Monitoring of the alcohol biomarkers PEth, CDT and EtG/EtS in an outpatient treatment setting

Phosphatidylethanol (PEth) as a Biomarker of Alcohol Consumption in HIV-Infected Young Russian Women: Comparison to Self-Report Assessments of Alcohol Use

Alcohol use is particularly deleterious for HIV-infected individuals and thus accurate assessment of alcohol consumption is crucial in this population. Phosphatidylethanol (PEth) provides an objective assessment of drinking and can be compared to self-reported alcohol assessments to detect underreporting. The purpose of this study was to identify underreporting and its potential predictors in an HIV-infected sample of young Russian women. The current study examined the concordance between a quantitative measure of PEth and self-reported recent alcohol consumption in a prospective sample of HIV-infected young women (N = 204) receiving medical care in Saint Petersburg, Russia. At baseline, 53% of participants who denied drinking in the prior 30 days tested positive for PEth (i.e., underreporters), although this rate decreased significantly at a three-month follow-up assessment. Further exploration did not identify consistent predictors of underreporting status. Quantitative PEth levels showed, at best, modest overlap to self-reported alcohol consumption among those reporting alcohol use (e.g., Spearman's r = 0.27 between PEth and total drinks past-30 days at baseline). Objective measures of alcohol consumption demonstrate modest overlap with self-report measures of use in HIV-infected young Russian women. Incorporating objective and quantifiable biological markers are essential for valid assessments of alcohol use.

Binge Drinking Episodes in Young Adults: How Should We Measure Them in a Research Setting?

OBJECTIVE

Worldwide, consequences of binge drinking are a major health and policy concern. This article reviews contemporary binge drinking definitions as well as different questionnaires and biomarkers that have been used in research settings to examine binge drinking behavior among young adults.

METHOD

A review of electronic databases was conducted for binge drinking definitions, questionnaires, and biomarkers for the measurement of binge drinking in young adults (18-30 years).

RESULTS

Binge drinking is often defined as four or more drinks for females and five or more drinks for males on an occasion or in one sitting within a designated time frame (2 weeks vs. past 30 days). Several tools and questionnaires are available to identify young adult repeated binge drinkers. Biomarkers have been used to corroborate self-reported alcohol consumption, of which direct biomarkers such as phosphatidylethanol may be useful in confirming recent heavy drinking.

CONCLUSIONS

It is important to measure binge drinking along a continuum and to use questions that allow for assessment of intensity, frequency, duration, and daily versus weekend consumption patterns. Open-ended questions that allow for intensity (number of drinks) and frequency can be used to determine dose-response relationships with respect to specific outcome measures. Direct alcohol biomarkers reflecting alcohol consumption over a period of several days are useful in conjunction with questionnaire data for identifying young adult binge drinkers.

Infrared analysis of lipoproteins in the detection of alcohol biomarkers

Background:

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

Methods:

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

Results:

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

Conclusions:

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

Sparse canonical correlation analysis between an alcohol biomarker and self-reported alcohol consumption

In investigating the correlation between an alcohol biomarker and self-report, we developed a method to estimate the canonical correlation between two high-dimensional random vectors with a small sample size. In reviewing the relevant literature, we found that our method is somewhat similar to an existing method, but that the existing method has been criticized as lacking theoretical grounding in comparison with an alternative approach. We provide theoretical and empirical grounding for our method, and we customize it for our application to produce a novel method, which selects linear combinations that are step functions with a sparse number of steps.

Alcohol Consumption in Concomitant Liver Disease: How Much is Too Much?

Purpose of Review

High consumption of alcohol can lead to cirrhosis. The risk of a low to moderate consumption of alcohol in the setting of a concurrent liver disease is less clear. The aim of this review is to sum the evidence on the risk of adverse outcomes in patients with liver diseases other than alcoholic liver disease who consume alcohol.

Recent Findings

High alcohol consumption is strongly associated with adverse outcomes in most liver diseases. For hepatitis C, some evidence points to an increased risk for fibrosis progression also with low amounts. For non-alcoholic fatty liver disease, most studies indicate an inverse association between fibrosis and alcohol consumption, but methodological limitations reduce inference.

Summary

High alcohol consumption is associated with an increased risk of fibrosis progression and other adverse outcomes, while less is clear regarding low to moderate consumption. Obtaining high-level evidence on this topic ought to be the objective of future studies. Currently, an individual risk profile should be obtained in patients with liver disease who consume alcohol.

