Dose-Response Characteristics of the Alcohol Biomarker Phosphatidylethanol (PEth)-A Study of Outpatients in Treatment for Reduced Drinking

Phosphatidylethanol clearance after packed red blood cell transfusion

OBJECTIVES

Phosphatidylethanol (PEth) is a long-term marker of alcohol consumption used clinically for evaluating abstinence in patients including transplant candidates. Packed red blood cell (pRBC) transfusion can introduce exogenous PEth to recipients, complicating interpretation. This study evaluated the kinetics and duration of PEth 16:0/18:1 positivity post-transfusion.

DESIGN & METHODS

This study evaluated liver transplant recipients (n = 76) who received ≥ 1 pRBC during transplantation surgery. PEth 16:0/18:1 concentrations were monitored up to 2 weeks post-transfusion to determine clearance kinetics.

RESULTS

Post-transfusion PEth was ≥ 10 ng/mL (range 10.0 - 79.7 ng/mL [0.014-0.113 µmol/L]) in 37 (48.7 %) recipients. Approximately 24 h after transfusion, pRBC-derived PEth decreased by a mean of 19 %, consistent with pRBC turnover post-transfusion. After 24-36 h, the apparent half-life of PEth was 6.6 d but was highly variable (SD 3.6 d). Correction for hemoglobin or hematocrit improved variability, with mean half-life estimated at 4.9 d (SD 1.6 d) and 4.6 d (SD 1.4 d), respectively. Time to clearance of PEth < 10 ng/mL ([<0.014 µmol/L]) ranged from < 1 d to > 19 d; 15 (40.5 %) pRBC recipients cleared PEth within 5 d post-transfusion. Using the consensus cutoff for PEth interpretation, only 10 had PEth > 20 ng/mL (>0.028 µmol/L) at 5 d and all had 14 d values < 20 ng/mL (<0.028 µmol/L).

CONCLUSIONS

These findings suggest that PEth positivity after pRBC transfusion might be more common than previously recognized, and that higher decision-making thresholds (e.g., 20 ng/mL [<0.028 µmol/L]) are appropriate. Post-transfusion kinetics are not identical to clearance of endogenously-produced PEth after alcohol consumption (half-life 5-8 d), likely due to both patient and pRBC characteristics. Transplant care teams should recognize the risk for pRBC transfusion to impact PEth concentrations in recipients, and interpret PEth cautiously for 2-3 weeks after transfusion.

The effectiveness of a drink-counting and a breathalyser-coupled smartphone application for reduced heavy drinking among alcohol-dependent adults in Sweden: A randomised controlled trial

BACKGROUND AND AIMS

Studies using smartphone apps in treatment for alcohol dependence are lacking. This study aimed to test the consumption-reducing effects of using two app-based alcohol interventions as complement to treatment as usual (TAU).

DESIGN

Three-armed, parallel, randomised controlled trial.

SETTING

Specialised outpatient clinic within the Stockholm Centre for Dependency Disorders, Stockholm, Sweden.

PARTICIPANTS

162 alcohol-dependent adults (46% female), with no social problems or mental disorders, who had no other drug use, were included. Mean age was 50 years, and the majority were highly educated, employed and had not previously received any alcohol treatment.

INTERVENTIONS

Participants were randomised to (1) TAU+drink-counting app (Glasklart, n = 52), (2) TAU+app-coupled breathalyser (iBAC Pro, n = 58) or (3) TAU only (n = 52). TAU included four sessions of clinician-led psychological treatment based on motivational interviewing/cognitive behavioural therapy, combined with pharmacotherapy when requested, for 12 weeks.

MEASUREMENTS

The primary outcome was past 4-week heavy drinking days (HDD) at 26 weeks post-randomisation, adjusted for baseline HDD, and assessed by structured interviews using Timeline Followback. Secondary outcomes included weekly consumption, consumption patterns, phosphatidylethanol and dependence at 12 and 26 weeks. Analyses compared TAU+drink-counting app and TAU+breathalyser each with TAU alone.

FINDINGS

At 26 weeks, participants with TAU+breathalyser had statistically significantly lower HDD [incidence rate ratio (IRR) = 0.67, 95% confidence interval (CI) = 0.49, 0.91] compared with those with TAU alone. There was no evidence of any effects on HDD for those with TAU+drink-counting app, compared with TAU alone (IRR = 0.94, 95% CI = 0.70, 1.25) or of any other effects.

CONCLUSIONS

In Sweden, treatment as usual (TAU) for alcohol dependence combined with a smartphone application coupled with a breathalyser was more effective than TAU alone in reducing self-reported heavy drinking. There was no evidence that TAU combined with a smartphone application for drink-counting was more effective than TAU alone.

