Hair ethyl glucuronide is highly sensitive and specific for detecting moderate-to-heavy drinking in patients with liver disease

ACG Clinical Guideline: Alcohol-Associated Liver Disease

ABSTRACT

Alcohol-associated liver disease (ALD) is the most common cause of advanced hepatic disease and frequent indication for liver transplantation worldwide. With harmful alcohol use as the primary risk factor, increasing alcohol use over the past decade has resulted in rapid growth of the ALD-related healthcare burden. The spectrum of ALD ranges from early asymptomatic liver injury to advanced disease with decompensation and portal hypertension. Compared with those with other etiologies of liver disease, patients with ALD progress faster and more often present at an advanced stage. A unique phenotype of advanced disease is alcohol-associated hepatitis (AH) presenting with rapid onset or worsening of jaundice, and acute on chronic liver failure in severe forms conveying a 1-month mortality risk of 20%-50%. The model for end stage disease score is the most accurate score to stratify AH severity (>20 defined as severe disease). Corticosteroids are currently the only available therapeutic with proven efficacy for patients with severe AH, providing survival benefit at 1 month in 50%-60% of patients. Abstinence of alcohol use, a crucial determinant of long-term outcomes, is challenging to achieve in ALD patients with concurrent alcohol use disorder (AUD). As patients with ALD are rarely treated for AUD, strategies are needed to overcome barriers to AUD treatment in patients with ALD and to promote a multidisciplinary integrated care model with hepatology, addiction medicine providers, and social workers to comprehensively manage the dual pathologies of liver disease and of AUD. Liver transplantation, a definitive treatment option in patients with advanced cirrhosis, should be considered in selected patients with AH, who are unresponsive to medical therapy and have a low risk of relapse to posttransplant alcohol use. Level of evidence and strength of recommendations were evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations system. This guideline was developed under the American College of Gastroenterology Practice Parameters Committee.

Driving license regranting: Hair EtG, serum CDT, and the role of sociodemographic and medicolegal variables

Driving under the influence (DUI) of alcohol is a road safety problem. Driving license regranting is based on the evaluation of medicolegal and toxicological variables that may include serum carbohydrate-deficient transferrin (CDT) and hair ethyl glucuronide (hEtG). The aim of the study was to compare the diagnostic performance of CDT and hEtG in a population of DUI offenders. Other factors potentially associated with heavy alcohol use were explored. The population included DUI offenders examined during the period of January 1, 2019, through June 30, 2022. Sociodemographic, medicolegal, and toxicological variables were collected. CDT in serum and EtG in head hair were determined in all subjects. Excessive alcohol intake (hEtG ≥30 pg/mg) was considered cause for unfitness to drive. Cohen's kappa coefficient was calculated. Descriptive analyses were performed using chi-square and Mann-Whitney tests. Variables significantly different between the groups were included in a multivariate binary logistic regression model. The sample encompassed 838 subjects (case group: 179, comparison group: 689). CDT exhibited poor agreement (κ = 0.053) with hEtG as the reference test. Lower education, age at DUI, heavy smoking, and GGT levels associated with heavy alcohol consumption differentiated the two groups. For DUI offenders, the use of CDT to assess heavy alcohol consumption is limited, possibly due to the time-window assessed, the time required for normalization, and the different amount of ethanol needed to reach higher CDT levels, in comparison to hEtG; thus, hEtG assessment is strongly recommended for this population. Heavy smoking, GGT, education, and age could be related to heavy alcohol consumption and higher risk of DUI.

Role of Biomarkers to Assess the Use of Alcohol

Alcohol-associated liver disease has seen a significant rise in the last 2 decades, with an associated rise in the need for accurate alcohol use assessment. Alcohol use has been associated with poor outcomes in both the pre-liver transplant and post-liver transplant patients. Patients with alcohol use disorder often under-report their alcohol consumption because of varying factors, highlighting the need for objective assessment of alcohol use. Aside from the available self-report questionnaires, multiple serologic biomarkers are currently available to assist clinicians to assess recent alcohol consumption among patients with chronic liver disease, liver transplant candidates, and recipients. In this review, we will assess some of these alcohol biomarkers, discuss their strengths and weakness, and review-available data to discuss their role in pre-liver transplant and post-liver transplant population.

Does ethyl glucuronide in hair correlate with alcohol consumption? A comparative study with other traditional biomarkers among individuals with alcohol dependence syndrome

AIM

Ethyl glucuronide (EtG) in hair is a direct biomarker proven to be useful for the detection of chronic excessive alcohol use. This study investigated the association of self-reported alcohol consumption with traditional biomarkers: GGT, AST, ALT, CDT, and MCV in blood and a direct biomarker, hair EtG, in a total of 122 patients with alcohol dependence syndrome. The diagnostic accuracy of the biomarkers to differentiate heavy from non-heavy drinkers was also evaluated.

