Ethyl glucuronide

Confirmation of ethanol administration in racing greyhounds by LC-MS-MS

Ethanol is a prohibited substance in professional animal racing as its administration causes physiological effects such as depression of the central nervous system. Regulation of potential doping agents, including those that inhibit performance, is critical to ensure integrity and animal welfare in greyhound racing, but the detection of ethanol is complicated by dietary and/or environmental exposure. In response, a reliable analytical method capable of detecting recent ethanol administration in greyhound urine samples was validated and implemented. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) was used to investigate the variation in urinary ethanol metabolites; ethyl-β-D glucuronide (EG;γ ¯ EG $$ {\overline{\gamma}}_{\mathrm{EG}} $$  = 1.0 μg/ml,s EG $$ {s}_{\mathrm{EG}} $$  = 3.3 μg/ml) and ethyl sulfate (ES;γ ¯ ES $$ {\overline{\gamma}}_{\mathrm{ES}} $$  = 0.9 μg/ml,s ES $$ {s}_{\mathrm{ES}} $$  = 1.9 μg/ml) levels from a reference population of 202 racing greyhounds. These were compared to urine samples collected following administration of ethanol to one male and one female greyhound. Results were used to establish a threshold within the national rules of greyhound racing:γ ¯ EG $$ {\overline{\gamma}}_{\mathrm{EG}} $$ andγ ¯ ES $$ {\overline{\gamma}}_{\mathrm{ES}} $$  > 20 μg/ml in urine are defensible criteria to confirm ethanol administration to greyhounds. Case studies of competition samples are provided to demonstrate the forensic translation of this work.

Elimination of matrix effects in urine for determination of ethyl glucuronide by liquid chromatography-tandem mass spectrometry

RATIONALE

Alcohol use disorder affects 4% to 5% of the world's population. Analysis methods are available for various biological fluids to detect this disorder. Determination of ethyl glucuronide in urine by the liquid chromatography-tandem mass spectrometry (LC/MS/MS) method is frequently used in forensic toxicology. These analyses are known to cause matrix effects.

METHODS

The presented study describes the elimination of matrix effects for ethyl glucuronide. This study used two different LC/MS/MS systems containing orthogonal and z-spray ion sources. Ethyl glucuronide was analyzed in negative polarity in electrospray ionization. A different dilution method was chosen for each study. The methods were developed and validated according to the European Medicines Agency bioanalytical method validation parameters.

RESULTS

The lower limit of quantitation of the developed methods was 0.025 μg/mL for ethyl glucuronide. The calibration curve of ethyl glucuronide was between 0.025 and 100 μg/mL with a correlation coefficient of >0.99 for the two methods.

CONCLUSIONS

It was determined that the analyses using the z-spray ion source were more affected by the matrix effect. The two validated methods involve rapid analysis time and simple sample preparation. Also, the methods were applied to real patients' urine.

Validation of serotonin transporter mRNA as a quantitative biomarker of heavy drinking and its comparison to ethyl glucuronide/ethyl sulfate: A randomized, double-blind, crossover trial

BACKGROUND

The serotonin transporter (SERT) mRNA was previously reported to be a quantitative and pathophysiology-based biomarker of heavy drinking in 5HTTLPR:LL genotype-carriers treated with ondansetron. Here, we validated the potential use of SERT mRNA for quantitative prediction of recent alcohol consumption (in the absence of treatment) and compared it with the known biomarkers ethyl glucuronide (EtG) and ethyl sulfate (EtS).

METHODS

Binge drinking men and women of European ancestry aged 21 to 65 years were enrolled in a 12-day, in-patient, randomized, double-blind, crossover study, where they were administered three beverage doses (placebo, 0.5 g/kg [0.4 g/kg] ethanol, and 1 g/kg [0.9 g/kg] ethanol for men [women]) individually in three 4-day periods (experiments), separated by minimum 7-day washout period. Diet, sleep, and physical activity were controlled throughout the inpatient experiments. Twenty-nine participants were randomized to receive beverage doses counterbalancing the sequence of treatment and gender within subgroups stratified by SERT genotypes 5HTTLPR:LL+rs25531:AA (LA LA ) versus 5HTTLPR:LS/SS. Peripheral venous blood was collected daily for (1) quantification of SERT mRNA (the primary outcome measure) using qRT-PCR and (2) plasma EtG and EtS levels using tandem mass-spectrometry.

RESULTS

The association between administered beverage dose and SERT mRNA from completers of at least one 4-day experiment (N = 18) assessed by a linear mixed model was not statistically significant. Significant positive associations were found with beverage dose and plasma EtG, EtS and EtG/EtS ratio (β = 5.8, SE = 1.2, p < 0.0001; β = 1.3, SE = 0.6, p = 0.023; and β = 3.0, SE = 0.7, p < 0.0001, respectively; the C-statistics for discriminating outcomes were 0.97, 0.8, and 0.92, respectively). Additionally, we observed a sequence effect with a greater placebo effect on SERT mRNA when it was administered during the first experiment (p = 0.0009), but not on EtG/EtS measures.

CONCLUSION

The findings do not validate the use of SERT as a biomarker of heavy drinking. Larger and more innovative studies addressing the effects of placebo, race, gender, and response to treatment with serotonergic agents are needed to fully assess the utility of SERT as a biomarker of heavy and binge drinking.

Review of Ethanol Intoxication Sensing Technologies and Techniques

The field of alcohol intoxication sensing is over 100 years old, spanning the fields of medicine, chemistry, and computer science, aiming to produce the most effective and accurate methods of quantifying intoxication levels. This review presents the development and the current state of alcohol intoxication quantifying devices and techniques, separated into six major categories: estimates, breath alcohol devices, bodily fluid testing, transdermal sensors, mathematical algorithms, and optical techniques. Each of these categories was researched by analyzing their respective performances and drawbacks. We found that the major developments in monitoring ethanol intoxication levels aim at noninvasive transdermal/optical methods for personal monitoring. Many of the "categories" of ethanol intoxication systems overlap with each other with to a varying extent, hence the division of categories is based only on the principal operation of the techniques described in this review. In summary, the gold-standard method for measuring blood ethanol levels is through gas chromatography. Early estimation methods based on mathematical equations are largely popular in forensic fields. Breath alcohol devices are the most common type of alcohol sensors on the market and are generally implemented in law enforcement. Transdermal sensors vary largely in their sensing methodologies, but they mostly follow the principle of electrical sensing or enzymatic reaction rate. Optical devices and methodologies perform well, with some cases outperforming breath alcohol devices in terms of the precision of measurement. Other estimation algorithms consider multimodal approaches and should not be considered alcohol sensing devices, but rather as prospective measurement of the intoxication influence. This review found 38 unique technologies and techniques for measuring alcohol intoxication, which is testament to the acute interest in the innovation of noninvasive technologies for assessing intoxication.

