Interpretation of a highly positive ethyl glucuronide result together with negative fatty acid ethyl esters result in hair and negative blood results

Abstract

Considering the widespread nature of alcohol-related problems, the diagnosis of excessive alcohol consumption is an important task from medical and legal viewpoints. Alcohol abuse can be documented by usual blood [e.g., carbohydrate deficient transferrin (CDT)] and liver function [e.g., γ-GT or mean corpuscular volume (MCV)] tests, and, over a long-term basis, by hair analysis. Major markers of ethanol consumption in hair are ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs). Detection of EtG in hair is said to be associated with excessive alcohol consumption, whereas a negative result does not unambiguously exclude alcohol abuse. Investigations on FAEEs can also be used to monitor excessive alcohol consumption. Four FAEEs (ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate) are the most suitable markers for the detection of heavy alcohol consumption and show different concentrations in hair of children, adult teetotalers, and social drinkers in comparison with FAEEs concentrations found in the hair of alcoholics. The Society of Hair Testing has provided guidelines for hair testing for chronic excessive alcohol consumption, and states positive cutoffs for a 0–3 cm hair segment as 30 pg/mg and 0.5 ng/mg for EtG and FAEEs, respectively. This study reviews the difficulties in interpreting blood and hair results of a 41-year-old woman involved in a child custody legal dispute. Her EtG and FAEEs concentrations in a 0–3 cm segment were 203 pg/mg and 0.29 ng/mg, respectively, and blood parameters were in the normal range (0.6 %, 93 fl, 14 IU/l for CDT, MCV, and γ-GT, respectively). Although the high EtG concentration suggested excessive drinking behavior, the second hair marker, FAEEs, and the three bloods tests were inconspicuous and in accordance with the claim of abstinence from alcohol by the subject. The woman declared having dyed her hair more than 6 months prior to sampling, use of weight-loss medication, and consumption of about four energy drinks per day. A hair lotion based on ethanolic plant extracts was regularly used by the subject, and could have been a source of contamination. Therefore, we recommend that possible external sources of hair contamination always be taken into consideration, especially if contradictory biological results are obtained and if the subject denies any alcohol intake.