Phosphatidylethanol (PEth) in blood samples from “driving under the influence” cases as indicator for prolonged excessive alcohol consumption

Abstract

Phosphatidylethanol (PEth) is considered as specific biomarker of alcohol consumption. Due to accumulation after repeated drinking, PEth is suitable to monitor long-term drinking behavior. To examine the applicability of PEth in "driving under the influence of alcohol" cases, 142 blood samples with blood alcohol concentrations (BAC) ranging from 0.0-3.12‰ were analyzed for the presence of PEth homologues 16:0/18:1 (889 ± 878 ng/mL; range <LOQ to 5400 ng/mL) and 16:0/18:2 (355 ± 315 ng/mL; range <LOQ to 1440 ng/mL) by LC-MS/MS. With receiver operating characteristic analysis, PEth thresholds were evaluated to differentiate moderate and excessive alcohol consumption with acceptable sensitivity and specificity in accordance with the 1.6‰ BAC limit. With a threshold of 700 ng/mL for PEth 16:0/18:1, prolonged excessive alcohol consumption was detected in 65.9% of drunk drivers with a BAC ≥ 1.6‰ and in 31.6% of the samples with a BAC < 1.6‰. Similar results were obtained for PEth 16:0/18:2 with a threshold of 300 ng/mL. Both criteria, PEth 16:0/18:1 and PEth 16:0/18:2, were conform in the evaluation of drinking habits in 88.7% of blood samples. These results show the possibility to detect prolonged excessive alcohol consumption, even if the BAC is below the legal threshold of 1.6‰ for driving aptitude assessment. As a consequence, concentrations of PEth 16:0/18:1 ≥ 700 ng/mL and of PEth 16:0/18:2 ≥ 300 ng/mL may be considered as indicators for the necessity of driving aptitude assessment in addition to BAC.

Application of phosphatidylethanol (PEth) in whole blood in comparison to ethyl glucuronide in hair (hEtG) in driving aptitude assessment (DAA)

“…In Switzerland, administrative regulations require a driving aptitude assessment (DAA) for convicted driving under the influence (DUI) of alcohol offenders having a blood alcohol concentration of 1.6 ‰ and higher, as prolonged excessive alcohol misuse is suspected above this limit [1,2]. In consequence of a DUI of alcohol offence, the driver's license is revoked.…”

Metabolomics in the Context of Forensic Omics Biomarkers

“…Furthermore, in North America, indirect parameters of ethanol consumption are not systematically applicable according to the law [52]. This situation is a consequence of the low specificity and sensitivity of indirect biomarkers, as commented in the introduction section [8], since they can be affected by factors different from alcohol consumption. Examples of indirect biomarkers are carbohydrate deficient transferrin, γ-glutamyl transpeptidase, aspartate transferase, alanine transferase, mean corpuscular volume of the erythrocytes, and even serotonin metabolites such as 5-hydroxytryptophol, which allow consumption detection in body fluids (mainly in blood) providing different type of information.…”

“…An example is found in biomarkers of alcohol consumption, which can reveal recent alcohol exposure or a prolonged risk of alcohol consumption.Among the latter are carbohydrate deficient transferrin, γ-glutamyltranspeptidase and phosphatidylethanol. The last is present in the body only after alcohol intake, while the first two are influenced by factors different from alcohol intake such as sex, age and smoking habit, among others [8]. Therefore, in order to obtain a more complete and unequivocal information multiple biomarkers should be used.…”

“…Direct biomarkers of alcohol consumption --e.g., blood alcohol concentration (BAC), ethyl glucuronide (EtG), ethyl sulfate (EtS), phosphatidylethanol (PEth) -have also been widely investigated [8]. Figure 1 schematizes the oxidative and no oxidative pathways OPEN ACCESS http://scidoc.org/IJFP.php of ethanol metabolism and formation of the biomarkers from it [51].…”

“…Countless are also metabolomics biomarkers of drug intake (including alcohol), clearly based on the determination of metabolites from the drug found in samples as varied as hair [40], blood [8], urine [36], saliva [48], human breath [49] or sweat [50].…”