A home-based, multidisciplinary liver optimisation programme for the first 28 days after an admission for acute-on-chronic liver failure (LivR well): a study protocol for a randomised controlled trial

Background

Acute-on-chronic liver failure (ACLF) represents a rising global healthcare burden, characterised by increasing prevalence among patients with decompensated cirrhosis who have a 28-day transplantation-free mortality of 33.9%. Due to disease complexity and a high prevalence of socio-economic disadvantage, there are deficits in quality of care and adherence to guideline-based treatment in this cohort. Compared to other chronic conditions such as heart failure, those with liver disease have reduced access to integrated ambulatory care services. The LivR Well programme is a multidisciplinary intervention aimed at improving 28-day mortality and reducing 30-day readmission through a home-based, liver optimisation programme implemented in the first 28 days after an admission with either ACLF or hepatic decompensation. Outcomes from our feasibility study suggest that the intervention is safe and acceptable to patients and carers.

Methods

We will recruit adult patients with chronic liver disease from the emergency departments, in-patient admissions, and an ambulatory liver clinic of a multi-site quaternary health service in Melbourne, Australia. A total of 120 patients meeting EF-Clif criteria will be recruited to the ACLF arm, and 320 patients to the hepatic decompensation arm. Participants in each cohort will be randomised to the intervention arm, a 28-day multidisciplinary programme or to standard ambulatory care in a 1:1 ratio. The intervention arm includes access to nursing, pharmacy, physiotherapy, dietetics, social work, and neuropsychiatry clinicians. For the ACLF cohort, the primary outcome is 28-day mortality. For the hepatic decompensation cohort, the primary outcome is 30-day re-admission. Secondary outcomes assess changes in liver disease severity and quality of life. An interim analysis will be performed at 50% recruitment to consider early cessation of the trial if the intervention is superior to the control, as suggested in our feasibility study. A cost-effectiveness analysis will be performed. Patients will be followed up for 12 weeks from randomisation. Three exploratory subgroup analyses will be conducted by (a) source of referral, (b) unplanned hospitalisation, and (c) concurrent COVID-19. The trial has been registered with the Australian New Zealand Clinical Trials Registry.

Discussion

This study implements a multidisciplinary intervention for ACLF patients with proven benefits in other chronic diseases with the addition of novel digital health tools to enable remote patient monitoring during the COVID-19 pandemic. Our feasibility study demonstrates safety and acceptability and suggests clinical improvement in a small sample size. An RCT is required to generate robust outcomes in this frail, high healthcare resource utilisation cohort with high readmission and mortality risk. Interventions such as LivR Well are urgently required but also need to be evaluated to ensure feasibility, replicability, and scalability across different healthcare systems. The implications of this trial include the generalisability of the programme for implementation across regional and urban centres.

Trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12621001703897. Registered on 13 December 2021.

WHO Trial Registration Data Set. See Appendix 1

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06679-x.

Rapid and simple LC–MS/MS determination of urinary ethyl glucuronide, naltrexone, 6β-naltrexol, chlordiazepoxide, and norchlordiazepoxide for monitoring alcohol abuse

In this study, a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed to detect ethyl glucuronide (EtG), which is a biomarker for monitoring alcohol consumption, and naltrexone (NTX), 6β-naltrexol (6βNTX), chlordiazepoxide (CDP), and norchlordiazepoxide (norCDP), which are analyzed to confirm the presence of medications for alcohol dependence treatment. The protein precipitation method was conducted to rapidly prepare samples. LC–MS/MS analysis was performed in the multiple-reaction monitoring mode. The analytes were separated using a Scherzo SM-C18 (2.0 × 100 mm, 3 µm) column. The calibration ranges were 5–1000 ng/mL for EtG, 6βNTX, CDP, and norCDP, and 1–100 ng/mL for NTX, with the correlation coefficients (r) being ≥ 0.994, and the weighting factor being 1/x2. The lower limit of quantification was 1–5 ng/mL. The method was also validated for precision, accuracy, selectivity, dilution integrity, recovery, matrix effect, and stability. The developed method was successfully applied for the determination of EtG, NTX, 6βNTX, CDP, and norCDP in urine samples obtained from 49 probationers who received alcohol dependence treatment orders. The method developed herein can be used to monitor the drug-based treatment of alcohol abuse and alcohol consumption during the treatment of individuals under probation.

Alcohol Consumption as a Causator and/or an Accelerator of Neuropathy in People With Diabetes Is Regularly Overlooked

Patients with diabetes and distal symmetrical polyneuropathy (DSP) are routinely evaluated for etiologies other than diabetes, including vitamin B12 deficiency, paraproteinemia, hypothyroidism and drug or autoimmune-induced neuropathy. However, the most common cause of DSP, next to that of diabetes, is alcohol intake, which is almost never evaluated. In addition to assessment of alcohol intake based on patient history, which often leads to an underestimation of alchohol intake, markers of a high alcohol intake (elevated liver enzymes, uric acid, triglycerides, low magnesium or low folic acid levels) should be obtained. However, the test that is most likely to detect surreptitious alcohol intake is urinary ethyl glucuronide (EtG), which will detect the intake of alcohol within the previous 90 h. Detection of alcohol use is important since if alcohol consumption is not discontinued, DSP, whatever the etiology, will not improve. In addition, the use of drugs to improve symptoms of DSP (tricyclics, anti-epileptics, serotonin, norepinephrine reuptake inhibitors and analgesics) may in combination with alcohol excessively suppress respiration and cognitive function such that these drugs should not be prescribed or utilized if use of alcohol continues. In the future, all patients with DSP, and especially those with symptomatic DSP, should be biochemically screened for excessive alcohol intake and appropriate action taken.