Phosphatidylethanol levels distinguish steatotic liver disease subgroups and are associated with risk of major liver outcomes

BACKGROUND & AIMS

Phosphatidylethanol (PEth) is an ethanol metabolite used as a specific biomarker for recent alcohol consumption. We aimed to determine the proportion of patients with or at risk for metabolic dysfunction-associated steatotic liver disease (MASLD) who had PEth levels indicative of harmful alcohol consumption, and to assess associations between PEth levels and the risk of major adverse liver outcomes (MALOs).

METHODS

We conducted a cohort study involving persons tested for PEth in Stockholm, Sweden between 2012 and 2020 (N=46,406), including patients with various steatotic liver disease (SLD) subtypes and individuals without SLD. Cumulative incidences of MALOs were calculated for the different groups while accounting for competing risk. Cox regression was used to evaluate the association between baseline PEth levels and the incidence of MALOs.

RESULTS

Among 6,377 patients with presumed MASLD, 1,294 (20%) had baseline PEth levels between 0.05 and 0.30 μmol/L (35-210 ng/ml), indicating excessive alcohol intake (MetALD), while 854 patients (13%) had values >0.30 μmol/L, indicating alcohol-related liver disease (ALD). Patients with MASLD and PEth levels between 0.05-0.30 μmol/L had similar median FIB-4 scores and cirrhosis prevalence as those with MASLD and PEth levels <0.05 μmol/L. However, patients with PEth levels between 0.05-0.30 μmol/L had higher cumulative incidences of MALOs compared to those with PEth levels <0.05 μmol/L. Elevated PEth levels were significantly linked to higher rates of MALOs in patients without cirrhosis, even after adjustments for age, sex, SLD subtype, and FIB-4 score. Patients with ALD had the highest PEth levels and worst prognosis.

CONCLUSIONS

PEth is a valuable alcohol biomarker for distinguishing between SLD subtypes, especially ALD, and predicts adverse outcomes in people with and without SLD.

IMPACT AND IMPLICATIONS

There is controversy regarding the various proposed steatotic liver disease (SLD) subtypes, the most recent definition suggesting that patients with an elevated alcohol consumption and MASLD should be classified as having MetALD. Here, we address this challenge by classifying patients with SLD by utilizing the biomarker phosphatidylethanol (PEth), a direct and reliable biomarker for recent alcohol consumption. Our analysis of this large cohort-comprising 46,406 patients-revealed that using the objective PEth biomarker may be a valuable tool for distinguishing between MASLD and MetALD, and that PEth is strongly associated with the risk of liver outcomes in individuals with and without known SLD. Integrating PEth testing into routine diagnostic evaluations could enhance knowledge on the underlying pathophysiology in SLD, reduce the potential for misclassification, and ultimately improve patient outcomes by enabling clinicians to offer appropriate therapies. Further research is needed to validate these findings in other populations and to explore the potential integration of PEth into broader clinical guidelines for managing SLD.

A validated method for capillary phosphatidylethanol 16:0/18:1 quantification with two different 10-µl volumetric absorptive microsample devices in the same setup

There is a growing interest for quantification of drugs in capillary blood. Phosphatidylethanol (PEth) is a biomarker for alcohol intake measured in whole blood, thus making it a candidate for capillary sampling. Our laboratory has been running a method for PEth quantification in venous blood since 2016, and we aimed to expand this method to also include capillary dried blood spot (DBS) samples. Two 10-µl volumetric absorptive microsampling (VAMS) devices, Capitainer®B Vanadate and Mitra®, were included in the method development and validated. Calibrators and quality controls were spiked during automatic sample extraction without the VAMS devices present, making it possible to extract and analyze both types of VAMS samples in the same setup. With the Mitra device, all pre-established validation criteria were fulfilled in the measuring range of 0.03 to 4.0 µM (21-2812 ng/mL), including method comparison with our venous blood method. Capitainer fulfilled all validation criteria, except for the accuracy of samples with PEth levels ≥ 0.5 µM (≥ 352 ng/mL) (deviation -17.1% to -20.5%). The correlation analysis between Capitainer and the venous blood results showed no constant bias, but an acceptable small proportional mean difference of -7.6%. Overall, the method validation results for both Capitainer and Mitra were considered acceptable. Both devices were found to be suitable for the analyses of PEth.

Identifying hazardous alcohol use in primary care using phosphatidylethanol: Timing of screening matters

BACKGROUND AND AIMS

Alcohol is a well-established risk factor for numerous health conditions, making screening for hazardous alcohol use in healthcare a critical task. While self-reported data suggest that alcohol consumption varies across seasons, this seasonal fluctuation has not yet been confirmed using objective biological markers. This study aimed to measure whether phosphatidylethanol (PEth) captures variations in hazardous alcohol use across two temporal resolutions: month of the year and day of the week.

DESIGN

Observational cross-sectional study based on data from medical records.

SETTING

Healthcare services, Region Dalarna, Sweden, between 2017 and 2023.

