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]

Comparison of two methods for the extraction of ethylglucuronide from hair

The aim was the comparison between the Society of Hair Testing (SoHT) consensus for the use of alcohol markers which powdering hair for the extraction of ethylglucuronide (EtG) in water and extraction using the patented M3 Reagent Test kit on cut hair. Hair samples were cut into small segments and washed twice with methanol and diethyl ether. The SoHT-Consensus entails the extraction of pulverised hair in water. This is obtained by incubation of 25 mg of hair at room temperature overnight and 2 h sonication, even if the overnight incubation is not mandatory. The M3 method entails incubation of 25 mg of cut hair with the M3-Reagent at 100°C for 60 min. After centrifugation, the supernatant is injected into a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples (191) were collected in the APSS laboratory in Trento, Italy, between 2021 and 2022. The limit of quantification (LOQ) was set at 5 pg/mg for the pulverised and M3-Reagent methods. Assays showed good linearity above the range of LOQ-300 pg/mg. Precision (within 20%) values were also obtained using both methods. In the Passing-Bablock linear regression, the final regression curve between M3 (y) and the pulverising method (x) showed good agreement; the Bland-Altman analysis did not show any significant bias between the two methods. The M3-Reagent method, due to cut hair use, is easy to perform, saves time and allows for a smaller sample quantity loss with use of nondisposable grinding jars for the ball mill to obtain the extraction of EtG.

Biomarkers for monitoring alcohol sobriety after liver transplantation for alcoholic liver disease

Alcoholic liver disease (ALD) has become the most common indication for liver transplantation in Western countries, and its incidence is rapidly increasing in East Asia. Alcohol abstinence remains the standard of care for promoting liver transplantation for ALD and for preventing posttransplant graft loss. However, efficient monitoring methods are still being developed due to the limitations of traditional biomarkers, interviews, and questionnaires. The development of alcohol biomarkers has shifted from detecting alcohol and methanol to indirect byproducts, and to current mid-term and long-term direct alcohol metabolites, which provide higher accuracy and cover almost all types of alcohol relapse detection. However, in most clinical studies, biomarkers are used and validated in healthy individuals and alcohol use disorder (AUD) patients and for pretransplant evaluations. The evidence for their use in posttransplant abstinence monitoring is still lacking, but it is crucial for early detection of alcohol relapse and initiating intervention. This review aims to summarize the current evidence of the use of biomarkers for monitoring sobriety and alcohol relapse after liver transplantation, as well as to cover the diagnostic accuracy, detection window, and optimal multidisciplinary strategies.

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.

Comparison of self-reported alcohol consumption and ethyl glucuronide in hair in a sample of 60+ year -olds treated for DSM-5 alcohol use disorder

There is a lack of evidence for the consistency between self-reported alcohol consumption (SRAC) and concentrations of ethyl glucuronide in hair (hEtG) among elderly patients treated exclusively for alcohol use disorder (AUD). Hence, this study assessed the consistency between these two measures in these patients. A total of 190 patients with AUD were assessed for SRAC using Form 90 and hEtG, 14 or 22 weeks after treatment conclusion. Patients were grouped according to SRAC (g/day) and corresponding hEtG concentrations (pg/mg): 0 and <5 (abstinence), 0.1-14.3 and 5.0-9.9 (low consumption), 14.4-21.4 and 10.0-15.9 (moderate consumption), 21.5-59.9 and 16.0-30 (high consumption) and ≥60 and >30 (excessive consumption). The extent of underreporting and overreporting was examined by crosstabulations, and inter-rater reliability was reported by kappa correlations. Associations and effect modification were examined by conditional logistic regression. Due to multitesting, p-values ≤0.01 were considered significant. Underreporting was found in 96 patients (50.5%) and overreporting in 41 patients (21.6%). The kappa coefficients varied between 0.19 and 0.34. HEtG was more likely to detect low, moderate and high alcohol consumption compared with SRAC (ORs between 5.1 and 12.6, all p-values <0.01), but SRAC and hEtG did not differ significantly with respect to identification of abstinence (OR = 1.9, p = 0.05). Inconsistency between the outcome measures was found in a considerable number of the patients. More studies examining the consistency between SRAC and specific direct biomarkers of alcohol in this population seem warranted.

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.

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.

Diagnosis and Management of Alcohol Use Disorder in Patients with Liver Disease: Lights and Shadows

Alcohol use disorder is the most common cause of advanced liver disease in the Western world. Diagnosis of alcohol use disorder can be difficult because patients with liver disease tend to deny alcohol intake for the fear of being excluded from treatment and because available biomarkers of alcohol intake have poor specificity in these patients. Alcohol abstinence is the cornerstone of the therapy in these patients. However, pharmacological treatments for alcohol use disorders have not been formally tested in patients with advanced liver disease, except for baclofen. Psychosocial intervention became crucial in these patients considering the limited pharmacological choice. However, psychosocial approach and an appropriate team to manage these patients are not still well defined. In this review, we critically discuss the diagnosis and the management of alcohol use disorder in patients with liver disease.

