Non-oxidative ethanol metabolites as a measure of alcohol intake

Evaluation of harmful drinking among professional drivers by direct ethanol biomarkers and its relation with psychological distress

OBJECTIVE

This study aimed to evaluate the alcohol consumption among professional truck and bus drivers using direct ethanol biomarkers, and to explore its relationship with anxiety, depression, and stress.

METHODS

The assessment of potential harmful drinking was conducted through the measurement of direct biomarkers: phosphatidylethanol (PEth), ethyl glucuronide (EtG), and ethyl sulfate (EtS), using dried blood spots (DBS). Additionally, self-reported data from the Alcohol Use Disorders Identification Test (AUDIT-C) were used. Emotional states, including depression, anxiety, and stress, were evaluated using the Depression, Anxiety, and Stress Scale (DASS-21).

RESULTS

A total of 97 drivers participated in the study, with the majority being male (96%) and identified as truck drivers (75.3%). Among them, 43.3% reported working more than 10 h daily. The majority of volunteers exhibited normal levels of stress (81.4%), anxiety (83%), and depression (86.6%). According to the AUDIT-C assessment, 30.9% were categorized as having a moderate risk, while 11.3% were deemed to be at high risk for harmful alcohol consumption behavior. Ethyl glucuronide (EtG) and ethyl sulfate (EtS) levels, indicating recent ethanol consumption, were detected in 14.4% of the drivers. In contrast, the long half-life metabolite PEth (16:0-18:1) was present in 88.7% of the volunteers. A moderate correlation (rs = 0.45, p < .01) was observed between PEth levels and AUDIT-C scores. The Receiver Operating Characteristic (ROC) curve, utilizing a PEth threshold of ≥ 59.0 ng ml-1, displayed 78% sensitivity and 73% specificity in effectively distinguishing high risk for alcohol intake. Notably, no significant associations were found between alcohol consumption and levels of stress, depression, and anxiety.

CONCLUSIONS

The study findings indicate a noteworthy proportion of drivers engaging in regular alcohol consumption alongside a demanding workload. Notably, PEth measurements highlighted an underreporting within the AUDIT-C self-reports. These results lend robust support for the utilization of biomarkers in assessing alcohol consumption patterns among drivers.

[Problems of ethyl glucuronide use in ethanol consumption diagnosis]

Quantitative determination of ethyl glucuronide (EtG) in different biological objects in recent years has been positioned as one of the most reliable biomarkers of unconditional alcohol consumption. The aim of the study is to summarize the analytical methods of alcohol consumption testing with the use of EtG currently available in domestic and foreign literature and to present a schematic overview of possible errors in reproducibility and interpretation of research on EtG results, which may limit their use in forensic medical practice. The main objective is to increase the reliability and validity of EtG as a marker of ethanol consumption.

Insights of mitochondrial involvement in alcoholic fatty liver disease

Alcoholic liver disease (ALD) is a global concern affecting most of the population and leading to the development of end-stage liver disease. Metabolic alterations due to increased alcohol consumption surge the hepatic accumulation of lipids and develop into a severe form of alcoholic steatohepatitis (ASH), depending on age and the consumption rate. The mitochondria in the hepatocyte actively regulate metabolic homeostasis and are disrupted in ALD pathogenesis. The increased NADH upon ethanol metabolism inhibits the mitochondrial oxidation of fatty acids, alters oxidative phosphorylation, and favors de novo lipogenesis. The higher mitochondrial respiration in early ALD increases free radical generation, whereas mitochondrial respiration is uncoupled in chronic ALD, affecting the cellular energy status. The defective glutathione importer due to excessive cholesterol loading and low adenosine triphosphate accounts for additional oxidative stress leading to hepatocyte apoptosis. The defective mitochondrial transcription machinery and sirtuins function in ALD affect mitochondrial function and biogenesis. The metabolites of ethanol metabolism epigenetically alter the gene expression profile of hepatic cell populations by modulating the promoters and sirtuins, aiding hepatic fibrosis and inflammation. The defect in mitophagy increases the accumulation of megamitochondria in hepatocytes and attracts immune cells by releasing mitochondrial damage-associated molecular patterns to initiate hepatic inflammation and ASH progression. Thus, maintaining mitochondrial lipid homeostasis and antioxidant capacity pharmacologically could provide a better outcome for ALD management.

Tumor progression locus 2 (TPL2): A Cot-plicated progression from inflammation to chronic liver disease

The cytoplasmic protein tumor progression locus 2 (TPL2), also known as cancer Osaka thyroid (Cot), or MAP3K8, is thought to have a significant role in a variety of cancers and illnesses and it is a key component in the activation pathway for the expression of inflammatory mediators. Despite the tight connection between inflammation and TPL2, its function has not been extensively studied in chronic liver disease (CLD), a major cause of morbidity and mortality worldwide. Here, we analyze more in detail the significance of TPL2 in CLD to shed light on the pathological and molecular transduction pattern of TPL2 during the progression of CLD. This might result in important advancements and enable progress in the diagnosis and treatment of CLD.

Determination of Ethyl Glucuronide and Ethyl Sulfate in Dried Blood Spots by UHPLC-MS-MS: Method Validation and Assessment of Ethanol Exposure in Postmortem Samples from Road Traffic Victims