PARTICIPANTS/CASES

Adult patients (n = 62 431, 50% females) screened for hazardous alcohol use with PEth within primary care.

MEASUREMENTS

This study utilizes test results from PEth, with results >0.30 μmol/l defined as hazardous alcohol use. We compared the prevalence of hazardous alcohol use across months and weekdays using logistic regression while adjusting for sex, age, smoking status, the Charlson Comorbidity Index and psychiatric diagnoses.

FINDINGS

The prevalence of hazardous alcohol use increased between May and August, ranging from 13.2% to 15.9%, compared with 10.7% in November. This corresponds to a 48% relative increase in the peak month of July [prevalence ratio (PR) = 1.48, 95% confidence interval (CI) = 1.33-1.64]. Hazardous alcohol use was also more prevalent among patients tested on Mondays (13.0%) compared with Thursdays, with the lowest prevalence (12.0%). The difference was particularly pronounced among female patients, with a 14.0% higher relative prevalence on Mondays (PR = 1.14, 95% CI = 1.02-1.27).

CONCLUSIONS

In Sweden, the prevalence of hazardous alcohol use appears to fluctuate seasonally and, to a lesser extent, across weekdays, as measured by blood tests for phosphatidylethanol, a biomarker for hazardous alcohol use. November showed the lowest prevalence and July the highest, consistent across age, sex and the year of the observational period. Hazardous alcohol use showed a slight elevation of prevalence during Mondays compared with Tuesday to Friday.

Calibration and evaluation of a refined pharmacokinetic model for three homologs of phosphatidylethanol

The use of phosphatidylethanol (PEth) as a biomarker for alcohol consumption is increasing likely due to its relatively long half-life in blood. Here, we present a pharmacokinetic model for three common homologs of PEth based on concentrations of each observed in a 5-day study of daily alcohol consumption. Adult participants were 11 females and 6 males with a median age of 32 years and median BMI of 24.3, all of whom drank on 1 or more days per week with at least 1 day per month of "heavy" drinking and also free from psychiatric disorders. All participants were abstinent for one week prior to beginning the study. The overall goals of this modeling effort are the use of PEth for assessment of alcohol consumption behavior and better understanding of the biological mechanisms underlying PEth pharmacokinetics. The modeling presented encompasses both the calibration of the pharmacokinetic model from daily individual PEth measurements and the prediction of model parameters in the study population with a regression model. The overall model was then evaluated by comparison of predicted PEth levels in blood with those measured in several groups of subjects in controlled drinking experiments. The results of this modeling effort indicate that the model can predict PEth concentrations in blood from alcohol consumption albeit with high variability both between individuals and within a single individual between drinking occasions. These results suggest the possible need to refine currently used cutoffs used in clinical and forensic contexts to predict alcohol consumption amounts. (249 words).

Volumetric dried blood spots for determination of phosphatidylethanol: Validation of a liquid chromatography tandem masspectrometry method and clinical application

Phosphatidylethanol (PEth) measurement in whole blood samples is established as a specific alcohol biomarker with clinical and forensic applications. Establishment of dried blood spots (DBSs) as a specimen for PEth determination offers several advantages and was the focus of this work. A liquid chromatography tandem mass spectrometry method using a 96-well format for sample preparation was developed and validated. PEth was extracted from DBSs by using isopropanol containing PEth-d5 as internal standard. The blood sampling used a commercial volumetric DBS device having a phosholipase D inhibitor incorporated to stop continuous PEth formation. The method quantified PEth in the range of 0.05-10 μmol/L, with a bias and imprecision of less than 15%. In a clinical study (n = 25) using fingerprick blood, the volumetric device offered more precise quantifications (CV 4.6%) compared with the Whatman 903 Protein Saver card device (CV 16.6%). In another clinical study (n = 48), the use of dried venous and capillary blood, and liquid venous blood was compared under real-life conditions with samples sent by postal service. The capillary and venous DBS samples gave identical results while the liquid blood gave slightly higher values. Calculation of elimination half-life (PEth 16:0/18:1) in 31 cases based on two consecutive samples with 2-9 days in between gave results (mean 6.2 days) that agree with literature but several cases with values over 10 days. In conclusion, this study demonstrates that volumetric DBS is a valid specimen for determination of PEth blood concentrations, offering several advantages.

Evaluating the Impact of Phosphatidylethanol Testing on Hospital Outcomes

Background

Alcohol dependence remains a significant global health issue, exacerbated by the coronavirus disease 2019 (COVID-19) pandemic. Phosphatidylethanol (PEth), a direct biomarker of recent alcohol consumption, offers improved specificity, sensitivity, and a longer detection window of 2 - 4 weeks compared to traditional biomarkers. This study evaluates the association between PEth testing and hospital outcomes in hospitalized patients by comparing outcomes among patients with positive PEth and negative PEth test results.

