Characterization of Sialic Acid Index of Plasma Apolipoprotein J and Phosphatidylethanol During Alcohol DetoxificationuA Pilot Study

Background: Apolipoprotein J (ApoJ) is a component of plasma high-density lipoproteins. Previous studies have shown progressive recovery of ApoJ sialic acid content with increased duration of alcohol abstinence. Therefore, the sialic acid index of plasma apolipoprotein J (SIJ) seems to be a promising alcohol biomarker. Phosphatidylethanol (PEth) is a direct ethanol metabolite and has recently attracted attention as a biomarker of prolonged intake of higher amounts of alcohol. The aim of the pilot study was to explore sensitivity, specificity, and normalization of SIJ and PEth in comparison with traditional and emerging biomarkers. Methods: Five male alcohol-dependent patients (International Classification of Diseases 10, F 10.25) were included (median: 40 years old; Alcohol Use Disorders Identification Test value, 30; alcohol consumption in the previous 7 days, 1,680 g). SIJ, PEth, urinary ethyl glucuronide (UEtG), urinary ethyl sulfate (UEtS), and gamma glutamyl-transpeptidase (GGT) were determined at days 1, 3, 7, 10, 14, 21, and 28. Results: At study entry, SIJ, PEth, UEtG, and UEtS were positive in all subjects, whereas GGT and mean corpuscular volume were positive in 3 of 5 (60%) of the subjects. Individual SIJ levels increased between day 1 and 28 between 13.7 and 44.3%, respectively. For SIJ and PEth, the ANOVA (p < 0.005) showed a significant trend with the average subject's SIJ and PEth changing 1.22 and 1.02, respectively, per week. Conclusions: Our preliminary data suggest that SIJ and PEth might hold potential as markers of heavy ethanol intake.