The determination of ethyl glucuronide (EtG) and ethyl sulfate (EtS) in blood has been proposed in clinical and forensic applications to identify recent alcohol consumption. Also, there is a growing interest on the use of dried blood spots (DBS) in toxicological analysis, allowing increased stability of the analytes and simplifying sample transportation and storage. This study presents the development and validation of a method for quantifying EtG and EtS in DBS using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS). The DBS samples were extracted with a mixture of methanol and acetonitrile (80:20 v/v) and analyzed using UHPLC-MS-MS with electrospray source in negative mode, after separation with a fluoro-phenyl stationary phase. Validation was performed according to the Scientific Working Group for Forensic Toxicology (SWGTOX) guidelines, with calibrations ranging from 0.10 to 18 µg/mL for EtG and 0.02 to 6 µg/mL for EtS. The analytes were stable in DBS stored from -20 to 45°C for 21 days. The method was successfully applied to capillary and venous DBS samples from 20 volunteers after ethanol ingestion and to DBS samples from 99 fatal victims of road traffic injuries. Capillary DBS was comparable to venous DBS and fresh whole blood in Passing-Bablok and Bland-Altman analysis, with correlation coefficients >0.91 (P < 0.001) for all comparisons. In postmortem application, the DBS EtG and EtS analysis indicated positive exposure to ethanol in 72.7% of the cases (EtG: 0.10-24.0 µg/mL and EtS: 0.03-4.11 µg/mL). The identification of ethanol consumption from blood alcohol concentrations (BACs) and EtG/EtS in DBS was in agreement in 98.6% of positive and 96.3% of negative cases (kappa 0.877, P < 0.001), indicating a high level of concordance with BAC in assessing alcohol use in postmortem samples.

MyD88 in hepatic stellate cells promotes the development of alcoholic fatty liver via the AKT pathway

Myeloid differentiation primary response gene 88 (MyD88), an adaptor protein in the Toll-like receptors (TLRs) signalling pathway, is expressed in various liver cells including hepatocytes, Kupffer cells and hepatic stellate cells (HSCs). And yet, the functional role of MyD88 in HSCs is poorly elucidated in alcoholic fatty liver (AFL). Here, to study the functional role of MyD88 in HSCs and the molecular mechanism related to the development of AFL, chronic-binge ethanol mouse models were established in mice with specific MyD88 knockout in quiescent (MyD88^GFAP-KO) and activated HSCs (MyD88^SMA-KO), respectively. Our results clearly showed an elevated expression of MyD88 in liver tissues of ethanol treated mouse model which harbours the wild type. Intriguingly, ethanol treatment profoundly inhibited inflammation in both MyD88^GFAP-KO and MyD88^SMA-KO mice, but the suppression of lipogenesis was only observed in MyD88^GFAP-KO mice. Molecularly, our study indicated that MyD88 induced osteopontin (OPN) secretion in HSCs, which consequently resulted in activation of AKT signalling pathway and accumulation of fat in hepatocytes. Additionally, our data also suggested that OPN promoted inflammation by activating p-STAT1. Thus, targeting MyD88 may be a potentially represent a promising strategy for the prevention and treatment of AFL. KEY MESSAGES: The expression of MyD88 in HSCs was significantly increased in ethanol-induced liver tissues of wild-type mice. MyD88 deficiency in quiescent HSCs inhibited inflammation and lipogenesis under the ethanol feeding condition. MyD88 deficiency in activated HSCs only inhibited inflammation under the ethanol feeding condition. MyD88 promoted the OPN secretion of HSCs, which further activated the AKT signalling pathway of hepatocytes and upregulated lipogenic gene expression to promote fat accumulation. OPN also promotes inflammation by activating p-STAT1.

Alcoholic liver disease: a new insight into the pathogenesis of liver disease

Excessive alcohol consumption contributes to a broad clinical spectrum of liver diseases, from simple steatosis to end-stage hepatocellular carcinoma. The liver is the primary organ that metabolizes ingested alcohol and is exquisitely sensitive to alcohol intake. Alcohol metabolism is classified into two pathways: oxidative and non-oxidative alcohol metabolism. Both oxidative and non-oxidative alcohol metabolisms and their metabolites have toxic consequences for multiple organs, including the liver, adipose tissue, intestine, and pancreas. Although many studies have focused on the effects of oxidative alcohol metabolites on liver damage, the importance of non-oxidative alcohol metabolites in cellular damage has also been discovered. Furthermore, extrahepatic alcohol effects are crucial for providing additional information necessary for the progression of alcoholic liver disease. Therefore, studying the effects of alcohol-producing metabolites and interorgan crosstalk between the liver and peripheral organs that express ethanol-metabolizing enzymes will facilitate a comprehensive understanding of the pathogenesis of alcoholic liver disease. This review focuses on alcohol-metabolite-associated hepatotoxicity due to oxidative and non-oxidative alcohol metabolites and the role of interorgan crosstalk in alcoholic liver disease pathogenesis.

The Application of Metabolomics in Forensic Science with Focus on Forensic Toxicology and Time-of-Death Estimation

Recently, the diagnostic methods used by scientists in forensic examinations have enormously expanded. Metabolomics provides an important contribution to analytical method development. The main purpose of this review was to investigate and summarize the most recent applications of metabolomics in forensic science. The primary research method was an extensive review of available international literature in PubMed. The keywords “forensic” and “metabolomics” were used as search criteria for the PubMed database scan. Most authors emphasized the analysis of different biological sample types using chromatography methods. The presented review is a summary of recently published implementations of metabolomics in forensic science and types of biological material used and techniques applied. Possible opportunities for valuable metabolomics’ applications are discussed to emphasize the essential necessities resulting in numerous nontargeted metabolomics’ assays.

Pathophysiological Aspects of Alcohol Metabolism in the Liver

Alcoholic liver disease (ALD) is a globally prevalent chronic liver disease caused by chronic or binge consumption of alcohol. The liver is the major organ that metabolizes alcohol; therefore, it is particularly sensitive to alcohol intake. Metabolites and byproducts generated during alcohol metabolism cause liver damage, leading to ALD via several mechanisms, such as impairing lipid metabolism, intensifying inflammatory reactions, and inducing fibrosis. Despite the severity of ALD, the development of novel treatments has been hampered by the lack of animal models that fully mimic human ALD. To overcome the current limitations of ALD studies and therapy development, it is necessary to understand the molecular mechanisms underlying alcohol-induced liver injury. Hence, to provide insights into the progression of ALD, this review examines previous studies conducted on alcohol metabolism in the liver. There is a particular focus on the occurrence of ALD caused by hepatotoxicity originating from alcohol metabolism.