METHOD

GGT, AST, and ALT in serum were measured by Automated Chemistry Analyzer, MCV in blood was measured by Haematology Analyzer, serum CDT was analyzed by ELISA, and EtG in hair was evaluated by gas chromatography-mass spectrometry. The association between the biomarkers and the amount of alcohol consumed (self-reported) was determined using Spearman's rank correlation.

RESULTS

All participants showed EtG level above the cut-off (0.03 ng/mg). Hair EtG showed a statistically significant linear and positive correlation with the amounts (in grams) of alcohol consumed (r = 0.60; p < 0.001). No correlation was observed among the traditional biomarkers and the quantity of alcohol consumed. Also, EtG showed an excellent receiver operating characteristic (ROC) curve (98%) with good sensitivity (85%) and specificity (60%) to classify heavy drinkers among individuals with alcohol dependence syndrome.

CONCLUSION

Hair EtG can be helpful to estimate retrospective alcohol consumption in long-term chronic alcohol consumption cases. Hair EtG also provides a reliable diagnostic test to detect heavy drinkers among individuals with alcohol dependence syndrome.

EtG Quantification in Hair and Different Reference Cut-Offs in Relation to Various Pathologies: A Scoping Review

Ethyl glucuronide (EtG) is a non-volatile, non-oxidative, hydrophilic, and stable ethanol phase II metabolite. EtG is produced through ethanol glucuronidation by UDP-glucuronosyltransferase (UGT), a phase II enzyme. EtG can be extracted from different biological matrices, including keratin ones, such as hair or nails. The purpose of this scoping review is to describe the relationship between EtG levels in hair and some of the most common and frequent pathological conditions and verify whether different reference cut-offs in relation to various pathologies have been identified in the scientific literature. In fact, in-depth knowledge of the influence of pathologies, such as diabetes mellitus, hepatic and renal dysfunction, on EtG production and its storage in keratin matrices would allow a more appropriate interpretation of obtained data and rule out false positives or false negatives. This scoping review is based on bibliographic research carried out on PubMed regarding the quantification of EtG in hair of subjects affected by different pathological conditions. According to the scientific literature, the main and most common pathologies that can affect the concentration of EtG in hair are liver and kidney diseases and diabetes. The EtG quantification analytical data should be interpreted carefully as they may have a great impact in both forensic and clinical contexts.

Liver transplantation for alcohol-related liver disease in the UK: revised UK Liver Advisory Group recommendations for referral

Liver disease, of which liver cirrhosis is the most advanced stage, constitutes the fourth most common cause of life-years lost in men and women younger than 75 years in England, where mortality rates from liver disease have increased by 25% in the past decade. Alcohol consumption is the most common modifiable risk factor for disease progression in these individuals, but within the UK, there is substantial variation in the distribution, prevalence, and outcome of alcohol-related liver disease, and no equity of access to tertiary transplantation services. These revised recommendations were agreed by an expert panel convened by the UK Liver Advisory Group, with the purpose of providing consensus on referral for transplant assessment in patients with alcohol-related disease, and clarifying the terminology and definitions of alcohol use in liver injury. By standardising clinical management in these patients, it is hoped that there will be an improvement in the quality of care and better access to liver transplant assessment for patients with alcohol-related liver disease in the UK.

Significance and clinical impact of routinely tested urinary ethyl glucuronide after liver transplantation - development of a risk score

BACKGROUND & AIMS

Alcohol abuse after liver transplantation can seriously impact graft and patient survival. However, to date, there is no defined standard procedure to identify patients consuming alcohol after liver transplantation. The aim of this study was to analyze the diagnostic value and clinical impact of routinely measured urinary ethyl glucuronide (uEtG) - a metabolite of ethanol - in patients after liver transplantation.

METHODS

Data of 362 consecutive patients after liver transplantation who visited the University Hospital of Tuebingen for outpatient follow-up were analyzed.

RESULTS

48 patients (13%) displayed positive uEtG results. The uEtG positive group contained significantly more patients with pre transplant alcoholic liver disease. However, two thirds of the uEtG positive patients had no history of pre transplant alcoholic liver disease. Several clinical parameters were significantly associated with positive uEtG. In order to enable a more cost-effective application of uEtG in the future, a clinical risk score was developed (specificity 0.95).

CONCLUSIONS

Routine testing for uEtG reveals a considerable percentage of patients practicing alcohol intake after liver transplantation. Application of our proposed risk score could help focusing uEtG testing on patients at risk.

Validation of hair ethyl glucuronide using transdermal monitoring and self-reported alcohol use in women of childbearing potential

AIM

The present study aimed to evaluate the validity of hair ethyl glucuronide concentrations compared with transdermal alcohol concentration and self-reported alcohol use.