Development and validation of an analytical method for the simultaneous determination of the alcohol biomarkers ethyl glucuronide, ethyl sulfate, N-acetyltaurine, and 16:0/18:1-phosphatidylethanol in human blood

As alcohol is the most common addictive substance worldwide, it is inevitable to advance the established research. New and more substantial analytical methods can be applied to reply to complex questions in legal or forensic contexts. Therefore, an analytical method for the simultaneous determination of four different alcohol biomarkers-ethyl glucuronide, ethyl sulfate, N-acetyltaurine, and 16:0/18:1-phosphatidylethanol-in human blood was developed, validated, and verified. Despite the different chemical properties of the analytes, a specific determination via HPLC-MS/MS was achieved using a novel type of a Phenomenex Luna® Omega Sugar column. Furthermore, all criteria for a successful validation were fulfilled according to forensic guidelines. The method proved to be linear and demonstrates selectivity and sufficient sensitivity for every biomarker. LODs obtained with this method of 2.6 ng/ml (EtG), 4.7 ng/ml (EtS), 12.5 ng/ml (NAcT), and 6.9 ng/ml (PEth) were in an acceptable range for routine applications, and the stability of all analytes over a range of 12 h is given. The verification of the new developed method was performed with authentic samples. Thus, whole blood and postmortem samples were analyzed to obtain information about the drinking behavior, which can answer complex questions regarding alcohol consumption.

A simplified approach for determination of urinary ethyl glucuronide by gas chromatography–mass spectrometry

Urinary ethyl glucuronide (EtG), an alcohol biomarker, plays an essential role in monitoring alcohol abstinence and relapse during treatment for alcohol dependence. Detection of this biomarker has become a routine in many clinical and forensic laboratories over the last few years. Most previously published methods commonly use hyphenated chromatographic techniques along with extensive extraction procedure before analysis. This work aimed to develop and validate an electron impact ionization mode gas chromatography–mass spectrometry method to measure ethyl glucuronide levels in human urine. For its determination, urine samples were dried under a gentle stream of nitrogen, derivatized with N,O-bis(trimethylsilyl) trifluoroacetamide, incubated, and injected into the instrument. The analysis was performed using single quadrupole gas chromatography–mass spectrometry (GC-MS) technology and validation was performed according to the guidelines of the German Society of Toxicology and Forensic Chemistry (GTFCh). The linearity of urinary EtG was obtained in the range of 30–5000 ng/ml with a correlation coefficient (r) above 0.999. The extraction recoveries exceeded 80%, and the obtained inter-day and intra-day precisions were below 15%. The achieved limit of detection was 10 ng/ml and limit of quantification achieved was 30 ng/ml. The electron ionization gas chromatography–mass spectrometry technique proves to be a feasible option for determining EtG in human urine when other sophisticated techniques are unapproachable. This method provides a good sensitivity and proves to be cost-effective, robust, and advantageous for both clinical as well as forensic settings.

Biochemical Mechanisms Associating Alcohol Use Disorders with Cancers

Simple Summary

Of all yearly deaths attributable to alcohol consumption globally, approximately 12% are due to cancers, representing approximately 0.4 million deceased individuals. Ethanol metabolism disturbs cell biochemistry by targeting the structure and function of essential biomolecules (proteins, nucleic acids, and lipids) and by provoking alterations in cell programming that lead to cancer development and cancer malignancy. A better understanding of the metabolic and cell signaling realm affected by ethanol is paramount to designing effective treatments and preventive actions tailored to specific neoplasias.

Abstract

The World Health Organization identifies alcohol as a cause of several neoplasias of the oropharynx cavity, esophagus, gastrointestinal tract, larynx, liver, or female breast. We review ethanol’s nonoxidative and oxidative metabolism and one-carbon metabolism that encompasses both redox and transfer reactions that influence crucial cell proliferation machinery. Ethanol favors the uncontrolled production and action of free radicals, which interfere with the maintenance of essential cellular functions. We focus on the generation of protein, DNA, and lipid adducts that interfere with the cellular processes related to growth and differentiation. Ethanol’s effects on stem cells, which are responsible for building and repairing tissues, are reviewed. Cancer stem cells (CSCs) of different origins suffer disturbances related to the expression of cell surface markers, enzymes, and transcription factors after ethanol exposure with the consequent dysregulation of mechanisms related to cancer metastasis or resistance to treatments. Our analysis aims to underline and discuss potential targets that show more sensitivity to ethanol’s action and identify specific metabolic routes and metabolic realms that may be corrected to recover metabolic homeostasis after pharmacological intervention. Specifically, research should pay attention to re-establishing metabolic fluxes by fine-tuning the functioning of specific pathways related to one-carbon metabolism and antioxidant processes.

Molecular mechanisms of ethanol biotransformation: enzymes of oxidative and nonoxidative metabolic pathways in human

Ethanol, as a small-molecule organic compound exhibiting both hydrophilic and lipophilic properties, quickly pass through the biological barriers. Over 95% of absorbed ethanol undergoes biotransformation, the remaining amount is excreted unchanged, mainly with urine and exhaled air.The main route of ethyl alcohol metabolism is its oxidation to acetaldehyde, which is converted into acetic acid with the participation of cytosolic NAD⁺ - dependent alcohol (ADH) and aldehyde (ALDH) dehydrogenases. Oxidative biotransformation pathways of ethanol also include reactions catalyzed by the microsomal ethanol oxidizing system (MEOS), peroxisomal catalase and aldehyde (AOX) and xanthine (XOR) oxidases. The resulting acetic acid can be activated to acetyl-CoA by the acetyl-CoA synthetase (ACS).It is also possible, to a much smaller extent, non-oxidative routes of ethanol biotransformation including its esterification with fatty acids by ethyl fatty acid synthase (FAEES), re-esterification of phospholipids, especially phosphatidylcholines, with phospholipase D (PLD), coupling with sulfuric acid by alcohol sulfotransferase (SULT) and with glucuronic acid using UDP-glucuronyl transferase (UGT, syn. UDPGT).The intestinal microbiome plays a significant role in the ethanol biotransformation and in the initiation and progression of liver diseases stimulated by ethanol and its metabolite - acetaldehyde, or by lipopolysaccharide and ROS.