Methods

This retrospective cohort study used data from the TriNetX database, comprising de- identified medical records from 66 US healthcare organizations from 2015 to 2024. The study population included patients with documented PEth test results. Patients were divided into two groups: positive PEth test results (≥ 20 ng/mL) and negative PEth test results (≤ 19 ng/mL). Propensity score matching was performed to minimize bias, balancing for age, sex, race, ethnicity, and comorbidities such as cirrhosis, diabetes mellitus, hypertension, coronary artery disease, and chronic obstructive pulmonary disease (COPD). Key hospital outcomes assessed included mortality, delirium tremens, endoscopy/colonoscopy, liver transplant status, liver transplant rejection, liver transplant complications, hepatorenal syndrome, intensive care unit (ICU) admission, hepatic encephalopathy, and sarcopenia. These outcomes were chosen based on their prevalence in patients with alcohol use.

Results

Patients with positive PEth results demonstrated significantly worse outcomes compared to patients in the negative PEth group. Positive PEth results were associated with higher mortality (odds ratio, 10.037; P < 0.001), ICU admissions, and rates of complications such as hepatorenal syndrome, hepatic encephalopathy, and sarcopenia. Postoperative liver transplant complications and rejection were also more frequent in the positive cohort.

Conclusions

This study highlights the association between recent alcohol use, as identified by PEth testing, and severe hospital outcomes. While PEth testing provides an objective measure of recent alcohol consumption, further research is needed to explore its role in improving clinical outcomes and guiding interventions for patients with alcohol use.

Assessing alcohol consumption across phosphatidylethanol levels using HDL-cholesterol as a predictor

AIMS

Prior research has established a correlation between increases of High-Density Lipoprotein Cholesterol (HDL-C) levels and alcohol consumption. This study aimed to explore the association between phosphatidylethanol (PEth) levels and the amount of consumed ethanol, utilizing HDL-C as a surrogate marker on a population level. This endeavor offers an adjunct to other studies.

METHODS

PEth and HDL-C levels in 50 751 samples from 29 899 patients in Norway were measured simultaneously in whole blood and serum, respectively. Linear mixed model analyses were employed to assess HDL-C levels within different PEth intervals. Drawing on previous research indicating an increase of .0035 mmol/L in HDL-C per gram of pure ethanol consumed per day, and assuming no alcohol intake in the zero PEth group, we estimated mean daily ethanol intake at the group level for males in each PEth interval.

RESULTS

Results revealed a significant correlation between PEth and HDL-C levels (Spearman's rho = .385 for women, .420 for men, P < .001). Estimated mean HDL-C levels indicated higher alcohol consumption with increasing PEth. Specifically, men with PEth values in the .031-0.100 μmol/L (22-70 ng/ml) interval were estimated to consume approximately mean 20 grams of ethanol daily, while those in the .301-0.500 μmol/L (212-351 ng/ml) PEth interval had an estimated mean daily ethanol intake of 51 grams.

CONCLUSIONS

The results from this study suggest an approximate estimation of mean daily amounts of consumed ethanol at group levels in different PEth intervals, based on previously shown correlation of ethanol consumption and HDL-C increase.

Phosphatidylethanol as an outcome measure in treatment aimed at controlled drinking

BACKGROUND

Phosphatidylethanol (PEth) is a specific marker of alcohol intake, used both as a screening method for hazardous use and as an outcome measure in the treatment of alcohol use disorder (AUD). However, what cut-off values to apply for hazardous use in a treatment setting is still unclear. We aimed to investigate the correlation between PEth and self-reported drinking and identify the optimal cut-off for hazardous use, for patients with AUD and a stated goal of controlled drinking.

METHODS

We used data from a randomized controlled trial of two different psychological treatments aiming for controlled drinking, conducted within specialized addiction care in Stockholm, Sweden. A total of 181 patients left samples that could be included in the current analysis. Outcomes were measured at five different time points over 2 years of follow-up. PEth 16:0/18:1 values were correlated with subjective reports of recent drinking based on the Timeline Follow-Back Method.

RESULTS

The correlation between PEth and self-reported alcohol intake increased significantly over time, with the weakest correlation found at baseline (Spearman's ρ = 0.42) and the strongest at the 104-week follow-up (ρ = 0.69). When used to indicate hazardous drinking according to Swedish guidelines (≥10 units per week), receiver operating characteristic analysis revealed PEth ≥ 0.22 μmol/l to be the optimal cut-off.

CONCLUSIONS

PEth is a useful outcome measure that can be used to validate subjective reports of current drinking. In a treatment setting aimed at controlled drinking, the accuracy of patients' self-report measures seems to improve over time. In this context, a PEth value of ≥0.22 μmol/l is a sensitive and specific indicator of hazardous drinking.