Treatment of Alcohol Use Disorder in Patients with Alcoholic Liver Disease

Alcohol is a leading cause of liver disease worldwide. Although alcohol abstinence is the crucial therapeutic goal for patients with alcoholic liver disease, these patients have less access to psychosocial, behavioral, and/or pharmacologic treatments for alcohol use disorder. Psychosocial and behavioral therapies include 12-step facilitation, brief interventions, cognitive behavioral therapy, and motivational enhancement therapy. In addition to medications approved by the US Food and Drug Administration for alcohol use disorder (disulfiram, naltrexone, and acamprosate), recent efforts to identify potential new treatments have yielded promising candidate pharmacotherapies. Finally, more efforts are needed to integrate treatments across disciplines toward patient-centered approaches in the management of patients with alcohol use disorder and alcoholic liver disease.

Low to moderate lifetime alcohol consumption is associated with less advanced stages of fibrosis in non-alcoholic fatty liver disease

BACKGROUND AND AIM

Moderate alcohol consumption has been associated with a lower risk of disease severity in non-alcoholic fatty liver disease (NAFLD). It is unclear if this reflects current or lifetime drinking, or can be attributed to confounders such as diet and exercise. We evaluated the impact of lifetime alcohol consumption on fibrosis severity in NAFLD.

METHODS

We prospectively enrolled 120 subjects with biopsy-proven NAFLD and through detailed questionnaires examined lifetime alcohol consumption, diet and physical activity. Main outcome measures were odds ratios (OR) for fibrosis stage, calculated through ordinal regression after adjustment for body mass index, diabetes mellitus type 2, smoking and age at biopsy. A biomarker for recent alcohol consumption, phosphatidyl ethanol (PEth) was sampled.

RESULTS

An increase in median weekly alcohol consumption to a maximum of 13 drinks per week was associated with lower fibrosis stage (adjusted OR for each incremental unit, 0.86; 95% CI, 0.76-0.97; p = .017). The lowest risk for fibrosis was found with the lowes`t odds seen in the top quartile of alcohol consumption (aOR 0.23; 95% CI 0.08-0.66; p = .006). Adding soft drink and coffee consumptions, and physical activity to the model did not change the estimates. Subjects with PEth ≥0.3 μmol/L had higher ORs for a higher fibrosis stage (aOR 2.77; 95% CI 1.01-7.59; p = .047).

CONCLUSION

Lifetime alcohol consumption with up to 13 units per week is associated with lower fibrosis stage in NAFLD. Elevated PEth is associated with higher stages of fibrosis.

Counselling for Alcohol Problems (CAP), a lay counsellor-delivered brief psychological treatment for harmful drinking in men, in primary care in India: a randomised controlled trial

BACKGROUND

Although structured psychological treatments are recommended as first-line interventions for harmful drinking, only a small fraction of people globally receive these treatments because of poor access in routine primary care. We assessed the effectiveness and cost-effectiveness of Counselling for Alcohol Problems (CAP), a brief psychological treatment delivered by lay counsellors to patients with harmful drinking attending routine primary health-care settings.

METHODS

In this randomised controlled trial, we recruited male harmful drinkers defined by an Alcohol Use Disorders Identification Test (AUDIT) score of 12-19 who were aged 18-65 years from ten primary health centres in Goa, India. We excluded patients who needed emergency medical treatment or inpatient admission, who were unable to communicate clearly, and who were intoxicated at the time of screening. Participants were randomly allocated (1:1) by trained health assistants based at the primary health centres to enhanced usual care (EUC) alone or EUC combined with CAP, in randomly sized blocks of four to six, stratified by primary health centre, and allocation was concealed with use of sequential numbered opaque envelopes. Physicians providing EUC and those assessing outcomes were masked. Primary outcomes were remission (AUDIT score of <8) and mean daily alcohol consumed in the past 14 days, at 3 months. Secondary outcomes were the effect of drinking, disability score, days unable to work, suicide attempts, intimate partner violence, and resource use and costs of illness. Analyses were on an intention-to-treat basis. We used logistic regression analysis for remission and zero-inflated negative binomial regression analysis for alcohol consumption. We assessed serious adverse events in the per-protocol population. This trial is registered with the ISCRTN registry, number ISRCTN76465238.