Consistency between self-reported alcohol consumption and biological markers among patients with alcohol use disorder - A systematic review

BACKGROUND

No systematic review has yet examined the consistency between self-reports of alcohol consumption and alcohol biomarkers among patients in treatment for alcohol use disorders (AUD). Therefore, we aimed to provide an overview of the consistency between self-reported alcohol intake and biomarkers among patients in treatment for AUD.

METHODS

The electronical databases MEDLINE, PsycINFO, EMBASE, Cochrane Database of Systematic Reviews (CDSR) and CENTRAL were searched for all original studies that examined the validity of self-reported alcohol consumption using a biological marker in samples of patients with AUD. Eligible studies were included in a qualitative synthesis of the outcomes. Quality assessment was conducted with the quality assessment tool for Observational Cohort and Cross-sectional studies, developed by The National Heart, Lung and Blood Institute.

RESULTS

The search identified 7672 hits, and 11 papers comprising 13 eligible studies were included. All the identified studies revealed inconsistencies between self-reporting and biomarkers. Under-reporting was the most common type of inconsistency across short-, intermediate- and long-term biomarkers. For short-term markers, under-reporting was indicated in 7 studies (n = 15-585) in a range from 5.5%-56.0% of the patients, and over-reporting in 2 studies (n = 34-65) in a range from 5.9%-74.1%. Only under-reporting was reported for intermediate-term, direct markers and was indicated in 2 studies (n = 18-54) in a range from 5.0%-50.0% of the patients. Although the results for long-term biomarkers were not reported consistently across the studies, under-reporting was indicated in 3 studies (n = 73-1580) in a range from 0.1%-40.0% of the patients, and over-reporting in 2 studies (n = 15-1580) in a range from 13.0%-70.6%. Correlations between self-reported alcohol consumption and biological markers were strongest for the intermediate-term direct markers, ranging from moderate to strong. For short-term and long-term markers, the correlations were mostly weak. Most of the studies were quality rated as fair.

CONCLUSION

The findings indicate that inconsistency between self-reported alcohol consumption and biomarkers may occur in a considerable proportion of patients with AUD. However, further studies applying more sensitive, specific, and easily assessable biological markers are warranted to confirm this preliminary synthesis. PROSPERO registration no.: CRD42018105308.

Evaluation and review of ways to differentiate sources of ethanol in postmortem blood

Accurate determination of a person's blood alcohol concentration (BAC) is an important task in forensic toxicology laboratories because of the existence of statutory limits for driving a motor vehicle and workplace alcohol testing regulations. However, making a correct interpretation of the BAC determined in postmortem (PM) specimens is complicated, owing to the possibility that ethanol was produced in the body after death by the action of various micro-organisms (e.g., Candida species) and fermentation processes. This article reviews various ways to establish the source of ethanol in PM blood, including collection and analysis of alternative specimens (e.g., bile, vitreous humor (VH), and bladder urine), the identification of non-oxidative metabolites of ethanol, ethyl glucuronide (EtG) and ethyl sulfate (EtS), the urinary metabolites of serotonin (5-HTOL/5-HIAA), and identification of n-propanol and n-butanol in blood, which are known putrefaction products. Practical utility of the various biomarkers including specificity and stability is discussed.

An LC-MS/MS method for comparing the stability of ethanol's non-oxidative metabolites in dried blood spots during 90 days

Problems of stability were found for biomarkers of alcohol consumption: ethyl glucuronide (EtG), ethyl sulfate (EtS), phosphatidylethanols (PEths), and fatty acid ethyl esters (FAEEs) in whole blood. The purpose of this study was to establish a method for the determination of these four kinds of ethanol's non-oxidative metabolites in dried blood spots (DBS) by liquid chromatography tandem mass spectrometry (LC-MS/MS), and to evaluate their stability. In this method, 50 μL of human blood was spotted onto a filter paper for DBS analysis. Samples were extracted by methanol, reconstituted by 2-propanol, and injected into the LC-MS/MS system. Limits of detection were among 0.5-50 ng/mL, and deviations in accuracy and precision were all lower than 15% at three quality control levels. The stability of the four kinds of ethanol non-oxidative metabolites in DBS was investigated during a 90-day range under three temperatures, -20 °C, 4 °C, and 25 °C. EtG and EtS showed a high level of stability in DBS in the 90-day range, regardless of the temperature. FAEEs were unstable after three days. PEths showed stability within 15 days in postmortem DBS and 60 days in antemortem DBS, respectively, at all temperatures.

Fully Automated Determination of Phosphatidylethanol 16:0/18:1 and 16:0/18:2 in Dried Blood Spots

Purpose

Direct alcohol markers are widely applied during abstinence monitoring, driving aptitude assessments and workplace drug testing. The most promising direct alcohol marker was found to be phosphatidylethanol (PEth). Compared to other markers it shows a long window of detection due to accumulation in blood. To facilitate and accelerate the determination of PEth in DBS, we developed a fully automated analysis approach.

Methods

The validated and novel online-SPE-LC-MS/MS method with automated sample preparation using a CAMAG DBS-MS 500 system reduces manual sample preparation to an absolute minimum, only requiring calibration and quality control DBS.

Results

During the validation process, the method showed a high extraction efficiency (>88%), linearity (correlation coefficient >0.9953), accuracy and precision (within ±15%) for the determination of PEth 16:0/18:1 and PEth 16:0/18:2. Within a run time of about 7 min, the two monitored analogs could be baseline separated. A method comparison in liquid whole blood of 28 authentic samples from alcohol use disorder patients showed a mean deviation of less than 2% and a correlation coefficient of >0.9759. The comparison with manual DBS extraction showed a mean deviation of less than 8% and a correlation coefficient of >0.9666.

Conclusions

The automated analysis of PEth in DBS can provide a fast and accurate solution for abstinence monitoring. In contrast to the manual extraction of PEth in DBS, no laborious sample preparation is required with this automated approach. Furthermore, the application of the internal standard by a spray module can compensate for extraction bias and matrix effects.

