Unnecessary Use of Medications for Alcohol Withdrawal Among Hospitalized Patients: A Retrospective Study of Phosphatidylethanol Testing in Patients With Suspected Alcohol Use Disorder

OBJECTIVES

Alcohol withdrawal is frequently encountered in hospital settings, but the decision to treat the withdrawal with pharmacotherapy is often made without knowing if treatment is even necessary. Testing for phosphatidylethanol (PEth), results of which correlate well with recent alcohol consumption, may allow hospital teams to avoid treating alcohol withdrawal unnecessarily. To investigate PEth values of those suspected of alcohol withdrawal syndrome (AWS) among hospital inpatients, we conducted a retrospective study to determine the prevalence of hospitalized patients who received pharmacotherapy for withdrawal who also demonstrated PEth values suggesting minimal recent drinking.

METHODS

This retrospective study examined the electronic health records of hospitalized adult patients suspected of recent heavy alcohol use for whom PEth tests were ordered. PEth tests were ordered at the time to inform treatment decisions such as the provision of naltrexone or referral to ongoing psychosocial treatments, but not to inform the decision to treat AWS given that results would only be available 3 or more days later. Hospital inpatients, excluding emergency room encounters, for whom PEth was ordered at 2 affiliated academic hospitals from January 2021 to April 2024 were included.

RESULTS

The included cohort was composed of 73 individual encounters. Among the 45 (62%) encounters where pharmacotherapy for AWS was administered, 14 (31%) had PEth values (≤200 ng/ml) inconsistent with heavy alcohol use.

CONCLUSIONS

Results suggest that a substantial proportion of hospital inpatients may have received pharmacotherapy for AWS despite PEth levels inconsistent with recent heavy alcohol use. If PEth results are available in real-time, results could help clinicians decide if pharmacotherapy is warranted. Further study of PEth testing and its role in the care of hospitalized patients is recommended.

Concordance of Ethyl Glucuronide, Blood Alcohol Content, and Self-Reported Alcohol Use in Russian Women with HIV and Hepatitis C Virus Co-Infection

Problematic alcohol use is prevalent in Russia and is deleterious for individuals with HIV and Hepatitis C Virus (HCV). Ethyl glucuronide (EtG) and blood alcohol content (BAC) provide objective biomarkers of drinking that can be compared to self-reported alcohol use. This paper describes patterns of alcohol use measured by biomarkers and self-report along with concordance across measures. Participants were Russian women with HIV and HCV co-infection (N = 200; Mean age = 34.9) from two Saint Petersburg comprehensive HIV care centers enrolled in an alcohol reduction intervention clinical trial. Measures were: (a) urine specimen analyzed for EtG; (b) breathalyzer reading of BAC; and (c) self-reported frequency of drinking, typical number of drinks consumed, and number of standard drinks consumed in the past month. At baseline, 64.0% (n = 128) had a positive EtG (> 500 ng/mL) and 76.5% (n = 153) had a positive breathalyzer reading (non-zero reading). There was agreement between EtG and BAC (kappa = 0.66, p < .001; Phi coefficient = 0.69, p < .001); self-reported alcohol measures were positively correlated with positive EtG and BAC (p's < 0.001). There was concordance between EtG and BAC measures, which have differing alcohol detection windows. Most participants endorsed frequent drinking at high quantities, with very few reporting no alcohol consumption in the past month. Concordance between biomarkers and self-reported alcohol use suggests that underreporting of alcohol use was minimal. Results highlight the need for alcohol screening within HIV care. Implications for alcohol assessment within research and clinical contexts are discussed.

High-resolution imaging in studies of alcohol effect on prenatal development

Fetal alcohol syndrome represents the leading known preventable cause of mental retardation. FAS is on the most severe side of fetal alcohol spectrum disorders that stem from the deleterious effects of prenatal alcohol exposure. Affecting as many as 1 to 5 out of 100 children, FASD most often results in brain abnormalities that extend to structure, function, and cerebral hemodynamics. The present review provides an analysis of high-resolution imaging techniques that are used in animals and human subjects to characterize PAE-driven changes in the developing brain. Variants of magnetic resonance imaging such as magnetic resonance microscopy, magnetic resonance spectroscopy, diffusion tensor imaging, along with positron emission tomography, single-photon emission computed tomography, and photoacoustic imaging, are modalities that are used to study the influence of PAE on brain structure and function. This review briefly describes the aforementioned imaging modalities, the main findings that were obtained using each modality, and touches upon the advantages/disadvantages of each imaging approach.