METHODS

This trial included 25 adolescent and young adult females, aged 16-24, who reported at least one heavy drinking episode (≥4 drinks) in the two weeks prior to baseline. All participants were asked to wear an alcohol biosensor over a one-month prospective study. Detailed self-report of drinking behaviors was assessed weekly. Estimates of blood alcohol concentration were computed from self-report data using the National Highway and Transportation Safety Administration equation. Transdermal alcohol concentration and estimated blood alcohol concentration data were categorized into at-risk (>0.05 g/dL alcohol) and high-risk (>0.08 g/dL alcohol) drinking events. Hair ethyl glucuronide concentration, total number of drinking events, moderate (>0.05 g/dL) and high level (>0.08 g/dL) of transdermal alcohol concentration, and estimated blood alcohol concentration drinking events were analyzed with Spearman's rank correlation test for validity comparisons.

RESULTS

No significant correlations were found between hair ethyl glucuronide values and total number, and moderate or high levels of detected drinking events by estimated blood alcohol concentration or transdermal alcohol concentration. Total number of drinking events detected and number of drinking events >0.08 g/dL using estimated blood alcohol concentration and transdermal alcohol concentration methods were significantly correlated with each other (respectively, R = .33, P < .05; R = .42, P < .05).

CONCLUSION

Our findings indicate that, due to the number of false negatives, hair ethyl glucuronide concentrations should be used with caution for monitoring abstinence from alcohol use.

Validation of hair ethyl glucuronide using transdermal monitoring and self-reported alcohol use in women of childbearing potential

Aim

The present study aimed to evaluate the validity of hair ethyl glucuronide concentrations compared with transdermal alcohol concentration and self‐reported alcohol use.

Methods

This trial included 25 adolescent and young adult females, aged 16‐24, who reported at least one heavy drinking episode (≥4 drinks) in the two weeks prior to baseline. All participants were asked to wear an alcohol biosensor over a one‐month prospective study. Detailed self‐report of drinking behaviors was assessed weekly. Estimates of blood alcohol concentration were computed from self‐report data using the National Highway and Transportation Safety Administration equation. Transdermal alcohol concentration and estimated blood alcohol concentration data were categorized into at‐risk (>0.05 g/dL alcohol) and high‐risk (>0.08 g/dL alcohol) drinking events. Hair ethyl glucuronide concentration, total number of drinking events, moderate (>0.05 g/dL) and high level (>0.08 g/dL) of transdermal alcohol concentration, and estimated blood alcohol concentration drinking events were analyzed with Spearman's rank correlation test for validity comparisons.

Results

No significant correlations were found between hair ethyl glucuronide values and total number, and moderate or high levels of detected drinking events by estimated blood alcohol concentration or transdermal alcohol concentration. Total number of drinking events detected and number of drinking events >0.08 g/dL using estimated blood alcohol concentration and transdermal alcohol concentration methods were significantly correlated with each other (respectively, R = .33, P < .05; R = .42, P < .05).

Conclusion

Our findings indicate that, due to the number of false negatives, hair ethyl glucuronide concentrations should be used with caution for monitoring abstinence from alcohol use.

The Impact of COVID-19 Pandemic and Lockdown on Alcohol Consumption: A Perspective From Hair Analysis

Introduction and Aims: The increase in stress levels, social confinement, and addiction's physical consequences play an essential role in the proliferation of drug abuse. In this context, the Covid-19 pandemic produced remarkable effects on those individuals prone to addictions, especially to alcohol. Alcohol is linked to multiple dangerous conditions such as social issues, severe medical conditions, and road accidents. The determination of ethylglucuronide (EtG) in hair is frequently performed to test and monitor chronic excessive alcohol intake conditions, as it allows differentiation among low-risk/moderate drinkers, and excessive/chronic drinkers. Our study aimed to explore hair EtG levels in a controlled population to assess the impact of Covid-19 lockdown on alcohol intake along March-May 2020. Materials and Methods: EtG levels were measured in all hair samples collected in the months following April 2020 to evaluate the behaviors related to alcohol intake along with the time frame from March to May 2020. The measured concentration distributions for each month were compared with those reported in the same month during the previous 4 years (2016-2019). The dataset was built to highlight possible differences between genders, and the different categories of alcohol consumption, separately. Results: The samples collected from April to August 2020 (500 < N <1,100 per month) showed an increase in the percentage of subjects classified as abstinent/low-risk drinkers (from 60 up to 79%) and a decrease of subjects classified as moderate and chronic drinkers (-12 and -7%, respectively) when compared to the previous 4 years. A decrease in the overall mean value of EtG in the period April-June 2020 was observed, while the EtG levels of both June and July 2020 provided an increasing trend for chronic/excessive consumers (+27 and +19% for June and July 2020, respectively). A peculiar rise in the EtG levels of moderate and chronic/excessive female consumers was observed along April-June 2020, too. Discussion and Conclusions: Behavioral and social studies generally report a decrease in alcohol consumption during the Covid-19 lockdown. However, people already suffering from drug or alcohol addictions before Covid-19 pandemic seemingly enhance their harmful behavior. Our data from April to August 2020 are consistent with both suppositions. Our observations confirm once again the utility of EtG to investigate the patterns of alcohol consumption in the population.

