A comparison between serum carbohydrate-deficient transferrin and hair ethyl glucuronide in detecting chronic alcohol consumption in routine.

Aims: In heavy alcohol consumption laboratory tests represent an objective evidence. In this study we compared older and newer biomarkers in blood and in hair.

Methods: Carbohydrate-deficient transferrin (CDT), ethyl glucuronide (EtG), AST, ALT, GGT, MCV were measured in a large sample (n = 562). All people declared no alcohol consumption within the last 3 months. Serum CDT was measured by the candidate HPLC reference method and expressed as relative amount of disialotransferrin (%DST: cutoff 1.7%). EtG was measured in hair by a validated in-house method by LC-MS/MS (cutoff 30 pg/mg).

Results: Respectively, 42 (7.5%) and 76 (13.5%) subjects were positive to CDT and EtG. In particular, 30 (5.3%) subjects were positive to both tests, 12 (2.1%) only to CDT, while 46 (8.2%) only to EtG. The agreement (positive and negative pairs) between CDT and EtG was 89.7%. Interestingly, 6 out of 12 (50%) CDT-positive subjects had EtG < 15 pg/mg, whereas 27 out of 46 (59%) EtG-positive subjects had CDT < 1.1%. Forty-one out of 76 (54%) EtG-positive subjects display EtG values within 30-50 pg/mg.

Conclusion: Large variability exists between CDT and EtG in detecting chronic alcohol consumption. We suggest to use CDT, or a combination of different biomarkers, to identify alcohol abuse in a forensic context. EtG results close to the cutoff (30-50 pg/mg) should be cautiously considered before any sanction is assigned.