FINDINGS

Between Oct 28, 2013, and July 29, 2015, we enrolled and randomly allocated 377 participants (188 [50%] to the EUC plus CAP group and 190 [50%] to the EUC alone group [one of whom was subsequently excluded because of a protocol violation]), of whom 336 (89%) completed the 3 month primary outcome assessment (164 [87%] in the EUC plus CAP group and 172 [91%] in the EUC alone group). The proportion with remission (59 [36%] of 164 in the EUC plus CAP group vs 44 [26%] of 172 in the EUC alone group; adjusted prevalence ratio 1·50 [95% CI 1·09-2·07]; p=0·01) and the proportion abstinent in the past 14 days (68 [42%] vs 31 [18%]; adjusted odds ratio 3·00 [1·76-5·13]; p<0·0001) were significantly higher in the EUC plus CAP group than in the EUC alone group, but we noted no effect on mean daily alcohol consumed in the past 14 days among those who reported drinking in this period (37·0 g [SD 44·2] vs 31·0 g [27·8]; count ratio 1·08 [0·79-1·49]; p=0·62). We noted an effect on the percentage of days abstinent in the past 14 days (adjusted mean difference [AMD] 16·0% [8·1-24·1]; p<0·0001), but no effect on the percentage of days of heavy drinking (AMD -0·4% [-5·7 to 4·9]; p=0·88), the effect of drinking (Short Inventory of Problems score AMD-0·03 [-1·93 to 1·86]; p=0.97), disability score (WHO Disability Assessment Schedule score AMD 0·62 [-0·62 to 1·87]; p=0·32), days unable to work (no days unable to work adjusted odds ratio 1·02 [0·61-1·69]; p=0.95), suicide attempts (adjusted prevalence ratio 1·8 [-2·4 to 6·0]; p=0·25), and intimate partner violence (adjusted prevalence ratio 3·0 [-10·4 to 4·4]; p=0·57). The incremental cost per additional remission was $217 (95% CI 50-1073), with an 85% chance of being cost-effective in the study setting. We noted no significant difference in the number of serious adverse events between the two groups (six [4%] in the EUC plus CAP group vs 13 [8%] in the EUC alone group; p=0·11).

INTERPRETATION

CAP delivered by lay counsellors plus EUC was better than EUC alone was for harmful drinkers in routine primary health-care settings, and might be cost-effective. CAP could be a key strategy to reduce the treatment gap for alcohol use disorders, one of the leading causes of the global burden among men worldwide.

FUNDING

Wellcome Trust.

[New biomarkers for assesing alcohol consumption]

Alcohol abuse has significant medical, social and socioeconomic consequences. Alcohol biomarkers may serve as a useful tool in identifying individuals with excessive alcohol consumption in medical as well as medico-legal contexts.

Quantification of EtG in hair, EtG and EtS in urine and PEth species in capillary dried blood spots to assess the alcohol consumption in driver's licence regranting cases

BACKGROUND

In Belgium, the analysis of indirect biomarkers such as carbohydrate deficient transferrin (CDT%), gamma-glutamyltransferase (GGT), aspartate aminotransferase/alanine aminotransferase (AST/ALT) and mean corpuscular volume (MCV), is currently used to monitor the alcohol consumption in cases of fitness to drive assessment. We evaluated the use of direct ethanol markers for this purpose, exclusively determined in matrices obtained via non- or minimally invasive sampling.

METHODS

Three validated quantitative methods (ethylglucuronide (EtG) in hair and urine, ethylsulfate (EtS) in urine, and phosphatidylethanol species (PEth 16:0/18:1, PEth 18:1/18:1 and PEth 16:0/16:0) in capillary dried blood spots (C-DBS)) were used. Fifty volunteers, for whom fitness to drive had to be assessed and for whom a blood analysis for indirect biomarkers was requested, were included in the study. The sampling and analysis of hair, urine and C-DBS were added to the process currently used.

RESULTS

Hair EtG (24/50) and C-DBS PEths (29/50) are more sensitive than the currently used indirect biomarkers (13/50 for CDT%) to detect excessive and chronic alcohol consumption and allow to disprove an abstinence period. Urinary EtG and EtS are useful parameters to determine recent alcohol consumption.

CONCLUSION

The combined use of the three strategies allows better inference about the evolution of the alcohol consumption prior to the sampling. Moreover, the exclusive use of non- or minimally invasive sampling (hair, urine and C-DBS) allows this to be performed directly during the fitness to drive assessment by regular staff members. This approach offers the potential to improve the Belgian driver's licence regranting process.

Fetal alcohol-spectrum disorders: identifying at-risk mothers

Fetal alcohol-spectrum disorders (FASDs) are a collection of physical and neurobehavioral disabilities caused by prenatal exposure to alcohol. To prevent or mitigate the costly effects of FASD, we must identify mothers at risk for having a child with FASD, so that we may reach them with interventions. Identifying mothers at risk is beneficial at all time points, whether prior to pregnancy, during pregnancy, or following the birth of the child. In this review, three approaches to identifying mothers at risk are explored: using characteristics of the mother and her pregnancy, using laboratory biomarkers, and using self-report assessment of alcohol-consumption risk. At present, all approaches have serious limitations. Research is needed to improve the sensitivity and specificity of biomarkers and screening instruments, and to link them to outcomes as opposed to exposure. Universal self-report screening of all women of childbearing potential should ideally be incorporated into routine obstetric and gynecologic care, followed by brief interventions, including education and personalized feedback for all who consume alcohol, and referral to treatment as indicated. Effective biomarkers or combinations of biomarkers may be used during pregnancy and at birth to determine maternal and fetal alcohol exposure. The combination of self-report and biomarker screening may help identify a greater proportion of women at risk for having a child with FASD, allowing them to access information and treatment, and empowering them to make decisions that benefit their children.

