Alcoholic beverages and the heavy problems linked to their abuse have been familiar in human societies since the beginning
of recorded history. Alcoholism is a social, economic and medical question, that involve a wide population in almost all ethnic
groups, and the evidence of alcohol abuse is often very difficult mainly for the capability of abusers to keep secret their
trouble. Hence the clinician needs various information to make the exact diagnosis, including the acquisition of the complete
history of the patient and the investigation of clinical signs. Today, the study of such a topic could be markedly improved
by the systematic use of laboratory tests, such as blood ethanol, serum gamma-glutamyl transferase (γ-GT), the mean corpuscular
volume of erythrocytes (MCV) and the carbohydrate-deficient transferrin (CDT), currently the most specific marker of alcohol
abuse.
In the last years some minor ethanol metabolites in hair matrix (in particular ethyl glucuronide and fatty acid ethyl esters)
have been studied, for the unique ability of hair to serve as a long-term storage of xenobiotics with respect to the temporal
appearance in blood. Over the last 20 years in fact, hair testing has gained increasing attention for the retrospective investigation
of chronic drug abuse because of the window of drug detection is dramatically extended to weeks and months. The chance to
detect minor ethanol metabolites in hair have been proposed in the early 2000 and ethyl glucuronide and fatty acid ethyl esters
seem to satisfy the prerequisites requested by the alcoholism diagnosis.
Ethyl glucuronide (EtG) is a non-volatile, watersoluble, direct metabolite of ethanol. It has received much recent attention
as a sensitive and specific biological marker of alcoholism. Formed in the liver via conjugation of ethanol with activated
glucuronate, EtG remains detectable in serum, plasma, and hair for days after ethanol abuse. The use of this marker detected
in hair alone and complementary with other biological state markers is expected to lead to significant improvement in treatment
outcome, therapy efficacy and cost reduction.
Fatty acid ethyl esters (FAEE) are products of the non-oxidative ethanol metabolism, which are known to be detectable in blood
about 24 h after the last alcohol intake. After deposition in hair they should be suitable long-term markers of chronically
elevated alcohol consumption. It was shown by some investigations that FAEE are also present in sebum, that there is no strong
difference in their concentrations between pubic, chest and scalp hair, and that they are detectable in hair segments after
a 2 months period of abstinence. From these experiences it follows that the measurement of FAEE concentrations in hair is
a useful way for a retrospective detection of alcohol abuse, able to discriminate between heavy drinkers and teetotallers.
Moreover the use of FAEE into neonatal hair to objectively identify children exposed to alcohol in utero may be a helpful
approach to diagnose foetal alcohol spectrum disorder.
Keywords Alcoholism - biochemical markers - hair - ethyl glucuronide - fatty acid ethyl esters