Biomarkers of Alcohol Consumption in Body Fluids - Possibilities and Limitations of Application in Toxicological Analysis

BACKGROUND

Ethyl alcohol is the most popular legal drug, but its excessive consumption causes social problems. Despite many public campaigns against alcohol use, car accidents, instances of aggressive behaviour, sexual assaults and deterioration in labor productivity caused by inebriated people is still commonplace. Fast and easy diagnosis of alcohol consumption is required in order to introduce proper and effective therapy, and is crucial in forensic toxicology analysis. The easiest method to prove alcohol intake is determination of ethanol in body fluids or in breath. However, since ethanol is rapidly metabolized in the human organism, only recent consumption can be detected using this method. Because of that, the determination of alcohol biomarkers was introduced for monitoring alcohol consumption over a wider range of time.

OBJECTIVE

The objective of this study was to review published studies focusing on the sample preparation methods and chromatographic or biochemical techniques for the determination of alcohol biomarkers in whole blood, plasma, serum and urine.

METHODS

An electronic literature search was performed to discuss possibilities and limitations of application of alcohol biomarkers in toxicological analysis.

RESULTS

Authors described the markers of alcohol consumption such as: ethanol, its nonoxidative metabolites (ethyl glucuronide, ethyl sulfate, phosphatidylethanol, ethyl phosphate, fatty acid ethyl esters) and oxidative metabolites (acetaldehyde and acetaldehyde adducts). We also discussed issues concerning the detection window of these biomarkers, and possibilities and limitations of their use in routine analytical toxicology for monitoring alcohol consumption or sobriety during alcohol therapy.

Translating transdermal alcohol monitoring procedures for contingency management among adults recently arrested for DWI

Recent developments in alcohol monitoring devices have made it more feasible to use contingency management (CM) procedures to reduce alcohol use. A growing body of literature is demonstrating the effectiveness of CM to reduce alcohol use among community recruited adults wearing transdermal alcohol concentration (TAC) monitoring devices. This article describes the quality improvement process aimed at adapting TAC-informed CM aimed at minimizing alcohol use and maximizing treatment completion. This extends literature to a high-risk population; adults arrested and awaiting trial (pretrial) for criminal charge of driving while intoxicated (DWI). Participants were enrolled during their orientation to pretrial supervision conditions of DWI bond release. At enrollment, participants completed a screening, brief intervention, and referral to treatment; those with high risk alcohol histories were enrolled in an 8-week CM procedure to avoid TAC readings. Four Plan-Do-Study-Act (PDSA) quality improvement cycles were conducted where the TAC cutoff for determining alcohol use, the quantity of reinforcer, and handling of tampers on the transdermal alcohol monitor were manipulated. Across four PDSA cycles, the retention for the full 8-weeks of treatment was increased. The proportion of weeks with alcohol use was not decreased across cycles, the peak TAC values observed during drinking weeks were significantly lower in Cycles 1 and 4 than 3. CM may be developed as a tool for pretrial supervision to be used to increase bond compliance of those arrested for DWI and for others as a method to identify the need for additional judicial services.

Monitoring wastewater for assessing community health: Sewage Chemical-Information Mining (SCIM)

Timely assessment of the aggregate health of small-area human populations is essential for guiding the optimal investment of resources needed for preventing, avoiding, controlling, or mitigating human exposure risks, as well as for maintaining or promoting health. Seeking those interventions yielding the greatest benefit with respect to the allocation of resources is critical for making progress toward community sustainability, reducing health disparities, promoting social justice, and maintaining or improving collective health and well-being. More informative, faster, and less-costly approaches are needed for guiding investigation of cause-effect linkages involving communities and stressors originating from both the built and natural environments. One such emerging approach involves the continuous monitoring of sewage for chemicals that serve as indicators of the collective status of human health (or stress/disease) or any other facet relevant to gauging time-trends in community-wide health. This nascent approach can be referred to as Sewage Chemical-Information Mining (SCIM) and involves the monitoring of sewage for the information that resides in the form of natural and anthropogenic chemicals that enter sewers as a result of the everyday actions, activities, and behaviors of humans. Of particular interest is a specific embodiment of SCIM that would entail the targeted monitoring of a broad suite of endogenous biomarkers of key physiologic processes (as opposed to xenobiotics or their metabolites). This application is termed BioSCIM-an approach roughly analogous to a hypothetical community-wide collective clinical urinalysis, or to a hypothetical en masse human biomonitoring program. BioSCIM would be used for gauging the status or time-trends in community-wide health on a continuous basis. This paper presents an update on the progress made with the development of the BioSCIM concept in the period of time since its original publication in 2012, as well as the next steps required for its continued development.

Monitoring people at risk of drinking by a rapid urinary ethyl glucuronide test

Alcohol and illicit drug abuse are major public health problems worldwide. Since alcohol is the predominant substance of choice in polydrug abusers, monitoring its use, along with urinary drug screening in patients in rehabilitation programs, appeared to be crucial in identifying patients at risk of alcohol disorders leading to impaired quality of life. Ethyl β-D-6-glucuronide, a non-oxidative, non-volatile, stable and minor direct ethanol metabolite, has a 6h to 4 day window of detection in urine after the last alcohol intake. Each of the 119 subjects (85 males, 34 females) registered with the Public Health Service for Drug Dependence Treatment provided a urine sample for ethylglucoronide (EtG) determination in an immunochemical test with a 500 ng/ml cutoff. All results were evaluated with confirmation criteria of a fully validated gas chromatography/mass spectrometry assay. The diagnostic performance of the EtG immunochemical test was assessed using Receiver Operating Characteristic Curve analysis. The immunochemical test specificity was 100% for EtG urinary values above 500 ng/ml. No false positive results were found. With levels below 500 ng/ml, 12% of the samples were classified as negative. The average consumption of the incorrectly classified subjects was 171 ng/ml, with a misclassification error of 6.5% to 18.5%. High agreement between EtG as determined in an immunochemical test and gas chromatography/mass spectrometry, suggests that the rapid EtG test is a reliable, cost-effective alcohol monitoring assay for patient management in many non-forensic settings, such as drug rehabilitation programs.