Emerging Biomarkers in Alcohol-associated Hepatitis

Alcohol-associated hepatitis (AH) is a clinical syndrome of jaundice, abdominal pain, and anorexia due to prolonged heavy alcohol intake. AH is associated with changes in gene expression, cytokines, immune response, and the gut microbiome. There are limited biomarkers to diagnose and prognosticate in AH, but several non-invasive biomarkers are emerging. In this review, clinical risk-stratifying algorithms, promising AH biomarkers like cytokeratin-18 fragments, genetic polymorphisms, and microRNAs will be reviewed.

A Review on Flexible Electrochemical Biosensors to Monitor Alcohol in Sweat

The continued focus on improving the quality of human life has encouraged the development of increasingly efficient, durable, and cost-effective products in healthcare. Over the last decade, there has been substantial development in the field of technical and interactive textiles that combine expertise in electronics, biology, chemistry, and physics. Most recently, the creation of textile biosensors capable of quantifying biometric data in biological fluids is being studied, to detect a specific disease or the physical condition of an individual. The ultimate goal is to provide access to medical diagnosis anytime and anywhere. Presently, alcohol is considered the most commonly used addictive substance worldwide, being one of the main causes of death in road accidents. Thus, it is important to think of solutions capable of minimizing this public health problem. Alcohol biosensors constitute an excellent tool to aid at improving road safety. Hence, this review explores concepts about alcohol biomarkers, the composition of human sweat and the correlation between alcohol and blood. Different components and requirements of a biosensor are reviewed, along with the electrochemical techniques to evaluate its performance, in addition to construction techniques of textile-based biosensors. Special attention is given to the determination of biomarkers that must be low cost and fast, so the use of biomimetic materials to recognize and detect the target analyte is turning into an attractive option to improve electrochemical behavior.

Current and Future Biomarkers in Alcoholic Hepatitis

Alcoholic hepatitis (AH) is a clinical syndrome of jaundice, abdominal pain, and anorexia due to prolonged heavy alcohol intake, and is associated with alterations in gene expression, cytokines, immune response, and the gut microbiome. Currently, we have limited biomarkers to diagnose and prognosticate in AH, but there are many novel noninvasive biomarkers under development. We evaluate the currently used algorithms to risk-stratify in AH (such as the Maddrey modified discriminant function), and discuss novel biomarkers in development, such as breath biomarkers, microRNAs, cytokeratin-18 fragments, and the AshTest. We also review the characteristics of an ideal biomarker in AH.

The History of Alcoholic Liver Disease: From an Unrecognized Disease to One of the Most Frequent Diseases in Hepatology

This review describes the history of alcoholic liver disease from the beginning of the 1950s until now. It details how the hepatotoxicity of alcohol was discovered by epidemiology and basic research primarily by using new feeding techniques in rodents and primates. The article also recognizes the pioneering work of scientists who contributed to the understanding of the pathophysiology of alcoholic liver disease. In addition, clinical aspects, such as the development of diagnostics and treatment options for alcoholic liver disease, are discussed. Up-to-date knowledge of the mechanism of the disease in 2020 is presented.

Distributions of alcohol use biomarkers including ethanol, phosphatidylethanol, ethyl glucuronide and ethyl sulfate in clinical and forensic testing