Urinary Ethyl Glucuronide as Measure of Alcohol Consumption and Risk of Cardiovascular Disease: A Population-Based Cohort Study

Background

Moderate alcohol consumption has been associated with a lower risk of cardiovascular disease (CVD) and all‐cause mortality compared with heavy drinkers and abstainers. To date, studies have relied on self‐reported consumption, which may be prone to misclassification. Urinary ethyl glucuronide (EtG) is an alcohol metabolite and validated biomarker for recent alcohol consumption. We aimed to examine and compare the associations of self‐reported alcohol consumption and EtG with CVD and all‐cause mortality.

Methods and Results

In 5676 participants of the PREVEND (Prevention of Renal and Vascular End‐Stage Disease) study cohort, EtG was measured in 24‐hour urine samples and alcohol consumption questionnaires were administered. Participants were followed up for occurrence of first CVD and all‐cause mortality. Cox proportional hazards regression models, adjusted for age, sex, and CVD risk factors, were fitted for self‐reported consumption, divided into 5 categories: abstention, 1 to 4 units/month (reference), 2 to 7 units/week, 1 to 3 units/day, and ≥4 units/day. Similar models were fitted for EtG, analyzed as both continuous and categorical variables. Follow‐up times differed for CVD (8 years; 385 CVD events) and all‐cause mortality (14 years; 724 deaths). For both self‐reported alcohol consumption and EtG, nonsignificant trends were found toward J‐shaped associations between alcohol consumption and CVD, with higher risk in the lowest (hazard ratio for abstention versus 1–4 units/month, 1.42; 95% CI, 1.02–1.98) and highest drinking categories (hazard ratio for ≥4 units/day versus 1–4 units/month, 1.11; 95% CI, 0.68–1.84). Neither self‐report nor EtG was associated with all‐cause mortality.

Conclusions

Comparable associations with CVD events and all‐cause mortality were found for self‐report and EtG. This argues for the validity of self‐reported alcohol consumption in epidemiologic research.

Confronting the Crisis of Comorbid Alcohol Use Disorder and Alcohol-Related Liver Disease With a Novel Multidisciplinary Clinic

BACKGROUND

Alcohol-related liver disease (ALD) is prevalent and deadly and increasingly affects younger people and women. No single discipline is adequately equipped to manage its biopsychosocial complexity.

OBJECTIVES

Depict the scope of the ALD problem, provide a narrative review of other integrated care models, share our experience forming and maintaining a multidisciplinary ALD clinic for over a year, and provide recommendations for replication elsewhere.

METHODS

Critical evaluation of clinic implementation and its first year of operation.

RESULTS

The clinical rationale for multidisciplinary ALD treatment is clear and supported by the literature. Such models are feasible although surprisingly rare and vulnerable to various surmountable challenges.

CONCLUSIONS

Successful ALD clinics must be built by teams with solid personal and professional relationships, supported by institutional leadership, and must use a new kind of multidisciplinary paradigm and training. Consultation-liaison psychiatry is uniquely positioned to lead future efforts in the care and study of ALD.

Urinary Ethyl Glucuronide Can Be Used as a Biomarker of Habitual Alcohol Consumption in the General Population

BACKGROUND

Alcohol consumption is a frequently studied risk factor for chronic diseases, but many studies are hampered by self-report of alcohol consumption. The urinary metabolite ethyl glucuronide (EtG), reflecting alcohol consumption during the past 72 h, is a promising objective marker, but population data are lacking.

OBJECTIVE

The objective of this study was to assess the reliability of EtG as a marker for habitual alcohol consumption compared with self-report and other biomarkers in the general population.

METHODS

Among 6211 participants in the Prevention of Renal and Vascular End-Stage Disease (PREVEND) cohort, EtG concentrations were measured in 24-h urine samples. EtG was considered positive when concentrations were ≥100 ng/mL. Habitual alcohol consumption was self-reported by questionnaire (categories: no/almost never, 1-4 units per month, 2-7 units per week, 1-3 units per day or ≥4 units per day). Plasma HDL cholesterol concentration, erythrocyte mean corpuscular volume (MCV), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyltransferase (GGT) were determined as indirect biomarkers of alcohol consumption. Sensitivity, specificity, positive and negative predictive value, and proportions of agreement between reported consumption and EtG were calculated. To test the agreement of EtG concentration and alcohol consumption in categories, linear regression analysis was performed. In addition, the association between EtG concentrations and indirect biomarkers was analyzed.

RESULTS

Mean age was 53.7 y, and 52.9% of participants men. Of the self-reported abstainers, 92.3% had an EtG concentration <100 ng/mL. Sensitivity was 66.3%, positive predictive value was 96.3%, and negative predictive value was 47.4%. The proportion of positive agreement was 78.5%, and the proportion of negative agreement was 62.7%. EtG concentrations were linearly associated with higher categories of alcohol consumption (P-trend < 0.001), adjusted for age, sex, and renal function. EtG was positively related to MCV, HDL cholesterol, and GGT but not to AST and ALT concentrations.

CONCLUSIONS

This study shows that urinary EtG is in reasonable agreement with self-reported alcohol consumption and therefore can be used as an objective marker of habitual alcohol consumption in the general population.