Diagnostic Accuracy of Biomarkers of Alcohol Use in Patients With Liver Disease: A Systematic Review

BACKGROUND AND AIMS

Alcohol-related liver disease is the most frequent cause of cirrhosis and a major indication for liver transplantation. Several alcohol use biomarkers have been developed in recent years and are already in use in several centers. However, in patients with liver disease their diagnostic performance might be influenced by altered biomarker formation by hepatic damage, altered excretion by kidney dysfunction and diuretics use, and altered deposition in hair and nails. We systematically reviewed studies on the diagnostic accuracy of biomarkers of alcohol use in patients with liver disease and performed a detailed study quality assessment.

METHODS

A structured search in PubMed/Medline/Embase databases was performed for relevant studies, published until April 28, 2019. The risk of bias and applicability concerns was assessed according to the adapted quality assessment of diagnostic accuracy studies-2 (QUADAS-2) checklist.

RESULTS

Twelve out of 6,449 studies met inclusion criteria. Urinary ethyl glucuronide and urinary ethyl sulfate showed high sensitivity (70 to 89 and 73 to 82%, respectively) and specificity (93 to 99 and 86 to 89%, respectively) for assessing any amount of alcohol use in the past days. Serum carbohydrate-deficient transferrin showed low sensitivity but higher specificity (40 to 79 and 57 to 99%, respectively) to detect excessive alcohol use in the past weeks. Whole blood phosphatidylethanol showed high sensitivity and specificity (73 to 100 and 90 to 96%, respectively) to detect any amount of alcohol use in the previous weeks. Scalp hair ethyl glucuronide showed high sensitivity (85 to 100%) and specificity (97 to 100%) for detecting chronic excessive alcohol use in the past 3 to 6 months. Main limitations of the current evidence are the lack of an absolute gold standard to assess alcohol use, heterogeneous study populations, and the paucity of studies.

CONCLUSIONS

Urinary and scalp hair ethyl glucuronide are currently the most validated alcohol use biomarkers in patients with liver disease with good diagnostic accuracies. Phosphatidylethanol is a highly promising alcohol use biomarker, but so far less validated in liver patients. Alcohol use biomarkers can complement each other regarding diagnostic time window. More validation studies on alcohol use biomarkers in patients with liver disease are needed.

Impaired diagnostic accuracy of hair ethyl glucuronide testing in patients with renal dysfunction

The impact of renal impairment and hemodialysis on ethyl glucuronide concentrations in hair (hEtG) is not well known. Here, hEtG levels were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in patients presenting to the transplant outpatient clinic and compared with the self-reported alcohol consumption in an anonymous validated questionnaire. Estimated daily alcohol intake (EDI) was calculated. A total of 94 patients with varying renal function (Glomerular filtration rate (GFR) > 60 mL/min: group 1 (n = 47); GFR 30-60 ml/min: group 2 (n = 29); GFR < 30 mL/min: group 3 (n = 18)) were included in the study. Fifteen of 18 (83.3%) patients in group 3 were on dialysis. Altogether, hEtG tested positive (> 5 pg/mg) in 25.5% (n = 24) of patients, while 36.2% (n = 34) and 14.9% (n = 14) of patients reported any or regular (> 10 g/d) alcohol consumption, respectively. The median hEtG concentration of positive samples was much higher in patients in group 3 with advanced renal dysfunction or on dialysis than in patients in group 1 or 2 (group 1, 2, 3 dialysis patients: 74, 52, 145 and 155 pg/mg, respectively), although they consumed on average much less alcohol per day (median EDI group 1, 2, 3, dialysis patients: 16, 17, 3 and 3 g/d, respectively). Also, there was a significant correlation between the hEtG concentration and EDI for patients in group 1 (ρ = 0.84; p = 0.01), but not for patients in group 2 (ρ = -0.35, p = 0.39) or 3 (ρ = 0.02, p = 0.96). Furthermore, the ability of hEtG to correctly identify abstainers as such was lower for patients with advanced renal dysfunction than for the remaining patients (specificity for group 1, 2, 3: 92%, 87%, 82%, respectively). So, monitoring hEtG concentration was less reliable in patients with advanced renal dysfunction or on hemodialysis and by far overestimated the amount of alcohol consumed.

Management of end-stage alcohol-related liver disease and severe acute alcohol-related hepatitis: position paper of the Italian Society on Alcohol (SIA)

Worldwide, the prevalence of alcohol use disorder (AUD) is 20-30% in men and 10-15% in women, and cirrhosis due to alcohol-related liver disease (ALD) is responsible for 0.9% of global deaths and 47.9% of cirrhosis-related deaths. End-stage ALD (ESALD) is the final condition of alcohol-related cirrhosis, and severe acute alcohol-related hepatitis (SAAH) is a distinct clinical syndrome associated with the consumption of large amounts of alcohol. In some cases, ESALD, and SAAH may need liver transplantation (LT). Thus, the management of ESALD and SAAH in patients affected by AUD may be an essential part of the clinical skills for hepatologists. For these reasons, the national board of the Italian Society on Alcohol have reviewed the most recent data on the management of ESALD, SAAH and LT for ALD in patients with AUD, formulating a position paper with related recommendations regarding four issues of specific clinical interest in this field: (a) the management of hepatic encephalopathy in patients with AUD, and LT in patients with ESALD; (b) the management of SAAH; (c) the management of AUD in patients with ESALD and SAAH; (d) special populations: polydrug addicts.