Urine ethyl glucuronide and ethyl sulphate using liquid chromatography-tandem mass spectrometry in a routine clinical laboratory

Background

Detection of alcohol consumption in clients undergoing treatment for alcohol dependence can be difficult. The ethanol metabolites ethyl glucuronide and ethyl sulphate are detectable for longer in urine than either breath ethanol or urine ethanol. Our aim was to develop a liquid chromatography-tandem mass spectrometry method for urine ethyl glucuronide and ethyl sulphate for use in a routine clinical laboratory and define clinical cut-offs in a large population who had not consumed alcohol for at least two weeks.

Methods

Urine samples were diluted in 0.05% formic acid in HPLC grade water and then directly injected onto a Waters Acquity ultra high performance liquid chromatography coupled to a Waters TQ Detector. Eighty participants were recruited who had not consumed alcohol for at least two weeks to define cut-offs for urine ethyl glucuronide and ethyl sulphate. Samples and alcohol diaries were also collected from 12 alcohol-dependent clients attending a treatment programme.

Results

The assay was validated with a lower limit of quantitation of 0.20 mg/L for ethyl glucuronide and 0.04 mg/L for ethyl sulphate. Accuracy, precision, linearity and recovery were acceptable. Cut-offs were established for ethyl glucuronide, ethyl sulphate and ethyl sulphate/creatinine ratio (≤0.26 mg/L, ≤0.22 mg/L and ≤0.033 mg/mmol, respectively) in a non-drinking population. The validated cut-offs correctly identified clients in alcohol treatment who were continuing to drink alcohol.

Conclusions

A simple liquid chromatography-tandem mass spectrometry method for urine ethyl glucuronide and ethyl sulphate has been validated and cut-offs defined using 80 participants who had not consumed alcohol for at least two weeks. This is the largest study to date to define cut-offs for ethyl glucuronide, ethyl sulphate and ethyl sulphate/creatinine ratio.

Associations Between the Phosphatidylethanol Alcohol Biomarker and Self-Reported Alcohol Use in a Sample of HIV-Infected Outpatient Drinkers in Western Kenya

BACKGROUND

To counteract the syndemics of HIV and alcohol in Sub-Saharan Africa, international collaborations have developed interventions to reduce alcohol consumption. Reliable and accurate methods are needed to estimate alcohol use outcomes. A direct alcohol biomarker called phosphatidylethanol (PEth) has been shown to validate heavy, daily drinking, but the literature indicates mixed results for moderate and nondaily drinkers, including among HIV-infected populations. This study examined the associations of the PEth biomarker with self-report alcohol use at 2 time points in 127 HIV-infected outpatient drinkers in western Kenya.

METHODS

Participants were consecutively enrolled in a randomized clinical trial to test the efficacy of a behavioral intervention to reduce alcohol use in Eldoret, Kenya. They endorsed current alcohol use, and a minimum score of 3 on the Alcohol Use Disorders Identification Test-Consumption or consuming ≥6 drinks per occasion at least monthly in the past year. Study interviews and blood draws were conducted at baseline and at 3 months post treatment from July 2012 through September 2013. Alcohol use was assessed using the Timeline Followback questionnaire. Blood samples were analyzed for the presence of the PEth biomarker and were compared to self-reported alcohol use. We also conducted semistructured interviews with 14 study completers in February through March 2014.

RESULTS

Baseline data indicated an average of moderate-heavy alcohol use: 50% drinking days and a median of 4.5 drinks per drinking day. At baseline, 46% of women (31 of 67) and 8% of men (5 of 60) tested negative for PEth (p < 0.001). At the 3-month follow-up, 93% of women (25 of 27) and 97% of men (30 of 31) who reported drinking tested positive, while 70% of women (28 of 40) and 35% of men (10 of 29) who denied drinking tested negative for PEth. Interviews were consistent with self-reported alcohol use among 13 individuals with negative baseline results.

CONCLUSIONS

These results add to the growing literature showing lack of agreement between self-report and PEth results among unhealthy and nondaily drinkers, particularly women. More research is needed to determine at what level of consumption over what period of time PEth becomes a reliable and accurate indicator of alcohol use.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Biomarkers for detection of alcohol consumption in liver transplantation

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

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.