Infrared analysis of lipoproteins in the detection of alcohol biomarkers

Background:

Alcoholism is a major public health problem. Alcohol causes modifications in the composition and concentration of lipoproteins and influences the enzymes and transfer proteins that transform lipoproteins in plasma. Alcohol is associated with the presence of alcohol biomarkers (fatty acid ethyl esters [FAEEs] and phosphatidylethanol [PEth]) in lipoproteins. We explore the possibilities of detecting alcohol biomarkers in non-high-density-lipoproteins (non-HDLs) precipitated from serum using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR).

Methods:

Analyzes were carried out on stored serum samples, with known % carbohydrate-deficient transferrin (CDT) values, included in a driver’s license regranting program under the control of the Belgian Institute of Road Safety. The study consisted of 127 control samples (CDT≤1.3%) and 114 alcoholic samples (CDT>1.3%). Liver enzymes, CRP, triglycerides, total, HDL- and LDL-cholesterol values were determined. Non-HDLs were precipitated with sodium phosphotungstate and MgCl2 and analyzed using ATR-FTIR in the range from 4500 cm−1 to 450 cm−1 using a Perkin Elmer ATR-FTIR Spectrometer Two.

Results:

The area under the curve of the 1130–990 cm−1 region (AUC1130−990 cm−1) was able to discriminate controls from alcoholics (p<0.0001) due to the presence of FAEEs in lipoproteins. Multiple regression analysis significantly predicted the AUC1130−990 cm−1 (adj. r2=0.13, p<0.0001). Significant correlations were found between AUC1130−990 cm−1 and CDT values (r=0.32, p<0.0001), AST/ALT ratio (r=0.21, p=0.001). GGT showed no significant correlation.

Conclusions:

Infrared analysis of lipoproteins is a potential tool in the detection of alcohol biomarkers.

Continuous minimally-invasive alcohol monitoring using microneedle sensor arrays

The present work describes an attractive skin-worn microneedle sensing device for the minimally invasive electrochemical monitoring of subcutaneous alcohol. The device consists of an assembly of pyramidal microneedle structures integrated with Pt and Ag wires, each with a microcavity opening. The microneedle aperture was modified by electropolymerizing o-phenylene diamine onto the Pt wire microtransducer, followed by the immobilization of alcohol oxidase (AOx) in an intermediate chitosan layer, along with an outer Nafion layer. The resulting microneedle-based enzyme electrode displays an interference-free ethanol detection in artificial interstitial fluid without compromising its sensitivity, stability and response time. The skin penetration ability and the efficaciousness of the biosensor performance towards subcutaneous alcohol monitoring was substantiated by the ex vivo mice skin model analysis. Our results reveal that the new microneedle sensor holds considerable promise for continuous non-invasive alcohol monitoring in real-life situations.

Alternative sampling strategies for the assessment of alcohol intake of living persons

Monitoring of alcohol consumption by living persons takes place in various contexts, amongst which workplace drug testing, driving under the influence of alcohol, driving licence regranting programs, alcohol withdrawal treatment, diagnosis of acute intoxication or fetal alcohol ingestion. The matrices that are mostly used today include blood, breath and urine. The aim of this review is to present alternative sampling strategies that allow monitoring of the alcohol consumption in living subjects. Ethanol itself, indirect (carbohydrate deficient transferrin, CDT%) as well as direct biomarkers (ethyl glucuronide, EtG; ethyl sulphate, EtS; fatty acid ethyl esters, FAEEs and phosphatidylethanol species, PEths) of ethanol consumption will be considered. This review covers dried blood spots (CDT%, EtG/EtS, PEths), dried urine spots (EtG/EtS), sweat and skin surface lipids (ethanol, EtG, FAEEs), oral fluid (ethanol, EtG), exhaled breath (PEths), hair (EtG, FAEEs), nail (EtG), meconium (EtG/EtS, FAEEs), umbilical cord and placenta (EtG/EtS and PEth 16:0/18:1). Main results, issues and considerations specific to each matrix are reported. Details about sample preparation and analytical methods are not within the scope of this review.

Characterization of the Pharmacokinetics of Phosphatidylethanol 16:0/18:1 and 16:0/18:2 in Human Whole Blood After Alcohol Consumption in a Clinical Laboratory Study

BACKGROUND

The purpose of this study was to characterize the pharmacokinetics of 2 homologues of phosphatidylethanol (PEth) and their combined total in uncoagulated, whole blood samples taken from participants in a human clinical laboratory study after consumption of low doses of ethanol (EtOH).

METHODS

As part of a larger study, 14 male and 13 female participants received either 0.25 or 0.50 g/kg oral doses of EtOH during a 15-minute period. Blood samples were collected before and throughout 6 hours after each EtOH dose on the day of consumption and then every 3 days during the next 14 days. PEth 16:0/18:1 and PEth 16:0/18:2 levels were quantified in blood samples by HPLC/MS/MS and reported separately or as their combined total (combined PEth). Breath alcohol concentrations (BrACs) were measured concurrently with each blood collection. Transdermal alcohol concentrations were measured every 30 minutes during the entire 22-day study to confirm the absence of drinking during a 7-day period before and the 14-day period after EtOH consumption.

RESULTS

(i) Single doses of 0.25 and 0.50 g EtOH/kg produced proportional increases in BrAC and combined PEth levels of all participants; (ii) the areas under the curve (AUCs) for each participant's BrAC levels during the 6-hour period after EtOH administration were correlated with AUCs of cPEth (calculated as the AUC of the increase above baseline for combined PEth); (iii) the mean half-life of combined PEth, determined during the 14-day period after EtOH consumption, was 4.6 ± 3.5 (SD) days (range: 1.0 to 13.1 days).

CONCLUSIONS

Combined PEth is a sensitive biomarker for the identification of relatively low levels of EtOH consumption. The measurement of these 2 homologues may provide additional sensitivity to identify low levels of drinking.

