Chronic excessive alcohol consumption diagnosis: comparison between traditional biomarkers and ethyl glucuronide in hair, a study on a real population

Background: The study aimed to evaluate the diagnostic sensitivity (SE) and specificity (SP) of chronic alcohol misuse diagnosis by comparing traditional biomarkers with ethyl glucuronide (EtG), an ethanol direct metabolite, detected in the keratinic matrix. Methods: Seventy-six subjects tested for chronic alcohol abuse for different purposes were recruited. EtG was detected in hair, whereas the analyses of carbohydrate-deficient transferrin (CDT), alanine transaminase, aspartate transaminase, gamma-glutamyl transferase, mean corpuscular volume, and mean corpuscular hemoglobin were performed in serum samples. Results: Of the 76 patients examined, 26 were judged by the medical doctors as subjects with alcohol abuse problems and, therefore, not eligible for driving license renewal or liver transplant. EtG in hair (SE = 0.68, SP = 1.00) showed the best diagnostic SE and SP compared with the other biomarkers investigated. Among the traditional biomarkers, only CDT proved to be suitable for forensic purposes because of the high diagnostic specificity (SP = 1.00) although it showed poor diagnostic SE (0.27). The percentage of positive samples decreased for all the biomarkers by excluding the subjects with hepatic diseases, except for EtG and CDT, suggesting that these 2 biomarkers could be less affected by false positive results, because of hepatic diseases. Conclusions: This study showed that when EtG in hair and CDT results are combined, diagnostic SE in chronic alcohol abuse diagnosis clearly improved, suggesting that complementary analysis of both these biomarkers provides the best diagnostic tool in suspected cases of chronic excessive alcohol consumption