Laboratory tests vary widely in their utility and each test has unique advantages and disadvantages. For the detection of ethanol use and abuse, a variety of direct and indirect markers are available. Alcohol biomarkers provide objective measures for numerous areas of testing including clinical trials, alcohol abuse, postmortem assessment, and drugs of abuse screening. Because the utility of alcohol biomarkers vary depending on the context in which the results will be used, knowing the analogous distribution of results is of value. Herein we report distributions of ethanol in blood, phosphatidylethanol in blood, ethyl glucuronide in urine, and ethyl sulfate in urine for results reported in the last twelve months by our laboratory. Positivity rates were higher for directed analyses when compared to broad screening or panel tests with the highest overall positivity for ethyl glucuronide and ethyl sulfate. The distribution of results for ethyl glucuronide and ethyl sulfate were higher in clinical testing scenarios compared to forensic and a significant correlation between ethyl glucuronide and ethyl sulfate was found consistent with previous reports. Phosphatidylethanol was rarely ordered for forensic use while distributions between routine clinical and clinical trial use were similar. Approximately 21% of all phosphatidylethanol results were in the moderate to chronic alcohol use category. These results provide a summary of four commonly used direct markers for alcohol use with positivity rates and overall quantitative distributions. These data supply insights broken out by various disciplines where applicable providing a concise comparison of results for these markers.

Sensitivity and specificity of a commercial urinary ethyl glucuronide (ETG) test in heavy drinkers

Introduction

To advance the use of alcohol metabolites as biomarkers in the context of alcohol research, the present study tested the sensitivity and specificity of a commercially available urinary ethyl glucuronide (uEtG) test (DrugConfirm Advanced 80hr EtG) in a clinical research context.

Methods

A community sample of heavy drinkers (N = 68) completed the 30-day Timeline Follow-Back (TLFB) interview and provided a urine sample for uEtG analysis. Analyses of sensitivity and specificity of the uEtG assay were conducted using the following outcomes: (a) past day drinking, (b) past day binge drinking (defined as ≥4 drinks for women and ≥5 drinks for men), (c) past 3-day drinking, and (d) past 3-day binge drinking.

Results

The majority of participants reported past-3-day drinking (80.9%) and a sizeable minority reported past day drinking (33.8%). While uEtG-based detection of past day drinking and binge drinking was acceptable (sensitivity = 73.91%, and 83.33%; specificity = 80.00% and 66.13%, respectively), detection of any drinking and binge drinking in the past 3 days was poor (sensitivity and specificity of 43.64% and 84.62%, and 39.39% and 62.86%, respectively).

Conclusions

This study contributes to the mixed findings on the validity of EtG tests, which suggest that commercial uEtG tests with conservative detection thresholds are not a reliable alcohol biomarker without corroborating self-report data. Lower detection thresholds are recommended when using uEtG as an alcohol biomarker. Efforts to reach acceptable levels of sensitivity and specificity with commercial assays hold potential to advance the measurement of alcohol intake, overcoming the pitfalls of self-report data.

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.

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.

Human immunodeficiency virus and liver disease: A comprehensive update

Among persons living with human immunodeficiency virus (HIV) infection, liver disease remains a major cause of morbidity and mortality. While the etiologies are varied and often overlapping in the individual patient, the underlying mechanisms, including oxidative stress, direct activation of stellate cells, HIV interaction with hepatocytes, and bacterial translocation with systemic immune activation, seem to be unifying characteristics. Early and fully suppressive HIV antiretroviral therapy is a mainstay of management either before or concurrent with treatment of etiologic cofactors, including hepatitis C virus, hepatitis B virus, and nonalcoholic fatty liver disease/nonalcoholic steatohepatitis. Significant barriers to care that still exist include liver disease recognition, appropriate linkage to care, ongoing substance abuse, and psychiatric comorbidities in the HIV-infected population. Emerging issues in these patients include acute and chronic hepatitis E, underreported hepatitis D, and a rising incidence of hepatocellular carcinoma. (Hepatology Communications 2017;1:987-1001).

Sex-specific metabolic profiles of androgens and its main binding protein SHBG in a middle aged population without diabetes

The role of androgens in metabolism with respect to sex-specific disease associations is poorly understood. Therefore, we aimed to provide molecular signatures in plasma and urine of androgen action in a sex-specific manner using state-of-the-art metabolomics techniques. Our study population consisted of 430 men and 343 women, aged 20-80 years, who were recruited for the cross-sectional population-based Study of Health in Pomerania (SHIP-TREND), Germany. We used linear regression models to identify associations between testosterone, androstenedione and dehydroepiandrosterone-sulfate (DHEAS) as well as sex hormone-binding globulin and plasma or urine metabolites measured by mass spectrometry. The analyses revealed major sex-specific differences in androgen-associated metabolites, particularly for levels of urate, lipids and metabolic surrogates of lifestyle factors, like cotinine or piperine. In women, in particular in the postmenopausal state, androgens showed a greater impact on the metabolome than in men (especially DHEAS and lipids were highly related in women). We observed a novel association of androstenedione on the metabolism of biogenic amines and only a small sex-overlap of associations within steroid metabolism. The present study yields new insights in the interaction between androgens and metabolism, especially about their implication in female metabolism.