Phosphatidylethanol in post-mortem brain: Correlation with blood alcohol concentration and alcohol use disorder

Phosphatidylethanol (PEth) is an alcohol derivative that has been employed as a blood-based biomarker for regular alcohol use. This study investigates the utility of phosphatidylethanol (PEth) as a biomarker for assessing alcohol consumption in post-mortem brain tissue. Using samples from the New South Wales Brain Tissue Resource Centre, we analysed PEth(16:0/18:1) levels in the cerebellum and meninges of individuals with varying histories of alcohol use, including those diagnosed with alcohol use disorder (AUD) and controls. Our findings demonstrate a significant correlation between PEth levels and blood alcohol content (BAC) at the time of death, supporting the biomarker's sensitivity to recent alcohol intake. Furthermore, this study explores the potential of PEth levels in differentiating AUD cases from controls, taking into consideration the complexities of diagnosing AUD post-mortem. The study also examined the relationship between PEth levels and liver pathology, identifying a link with the severity of liver damage. These results underscore the value of PEth as a reliable indicator of alcohol consumption and its potential contributions to post-mortem diagnostics and consequently, research into alcohol-related brain damage.

AUDIT C compared to PEth in middle-aged volunteers

AIMS

To compare Alcohol Use Disorders Identification Test (AUDIT C) to phosphatidylethanol (PEth) in middle-aged randomly selected volunteers. Apply previously suggested lower cut-offs for PEth using moderate alcohol intake according to AUDIT C as a reference.

METHODS

Within the Swedish CardioPulmonary BioImage Study, 2255 middle-aged (50-64 years of age) volunteers in northern Sweden participated in comparing AUDIT C to PEth 16:0/18:1.

RESULTS

There was a moderate correlation between PEth 16:0/18:1 and AUDIT C (r = 0.66). None of the participants with the AUDIT C-score 0 had a measurable PEth. Of moderate alcohol consumers, according to AUDIT C (AUDIT C 1-3 women, 1-4 men), 96% had a PEth below 0.3 μmol/L, 91% had a PEth below 0.16 μmol/L, and 84% had a PEth below 0.11 μmol/L. With PEth equivalent to excessive alcohol consumption (≥0.3 μmol/L), 26% had an AUDIT C-score below excessive alcohol consumption (<4 for women and <5 for men). Thirty percent of patients with a PEth ≥0.16 μmol/L had an AUDIT C-score below excessive alcohol consumption, and 37% had a PEth ≥0.11 μmol/L. We found no significant correlation between BMI and PEth or AUDIT C.

CONCLUSIONS

There is a significant correlation between AUDIT C and PEth. Using AUDIT C alone, 26% of high-consumers, according to PEth, are not found in our cohort, but an AUDIT C-score of 0 will exclude high consumption, according to PEth. Our findings support the current cut-off for PEth of 0.3 μmol/L, but a lower cut-off seems reasonable.

Brief history of the alcohol biomarkers CDT, EtG, EtS, 5-HTOL, and PEth

This article traces the historical development of various biomarkers of acute and/or chronic alcohol consumption. Much of the research in this domain of clinical and laboratory medicine arose from clinics and laboratories in Sweden, as exemplified by carbohydrate deficient transferrin (CDT) and phosphatidylethanol (PEth). Extensive studies of other alcohol biomarkers, such as ethyl glucuronide (EtG), ethyl sulfate (EtS), and 5-hydroxytryptophol (5-HTOL), also derive from Sweden. The most obvious test of recent drinking is identification of ethanol in a sample of the person's blood, breath, or urine. However, because of continuous metabolism in the liver, ethanol is eliminated from the blood at a rate of 0.15 g/L/h (range 0.1-0.3 g/L/h), so obtaining positive results is not always possible. The widow of detection is increased by analysis of ethanol's non-oxidative metabolites (EtG and EtS), which are more slowly eliminated from the bloodstream. Likewise, an elevated ratio of serotonin metabolites in urine (5-HTOL/5-HIAA) can help to disclose recent drinking after ethanol is no longer measurable in body fluids. A highly specific biomarker of hazardous drinking is CDT, a serum glycoprotein (transferrin), with a deficiency in its N-linked glycosylation. Another widely acclaimed biomarker is PEth, an abnormal phospholipid synthesized in cell membranes when people drink excessively, having a long elimination half-life (median ~6 days) during abstinence. Research on the subject of alcohol biomarkers has increased appreciably and is now an important area of drug testing and analysis.

Relationship between alcohol intake based on daily smartphone-reported consumption and PEth concentrations in healthy volunteers

AIMS

To investigate the association between alcohol consumption registered daily with a digital smartphone-based diary and concentration of phosphatidylethanol (PEth) 16:0/18:1 in a population without a known alcohol use disorder (AUD), and evaluate whether prospective registration of alcohol consumption is better than retrospective registration and if the association between alcohol intake and PEth was affected by sex or body mass index (BMI).