Ethylene glycol: Evidence of glucuronidationin vivoshown by analysis of clinical toxicology samples

In the search for improved laboratory methods for the diagnosis of ethylene glycol poisoning, the in vivo formation of a glucuronide metabolite of ethylene glycol was hypothesized. Chemically pure standards of the β‐O‐glucuronide of ethylene glycol (EG‐GLUC) and a deuterated analog (d₄‐EG‐GLUC) were synthesized. A high‐performance liquid chromatography and tandem mass spectrometry method for determination of EG‐GLUC in serum after ultrafiltration was validated. Inter‐assay precision (%RSD) was 3.9% to 15.1% and inter‐assay %bias was −2.8% to 12.2%. The measuring range was 2–100 μmol/L (0.48–24 mg/L). Specificity testing showed no endogenous amounts in routine clinical samples (n = 40). The method was used to analyze authentic, clinical serum samples (n = 31) from patients intoxicated with ethylene glycol. EG‐GLUC was quantified in 15 of these samples, with a mean concentration of 6.5 μmol/L (1.6 mg/L), ranging from 2.3 to 15.6 μmol/L (0.55 to 3.7 mg/L). In five samples, EG‐GLUC was detected below the limit of quantification (2 μmol/L) and it was below the limit of detection in 11 samples (1 μmol/L). Compared to the millimolar concentrations of ethylene glycol present in blood after intoxications and potentially available for conjugation, the concentrations of EG‐GLUC found in clinical serum samples are very low, but comparable to concentrations of ethyl glucuronide after medium dose ethanol intake. In theory, EG‐GLUC has a potential value as a biomarker for ethylene glycol intake, but the pharmacokinetic properties, in vivo/vitro stability and the biosynthetic pathways of EG‐GLUC must be further studied in a larger number of patients and other biological matrices.

Quantitation of Ethyl-β-D-Glucuronide in Human Umbilical Cord Tissue by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

In utero exposure to alcohol may adversely affect the development of the embryo or fetus and result in adverse outcomes known as fetal alcohol spectrum disorders (FASD) which encompass a range of physical, behavioral, and cognitive impairments in the newborn. Since maternal self-reports are often unreliable, biomarkers of gestational alcohol consumption are necessary for accurate identification of exposed newborns at risk. Ethyl-β-D-glucuronide (EtG) is a minor phase II metabolite of ethyl alcohol (ethanol), formed by enzymatic conjugation of ethanol with glucuronic acid in the liver. As a direct biomarker for alcohol, detection of EtG in neonatal biological matrices provides accurate identification of maternal alcohol consumption and fetal alcohol exposure during pregnancy. This chapter describes the quantitation of EtG in human umbilical cord tissue by liquid chromatography tandem mass spectrometry (LC-MS/MS).

Alcohol Use Disorders in Alcoholic Liver Disease

Alcohol use disorder (AUD) is common in alcoholic liver disease (ALD) and intrinsic to its pathophysiology. Optimal treatment requires a multidisciplinary team approach and a working alliance between patients and providers. Diagnosing AUD involves a combination of thorough history taking, physical examination, screening questionnaires, and alcohol biomarkers. Alcohol biomarkers have advantages and limitations of use of which clinicians should be aware. AUD treatment is effective, multifaceted, and can be tailored to each individual. Available treatment modalities are myriad: motivational enhancement therapy, cognitive behavior therapy, 12-step facilitation, group therapies, intensive outpatient programs, inpatient and residential treatment, and relapse prevention medications.

Lessons learned from a case of tert-butyl glucuronide excretion in urine - "New" psychoactive alcohols knocking on the back door?

BACKGROUND

Ethyl glucuronide (EtG) in urine is considered a marker of recent ethanol consumption or ethanol exposition. tert-Butanol is primarily used as a solvent and intermediate chemical. Like tert-amyl alcohol, tert-butanol is discussed in Internet forums as ethanol replacement. We discuss false-positive immunological EtG screenings by excretion of different alcohol glucuronides (EtG homologs), mainly tert-butyl glucuronide in urine of a polytoxikomanic in-patient.

METHODS

Three consecutive urine samples from an in-patient with a long history of multiple substance abuse including solvents were analyzed by DRI EtG enzyme immunoassay (ThermoFisher Scientific Microgenics) on a Beckman Coulter AU680 analyzer, an in-house LC-MS/MS for EtG, 1-propyl, 2-propyl, 1-butyl, 2-butyl, and tert-butyl glucuronide, and an in-house headspace GC-FID of free congener substances methanol, 1-propanol, 2-butanone, 2-butanol, isobutanol, 1-butanol, 3-methyl-1-butanol, 2-methyl-1-butanol, and additionally for ethanol, acetone, 2-propanol, tert-butanol and 2-methyl-2-butanol.

RESULTS

EtG immunoassay yielded two positive urine samples (0.2 and 0.6mg/L or 0.1 and 0.2mg/g creatinine; cut-off 0.1mg/L) which were tested EtG negative by LC-MS/MS (cut-off 0.1mg/L) but positive for tert-butyl glucuronide (3.7 and 27.1mg/L), 2-butyl glucuronide (1.1 and 3.5mg/L), and 2-propyl glucuronide (0.1 and 0.4mg/L). Headspace GC-FID detected tert-butanol (0.97 and 4.01mg/L), methanol (0.96 and 0.62mg/L), 2-butanone (0.84 and 1.65mg/L), and 2-butanol (0.04 and 0.09mg/L), but no ethanol and no 2-methyl-2-butanol.

CONCLUSION

Cross-reaction of EtG homologs, mainly tert-butyl glucuronide after suspected tert-butanol or isobutane abuse, explains the false-positive EtG immunoassay findings. Future investigations could address the usefulness of alcohol glucuronides (EtG homologs) in urine as (a) biomarkers of an exposition to alkans or their corresponding alcohol metabolites and (b) as markers for using "old"-well known alcohols like tert-butanol or tert-amyl alcohol as easy to obtain, cheap, potent and "undetectable" ethanol replacements or "New" Psychoactive Alcohols.