Biomarkers for the Detection of Prenatal Alcohol Exposure: A Review

Alcohol exposure during pregnancy can cause adverse effects to the fetus, because it interferes with fetal development, leading to later physical and mental impairment. The most common clinical tool to determine fetal alcohol exposure is maternal self-reporting. However, a more objective and useful method is based on the use of biomarkers in biological specimens alone or in combination with maternal self-reporting. This review reports on clinically relevant biomarkers for detection of prenatal alcohol exposure (PAE). A systematic search was performed to ensure a proper overview in existing literature. Studies were selected to give an overview on clinically relevant neonatal and maternal biomarkers. The direct biomarkers fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG), ethyl sulfate, and phosphatidylethanol (PEth) were found to be the most appropriate biomarkers in relation to detection of PAE. To review each biomarker in a clinical context, we have compared the advantages and disadvantages of each biomarker, in relation to its window of detectability, ease of collection, and the ease and cost of analysis of each biomarker. The biomarkers PEth, FAEEs, and EtG were found to be applicable for detection of even low levels of alcohol exposure. Meconium is an accessible matrix for determination of FAEEs and EtG, and blood an accessible matrix for determination of PEth.

Diagnosis of Alcoholic Liver Disease: Key Foundations and New Developments

Alcoholic liver disease is a spectrum of conditions that include alcoholic fatty liver disease, alcoholic hepatitis, and chronic alcoholic liver disease. The diagnosis of alcoholic liver disease remains founded in an accurate patient history and detailed physical examination. Concurrent with the physical examination, objective data from laboratory, imaging, and histologic studies are helpful to confirm a diagnosis of alcoholic liver disease. Novel biomarkers, scoring systems, and imaging modalities are improving the ability to diagnose and manage alcoholic liver disease, but for most practicing clinicians, these have not been adopted widely because of their cost, but also because of limitations and uncertainty in their performance characteristics.

Quantitation of Ethyl Glucuronide and Ethyl Sulfate in Urine Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Ethyl glucuronide and ethyl sulfate are minor conjugated metabolites of ethanol that can be detected in urine for several days after last ingestion of ethanol. The monitoring of ethanol use has both clinical and forensic applications and a longer detection window afforded by monitoring these metabolites is obvious. LC-MS/MS is used to analyze diluted urine with deuterated analogs of each analyte as internal standards to ensure accurate quantitation and control for any potential matrix effects. High aqueous HPLC is used to chromatograph the metabolites. Negative ion electrospray is used to introduce the metabolites into the mass spectrometer. Selected reaction monitoring of two product ions for each analyte allows for the calculation of ion ratios which ensures correct identification of each metabolite, while a matrix-matched calibration curve is used for quantitation.

Confounding factors and genetic polymorphism in the evaluation of individual steroid profiling

In the fight against doping, steroid profiling is a powerful tool to detect drug misuse with endogenous anabolic androgenic steroids. To establish sensitive and reliable models, the factors influencing profiling should be recognised. We performed an extensive literature review of the multiple factors that could influence the quantitative levels and ratios of endogenous steroids in urine matrix. For a comprehensive and scientific evaluation of the urinary steroid profile, it is necessary to define the target analytes as well as testosterone metabolism. The two main confounding factors, that is, endogenous and exogenous factors, are detailed to show the complex process of quantifying the steroid profile within WADA-accredited laboratories. Technical aspects are also discussed as they could have a significant impact on the steroid profile, and thus the steroid module of the athlete biological passport (ABP). The different factors impacting the major components of the steroid profile must be understood to ensure scientifically sound interpretation through the Bayesian model of the ABP. Not only should the statistical data be considered but also the experts in the field must be consulted for successful implementation of the steroidal module.