Diagnosis and Treatment of Alcohol Use Disorder in Patients With End-Stage Alcoholic Liver Disease

Between 14%-30% of the world's population is affected by alcohol use disorder (AUD), and excessive alcohol consumption represents the most common cause of liver disease in the western world. The clinical picture of alcoholic end-stage liver disease is rendered extremely complex, as manifestations such as alcohol withdrawal syndrome, craving and physical dependence, as well as extrahepatic alcohol-related diseases merge with the complications of advanced cirrhosis. This makes AUD recognition and assessment difficult and its management arduous as many drugs commonly used to treat complications such as alcohol withdrawal syndrome are often contraindicated by the presence of hepatic encephalopathy or hepatorenal syndrome. Reaching and maintaining abstinence represents the mainstay of managing patients with AUD and end-stage liver disease. Psychosocial interventions are an essential component of treatment to reach these goals. However, these interventions alone often prove insufficient in AUD patients and even more frequently in those with end-stage liver disease because of inadequate adherence due to poor functional and physical status. Pharmacological treatments need to be associated, but the available options are greatly limited in end-stage liver disease because many GABA-Ergic drugs can favor the development of hepatic encephalopathy, whereas drugs undergoing extensive liver metabolism should be avoided or used with the greatest caution. Because of these limitations, the management of end-stage AUD is extremely challenging and requires an integrated multidisciplinary approach.

Ethyl glucuronide hair testing: A review

Ethyl glucuronide (EtG) is a minor, non-oxidative ethanol metabolite that can be detected in several matrices (e.g. blood, urine, hair, meconium) for variable periods of time. Quantification of EtG in hair (hEtG) has established itself, over recent years, as one of the most reliable biomarkers of long-term alcohol consumption habits, with the Society of Hair Testing (SoHT) offering cut-off values for assessment of both abstinence and heavy drinking (>60 g/day). Despite its high diagnostic performance, however, issues concerning inter- and intra-laboratory variability as well as data interpretation are still being investigated and represent the ultimate barrier to widespread acceptance of hEtG in the forensic context. The aim of this review is to summarize currently available analytical methods of hEtG testing, provide a framework to understand current hEtG cut-offs and their possible upcoming changes (in particular, a lower abstinence cut-off has been proposed for the 2019 revision of the SoHT consensus), and offer a schematic but exhaustive overview of the pitfalls in result reproducibility and interpretation that may limit applications of hEtG testing in the forensic context. Ultimately, the purpose of the authors is not to undermine the reliability of hEtG as an alcohol use marker, but rather to enhance it by promoting familiarization with all aspects related to it, from ethanol pharmacokinetics and EtG incorporation into hair, to sample preparation and analytical methods, to specific cases warranting close attention and additional tests for correct interpretation of hEtG results.

Ethyl Glucuronide as a Long-term Alcohol Biomarker in Fingernail and Hair. Matrix Comparison and Evaluation of Gender Bias

Aims

This work aimed to assess the performance of hair and fingernail ethyl glucuronide (EtG) measurement for use as a biomarker of alcohol consumption in persons with known drinking history across a range of drinking behaviours.

Methods

EtG concentrations were assessed from the hair and fingernails of 50 study participants. Alcohol consumption of the previous 90 days was assessed by participant interview using the alcohol timeline follow-back method. EtG concentration was determined using LC–MS-MS using a method which was validated and accredited to ISO/IEC 17025 standards.

Results

There was significant correlation between alcohol consumption and EtG concentrations found in hair and fingernail samples across the study group (n = 50). From participants testing positive for EtG (male n = 14, female n = 13) no significant difference was found between male and female EtG levels in either hair or fingernails. Across all participants there was no significant difference in hair or fingernail EtG concentration between male (n = 23) and females (n = 27).

Conclusions

Our results support the use of EtG to indicate alcohol consumption over the previous 90 days, or ~3 months as is the normal practice in hair analysis. The results confirm that fingernails can be a useful alternative matrix where hair samples are not available.

Alcohol and the Law

In the intersection of alcohol ingestion with the law, medical ethics, and public safety, physicians are often unsure about how to proceed. Physicians' primary focus should be on patient education with an ethical and legal duty to warn the patient of the adverse effects of alcohol. Warning third parties of potential harm related to alcohol-related impairment may involve a breach of patient confidentiality; therefore it should only be undertaken after careful analysis suggests that the risk for significant harm exceeds the burden that results to the patient from warning others. The law remains vague in this area.

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.