Profiles in drug metabolism and toxicology: Richard Tecwyn Williams (1909-1979)

This article pays homage to the life and work of a veritable pioneer in toxicology and drug metabolism, namely a Welshman, Richard Tecwyn Williams, FRS. Professor Williams, or RT as he was known, made major contributions to knowledge about the metabolism and toxicology of drugs and xenobiotics during a scientific career spanning nearly 50 years. Author or coauthor of close to 400 research articles and reviews, including a classic book, entitled Detoxication Mechanisms, Williams and his research school investigated virtually all aspects of drug metabolism, especially conjugations. In particular, the concepts of phase 1 and phase II metabolic pathways were introduced by Williams; the biliary excretion of drugs was extensively studied as were species differences in drug metabolism and detoxication. Besides investigating the metabolism of many pharmaceutical drugs, such as sulfonamides and thalidomide, Williams and his group investigated the disposition and fate in the body of organic pesticides and recreational drugs of abuse, such as amphetamine, methamphetamine and lysergic acid diethylamide (LSD).

Structural analysis of quazepam metabolites in bile by ion trap time-of-flight mass spectrometry

Quazepam (QZP) is a long-acting benzodiazepine-type hypnotic. We searched for novel QZP metabolites in bile and determined their structures by liquid chromatography-ion trap time-of-flight mass spectrometry (LC-IT-TOF MS). The metabolites were extracted with ethyl acetate after β-glucuronidase treatment. First, a single MS spectrum was acquired. Second, MS(n) spectra were acquired for peaks that consisted of ions with the isotope pattern corresponding to molecules bearing one chlorine atom. The novel QZP metabolites found in this study were hydroxyquazepam, hydroxy-methoxyquazepam, hydroxy-oxoquazepam, and hydroxy-methoxy-oxoquazepam, which have the hydroxy and methoxy groups on the fluorophenyl group, and dihydroxy-oxoquazepam and dihydroxy-methoxy-oxoquazepam, which have one hydroxy group at the 3-position of the seven-membered ring and the other hydroxy group and the methoxy group on the fluorophenyl group. We demonstrated that LC-IT-TOF MS was a useful tool for determining the structure of the metabolites. However, the exact locations of the hydroxy and methoxy groups on the fluorophenyl group could not be identified.

The UDP-glucuronosyltransferases of the blood-brain barrier: their role in drug metabolism and detoxication

UDP-glucuronosyltransferases (UGTs) form a multigenic family of membrane-bound enzymes expressed in various tissues, including brain. They catalyze the formation of β-D-glucuronides from structurally unrelated substances (drugs, other xenobiotics, as well as endogenous compounds) by the linkage of glucuronic acid from the high energy donor, UDP-α-D-glucuronic acid. In brain, UGTs actively participate to the overall protection of the tissue against the intrusion of potentially harmful lipophilic substances that are metabolized as hydrophilic glucuronides. These metabolites are generally inactive, except for important pharmacologically glucuronides such as morphine-6-glucuronide. UGTs are mainly expressed in endothelial cells and astrocytes of the blood brain barrier (BBB). They are also associated to brain interfaces devoid of BBB, such as circumventricular organ, pineal gland, pituitary gland and neuro-olfactory tissues. Beside their key-role as a detoxication barrier, UGTs play a role in the steady-state of endogenous compounds, like steroids or dopamine (DA) that participate to the function of the brain. UGT isoforms of family 1A, 2A, 2B and 3A are expressed in brain tissues to various levels and are known to present distinct but overlapping substrate specificity. The importance of these enzyme species with regard to the formation of toxic, pharmacologically or physiologically relevant glucuronides in the brain will be discussed.

Diagnosis of alcoholic liver disease

Alcohol is a hepatotoxin that is commonly consumed worldwide and is associated with a spectrum of liver injury including simple steatosis or fatty liver, alcoholic hepatitis, fibrosis, and cirrhosis. Alcoholic liver disease (ALD) is a general term used to refer to this spectrum of alcohol-related liver injuries. Excessive or harmful alcohol use is ranked as one of the top five risk factors for death and disability globally and results in 2.5 million deaths and 69.4 million annual disability adjusted life years. All patients who present with clinical features of hepatitis or chronic liver disease or who have elevated serum elevated transaminase levels should be screened for an alcohol use disorder. The diagnosis of ALD can generally be made based on history, clinical and laboratory findings. However, the diagnosis of ALD can be clinically challenging as there is no single diagnostic test that confirms the diagnosis and patients may not be forthcoming about their degree of alcohol consumption. In addition, clinical findings may be absent or minimal in early ALD characterized by hepatic steatosis. Typical laboratory findings in ALD include transaminase levels with aspartate aminotransferase greater than alanine aminotransferase as well as increased mean corpuscular volume, gamma-glutamyltranspeptidase, and IgA to IgG ratio. In unclear cases, the diagnosis can be supported by imaging and liver biopsy. The histological features of ALD can ultimately define the diagnosis according to the typical presence and distribution of hepatic steatosis, inflammation, and Mallory-Denk bodies. Because of the potential reversible nature of ALD with sobriety, regular screening of the general population and early diagnosis are essential.

The influence of cleansing shampoos on ethyl glucuronide concentration in hair analyzed with an optimized and validated LC-MS/MS method

Ethyl glucuronide (EtG) is widely used as a marker for assessment of alcohol consumption behavior. In this study the influence of special cleansing shampoos on ethyl glucuronide concentrations in hair was investigated. For that purpose an optimized LC-MS/MS method was developed using a Hypercarb™ porous graphitic carbon (PGC) column and validated according to the guidelines of the German Society of Toxicological and Forensic Chemistry (GTFCh). Twenty-five hair samples of persons with known alcohol consumption behavior were investigated (21 positive samples and 4 blank samples). The hair samples were divided into two strands of hair and were analyzed after treatment with one out of four cleansing shampoos and without shampoo treatment. EtG concentrations in hair did not show any significant differences after a single application of the different cleansing shampoos. EtG was still detectable in all the positive hair samples without significant concentration change. These results clearly demonstrated that a single application of the tested cleansing shampoos did not remove EtG from hair and therefore had no influence on EtG concentration in analytical hair analysis.

Current treatment options for alcohol-related liver disease

PURPOSE OF REVIEW

The burden of alcohol on global health is increasing, and there is a strong relationship between population alcohol consumption and liver-related deaths. As alcohol-related liver disease (ArLD) often develops with no signs or symptoms, the prevention of liver disease relies on the recognition of harmful drinking and screening of those patients at risk for early markers of liver disease.