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.

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.

Ethyl glucuronide in hair and fingernails as a long-term alcohol biomarker

AIMS

This study aimed to evaluate the performance of ethyl glucuronide (EtG) in hair and fingernails as a long-term alcohol biomarker.

DESIGN

Cross-sectional survey with probability sampling.

SETTING

Midwestern United States.

PARTICIPANTS

Participants were 606 undergraduate college students between the ages of 18 and 25 years at the time of selection for potential study participation.

MEASUREMENTS

EtG concentrations in hair and fingernails were measured by liquid chromatography-tandem mass spectrometry at three thresholds [30 picograms (pg) per milligram (mg); 20 pg/mg; and 8 pg/mg]. Any weekly alcohol use, increasing-risk drinking and high-risk drinking on average during the past 12 weeks was assessed by participant interview using the time-line follow-back method.

FINDINGS

In both hair and fingernails at all three EtG thresholds, sensitivity was greatest for the high-risk drinking group [hair: 0.43, confidence interval (CI)=0.17, 0.69 at 30 pg/mg, 0.71, CI=0.47, 0.95 at 20 pg/mg; 0.93, CI=0.79, 1.00 at 8 pg/mg; fingernails: 1.00, CI=1.00-1.00 at 30, 20 and 8 pg/mg] and specificity was greatest for any alcohol use (hair: 1.00, CI=1.00, 1.00 at 30 and 20 pg/mg; 0.97, CI=0.92-0.99 at 8 pg/mg; fingernails: 1.00, CI=1.00-1.00 at 30, 20 and 8 pg/mg). Areas under the receiver operating characteristic curves were significantly higher for EtG concentration in fingernails than hair for any weekly alcohol use (P = 0.02, DeLong test, two-tailed) and increasing-risk drinking (P = 0.02, DeLong test, two-tailed).

CONCLUSIONS

Ethyl glucuronide, especially in fingernails, may have potential as a quantitative indicator of alcohol use.

Proteomic approaches and identification of novel therapeutic targets for alcoholism

Recent studies have shown that gene regulation is far more complex than previously believed and does not completely explain changes at the protein level. Therefore, the direct study of the proteome, considerably different in both complexity and dynamicity to the genome/transcriptome, has provided unique insights to an increasing number of researchers. During the past decade, extraordinary advances in proteomic techniques have changed the way we can analyze the composition, regulation, and function of protein complexes and pathways underlying altered neurobiological conditions. When combined with complementary approaches, these advances provide the contextual information for decoding large data sets into meaningful biologically adaptive processes. Neuroproteomics offers potential breakthroughs in the field of alcohol research by leading to a deeper understanding of how alcohol globally affects protein structure, function, interactions, and networks. The wealth of information gained from these advances can help pinpoint relevant biomarkers for early diagnosis and improved prognosis of alcoholism and identify future pharmacological targets for the treatment of this addiction.

Ethyl glucuronide for detecting alcohol lapses in patients with an alcohol use disorder

Urine ethyl glucuronide (EtG) was screened in 75 patients during a hospital-based treatment for an alcohol use disorder. During follow-up, EtG was detected in 35 (14.6%) of the 239 urine samples. Positive screens were found in 22 patients (29%), of whom nine were outpatients (39.1% of all outpatients) and 13 inpatients (25.0% of all inpatients). Of the 22 patients with positive EtG, five (22%) also gave a positive breath alcohol test and 10 (45.5%) reported recent alcohol consumption; 12 (54.5%) gave a negative breath alcohol test and declared no alcohol lapse. Ethyl glucuronide has been found useful in detecting covered lapses.

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.

Protein biomarkers of alcohol abuse

Alcohol abuse can lead to a number of health and social issues. Our current inability to accurately assess long-term drinking behaviors is an important obstacle to its diagnosis and treatment. Biomarkers for chronic alcohol consumption have made a number of important advances but have yet to become highly accurate and as accepted as objective tests for other diseases. Thus, there is a crucial need for the development of more sensitive and specific markers of alcohol abuse. Recent advancements in proteomic technologies have greatly increased the potential for alcohol abuse biomarker discovery. Here, the authors review established and novel protein biomarkers for long-term alcohol consumption and the proteomic technologies that have been used in their study.

