ORIGINAL ARTICLES   

Minerva Medicolegale 2009 December;129(4):177-82

Copyright © 2010 EDIZIONI MINERVA MEDICA

language: Italian

Homogenous enzyme immunoassay for urinary ethyl glucuronide testing

Bianchi V. ¹, Piccinini S. ¹, Raspagni A. ¹, Arfini C. ²

¹ Laboratorio di Tossicologia, Alessandria, Italia 2 Dipartimento di Patologia Clinica, Azienda Ospedaliera SS Antonio e Biagio e C Arrigo, Alessandria, Italia

Aim. Ethyl glucuronide (EtG) is a direct minor ethanol metabolite, formed by uridine diphosphate-glucuronosyltransferase, an enzyme characterized by a genetic polymorphism. EtG is a direct marker of alcohol misuse, specific and sensitive, it is present in many body fluids, but it usually is detected in urine. The reference method is the liquid chromatographic-mass spectrometry, but recently a new homogenous enzyme immunoassay based on a monoclonal antibody has been introduced. In this study the performance of a commercial kit on several automated instruments has been evaluated.
Methods. ADVIA 2400 (Siemens Healthcare Diagnostics), reagents, controls and calibrators DRI Ethyl Glucuronide Enzyme Im-munoassay (Microgenics) and other controls from Medichem were used. An urinary pool was prepared (10 male and 10 female outpatients).
Results. This immunoassay for EtG measurement has shown good performances as regarding to the limit of detection and quantification, linearity, imprecision, recovery, stability of reagents on board.
Conclusion. When urine samples were measured, the initial absorbance of the specimens was too high and the detections of the absorbance was introduced a short time after mixing the samples and the reagents; this absorbance was set at zero. Because of the EtG high sensibility, it is important to fix exact cut-offs to identify people with different alcohol intake.