RECENT FINDINGS

A robust method of screening patients at risk of ArLD is essential. Once a patient develops ArLD, abstinence and early recognition of its complications are keys to improving outcomes. Corticosteroids remain the mainstay treatment in alcoholic hepatitis pending the results from large multicentre trials. More recently, there has been an increased interest in the use of rifaximin and albumin in various settings of ArLD.

SUMMARY

Advances in the treatment of ArLD and its complications, such as alcoholic hepatitis, will allow a greater proportion of patients chance for their liver to recover. However, new strategies to detect and intervene in those patients at higher risk of ArLD are likely to have the greatest overall impact.

Ethyl glucuronide and ethyl sulfate assays in clinical trials, interpretation, and limitations: results of a dose ranging alcohol challenge study and 2 clinical trials

BACKGROUND

The ethanol metabolites, ethyl glucuronide (EtG) and ethyl sulfate (EtS), are biomarkers of recent alcohol consumption that provide objective measures of abstinence. Our goals are to better understand the impact of cutoff concentration on test interpretation, the need for measuring both metabolites, and how best to integrate test results with self-reports in clinical trials.

METHODS

Subjects (n = 18) were administered, 1 week apart, 3 alcohol doses calibrated to achieve blood concentrations of 20, 80, and 120 mg/dl, respectively. Urinary EtG/EtS was measured at timed intervals during a 24-hour hospitalization and twice daily thereafter. In addition, participants from 2 clinical trials provided samples for EtG/EtS and drinking histories. Cutoffs for EtG/EtS of 100/50, 200/100, and 500/250 ng/ml were evaluated.

RESULTS

Twelve hours following each challenge, EtG was always positive at the 100 and 200 cutoffs, but at 24 hours sensitivity was poor at all cutoffs following the low dose, and poor after 48 hours regardless of dose or cutoff. Similarly, in the clinical trials EtG sensitivity was good for detecting any drinking during the last 24 hours at the 2 lowest cutoffs, but under 40% during the last 24 to 48 hours. Sensitivity was reduced at the 500 ng/ml cutoff. Discrepancies between EtG and EtS were few. Comparison of self-reports of abstinence and EtG-confirmed abstinence indicated underreporting of drinking.

CONCLUSIONS

Any drinking the night before should be detectable the following morning with EtG cutoffs of 100 or 200 ng/ml. Twenty-four hours after drinking, sensitivity is poor for light drinking, but good for heavier consumption. At 48 hours, sensitivity is low following 6 drinks or less. Increasing the cutoff to 500 ng/ml leads to substantially reduced sensitivity. Monitoring both EtG and EtS should usually be unnecessary. We recommend EtG-confirmed self-reports of abstinence for evaluation of outcomes in clinical trials.

Cellular photo digital breathalyzer for monitoring alcohol use: a pilot study

BACKGROUND

Monitoring alcohol use is important in numerous situations. Direct ethanol metabolites, such as ethyl glucuronide (EtG), have been shown to be useful tools in detecting alcohol use and documenting abstinence. For very frequent or continuous control of abstinence, they lack practicability. Therefore, devices measuring ethanol itself might be of interest. This pilot study aims at elucidating the usability and accuracy of the cellular photo digital breathalyzer (CPDB) compared to self-reports in a naturalistic setting.

METHOD

12 social drinkers were included. Subjects used a CPDB 4 times daily, kept diaries of alcohol use and submitted urine for EtG testing over a period of 5 weeks.

RESULTS

In total, the 12 subjects reported 84 drinking episodes. 1,609 breath tests were performed and 55 urine EtG tests were collected. Of 84 drinking episodes, CPDB detected 98.8%. The compliance rate for breath testing was 96%. Of the 55 EtG tests submitted, 1 (1.8%) was positive.

CONCLUSIONS

The data suggest that the CPDB device holds promise in detecting high, moderate, and low alcohol intake. It seems to have advantages compared to biomarkers and other monitoring devices. The preference for CPDB by the participants might explain the high compliance. Further studies including comparison with biomarkers and transdermal devices are needed.

[What ethanol metabolites as biological markers tell us about alcohol use]

Alcohol and tobacco related disorders are the two leading and most expensive causes of illness in central Europe. In addition to self reports and questionnaires, biomarkers are of relevance in diagnosis and therapy of alcohol use disorders. Traditional biomarkers such as gamma glutamyl transpeptidase or mean corpuscular volume are indirect biomarkers and are subject to influence of age, gender and non alcohol related diseases, among others.Direct ethanol metabolites such as ethyl glucuronide (EtG), ethyl sulphate (EtS) and phosphatidylethanol (PEth) are direct metabolites of ethanol, that are positive after intake of ethyl alcohol. They represent useful diagnostic tools for identifying alcohol use even more accurately than traditional biomarkers. Each of these drinking indicators remains positive in serum and urine for a characteristic time spectrum after the cessation of ethanol intake--EtG and EtS in urine up to 7 days, EtG in hair for months after ethanol has left the body. Applications include clinical routine use, emergency room settings, proof of abstinence in alcohol rehabilitation programs, driving under influence offenders, workplace testing, assessment of alcohol intake in the context of liver transplantation and fetal alcohol syndrome.

Risks, management, and monitoring of combination opioid, benzodiazepines, and/or alcohol use

The concurrent use of opioids, benzodiazepines (BZDs), and/or alcohol poses a formidable challenge for clinicians who manage chronic pain. While the escalating use of opioid analgesics for the treatment of chronic pain and the concomitant rise in opioid-related abuse and misuse are widely recognized trends, the contribution of combination use of BZDs, alcohol, and/or other sedative agents to opioid-related morbidity and mortality is underappreciated, even when these agents are used appropriately. Patients with chronic pain who use opioid analgesics along with BZDs and/or alcohol are at higher risk for fatal/nonfatal overdose and have more aberrant behaviors. Few practice guidelines for BZD treatment are readily available, especially when they are combined clinically with opioid analgesics and other central nervous system-depressant agents. However, coadministration of these agents produces a defined increase in rates of adverse events, overdose, and death, warranting close monitoring and consideration when treating patients with pain. To improve patient outcomes, ongoing screening for aberrant behavior, monitoring of treatment compliance, documentation of medical necessity, and the adjustment of treatment to clinical changes are essential. In this article, we review the prevalence and pharmacologic consequences of BZDs and/or alcohol use among patients with pain on chronic opioid therapy, as well as the importance of urine drug testing, an indispensable tool for therapeutic drug monitoring, which helps to ensure the continued safety of patients. Regardless of risk or known aberrant drug-related behaviors, patients on chronic opioid therapy should periodically undergo urine drug testing to confirm adherence to the treatment plan.