METHODS

A total of 41 women and 21 men without AUD-diagnosis registered their alcohol consumption prospectively with a digital diary for 14 days, and retrospectively with the Timeline Followback method in the same time interval. PEth was measured before and after the registration period.

RESULTS

The correlation between alcohol consumption and PEth varied from 0.65 to 0.87. It did not depend significantly on the reporting method, and was not influenced by sex or BMI. Based on the regression coefficient, a reduction of alcohol consumption by two alcohol units (26 g of pure ethanol) per day would lead to a reduction of the PEth concentration of about 0.1 μmol/l, and vice versa.

CONCLUSIONS

There was a good correlation between PEth concentration and alcohol consumption, both when alcohol consumption was reported prospectively and retrospectively. The preferred cut-off for PEth should be adjusted to the level of alcohol consumption considered harmful and a purposeful trade-off between sensitivity and specificity. In order to identify persons with a daily alcohol consumption of more than two or three units of alcohol with a sensitivity of 80% or 90%, we suggest a cut-off of around 0.1 μmol/l.

Phosphatidylethanol (B-PEth) and other direct and indirect biomarkers of alcohol consumption

When identifying, preventing and treating alcohol use disorder, a correct estimation of alcohol intake is essential. An objective marker is preferred as self-reported alcohol intake suffers from bias, and the use of alcohol biomarkers is increasing globally. An easy-to-use blood biomarker to correctly assess alcohol consumption is an invaluable asset in alcohol treatment strategies, as well as in alcohol research studies. The specific, cumulative, biomarker phosphatidylethanol, mirroring the past two weeks of consumption, has shown superiority over traditional biomarkers and is an attractive choice of proxy for alcohol intake.

The alcohol biomarker phosphatidylethanol (PEth) - test performance and experiences from routine analysis and external quality assessment

Phosphatidylethanol (PEth) are membrane molecules formed from phosphatidylcholine and ethanol through transphosphatidylation catalyzed by phospholipase D. Measurement of the main PEth form 16:0/18:1 is used as a specific and sensitive alcohol biomarker, since its formation requires ethanol, it accumulates in the blood upon repeated ethanol exposure, and it is only slowly eliminated during abstinence. PEth formation correlates with alcohol intake at the population level, albeit with considerable inter-individual variation as for the half-life during withdrawal. Over the past decade, the use of PEth has increased significantly and the applications have broadened. In Sweden, routine decision limits and the interpretation of test results for PEth were harmonized in 2013, using < 0.05 µmol/L (∼35 µg/L) as the recommended lower reporting limit and values > 0.30 µmol/L (∼210 µg/L) to indicate regular high alcohol intake. Routine test results show a large variation with about half being < 0.05 µmol/L and some even exceeding 10 µmol/L. In 2013, an external quality assessment (EQA) scheme for PEth 16:0/18:1 measurement in whole blood was also started (Equalis, Uppsala, Sweden), presently involving 56 laboratories from 13 countries. The agreement of PEth results between the laboratories has gradually improved to a CV < 15%. The current clinical and scientific information suggests that PEth values below the lower reporting limit (typically ∼0.03-0.05 µmol/L, or ∼20-35 µg/L) indicates sobriety or only low or occasional alcohol consumption, while regular high alcohol intake at levels corresponding to harmful drinking is required in most cases to reach PEth values > 0.30 µmol/L.

Biomarkers of moderate alcohol intake and alcoholic beverages: a systematic literature review

The predominant source of alcohol in the diet is alcoholic beverages, including beer, wine, spirits and liquors, sweet wine, and ciders. Self-reported alcohol intakes are likely to be influenced by measurement error, thus affecting the accuracy and precision of currently established epidemiological associations between alcohol itself, alcoholic beverage consumption, and health or disease. Therefore, a more objective assessment of alcohol intake would be very valuable, which may be established through biomarkers of food intake (BFIs). Several direct and indirect alcohol intake biomarkers have been proposed in forensic and clinical contexts to assess recent or longer-term intakes. Protocols for performing systematic reviews in this field, as well as for assessing the validity of candidate BFIs, have been developed within the Food Biomarker Alliance (FoodBAll) project. The aim of this systematic review is to list and validate biomarkers of ethanol intake per se excluding markers of abuse, but including biomarkers related to common categories of alcoholic beverages. Validation of the proposed candidate biomarker(s) for alcohol itself and for each alcoholic beverage was done according to the published guideline for biomarker reviews. In conclusion, common biomarkers of alcohol intake, e.g., as ethyl glucuronide, ethyl sulfate, fatty acid ethyl esters, and phosphatidyl ethanol, show considerable inter-individual response, especially at low to moderate intakes, and need further development and improved validation, while BFIs for beer and wine are highly promising and may help in more accurate intake assessments for these specific beverages.

