Determination of carbohydrate-deficient transferrin (CDT) in Italy

Background: Carbohydrate-deficient transferrin (CDT) in serum is a biomarker of heavy alcohol consumption. In Italy, CDT testing is primarily used for matters of road safety by the commissions that reissue drivers' licenses after alcohol-related offences. The purpose of this study was to examine how CDT determinations are carried out by Italian laboratories. Methods: Public (hospital and university) laboratories, the companies producing CDT assays, and the organizers of two external quality assurance (EQA) programs were approached and telephone interviews were conducted. The study was carried out between October, 2006 and January, 2007, and considered the situation as of 31 December, 2006. Results: In 2006, 142 Italian hospital and university laboratories performed CDT measurements and there were 67 license commissions using different protocols for the evaluation of alcohol abuse. Compared with 2005, the number of laboratories that assayed CDT had doubled in 2006. Several different CDT methods were in routine use and there were large differences in the ways results were expressed and in the cut-off limits applied, even for identical methods and instrumentations. Only approximately one-third of the laboratories participated in an EQA program for CDT. Conclusions: Despite that CDT testing is used almost exclusively for medico-legal purposes in Italy, many different methods, ways of expressing test results, and cut-off limits were routinely applied. This observation points at the urgent need for standardization of CDT measurement. Clin Chem Lab Med 2008; 46: 1759-62.