Ethyl glucuronide identified in commercial hair tonics

BACKGROUND

Ethyl glucuronide (EtG) in hair is considered as a specific marker of ethanol consumption. Prompted by a report of positive EtG hair testings due to hair treatment with an EtG containing hair lotion, commercially available herbal hair tonics from supermarkets, drug-stores, and health food stores were analyzed for the presence of EtG and ethyl sulfate (EtS).

METHODS

LC-MS/MS (QTRAP 5500 mass spectrometer) was done in multiple reaction monitoring (MRM), enhanced product ion (EPI) and MS(3) mode. The lower limit of quantitation was 0.05 mg/L for EtG and the cut-off for the detection of EtS 0.01 mg/L.

RESULTS

Altogether 11 hair tonics from 8 manufacturers were tested, with 1 product in 3 different lots. EtG ranged between 0.07 and 1.06 mg/L (7 products from 4 manufacturers) and was almost identical in the 3 lots of 1 product (1.01-1.06 mg/L). EtS was found in 3 out of the 11 hair tonics.

CONCLUSIONS

EtG is quite frequently present in commercially available herbal hair tonics. Using EtG in hair as a marker of alcohol (ab)use, one has to consider external sources of EtG and has to assess the use of hair care products, esp. if the patient denies any ethanol intake. Whether EtS is a more reliable alcohol (ab)use marker, as sometimes discussed, should be critically assessed against the background of its broad use in large amounts in industrial chemistry.

Phosphatidylethanol: the potential role in further evaluating low positive urinary ethyl glucuronide and ethyl sulfate results

BACKGROUND

Whereas urinary ethyl glucuronide (EtG) levels above 1,000 ng/ml reflect with a high probability ethanol (EtOH) consumption, levels below this cutoff are difficult to interpret as both extraneous (nonbeverage) EtOH exposure, recent drinking, and more distant high EtOH intake (several days ago) might yield similar results. This might be of particular relevance in medico-legal cases. To overcome this dilemma, phosphatidylethanol (PEth) might be a promising marker, because blood PEth is only positive following significant alcohol use. The aim of our study was therefore to employ PEth as a marker to differentiate between the different conditions.

METHODS

Subjects included were 252 participants in monitoring with the Alabama Physician Health Program. All subjects testing positive for EtG and/or ethyl sulfate (EtS) who denied drinking after routine supportive confrontation were subject to information about PEth testing. If they still denied drinking, PEth testing was performed and the result communicated. EtG, EtS, and PEth testing was performed in a commercial laboratory using liquid chromatography tandem mass spectrometry methods.

RESULTS

Of a total of 18 subjects who tested positive for EtG and/or EtS, 10 denied drinking. Of the 7 who denied drinking after PEth explanation, in 5 cases, their claim was supported by a negative PEth result. In 2 cases, a positive PEth result was in contrast to their claim.

CONCLUSIONS

PEth results in combination with previous low positive EtG/EtS results allow differentiating between innocent/extraneous exposure and drinking. Negative PEth testing following low positive EtG/EtS results helps to further elucidate the findings and support the claim of the patient of recent alcohol abstinence. Positive PEth testing following positive EtG/EtS results confirms recent drinking.

Monitoring population levels of alcohol consumption in pregnant women: a case for using biomarkers

A challenge to biochemically monitoring alcohol consumption in pregnancy is the prohibitive costs of collecting thousands of blood samples. This pilot study looks at the feasibility of using residual samples to monitor chronic and acute alcohol consumption in pregnancy. Residual anomalies screening samples (n = 150, 2006/7) were tested for carbohydrate-deficient transferrin (CDT, chronic marker) and ethyl glucuronide (EtG, acute marker). Valid readings were obtained for CDT but not EtG. These results pave the way for a larger representative study, to provide, for the first time, a national biochemical baseline estimate of chronic alcohol consumption in the pregnant population.

Assessing the drinking status of liver transplant patients with alcoholic liver disease

The accurate assessment of drinking by patients with alcoholic liver disease is important both before and after liver transplantation. Unfortunately, self-reports by these individuals often underestimate their actual alcohol consumption. Several recently developed biochemical measures can provide additional information on a patient's use of alcohol. This article describes ethyl glucuronide, ethyl sulfate, phosphatidyl ethanol, and carbohydrate-deficient transferrin as biomarkers of drinking and summarizes research dealing with their application in patients with alcohol use disorders who are candidates for or recipients of liver transplantation. The article also offers suggestions for enhancing the reliability of self-report measures of drinking status.

Non-oxidative ethanol metabolites as a measure of alcohol intake

Recent alcohol intake can be monitored by the measurement of indirect biomarkers. Elevated levels of liver enzymes (i.e. gamma-glutamyl transferase (GGT), alanine amino transferase (ALT) and aspartate amino transferase (AST)) in blood are commonly used in clinical practice as an indicator of alcohol-induced liver damage. With the exception of carbohydrate-deficient transferrin (CDT), the specificity of indirect markers is only moderate because many cases of elevated levels are unrelated to alcohol consumption. Because of their intermediate half-life and tendency to accumulate in hair, non-oxidative ethanol metabolites can be used as markers with an intermediate timeframe between ethanol measurements and GGT and CDT with regard to recent alcohol consumption occurring between hours to 1 week. Additionally, these biomarkers offer a high ethanol-specificity in combination with approximately a two-fold higher sensitivity in comparison with indirect alcohol markers. In case of forensic use of direct ethanol metabolites, caution has to be taken in interpretation and pre-analytical pitfalls should be considered.