Carbohydrate -deficient transferrin (CDT) as biomarker for forensic diagnosis of chronic alcohol abuse in drivers

Introduction: The chronic alcohol abuse diagnosis, when applied in drivers sanctioned for driving under alcohol effects, represents a strong forensic evaluation which must be supported by reliable inquiries. This diagnosis can’t even find a complete support in alcohol blood rate or in breath test, that are useful only to check the recent alcohol abuse. So that Carbohydrate-deficient transferrin (CDT) affirmed as a biomarker of chronic moderate to heavy alcohol consumption (more than 40-60 g ethanol/die). The main advantage of CDT is its high specificity when compared with others conventional markers, like gamma-glutamyltransferase (GGT) and mean corpuscular volume (MCV). Furthermore CDT underlines alcoholic beverages abuse in a time ranged from 2-3 weeks before a blood sampling. Materials and methods: The study was performed on two different subgroups of drivers (n. 739 subjects from Naples and n. 448 subjects from Salerno (Campania Region - Italy). For these drivers toxicological controls were requested in order to reapplication of the licence, after driving under alcohol influence. For each subject, 3 serum samples, were collected at random in a 30 days period, for quantification of the carbohydrate-deficient Transferrin (CDT %) by HPLC commercial method (BIO-RAD). Results: For the evaluation of toxicological results of the DisialoTf (DST%), measured as percentage of TetrasialoTf (TeST), were adopted these different criteria: DST<1,78% = true negative DST range 1,78- 2% = suspected for alcohol abuse DST > 2% = true positive for alcohol abuse. The distribution of the CDT% between two groups of drivers underlined, as chronic drinkers, the 9% of subjects from Salerno and 7% from Naples. Furthermore, on the basis of CDT values, ( for DST ranged from 1,78- 2%), 4% of controlled subject, as from Naples as from Salerno, where classified as “suspected for alcohol abuse”. The results demonstrate also that among drivers classified as chronic drinkers (CDT >2), were present about 5,4% of workers involved in public transportation activities (taxi, train, bus etc.). These workers moreover represents the 12,5% among drivers classified as “suspected for alcohol abuse” . Conclusion: The study confirms that CDT% can represent a marker in forensic medicine, useful for differential diagnosis both for cases of occasional or chronic heavy alcohol consumption and for patients with congenital disorders of glycosylation or others enzymatic disorders not alcohol related.