Comparison of ethyl glucuronide in hair with carbohydrate-deficient transferrin in serum as markers of chronic high levels of alcohol consumption

This study was designed with the aim to compare sensitivity and specificity of ethyl glucuronide in hair (HEtG) and carbohydrate-deficient transferrin (CDT) in serum as markers of heavy drinking. Eighty-six volunteers, including teetotalers, social, and heavy drinkers, were interviewed to evaluate their ethanol daily intake (EDI) during the last 2-week and 3-month periods. HEtG determination was performed by a fully validated LC-MS-MS procedure and ranged from <LOD (2 pg/mg) to 890.5 pg/mg. CDT was measured by immunonephelometry or by HPLC. Sensitivity and specificity of the two markers as indicators of an EDI higher than 60 g/day were calculated, with cut-off at 27 pg/mg (HEtG) and 2.5% (CDT). Considering the EDI of the last 2 weeks, HEtG showed equal selectivity (0.93 for both HEtG and CDT-immunonephelometry; 0.70 for both HEtG and CDT-HPLC) and 2 times the sensitivity of either of the two CDT methods (1.00 vs. 0.44 for CDT-immunonephelometry; 0.96 vs. 0.50 for CDT-HPLC). The same difference in performances but with higher absolute sensitivity and selectivity values for HEtG were observed considering the EDI of the last 3-months (selectivity: 1.00 for both HEtG and CDT-immunonephelometry, 0.89 and 0.78 for HEtG and CDT-HPLC, respectively; sensitivity: 1.00 vs. 0.47 for CDT-immunonephelometry; 0.98 vs.0.51 for CDT-HPLC). Our results indicate that HEtG, as compared to CDT measured using different methods, is a selective marker of ethanol heavy chronic use providing considerably higher sensitivity.