Indicators for elevated risk factors for alcohol-withdrawal seizures: an analysis using a random forest algorithm

Alcohol-withdrawal seizures (AWS) are an important and relevant complication during detoxification in alcohol-dependent patients. Therefore, it is important to evaluate the individual risk for AWS. We apply a random forest algorithm to assess possible predictive markers in a large sample of 200 alcohol-dependent patients undergoing alcohol withdrawal. This analysis showed that the combination of homocysteine, prolactin, blood alcohol concentration on admission, number of preceding withdrawals, age and the number of cigarettes smoked may successfully predict AWS. In conclusion, the results of this analysis allow for origination of further research, which should include additional biological and psychosocial parameters as well as consumption behaviour.

Plasma proteomic alterations in non-human primates and humans after chronic alcohol self-administration

Objective diagnostics of excessive alcohol use are valuable tools in the identification and monitoring of subjects with alcohol use disorders. A number of potential biomarkers of alcohol intake have been proposed, but none have reached widespread clinical usage, often due to limited diagnostic sensitivity and specificity. In order to identify novel potential biomarkers, we performed proteomic biomarker target discovery in plasma samples from non-human primates that chronically self-administer high levels of ethanol. Two-dimensional difference in-gel electrophoresis (2D-DIGE) was used to quantify plasma proteins from within-subject samples collected before exposure to ethanol and after 3 months of excessive ethanol self-administration. Highly abundant plasma proteins were depleted from plasma samples to increase proteomic coverage. Altered plasma levels of serum amyloid A4 (SAA4), retinol-binding protein, inter-alpha inhibitor H4, clusterin, and fibronectin, identified by 2D-DIGE analysis, were confirmed in unmanipulated, whole plasma from these animals by immunoblotting. Examination of these target plasma proteins in human subjects with excessive alcohol consumption (and control subjects) revealed increased levels of SAA4 and clusterin and decreased levels of fibronectin compared to controls. These proteins not only serve as targets for further development as biomarker candidates or components of biomarker panels, but also add to the growing understanding of dysregulated immune function and lipoprotein metabolism with chronic, excessive alcohol consumption.

Psoriasis and unreported excessive alcohol intake--a simple screening approach

Psoriasis is a chronic immune-mediated skin disease of complex aetiology. Alcohol overuse has long been suspected to contribute to psoriasis pathology, and the knowledge of individual's drinking pattern may be of substantial importance for managing the disease. Unfortunately, a number of patients fail to admit to their true alcohol consumption and there is no single sign, symptom or laboratory parameter adequate for alcohol abuse diagnosis. However, there are some laboratory findings that, when present, should raise physician's suspicion that alcohol may be a problem. The aim of this article was to present simple, widely available and relatively reliable laboratory markers that might effectively assist physicians in establishing patient's drinking status. A possible screening approach is illustrated by two distinct reports of psoriatic patients who initially concealed having the problem with alcohol.

Phosphatidylethanol in blood (B-PEth): a marker for alcohol use and abuse

Phosphatidylethanol (PEth) represents a group of glycerophospholipid homologues where ethanol by phospholipase D has been bound at the position that normally contains an amino-alcohol. Since the formation of PEth is specifically dependent on ethanol, the diagnostic specificity of PEth as an alcohol biomarker is theoretically 100%. The half-life of PEth in blood is approximately 4 days. The amount of alcohol consumed correlates to blood concentration of PEth and PEth has been shown to be a more sensitive indicator of alcohol consumption than traditional alcohol markers, such as CDT (carbohydrate-deficient transferrin), GGT (γ-glutamyl transferase), and MCV (mean corpuscular volume) or a combination of these. Almost all clinical data so far available are based on a high performance liquid chromatography (HPLC) method with limited analytical sensitivity. With the advent of methods with considerably higher analytical sensitivity (e.g. mass spectrometric methods), clinical sensitivity will increase correspondingly. The possibility of determining very low concentrations of PEth by new sensitive analytical techniques may, however, have both ethical and legal consequences that have to be considered.