Influence of Body Mass Index on Hair Ethyl Glucuronide Concentrations

AIM

Analysis of ethyl glucuronide (EtG) concentrations in hair is increasingly used to estimate the consumption of alcohol of the prior months. Linear correlations between the amount of alcohol consumed and the concentration of EtG in hair have been reported, and several variables that may influence this correlation have been investigated: e.g. cosmetic hair treatments, gender influences or hair color. Here, we investigate the influence of body mass index (BMI) on this correlation.

METHODS

A post hoc analysis on the influence of BMI on the relation between amounts of alcohol consumed and the measured EtG concentrations in hair in 199 participants.

RESULTS

Our data show higher EtG concentrations in participants with high BMI (≥25) compared to participants with low BMI (<25) (P = 0.001) across a wide range of amounts of alcohol consumed.

CONCLUSIONS

We conclude that BMI should be taken into account when interpreting hair EtG concentrations.

SHORT SUMMARY

Ethyl glucuronide concentrations in hair (hEtG) can be used to estimate the consumption of alcohol of the prior months. Body mass index (BMI) influences this relation and BMI should be taken into account when interpreting hEtG concentrations in participants with high BMI (≥25) compared to participants with low BMI (<25).

Effects of various sample pretreatment procedures on ethyl glucuronide quantification in hair samples: Comparison of positivity rates and appraisal of cut-off values

The quantification of ethylglucuronide (EtG) in hair is nowadays recognized as the approach with the highest diagnostic performance to evaluate harmful drinking. A widely accepted cut-off of 30pg/mg has been selected after several accurate compared studies. While most of the studies that were used to establish the appropriate cut-off value prescribed to cut hair into small segments before their extraction, hair milling has subsequently been identified as the most efficient pretreatment procedure and was therefore recommended in the last Consensus document issued by the Society of Hair Testing. In this study, we initially compared the results obtained with the two sample preparations, namely cutting and milling, both being applied to the same specimens (n=781). Among these, 205 samples produced measurable EtG values with both methods, with differences ranging from -41.7% up to +415% (the mean increase in EtG concentration, switching from cutting to milling, was +62.1% and the median was +42.3%). Among the aforementioned 205 samples, 29 specimens (3.7% of the total 781 samples) produced significantly different outcome, being classified as negative (i.e., below 30pg/mg) if the cutting procedure is used, but largely positive (above 40pg/mg) when milling is used. Subsequently, the positivity rates obtained on a large population dataset (>27,000 samples) with the two procedures, were retrospectively compared using variable cut-offs values. The percentage of head hair samples with EtG concentration exceeding 30pg/mg upon application of the milling procedure shows a 45% increase (from 10.9% to 15.8%) with respect to cutting procedure, whereas the fraction of hair samples with EtG exceeding 40pg/mg (10.5%) overlaps the percentage of positive samples obtained after cutting pretreatment and applying a cut-off of 30pg/mg. On the basis of these results, it would be worth considering the application of cut-off values linked with the pretreatment procedure, taking into account the results of forthcoming inter-laboratory calibrations.

Determination of Ethyl Glucuronide in Hair for Detection of Alcohol Consumption in Patients After Liver Transplantation. Ther Drug Monit. 2015;37:539-545. [PMID: 25525763 DOI: 10.1097/ftd.0000000000000160]

BACKGROUND

Early detection of alcohol misuse in orthotopic liver transplantation recipients is essential to offer patients support and prevent organ damage. Here, ethyl glucuronide, a metabolite of ethanol found in hair (hEtG), was evaluated for detection of alcohol consumption.

METHODS

In 104 transplant recipients, 31 with underlying alcoholic liver disease (ALD) and 73 with non-ALD, hEtG was determined in addition to the alcohol markers urine EtG, blood ethanol, methanol, and carbohydrate-deficient transferrin. Results were compared with patients' self-reports in a questionnaire and with physicians' assessments.

RESULTS

By physicians' assessments, 22% of the patients were suspected of consuming alcohol regularly, although only 6% of the patients acknowledged consumption of a moderate or high amount of alcohol. By testing all markers except for hEtG, alcohol consumption was detected in 7% of the patients. When hEtG testing was added to the assessment, consumption was detected in 17% of the patients. Hair-EtG determination alone revealed chronic alcohol consumption of >10 g/d in 15% of the patients. ALD patients had a positive hEtG result significantly more often than non-ALD patients did (32% versus 8%; P = 0.003). Also, the concentration of hEtG was higher in ALD patients (P = 0.049) and revealed alcohol abuse with consumption of >60 g ethanol per day in 23% of ALD and 3% of non-ALD patients. Patients' self-reports and physicians' assessments had a low sensitivity of 27% and 67%, respectively, for detecting regular alcohol intake as indicated by hEtG.

CONCLUSIONS

Hair-EtG determination improved the detection of liver transplant patients who used alcohol, and revealed regular alcohol consumption in 32% of ALD and 8% of non-ALD patients.