Hematocrit Correction of Whole Blood Phosphatidylethanol Concentrations to Estimate Erythrocyte PEth Concentrations: Sensitivity, Specificity and Influence on Test Utility

Phosphatidylethanol (PEth) forms in erythrocyte membranes after alcohol consumption, offering a persisting biomarker, that is measurable in whole blood, washed erythrocytes and dried blood spots. For a predominantly erythrocyte-restricted analyte, erythrocyte concentrations seem to have most validity in patients who are anemic through alcoholism or other pathologies, despite preparation increasing assay complexity. Differences in specimen preparation alter PEth concentrations for the same patient, meaning that criteria for interpreting PEth results should relate to specimen type, presenting a barrier to achieving harmonization. We therefore tested whether erythrocyte PEth might be validly calculated by hematocrit correction of a whole blood PEth measurement. PEth testing primarily serves to distinguish drinkers from non-drinkers. In choosing between specimen types, it is important to compare their utility in separating those two groups. We therefore processed 281 blood samples from 17 non-drinkers and 61 drinkers, to prepare matched whole blood and washed erythrocyte specimens. These were assayed by liquid chromatography-tandem mass spectrometry and compared in identifying alcohol consumption. The erythrocyte PEth concentration in the whole blood specimens was also calculated by correcting whole blood concentration by the specimen's hematocrit, as an alternative to prepare washed erythrocytes. The hematocrit-corrected erythrocyte concentrations were included in these comparisons. Predictably, this work found that sensitivity was consistently better at the lower cut-off of 8 µg/L than at 20 µg/L. Sensitivities were also higher for washed erythrocytes than whole blood, explained by the lower erythrocyte mass in the same volume of whole blood. Hematocrit-corrected whole blood PEth concentrations correlated with erythrocyte concentrations, except for the four highest values, which did not influence comparative sensitivity. Specificity was 100% for washed erythrocytes, whole blood and hematocrit-corrected whole blood at either cut-off because non-drinkers had undetectable PEth. We conclude that hematocrit correction of whole blood PEth concentrations theoretically provides an alternative to the preparation of washed erythrocytes.

Alcohol Biomarker Phosphatidylethanol as a Predictor of the Severity of Alcohol Withdrawal Syndrome

AIMS

to investigate the relationship between phosphatidylethanol (PEth) and withdrawal severity in patients with alcohol use disorder (AUD).

METHODS

in 34 patients with AUD admitted for treatment of acute alcohol withdrawal, data were available for initial blood PEth concentrations and scores throughout detoxification of symptoms of withdrawal assessed by trained medical staff using the alcohol withdrawal syndrome (AWS)-scale, a validated scale consisting of 11 items in the alcohol withdrawal syndrome (two subscales with seven physiological and five psychological symptoms).

RESULTS

a significant positive correlation between PEth and the severity of alcohol withdrawal was found. When the sample was divided into two groups, according to whether or not AWS score at some point in the treatment reached 6 or more, the median PEth score was higher in those whose peak score had been 6 or more (score of 6 being the suggested cutoff to start medicating the withdrawal syndrome). Although there was a trend for some aspects of the clinical history to be more 'severe' in those with higher AWS, no differences reached significance.

CONCLUSION

blood PEth on admission could have a role in identifying patients at risk of more severe AWS.

Falsely low phosphatidylethanol may be associated with biomarkers of haemolytic disease

AIMS

Falsely lower or even negative phosphatidylethanol (PEth) levels may theoretically be seen in patients with haemolytic diseases, and the present study aimed to elucidate this hypothesis.

METHODS

PEth and carbohydrate-deficient transferrin (CDT) from 9893 serum and whole blood samples were included along with markers of haemolysis (i.e. haptoglobin, HbA1c, reticulocytes, LD and Hb). Cases showing discrepancy between PEth and CDT, that is, a low PEth value and a high CDT value, were considered to be possibly caused by falsely lowered PEth despite high alcohol consumption. These cases (N = 233) were compared to the control group without PEth and CDT mismatch.

RESULTS

The levels of haptoglobin were significantly lower in the cases showing low PEth and high CDT (estimate = -0.62, p = 0.002). The levels of HbA1c (estimate = -3.26, p = 0.001) and Hb (estimate = -0.507, p < 0.001) were also significantly lower in this group. These findings indicate haemolytic diseases in the low PEth/high CDT group. There were no significant differences for reticulocytes and LD concentrations between the low PEth/high CDT group and the control group.

CONCLUSIONS

These results indicate that falsely low PEth values could be associated with markers of haemolytic diseases, although more research is needed to highlight this further.

