:Biomarkers / Q000652:urine; D001944:Breath Tests; D002492:Central Nervous System Depressants / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D000431:Ethanol / Q000652:urine; D020719:Glucuronides / Q000652:urine*; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000652:urine; D006917:Hydroxytryptophol / Q000031:analogs & derivatives* / Q000652:urine; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
C500750:5-hydroxytryptophol glucuronide; D015415:Biomarkers; D002492:Central Nervous System Depressants; D020719:Glucuronides; D006917:Hydroxytryptophol; D000431:Ethanol; D006897:Hydroxyindoleacetic Acid