Biomarkers for detection of alcohol consumption in liver transplantation

Alcoholic liver disease is an established, yet controversial, indication for liver transplantation. Although an abstinence period of up to 6 mo prior to transplantation is mandatory, alcohol relapse after transplantation is a common event. In case of recurrence of heavy drinking, graft survival is significantly impaired. Guidelines on detection and surveillance of alcohol consumption in this patient cohort are lacking. This review summarizes the challenge of patient selection as well as the current knowledge on established and novel alcohol biomarkers with special focus on liver transplant candidates and recipients.

Bioanalytical procedures and developments in the determination of alcohol biomarkers in biological specimens

Excessive alcohol consumption is a global problem, and consequently its evaluation is of great clinical and forensic interest. Alcohol biomarkers have been the focus of several research works in the past decades, with new compounds being studied in more recent years. The main objective of this review is to discuss topics for an analyst to consider when evaluating alcohol consumption through the analysis of alcohol biomarkers in biological specimens. For this, existing alcohol biomarkers will be reviewed, including carbohydrate-deficient transferrin, 5-hydroxytryptophol, ethanol, hemoglobin-associated acetaldehyde, fatty acid ethyl esters, ethyl glucuronide, ethyl sulfate and phosphatidylethanol. Additionally, their potential will be discussed, as well as analytical considerations, main challenges, limitations, data interpretation and existing methodologies for their determination in biological specimens.

Stability of Phosphatidylethanol in Dry Blood Spot Cards

BACKGROUND

The analysis of phosphatidylethanol, a promising direct ethanol metabolite, in dry blood spots (PEth-DBS) is advantageous due to ease of storage, transportation and minimal invasiveness of capillary blood collection. One potential application of PEth-DBS is to confirm prenatal alcohol exposure in newborns suspected of FASD; however, stability of PEth-DBS is largely unknown.

METHODS

Phlebotomized samples from 31 adults with a history of alcoholism, admitted to the University of New Mexico Emergency Department, were analyzed for blood alcohol content and pipetted onto DBS cards (13 spots per patient). The first spot was analyzed within 2 weeks of collection for a baseline PEth; the remaining 12 spots were allocated into three temperature conditions (room temperature, 4°C, -80°C) for the repeated measures analysis. In addition, 5 newborn DBS samples with a baseline PEth>LOD were obtained from a prospective cohort at UNM and re-analyzed at 4 months after storage at -80°C. A mixed linear model was fitted to examine the effects of temperature, time and temperature-time interaction on PEth degradation over the first 9 months.

RESULTS

The baseline PEth levels were 592.8 ± 86.7 ng/ml and 18.3 ± 4.8 ng/ml in adult and newborn samples, respectively. All DBS samples remained positive in successive samples in all temperature conditions. Results of mixed linear model demonstrated a significant effect of temperature (P < 0.001) on PEth degradation over 9 months.

CONCLUSIONS

PEth-DBS appears to be relatively stable, especially when stored at lower temperatures. These initial results are encouraging and highlight the PEth-DBS potential in retrospective assessment of alcohol exposure.

Ethyl Glucuronide Positivity Rate in a Pain Management Population

Ethanol may be consumed by some patients as a means to manage their pain or psychiatric disorder. Consequently, there is the potential to consider ethanol a co-therapeutic in pain management. The purpose of this study was to perform a retrospective analysis to evaluate the rate of ethanol use in a population of patients in pain management programs that were evaluated by our in-house pain management drug panel test. Results from this retrospective study showed that 12.6% of patients in a pain management population were positive for the direct ethanol metabolite, ethyl glucuronide (EtG), by immunoassay. Furthermore, 86% of the individuals positive for EtG were also positive for prescription pain medication and illicit drugs. Results presented here suggest that ethanol use should be routinely monitored in pain management populations in an effort to determine any potential adverse effects of ethanol-drug interactions and as a way to further evaluate the effect of ethanol on pain management outcomes. Testing this population of patients suggests that ethanol use is prevalent and the risk of drug-ethanol adverse effects should be monitored in a pain management population.

Biomolecules and Biomarkers Used in Diagnosis of Alcohol Drinking and in Monitoring Therapeutic Interventions

BACKGROUND

The quantitative, measurable detection of drinking is important for the successful treatment of alcohol misuse in transplantation of patients with alcohol disorders, people living with human immunodeficiency virus that need to adhere to medication, and special occupational hazard offenders, many of whom continually deny drinking. Their initial misconduct usually leads to medical problems associated with drinking, impulsive social behavior, and drunk driving. The accurate identification of alcohol consumption via biochemical tests contributes significantly to the monitoring of drinking behavior.

METHODS

A systematic review of the current methods used to measure biomarkers of alcohol consumption was conducted using PubMed and Google Scholar databases (2010-2015). The names of the tests have been identified. The methods and publications that correlate between the social instruments and the biochemical tests were further investigated. There is a clear need for assays standardization to ensure the use of these biochemical tests as routine biomarkers.

FINDINGS

Alcohol ingestion can be measured using a breath test. Because alcohol is rapidly eliminated from the circulation, the time for detection by this analysis is in the range of hours. Alcohol consumption can alternatively be detected by direct measurement of ethanol concentration in blood or urine. Several markers have been proposed to extend the interval and sensitivities of detection, including ethyl glucuronide and ethyl sulfate in urine, phosphatidylethanol in blood, and ethyl glucuronide and fatty acid ethyl esters in hair, among others. Moreover, there is a need to correlate the indirect biomarker carbohydrate deficient transferrin, which reflects longer lasting consumption of higher amounts of alcohol, with serum γ-glutamyl transpeptidase, another long term indirect biomarker that is routinely used and standardized in laboratory medicine.

Maternal and neonatal hair and breast milk in the assessment of perinatal exposure to drugs of abuse

Perinatal exposure to one or more drugs of abuse can affect the neonate temporarily or permanently. In addition to meconium, the evaluation of perinatal exposure to drugs of abuse has been achieved by testing biological matrices coming from the newborn (neonatal hair) and from the pregnant or nursing mother (maternal hair and breast milk). These matrices have the advantage of noninvasive collection and account for a sizable time window of active and passive exposure. Sensitive and specific analytical methods are required to determine minute amounts of drugs of abuse and metabolites in these matrices. The present manuscript reviews the newest analytical methods developed to detect drugs of abuse as well as ethanol biomarkers in maternal and neonatal hair and breast milk.