Molecular targets of alcohol action: Translational research for pharmacotherapy development and screening

Alcohol abuse and dependence are multifaceted disorders with neurobiological, psychological, and environmental components. Research on other complex neuropsychiatric diseases suggests that genetically influenced intermediate characteristics affect the risk for heavy alcohol consumption and its consequences. Diverse therapeutic interventions can be developed through identification of reliable biomarkers for this disorder and new pharmacological targets for its treatment. Advances in the fields of genomics and proteomics offer a number of possible targets for the development of new therapeutic approaches. This brain-focused review highlights studies identifying neurobiological systems associated with these targets and possible pharmacotherapies, summarizing evidence from clinically relevant animal and human studies, as well as sketching improvements and challenges facing the fields of proteomics and genomics. Concluding thoughts on using results from these profiling technologies for medication development are also presented.

Future prospects for biomarkers of alcohol consumption and alcohol-induced disorders

The lack of reliable measures of alcohol intake is a major obstacle to the diagnosis, treatment, and research of alcohol abuse and alcoholism. Successful development of a biomarker that allows for accurate assessment of alcohol intake and drinking patterns would not only be a major advance in clinical care but also a valuable research tool. A number of advances have been made in testing the validity of proposed biomarkers as well as in identifying potential new biomarkers through systems biology approaches. This commentary will examine the definition of a biomarker of heavy drinking, the types of potential biomarkers, the steps in biomarker development, the current state of biomarker development, and critical obstacles for the field. The challenges in developing biomarkers for alcohol treatment and research are similar to those found in other fields. However, the alcohol research field must reach a competitive level of rigor and organization. We recommend that NIAAA consider taking a leadership role in organizing investigators in the field and providing a common set of clinical specimens for biomarker validation studies.

Alcohol biomarkers in applied settings: recent advances and future research opportunities

During the past decade, advances have been made in the identification, development, and application of alcohol biomarkers. This is important because of the unique functions that alcohol biomarkers can serve in various applied settings. To carry out these functions, biomarkers must display several features including validity, reliability, adequacy of temporal window of assessment, reasonable cost, and transportability. During the past two decades, several traditional alcohol biomarkers have been studied in multiple human studies. Meanwhile, several new, promising biomarkers, including various alcohol metabolites and alcohol biosensors, are being explored in human studies. In addition, researchers have explored using biomarkers in combination and using biomarkers in combination with self-reports, resulting in increased sensitivity with little sacrifice in specificity. Despite these advances, more research is needed to validate biomarkers, especially the new ones, in humans. Moreover, recent advances in high-throughput technologies for genomics, proteomics, and metabolomics offer unique opportunities to discover novel biomarkers, while additional research is needed to perfect newly developed alcohol sensors. Development of more accurate biomarkers will help practicing clinicians to more effectively screen and monitor individuals who suffer from alcohol use disorders.

Circulating cytokines as biomarkers of alcohol abuse and alcoholism

There are currently no consistent objective biochemical markers of alcohol abuse and alcoholism. Development of reliable diagnostic biomarkers that permit accurate assessment of alcohol intake and patterns of drinking is of prime importance to treatment and research fields. Diagnostic biomarker development in other diseases has demonstrated the utility of both open, systems biology, screening for biomarkers and more rational focused efforts on specific biomolecules or families of biomolecules. Long-term alcohol consumption leads to altered inflammatory cell and adaptive immune responses with associated pathologies and increased incidence of infections. This has led researchers to focus attention on identifying cytokine biomarkers in models of alcohol abuse. Alcohol is known to alter cytokine levels in plasma and a variety of tissues including lung, liver, and very importantly brain. A number of cytokine biomarker candidates have been identified, including: tumor necrosis factor-alpha, interleukin (IL)-1-alpha, IL-1-beta, IL-6, IL-8, IL-12, and monocyte chemoattractant protein-1. This is an emerging and potentially exciting avenue of research in that circulating cytokines may contribute to diagnostic biomarker panels, and a combination of multiple biomarkers may significantly increase the sensitivity and specificity of the biochemical tests aiding reliable and accurate detection of excessive alcohol intake.