A wearable biochemical sensor for monitoring alcohol consumption lifestyle through Ethyl glucuronide (EtG) detection in human sweat

We demonstrate for the first time a wearable biochemical sensor for monitoring alcohol consumption through the detection and quantification of a metabolite of ethanol, ethyl glucuronide (EtG). We designed and fabricated two co-planar sensors with gold and zinc oxide as sensing electrodes. We also designed a LED based reporting for the presence of EtG in the human sweat samples. The sensor functions on affinity based immunoassay principles whereby monoclonal antibodies for EtG were immobilized on the electrodes using thiol based chemistry. Detection of EtG from human sweat was achieved through chemiresistive sensing mechanism. In this method, an AC voltage was applied across the two coplanar electrodes and the impedance across the sensor electrodes was measured and calibrated for physiologically relevant doses of EtG in human sweat. EtG detection over a dose concentration of 0.001–100 μg/L was demonstrated on both glass and polyimide substrates. Detection sensitivity was lower at 1 μg/L with gold electrodes as compared to ZnO, which had detection sensitivity of 0.001 μg/L. Based on the detection range the wearable sensor has the ability to detect alcohol consumption of up to 11 standard drinks in the US over a period of 4 to 9 hours.

Ethylglucuronide in maternal hair as a biomarker of prenatal alcohol exposure

While direct ethanol metabolites, including ethylglucuronide (EtG), play an important role for the confirmation of prenatal alcohol exposure (PAE), their utility is often limited by their short half-lives in blood and urine. Maternal hair allows for a retrospective measure of PAE for up to several months. This study examined the validity of hair EtG (hEtG) relative to self-reporting and five other biomarkers in 85 pregnant women. Patients were recruited from a UNM prenatal clinic, which provides care to women with substance abuse and addiction disorders. The composite index, which was based on self-reported measures of alcohol use and allowed us to classify subjects into PAE (n = 42) and control (n = 43) groups, was the criterion measure used to estimate the sensitivity and specificity of hEtG. Proximal segments of hair were collected at enrollment (average 22.0 gestational weeks) and analyzed by LC-MS/MS. At the same visit, maternal blood and urine specimens were collected for analysis of GGT, %dCDT, PEth, uEtG, and uEtS. The study population included mostly opioid-dependent (80%) patients, a large proportion of ethnic minorities (75.3% Hispanic/Latina, 8.2% American Indian, 4.7% African-American), and patients with low education (48.2% < high school). The mean maternal age at enrollment was 26.7 ± 4.8 years. Hair EtG demonstrated 19% sensitivity and 86% specificity. The sensitivities of other biomarkers were comparable (5-20%) to hEtG but specificities were higher (98-100%). Hair EtG sensitivity improved when combined with other biomarkers, especially with GGT (32.5%) and PEth (27.5%). In addition, validity of hEtG improved in patients with less frequent shampooing and those who did not use hair dyes/chemical treatments. These data suggest that hEtG alone is not a sufficiently sensitive or specific biomarker to be used separately for the identification of PAE, but might be useful in a battery along with other maternal biomarkers.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

Examination of sex differences in fatty acid ethyl ester and ethyl glucuronide hair analysis

Clinical studies examining performance of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in identifying excessive alcohol consumption have been primarily conducted in male populations. An impact of hair cosmetics in producing both false-negative EtG results and false-positive FAEE results has been demonstrated, suggesting a possible bias in female populations. This study evaluates FAEE-positive hair samples (>0.50 ng/mg) from n = 199 female and n = 73 male subjects for EtG. Higher FAEE/EtG concordance was observed amongst male over female subjects. Performance of multiple proposed EtG cut-off levels were assessed; amongst female samples, FAEE/EtG concordance was 36.2% (30 pg/mg), 36.7% (27 pg/mg), and 43.7% (20 pg/mg). Non-coloured hair demonstrated a two-fold increase in concordance (41.8 v. 20.8%) over coloured hair in the female cohort. FAEE levels did not differ between male and female subjects; however they were lower in coloured samples (p = 0.046). EtG was lower in female subjects (p = 0.019) and coloured samples (p = 0.026). A total of n = 111 female samples were discordant. Amongst discordant samples (EtG-negative), 26% had evidence of recent alcohol use including consultation histories (n = 20) and detectable cocaethylene (n = 9); 29% of discordant samples were coloured. False-negative risk with ethyl glucuronide analysis in females was mediated by cosmetic colouring. These findings suggest that combined analysis of FAEE and EtG is optimal when assessing a female population and an EtG cut-off of 20 pg/mg is warranted when using combined analysis. While concordant FAEE/EtG-positive findings constitute clear evidence, discordant FAEE/EtG findings should still be considered suggestive evidence of chronic excessive alcohol consumption.

Hair ethyl glucuronide as a biomarker of alcohol consumption in alcohol-dependent patients: role of gender differences

BACKGROUND

Ethyl glucuronide (EtG) is a minor alcohol metabolite that accumulates in hair and is proposed as a stable marker for the detection of chronic and excessive alcohol consumption above a cut-off level of 30pg/mg hair. A correlation between drinking behavior and EtG hair concentrations is observed, but large variability exists.