Validation of the MINI (DSM IV) Tool for the Assessment of Alcohol Dependence among Young People in Northern Tanzania Using the Alcohol Biomarker Phosphatidylethanol (PEth)

The alcohol dependence section of the Mini International Neuropsychiatric Interview questionnaire (MINI) has not been evaluated in young Africans. We applied the MINI in a cross-sectional study of 202 alcohol users from northern-Tanzania, aged 18-24 years (103 male casual workers and 99 students), and validated it against phophatidylethanol (PEth) at a cut-off suggesting heavy chronic alcohol use (≥0.30 µmol/L). Blood was assayed for PEth (16:0/18:1-subform) by liquid chromatography-tandem mass spectrometry. The MINI dependence criteria (≥3 positive responses) were met by 39% participants although their PEth levels were low. Contrary, many young people with high PEth levels were not classified as dependent. The sensitivity of the MINI ranged from 0% to 69% (female students and male workers, respectively) and specificity from 52% to 85% (workers and female students, respectively). The highest AUROC (0.68) occurred with a cut-off of ≥4 positive responses. A modified MINI with three affirmative responses to five questions increased specificity to 92%-97%; however, sensitivity remained low. The performance of the MINI in detecting dependence among young people from northern-Tanzania is unsatisfactory. Specificity was improved using a modified version but sensitivity remained low. An accurate tool for the diagnosis of alcohol dependence is needed for epidemiological and clinical purposes.

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.

Feasibility and Acceptability of an Alcohol Addiction Therapy Integrated in a Transplant Center for Patients Awaiting Liver Transplantation

AIMS

To evaluate the feasibility and acceptability of an addiction program within the setting of liver transplantation, with classification of behavior change techniques used to reduce excessive drinking.

METHOD

Patients with alcohol-related liver disease (N = 100) participated in a manualized addiction group therapy over 12 sessions, pre-transplantation. Relapses were identified by measurement of urinary ethyl glucuronide (EtG).

RESULTS

Two groups were identified according to the frequency of participation: completers (n = 42) vs. drop-outs (n = 58). A total of 16.5% of the samples of completers in comparison to 30.5% of the samples of drop-outs tested positive for EtG (P < 0.001).

CONCLUSIONS

The results suggest that implementation of an addiction therapy program during the waiting time might help to limit the frequency of drinking. These patients appeared often to under-report their alcohol consumption; including a biomarker such as urinary EtG in such settings is recommended.

Determining ethyl glucuronide cutoffs when detecting self-reported alcohol use in addiction treatment patients

BACKGROUND

Ethyl glucuronide (EtG) is an alcohol biomarker with potential utility as a clinical research and alcohol treatment outcome. Debate exists regarding the appropriate cutoff level for determining alcohol use, particularly with the EtG immunoassay. This study determined the EtG immunoassay cutoff levels that most closely correspond to self-reported drinking in alcohol-dependent outpatients.

METHODS

Eighty adults with alcohol dependence and mental illness, taking part in an alcohol treatment study, provided urine samples 3 times per week for up to 16 weeks (1,589 samples). Self-reported drinking during 120 hours prior to each sample collection was assessed. Receiver operating characteristic analyses were conducted to assess the ability of the EtG immunoassay to detect self-reported alcohol use across 24- to 120-hour time periods. Sensitivity and specificity of EtG immunoassay cutoff levels was compared in 100 ng/ml increments (100 to 500 ng/ml) across 24 to 120 hours.

RESULTS

Over half (57%) of the 1,589 samples indicated recent alcohol consumption. The EtG immunoassay closely corresponded to self-reported drinking from 24 (area under the curve [AUC] = 0.90, 95% confidence interval [CI]: 0.88, 0.92) to 120 hours (AUC = 0.88, 95% CI: 0.87, 0.90). When cutoff levels were compared across 24 to 120 hours, 100 ng/ml had the highest sensitivity (0.93 to 0.78) and lowest specificity (0.67 to 0.85). Relative to 100 ng/ml, the 200 ng/ml cutoff demonstrated a reduction in sensitivity (0.89 to 0.67), but improved specificity (0.78 to 0.94). The 300, 400, and 500 ng/ml cutoffs demonstrated the lowest sensitivity (0.86 to 0.33) and highest specificity (0.86 to 0.97) over 24 to 120 hours.

CONCLUSIONS

For detecting alcohol use for >24 hours, the 200 ng/ml cutoff level is recommended for use as a research and clinical outcome.

Alcohol intake measured by phosphatidylethanol in blood and the lifetime drinking history interview are correlated with the extent of psoriasis

BACKGROUND

Psoriasis has been reported to be associated with alcohol consumption.

OBJECTIVE

To investigate the level of alcohol intake in individuals with psoriasis and correlate intake with the extent of disease and pruritus.