Transdermal alcohol concentration data collected during a contingency management program to reduce at-risk drinking

BACKGROUND

Recently, we demonstrated that transdermal alcohol monitors could be used in a contingency management procedure to reduce problematic drinking; the frequency of self-reported heavy/moderate drinking days decreased and days of no to low drinking increased. These effects persisted for three months after intervention. In the current report, we used the transdermal alcohol concentration (TAC) data collected prior to and during the contingency management procedure to provide a detailed characterization of objectively measured alcohol use.

METHODS

Drinkers (n=80) who frequently engaged in risky drinking behaviors were recruited and participated in three study phases: a 4-week Observation phase where participants drank as usual; a 12-week Contingency Management phase where participants received $50 each week when TAC did not exceed 0.03g/dl; and a 3-month Follow-up phase where self-reported alcohol consumption was monitored. Transdermal monitors were worn during the first two phases, where each week they recived $105 for visiting the clinic and wearing the monitor. Outcomes focused on using TAC data to objectively characterize drinking and were used to classify drinking levels as either no, low, moderate, or heavy drinking as a function of weeks and day of week.

RESULTS

Compared to the Observation phase, TAC data indicated that episodes of heavy drinking days during the Contingency Management phase were reduced and episodes of no drinking and low to moderate drinking increased.

CONCLUSIONS

These results lend further support for linking transdermal alcohol monitoring with contingency management interventions. Collectively, studies to date indicate that interventions like these may be useful for both abstinence and moderation-based programs.

Ethanol pharmacokinetics in neonates and infants

Introduction

Ethanol has been used for years in neonatal and infant liquid medications, yet the pharmacokinetics, pharmacodynamics, and safety of ethanol in this vulnerable population have not been well characterized. The purpose of this review is to raise awareness of ethanol use as an excipient in neonatal and infant medications and to provide insight, based on the available evidence, into clearance rates of ethanol in babies. We also discuss ethanol pharmacokinetics in adults, theoretical pharmacokinetic changes in neonates and infants as it may apply to ethanol disposition, and case reports involving ethanol exposure in neonates and infants.

Materials and methods

This study was a narrative review in which relevant papers were selected using databases and scientific search engines such as PubMed with the key words ethanol, infant, and newborninfant.

Results

It remains unclear what ethanol exposure is safe for neonates and infants. The Food and Drug Administration and American Academy of Pediatrics have both taken action, by either setting limits of ethanol content in over-the-counter medications or by recommending restricted exposure to ethanol-containing pediatric formulations.

Conclusions

Until the short- and long-term health effects of chronic ethanol administration can be further characterized, ethanol-containing medications should be used with caution.

Use of continuous transdermal alcohol monitoring during a contingency management procedure to reduce excessive alcohol use

BACKGROUND

Research on contingency management to treat excessive alcohol use is limited due to feasibility issues with monitoring adherence. This study examined the effectiveness of using transdermal alcohol monitoring as a continuous measure of alcohol use to implement financial contingencies to reduce heavy drinking.

METHODS

Twenty-six male and female drinkers (from 21 to 39 years old) were recruited from the community. Participants were randomly assigned to one of the two treatment sequences. Sequence 1 received 4 weeks of no financial contingency (i.e., $0) drinking followed by 4 weeks each of $25 and then $50 contingency management; Sequence 2 received 4 weeks of $25 contingency management followed by 4 weeks each of no contingency (i.e., $0) and then $50 contingency management. During the $25 and $50 contingency management conditions, participants were paid each week when the Secure Continuous Remote Alcohol Monitor (SCRAM-II™) identified no heavy drinking days.

RESULTS

Participants in both contingency management conditions had fewer drinking episodes and reduced frequencies of heavy drinking compared to the $0 condition. Participants randomized to Sequence 2 (receiving $25 contingency before the $0 condition) exhibited less frequent drinking and less heavy drinking in the $0 condition compared to participants from Sequence 1.

CONCLUSIONS

Transdermal alcohol monitoring can be used to implement contingency management programs to reduce excessive alcohol consumption.

Spot them in the spot: analysis of abused substances using dried blood spots

Dried blood spot (DBS) sampling and DBS analysis have increasingly received attention during recent years. Furthermore, a substantial number of DBS methods has recently become available in clinical, forensic and occupational toxicology. In this review, we provide an overview of the different DBS-based methods that have been developed for detecting (markers of) abused substances. These include both legal and illegal drugs belonging to different categories, including cannabinoids, cocaine and metabolites, opioids, benzodiazepines and Z-drugs, amphetamines and analogs, gamma-hydroxybutyric acid, ketamine and novel psychoactive substances such as cathinones. Markers of ethanol consumption and tobacco use are also covered in this review. Since the majority of published methods has shown promising results overall, an interesting role for DBS analysis in diverse toxicological applications can be envisaged. For the distinct applications, we discuss the specific potential and benefits of DBS, the associated limitations and challenges, as well as recent developments and future perspectives.

Quantification of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in meconium for detection of alcohol abuse during pregnancy: Correlation study between both biomarkers

This article presents results from 47 meconium samples, which were analyzed for fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) for detection of gestational alcohol consumption. A validated microwave assisted extraction (MAE) method in combination with GC-MS developed in the Institute of Forensic Science (Santiago de Compostela) was used for FAEE and the cumulative concentration of ethyl myristate, ethyl palmitate and ethyl stearate with a cut-off of 600ng/g was applied for interpretation. A simple method for identification and quantification of EtG has been evaluated by ultrasonication followed solid phase extraction (SPE). Successful validation parameters were obtained for both biochemical markers of alcohol intake. FAEE and EtG concentrations in meconium ranged between values lower than LOD and 32,892ng/g or 218ng/g respectively. We have analyzed FAEE and EtG in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. Certain agreement between the two biomarkers was found as they are both a very specific alcohol markers, making it a useful analysis for confirmation.