The influence of caffeine on ethyl glucuronide levels in rat serum and in rat hair

BACKGROUND

Ethanol and caffeine are the most widely used psychoactive substances in the world, with an observed steady increase in the combined consumption of alcohol and caffeine. Specific signs of ethanol-caffeine interactions have been reported both in humans and in animals. The metabolic effects of these interactions have not been fully elucidated. There are no published reports on the influence of caffeine on ethyl glucuronide (EtG) formation. EtG is a direct metabolite of ethanol and is very often used as a biomarker of alcohol consumption. Here, we investigated the influence of caffeine on the formation of EtG in rat plasma and EtG incorporation into the hair.

METHODS

Studies were conducted on three male Wistar rat groups, each receiving either ethanol at 3 g/kg/day, ethanol (at the same dose) with caffeine at 3 mg/kg/day, or caffeine at 3 mg/kg/day for four weeks. EtG and caffeine levels were evaluated in hair and in blood after the last administration.

RESULTS

Blood EtG levels after the administration of ethanol together with caffeine were significantly higher than after the administration of ethanol alone. EtG levels in rat hair in the ethanol-and-caffeine group were also higher than in the ethanol-only group, but the difference was not statistically significant.

CONCLUSION

This study shows the possible effect of ethanol and caffeine co-administration on EtG formation. Caffeine stimulates EtG synthesis resulting in increased blood and, possibly, hair levels of this metabolite. However, the role of these changes in estimating alcohol consumption requires further studies.

Alcohol Biomarkers in Clinical and Forensic Contexts

BACKGROUND

Biomarkers of alcohol consumption are important not only in forensic contexts, e.g., in child custody proceedings or as documentation of alcohol abstinence after temporary confiscation of a driver's license. They are increasingly being used in clinical medicine as well for verification of abstinence or to rule out the harmful use of alcohol.

METHODS

This review is based on pertinent publications that were retrieved by a selective literature search in PubMed concerning the direct and indirect alcohol markers discussed here, as well as on the authors' experience in laboratory analysis and clinical medicine.

RESULTS

Alongside the direct demonstration of ethanol, the available markers of alcohol consumption include the classic indirect markers carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), and mean corpuscular volume (MCV) as well as direct alcohol markers such as ethyl glucuronide (EtG) and ethyl sulfate (EtS) in serum and urine and EtG and fatty acid ethyl esters (FAEE) in hair. Phosphatidylethanol (PEth) is a promising parameter that com - plements the existing spectrum of tests with high specificity (48-89%) and sensi - tivity (88-100%). In routine clinical practice, the demonstration of positive alcohol markers often leads patients to admit previously denied alcohol use. This makes it possible to motivate the patient to undergo treatment for alcoholism.

CONCLUSION

The available alcohol biomarkers vary in sensitivity and specificity with respect to the time period over which they indicate alcohol use and the minimum extent of alcohol use that they can detect. The appropriate marker or combination of markers should be chosen in each case according to the particular question that is to be answered by laboratory analysis.

Alcoholic hepatitis: appropriate indication for liver transplantation?

PURPOSE OF REVIEW

The majority of liver transplantation centers have required patients with alcohol-induced liver disease to demonstrate a period of abstinence (generally 6 months' duration) to qualify for transplant listing. This requirement has excluded patients with alcoholic hepatitis from transplant consideration. Since 2011, several studies have examined the outcomes of patients undergoing liver transplantation with brief abstinence as a lifesaving intervention for alcoholic hepatitis. This review includes each of the recent studies and discusses their implications for general transplant practice.

RECENT FINDINGS

A Medical Literature Analysis and Retrieval System search revealed five published studies - three prospective and two retrospective - pertaining to liver transplantation for alcoholic hepatitis. Among patients with medication-nonresponsive alcoholic hepatitis, those who underwent transplantation had superior survival. Liver recipients with alcoholic hepatitis had comparable survival to those with 6 or more months of abstinence. Their relapse rates were not statistically different in the short term over those transplanted with longer abstinence, although some patients in each prospective cohort relapsed to drinking despite narrow inclusion criteria and extensive pretransplant staff reviews and posttransplant surveillance.

SUMMARY

Liver transplantation is a reasonable treatment consideration for highly selective cases of alcoholic hepatitis. Further research is needed to refine inclusion criteria, address posttransplant relapse prevention interventions, and monitor long-term outcomes.

Biomarkers for detection of alcohol consumption in liver transplantation

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

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.