METHODS

Twenty-nine outpatients (15 females and 14 males) with stable chronic plaque psoriasis of moderate severity were recruited. The Psoriasis Area and Severity Index (PASI) and the degree of pruritus (visual analogue scale) were compared with measures of drinking habits as determined by the Lifetime Drinking History (LDH), the Alcohol Use Disorders Identification Test and whole-blood phosphatidylethanol (PEth), an alcohol-specific biomarker.

RESULTS

The majority of patients were social drinkers with moderate alcohol consumption as determined by PEth and LDH. Alcohol consumption correlated significantly with the PASI score. There was no correlation between alcohol use and pruritus.

CONCLUSION

The level of alcohol consumption is correlated with the extent of psoriasis.

High levels of agreement between clinic-based ethyl glucuronide (EtG) immunoassays and laboratory-based mass spectrometry

BACKGROUND

Immunoassay urine drug screening cups that detect use for two or more days are commonly used in addiction treatment settings. Until recently, there has been no comparable immunoassay test for alcohol use in these settings.

OBJECTIVES

The aim of this study was to assess the agreement of a commercially available ethyl glucuronide immunoassay (EtG-I) test conducted at an outpatient addiction clinic and lab-based EtG mass spectrometry (EtG-MS) conducted at a drug testing laboratory at three cut-off levels. High agreement between these two measures would support the usefulness of EtG-I as a clinical tool for monitoring alcohol use.

METHODS

Forty adults with co-occurring alcohol dependence and serious mental illnesses submitted 1068 urine samples over a 16-week alcohol treatment study. All samples were tested using EtG-I on a benchtop analyzer and 149 were randomly selected for EtG-MS analysis at a local laboratory. Agreement was defined as the number of samples where EtG-I and EtG-MS were both above or below a specific cut-off level. Agreement was calculated at low cut-off levels (100 and 250 ng/ml), as well as at a higher cut-off level (500 ng/ml) recommended by most by commercial drug testing laboratories.

RESULTS

Agreement between EtG-I and EtG-MS was high across all cut-off levels (90.6% at 100 ng/ml, and 96.6% at 250 and 500 ng/ml).

CONCLUSIONS

EtG immunoassays conducted at low cut-off levels in point-of-care testing settings have high agreement with lab-based EtG-MS. EtG-I can be considered a useful clinical monitoring tool for alcohol use in community-based addiction treatment settings.

The usefulness of biomarkers of alcohol abuse in hair and serum carbohydrate-deficient transferrin: a case report

The detection of carbohydrate-deficient transferrin (CDT) in serum is widely accepted to identify chronic alcohol consumption over the previous two weeks, but minor ethanol metabolites detected in hair often complete the information obtained. In particular, ethylglucuronide and cocaethylene (a marker of simultaneous intake of cocaine and alcohol) allow correct interpretation of data obtained in forensic cases. We refer to a negative CDT value obtained from a serum sample collected during hospitalization of a man admitted for cardiac arrest who died about 14 h later. Clinical analysis performed on admission showed a high ethanol level and a positive urinary screening for cocaine. The toxicological analyses of post-mortem samples found cocaine metabolites in his urine and blood. The negative CDT level suggested the ethanol concentration at admission to be an acute episode. Cocaine and cocaethylene well above the cut-off suggested by the literature were found in hair analyzed for the entire length (about 1 cm). Ethylglucuronide detected on the same hair sample confirmed chronic abuse of ethanol in the previous month, at least. The present report suggests caution in the interpretation of biomarkers of alcohol abuse, encouraging the detection of more than one marker to avoid misinterpretation.

Accounting for sex-related differences in the estimation of breath alcohol concentrations using transdermal alcohol monitoring

RATIONALE

Previously, we reported methods to estimate peak breath alcohol concentrations (BrAC) from transdermal alcohol concentrations (TAC) under conditions where alcohol consumption was controlled to produce similar BrAC levels in both sexes.

OBJECTIVE

This study characterized differences in the relationship between BrAC and TAC as a function of sex and developed a model to predict peak BrAC that accounts for known sex differences in peak BrAC.

METHODS

TAC and BrAC were monitored during the consumption of a varying number of beers on different days. Both men (n=11) and women (n=10) consumed one, two, three, four, and five beers at the same rate in a 2-h period. Sex and sex-related variables were considered for inclusion in a multilevel model to develop an equation to estimate peak BrAC levels from TAC.

RESULTS

While peak BrAC levels were significantly higher in women than men, sex differences were not significant in observed TAC levels. This lack of correspondence was evidenced by significant sex differences in the relationship between peak TAC and peak BrAC. The best model to estimate peak BrAC accounted for sex-related differences by including peak TAC, time-to-peak TAC, and sex. This model was further validated using previously collected data.