AIMS

To investigate the correlation between alcohol consumption and hair EtG concentrations in alcohol dependent patients, and the effect of gender differences as a factor for the variability on this correlation.

METHODS

EtG was measured by gas chromatography coupled to mass spectrometry in the hairs (first 3cm) of 36 alcohol dependent patients (25 males/11 females) starting and alcohol detoxification program. Factors that possibly influence EtG content in hair (except age and gender) were excluded. Detailed retrospective alcohol consumption was obtained over the last 3 months using the Timeline Follow Back interview.

RESULTS

Median total alcohol consumption over 3 months was 13,050g pure alcohol (range 60-650g/day). Hair EtG concentrations varied between 32 and 662pg/mg. There was a statistically significant linear and positive correlation between hair EtG and amounts of alcohol consumed (Pearson r=0.83; p<0.001), in both males (Pearson r=0.83; p<0.001) and females (Pearson r=0.76; p=0.007).

CONCLUSIONS

There is a linear correlation, with no significant effect of gender, between hair EtG concentrations and amounts of alcohol consumed in alcohol-dependent individuals. Analysis of EtG in hair can be applied to estimate retrospective alcohol consumption in both male and female alcohol dependent subjects using the same cut-off.

Validation of blood phosphatidylethanol as an alcohol consumption biomarker in patients with chronic liver disease

BACKGROUND

Blood phosphatidylethanol (PEth) is a promising biomarker of alcohol consumption. This study was conducted to evaluate its performance in patients with liver disease.

METHODS

This study included 222 patients with liver disease. Patient-reported alcohol use was obtained as a reference standard, and PEth was measured by tandem mass spectrometry. Receiver operating characteristic (ROC) and contingency table analyses were used to assess the performance of PEth in detecting any drinking and averaging 4 or more drinks daily in the past 30 days.

RESULTS

At the limit of quantitation (20 ng/ml), PEth was 73% sensitive (95% confidence interval [CI] 65 to 80) and 96% specific (95% CI 92 to 100) for any drinking in the past month. Subjects who drank but had a negative PEth result were mainly light drinkers. Subjects who reported 30-day abstinence but with quantifiable PEth either reported heavy drinking within the past 6 weeks or had data that suggested underreported drinking. At the optimal cutoff concentration of 80 ng/ml, PEth was 91% sensitive (95% CI 82 to 100) and 77% specific (95% CI 70 to 83) for averaging at least 4 drinks daily.

CONCLUSIONS

PEth is a useful test for detecting alcohol use in patients with liver disease, but cutoff concentrations for heavy drinking will result in misclassification of some moderate to heavy drinkers.

Ethyl glucuronide and ethyl sulfate

Alcohol misuse is associated with significant morbidity and mortality. Although clinical history, examination, and the use of self-report questionnaires may identify subjects with harmful patterns of alcohol use, denial or under-reporting of alcohol intake is common. Existing biomarkers for detecting alcohol misuse include measurement of blood or urine ethanol for acute alcohol consumption, and carbohydrate-deficient transferrin and gamma-glutamyl transferase for chronic alcohol misuse. There is a need for a biomarker that can detect excessive alcohol consumption in the timeframe between 1 day and several weeks. Ethyl glucuronide (EtG) is a direct metabolite of ethanol detectable in urine for up to 90 h and longer in hair. Because EtG has high specificity for excess alcohol intake, it has great potential for use in detecting "binge" drinking. Using urine or hair, this noninvasive marker has a role in a variety of clinical and forensic settings.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

[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.

Determination of ethyl glucuronide levels in hair for the assessment of alcohol abstinence

This study examined the potential of a highly sensitive LC-MS/MS method for the determination of EtG in head hair (i) to ascertain alcohol abstinence, (ii) to estimate the basal level of EtG (sub-ppb concentrations) in head hair in a population of alcohol abstainers and (iii) to suggest a revision of cut-off values for assessing alcohol abstinence. An UHPLC-MS/MS protocol previously developed was modified and validated again to detect low EtG levels in head hair samples from a population of 44 certain abstainers and teetotalers. Basal level of EtG in hair was determined by a standard addition quantification method. The validated UHPLC-MS/MS method allowed detecting and quantifying 0.5 and 1.0 pg/mg of EtG in hair, respectively. EtG concentrations lower than 1.0 pg/mg were determined for 95% of abstainers; 30% of them had non-detectable (<0.5 pg/mg) EtG values. Two samples evidenced EtG concentrations higher than 1.0 pg/mg that were subsequently explained by unintentional ethanol exposure. The method's feature of high analytical sensitivity makes it particularly suitable for alcohol abstinence ascertainment and, in the same time, allows to tentatively estimate basal EtG concentrations in hair around 0.8±0.4 pg/mg. This finding opens a discussion on the possible origin of basal EtG concentration and potential sources of bias in the evaluation of alcohol abstinence. Cut-off value in the range of 1.0-2.0 pg/mg can be reliably proposed to support alcohol abstinence.