Role of mitochondria in alcoholic liver disease

Alcohol abuse is the leading cause of liver related morbidity and mortality. Chronic or binge alcohol drinking causes hepatic steatosis which can develop to steatohepatitis, cirrhosis and ultimately hepatocellular carcinoma. The pathogenesis of alcoholic liver disease (ALD) is poorly characterized, however several recent studies point to a major role of mitochondria in this process. Mitochondria play a crucial role in cellular energy metabolism and in reactive species formation. Alcohol treatment causes mitochondrial DNA damage, lipid accumulation and oxidative stress. Studies in both animal models and in humans showed that alcohol administration causes changes in the mitochondrial morphology and function suggesting a role of these changes in the pathogenesis of ALD. We review recent findings on mechanisms by which alcohol negatively impacts mitochondrial biogenesis and function and we will discuss the specific intracellular pathways affected by alcohol consumption. Interestingly, recent findings indicate that a large number of mitochondrial proteins are acetylated and that mitochondrial proteins acetylation and sirtuins are modulated by alcohol. Understanding the mechanisms behind alcohol mediated impaired mitochondrial biogenesis and function may help identify potential therapeutic targets for treating ALD in humans.

Usefulness of indirect alcohol biomarkers for predicting recidivism of drunk-driving among previously convicted drunk-driving offenders: results from the recidivism of alcohol-impaired driving (ROAD) study

AIM

In several European countries, drivers under the influence (DUI), suspected of chronic alcohol abuse are referred for medical and psychological examination. This study (the ROAD study, or Recidivism Of Alcohol-impaired Driving) investigated the usefulness of indirect alcohol biomarkers for predicting drunk-driving recidivism in previously convicted drunk-driving offenders.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

The ROAD study is a prospective study (2009-13) that was performed on 517 randomly selected drivers in Belgium. They were convicted for drunk-driving for which their licence was confiscated. The initial post-arrest blood samples were collected and analysed for percentage carbohydrate-deficient transferrin (%CDT), transaminsase activities [alanine amino transferase (ALT), aspartate amino transferase (AST)], gamma-glutamyltransferase (γGT) and red cell mean corpuscular volume (MCV). The observation time for each driver was 3 years and dynamic.

FINDINGS

A logistic regression analysis revealed that ln(%CDT) (P < 0.001), ln(γGT) (P < 0.01) and ln(ALT) (P < 0.05) were the best biochemical predictors of recidivism of drunk-driving. The ROAD index (which includes ln(%CDT), ln(γGT), -ln(ALT) and the sex of the driver) was calculated and had a significantly higher area under the receiver operator characteristic curve (0.71) than the individual biomarkers for drunk-driving recidivism. Drivers with a high risk of recidivating (ROAD index ≥ 25%; third tertile) could be distinguished from drivers with an intermediate risk (16% ≤ ROAD index < 25%; second tertile; P < 0.001) and a low recidivism risk (ROAD index < 16%; first tertile; P < 0.05).

CONCLUSIONS

Of all routinely used indirect alcohol markers, percentage of carbohydrate-deficient transferrin is the major predictor of recidivism of drunk-driving. The association with gamma-glutamyltransferase, alanine amino transferase and the sex of the driver could have additional value for identifying drunk-drivers at intermediate risk of recidivism. Non-specific indirect alcohol markers, such as alanine amino transferase, gamma-glutamyltransferase, aspartate amino transferase and red cell mean corpuscular volume have minimal added value to % carbohydrate-deficient transferrin for distinguishing drunk drivers with a low or high risk of recidivism.

Alcohol-medical drug interactions

Concomitant use of alcohol and medications may lead to potentially serious medical conditions. Increasing prescription medication abuse in today's society necessitates a deeper understanding of the mechanisms involved in alcohol-medication interactions in order to help prevent adverse events. Interactions of medications with alcohol result in altered bioavailability of the medication or alcohol (pharmacokinetic interactions) or modification of the effects at receptor or ion channel sites to alter behavioral or physical outcome (pharmacodynamic interactions). The nature of pharmacokinetic or pharmacodynamic interactions involved in alcohol-medication interactions may differ between acute and chronic alcohol use and be influenced by race, gender, or environmental or genetic factors. This review focuses on the mechanisms underlying pharmacokinetic and pharmacodynamic interactions between alcohol and medications and provides examples for such interactions from replicated research studies. In conclusion, further translational research is needed to address several gaps in our current knowledge of alcohol-medication interactions, including those under various pathologic conditions.

Hair ethyl glucuronide levels as a marker for alcohol use and abuse: a review of the current state of the art

BACKGROUND

Ethyl glucuronide (EtG) is a minor alcohol metabolite that has been proposed as a stable marker in hair to detect and quantify alcohol consumption over long time periods.

METHODS

We provide an outline of currently available techniques for EtG hair sample analysis and highlight the pitfalls related to data interpretation. The literature of EtG analysis has been reviewed from January 1980 up to August 2013. In addition, we present an overview of the clinical and forensic studies which have used EtG quantification in hair as a marker for alcohol consumption/abstinence and we provide suggestions for future research.

RESULTS

EtG is a stable marker in hair that can be used to detect and quantify alcohol consumption over long time periods. This alcohol metabolite remains in hair after complete elimination of alcohol. Currently, there are three main analytical techniques used to quantify EtG in hair: gas chromatography-mass spectrometry (GC-MS), gas chromatography-tandem mass spectrometry (GC-MS/MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). No standardized protocols are yet available for the analysis of EtG levels in hair samples, and the current protocols vary in sample preparation and extraction procedures. Variables such as hair length, cosmetic treatment, gender, and pathophysiological conditions influence the final results and should be taken into account.

CONCLUSIONS

EtG quantification in hair is a useful tool for the objective detection of alcohol consumption over extended time periods, but care should be taken when interpreting the results.