CONCLUSIONS

The relationship between peak TAC and actual peak BrAC differs between men and women, and these differences can be accounted for in a statistical model to better estimate peak BrAC. Further studies are required to extend these estimates of peak BrAC to the outpatient environment where naturalistic drinking occurs.

Diagnosis of alcoholic liver disease

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

How accurate are blood (or breath) tests for identifying self-reported heavy drinking among people with alcohol dependence?

AIMS

Managing patients with alcohol dependence includes assessment for heavy drinking, typically by asking patients. Some recommend biomarkers to detect heavy drinking but evidence of accuracy is limited.

METHODS

Among people with dependence, we assessed the performance of disialo-carbohydrate-deficient transferrin (%dCDT, ≥1.7%), gamma-glutamyltransferase (GGT, ≥66 U/l), either %dCDT or GGT positive, and breath alcohol (> 0) for identifying 3 self-reported heavy drinking levels: any heavy drinking (≥4 drinks/day or >7 drinks/week for women, ≥5 drinks/day or >14 drinks/week for men), recurrent (≥5 drinks/day on ≥5 days) and persistent heavy drinking (≥5 drinks/day on ≥7 consecutive days). Subjects (n = 402) with dependence and current heavy drinking were referred to primary care and assessed 6 months later with biomarkers and validated self-reported calendar method assessment of past 30-day alcohol use.

RESULTS

The self-reported prevalence of any, recurrent and persistent heavy drinking was 54, 34 and 17%. Sensitivity of %dCDT for detecting any, recurrent and persistent self-reported heavy drinking was 41, 53 and 66%. Specificity was 96, 90 and 84%, respectively. %dCDT had higher sensitivity than GGT and breath test for each alcohol use level but was not adequately sensitive to detect heavy drinking (missing 34-59% of the cases). Either %dCDT or GGT positive improved sensitivity but not to satisfactory levels, and specificity decreased. Neither a breath test nor GGT was sufficiently sensitive (both tests missed 70-80% of cases).

CONCLUSIONS

Although biomarkers may provide some useful information, their sensitivity is low the incremental value over self-report in clinical settings is questionable.

The validity of phosphatidylethanol in dried blood spots of newborns for the identification of prenatal alcohol exposure

BACKGROUND

Accurate identification of prenatal alcohol exposure (PAE) in the newborn period offers an opportunity for early identification of children at risk of future neurocognitive problems and the implementation of interventional approaches earlier in life. PAE newborn screening by measuring phosphatidylethanol in dried blood spot (PEth-DBS) cards is feasible, logistically easier, and more cost-efficient compared with other biomarkers. However, the sensitivity and specificity of this method have yet to be established.

METHODS

This prospective cohort study examined validity of PEth-DBS among 28 infants with PAE and 32 controls relative to maternal self-report and other biomarkers. Pregnant women were recruited from a University of New Mexico clinic and followed to early postpartum period. The composite index, which was based on self-reported measures of alcohol use and allowed to classify subjects into PAE and control groups, was the criterion measure used to estimate sensitivity and specificity of PEth-DBS.

RESULTS

The study included large proportions of patients representing ethnic minorities (7.4% American Indian, 81.7% Hispanic/Latina), low education (54.2% <high school), and unplanned pregnancy (90.0%). No differences in sociodemographic characteristics, smoking or illicit drug use were observed among the study groups. The sensitivity of maternal biomarkers (gamma glutamyltranspeptidase [GGT], % carbohydrate-deficient transferrin [%CDT], urine ethyl glucuronide [UEtG], urine ethyl sulfate [UEtS]) was low (<15%) reflecting a moderate chronic or intermittent binge pattern of drinking in this cohort. PEth-DBS demonstrated 100% specificity and the highest sensitivity (32.1%) compared with other biomarkers. A battery consisting of maternal direct ethanol metabolites (UEtG, UEtS, PEth) and newborn PEth-DBS increased sensitivity to 50% without a substantial drop in specificity (93.8%).

CONCLUSIONS

Newborn PEth-DBS is a highly specific biomarker and can facilitate accurate detection of PAE in conjunction with other biomarkers. Minimal invasiveness, ease of storage and transportation of DBS cards, absence of postcollection synthesis, cost savings, and potential integration with routine newborn screening are all unique advantages of this method.

Ethyl glucuronide (EtG): better than breathalyser or self-reports to detect covert short-term relapses into drinking

AIMS

The assessment of relapses is widely used as an outcome measure of alcohol dependence treatment. However, the methods of assessing relapses range from questionnaires to biological markers of alcohol for different time spans. The aim of this study was to compare the relapse rates of weekend home stays during long-term alcohol dependence treatment, assessed by ethyl glucuronide (EtG), breath alcohol tests and self-reports.

METHODS

Two hundred and ninety-seven alcohol-dependent patients receiving a long-term inpatient treatment programme participated. After a weekend at home (Friday to Sunday) they were evaluated for relapse by personal interviews and with breath alcohol tests. A concomitantly collected urine sample was later assessed for EtG with liquid chromatography-tandem mass spectrometry (LC-MS/MS analysis).

RESULTS

Of the total, 37.7% of the patients were positive for EtG at least once. Breath alcohol tests had been positive in only 4.4% and in personal interviews only 5.7% of the patients had admitted relapse. 15.6% of EtG tests were positive, but breath alcohol tests were negative (Cohen's kappa = 0.056). Ninety-three per cent of the relapses were only detected by EtG.

CONCLUSION

In addition to breath alcohol tests and interviews, urinary EtG can clearly improve the verification of relapse in inpatient treatment programmes allowing for weekend stays at home. Without EtG testing, a high amount of relapses will stay undetected.

The feasibility and cost of neonatal screening for prenatal alcohol exposure by measuring phosphatidylethanol in dried blood spots

BACKGROUND

Accurate confirmation of prenatal alcohol exposure (PAE) is required as a diagnostic criterion for the majority of children adversely affected by PAE who do not manifest the physical features associated with fetal alcohol syndrome. A number of ethanol biomarkers have been used to assess PAE, often with suboptimal results. The purpose of this study was to evaluate the feasibility and cost of PAE screening in newborns by measuring phosphatidylethanol (PEth) in dried blood spot (DBS) cards.

METHODS

The feasibility of collecting an additional DBS card during routine newborn screening and the background prevalence of PAE were evaluated in a de-identified sample of newborn children delivered at the University of New Mexico Hospital. Electronic orders to collect DBS cards from newborns who continue to bleed after the routine newborn screen, glucose, or hematocrit testing were initiated for all infants delivered during a 4-week time frame. Specimens were sent to a contract laboratory for PEth analysis by liquid chromatography-tandem mass spectrometry. A cost analysis was conducted to compare the cost of PAE screening by PEth in DBS versus PEth in conventional blood specimens and by meconium fatty acid ethyl esters.

RESULTS

From 230 collected cards, 201 (87.4%) had at least 1 full blood spot (amount sufficient for PEth analysis), and 6.5% had PEth >20 ng/ml indicative of potential PAE in late pregnancy. PAE screening by PEth in DBS is logistically simpler and less expensive compared with 2 other screening approaches.

CONCLUSIONS

These results indicate that screening for PAE in DBS cards is a feasible procedure and that a majority of infants have enough blood after the routine heel prick to fill an additional card. Moreover, screening by PEth analysis from DBS cards is cost-efficient. The acceptability of such screening by parents and corresponding ethical issues remain to be investigated.

Effect of transferrin glycation on the use of carbohydrate-deficient transferrin as an alcohol biomarker

AIMS

Measurement of an alcohol-induced shift in the serum transferrin glycosylation pattern, termed carbohydrate-deficient transferrin (CDT), is used as a biomarker for sustained high alcohol consumption. The present work examined whether non-enzymatic reaction of transferrin with glucose (glycation) might interfere with the use of CDT as an alcohol biomarker.

METHODS

The blood specimens were leftover volumes from the routine sample pool. Plasma and serum were collected among samples submitted for hemoglobin A1c (HbA1c) and CDT testing. Quantification of individual transferrin glycoforms in percentage of total transferrin was performed by an HPLC candidate CDT reference method.

RESULTS

Incubating serum spiked with 20 or 200 mmol/l glucose caused time- and dose-dependent changes in the chromatographic profile of transferrin glycoforms, resulting in gradually wider peaks and reduced relative amounts of disialo- and trisialotransferrin. No similar chromatographic effects were seen in samples collected from diabetic patients with elevated HbA1c (>68 mmol/mol) values. These samples instead showed slightly higher mean %disialotransferrin levels (1.21%) compared with low HbA1c (<44 mmol/mol) samples (mean 1.06%; P = 0.023), pointing at a higher alcohol consumption level in the former group. Altogether ∼5% of the CDT values exceeded the cutoff. There was no significant difference in phosphatidylethanol (PEth) levels between the high and low HbA1c samples, but several (∼14%) showed elevated PEth concentrations.

CONCLUSION

Glycation of serum transferrin in vivo was indicated to differ from that in vitro, and suggested not to interfere with %CDT testing by the HPLC method. The results indicated that CDT and PEth are useful as objective, complementary alcohol biomarkers to identify risky drinking also in diabetic subjects.

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.