PEth 16:0/18:1 and 16:0/18:2 after consumption of low doses of alcohol-A contribution to cutoff discussion

Phosphatidylethanol in blood has gained recognition as a direct alcohol biomarker. Although different cutoffs have been suggested, there is no consensus for differentiating abstinence from alcohol consumption. In this study, 75 participants (72% female) consumed 20 g of ethanol on three consecutive evenings. Blood was sampled on each following day and PEth 16:0/18:1 and 16:0/18:2 were determined. PEth 16:0/18:1 ranged from 8.9-21.5, 8.7-19.3, and 8.8-42.3 ng/ml and PEth 16:0/18:2 from 8.7-31.7, 9.0-39.3, and 9.4-43.0 ng/ml after the respective days of ethanol consumption. PEth 16:0/18:1 yielded a sensitivity of 25%, 45%, and 49% and PEth 16:0/18:2 of 40%, 61%, and 68% for the consumption days, respectively (cutoff 10 ng/ml). PEth 16:0/18:1 reached >20 ng/ml in five samples overall. Sensitivity of PEth 16:0/18:2 > 20 ng/ml was better with 35% after the three drinking days. Overall, PEth 16:0/18:1 was >35 ng/ml in one sample and PEth 16:0/18:2 in three samples. Significantly, more women had PEth 16:0/18:1 > 10 ng/ml after the third day of consuming 20 g of alcohol (p = 0.02) and PEth 16:0/18:2 > 10 ng/ml after the second (p = 0.023) and the third (p = 0.002) consumption, which can be led back to the higher blood alcohol concentration women reach after consuming the same alcohol amount as men. Although the response rates of PEth to alcohol uptake are subject to strong interindividual differences, results suggest that PEth cutoff should be lowered for better detection of consumption of low to medium amounts of alcohol. Furthermore, it is advantageous to analyze both PEth 16:0/18:2 and 16:0/18:1.

Set-up of a population-based model to verify alcohol abstinence via monitoring of the direct alcohol marker phosphatidylethanol 16:0/18:1

BACKGROUND AND AIMS

Phosphatidylethanol 16:0/18:1 (PEth) is a biomarker for alcohol intake. It has a half-life of 7.9 days. Chronic alcohol consumption causes high PEth values. It can take weeks before PEth values fall below the decision limit for 'alcohol abstinence'. Our aim was to validate whether alcohol abstinence can be determined based on two consecutive PEth results above the decision limit.

DESIGN

Observational study.

SETTING

Belgium, February 2019. The study was linked to a social initiative in Belgium, 'Tournée Minérale'.

PARTICIPANTS

Adults (aged > 18 years, n = 796) with varying drinking habits who self-reportedly refrained from alcohol consumption during the study.

MEASUREMENTS

A validated liquid chromatography-tandem mass spectrometry method was used to quantify PEth in participants' dried blood samples, collected at three time-points via remote fingerprick-based self-sampling.

FINDINGS

A population-based algorithm to evaluate abstinence based on 95% prediction limits was developed by fitting a linear mixed-effect model to discern patterns in PEth elimination over time. It took intra- and inter-individual variability into consideration. The algorithm was included in a two-step decision tree, assessing whether (i) PEth values fell within the prediction interval and (ii) the slope between two PEth values was consistent with no alcohol consumption. Data for 74 participants reporting no alcohol intake during the study were used for validation. With a detection limit of 'four units spread over 14 days', the sensitivity and specificity of the decision tree was 89%.

CONCLUSIONS

Claims of alcohol abstinence can be verified using a two-step decision tree for phosphatidylethanol 16:0/18:1 values, even when those values are above the limit for 'alcohol abstinence'.

Unlocking the potential of forensic traces: Analytical approaches to generate investigative leads

Forensic investigation involves gathering the information necessary to understand the criminal events as well as linking objects or individuals to an item, location or other individual(s) for investigative purposes. For years techniques such as presumptive chemical tests, DNA profiling or fingermark analysis have been of great value to this process. However, these techniques have their limitations, whether it is a lack of confidence in the results obtained due to cross-reactivity, subjectivity and low sensitivity; or because they are dependent on holding reference samples in a pre-existing database. There is currently a need to devise new ways to gather as much information as possible from a single trace, particularly from biological traces commonly encountered in forensic casework. This review outlines the most recent advancements in the forensic analysis of biological fluids, fingermarks and hair. Special emphasis is placed on analytical methods that can expand the information obtained from the trace beyond what is achieved in the usual practices. Special attention is paid to those methods that accurately determine the nature of the sample, as well as how long it has been at the crime scene, along with individualising information regarding the donor source of the trace.

Change in Alcohol Use Based on Self-Report and a Quantitative Biomarker, Phosphatidylethanol, in People With HIV

The timeline followback (TLFB) takes more resources to collect than the Alcohol Use Disorder Identification Test (AUDIT-C). We assessed agreement of TLFB and AUDIT-C with the biomarker phosphatidylethanol (PEth) and compared changes in TLFB and PEth among persons with HIV (PWH) using secondary data from randomized trials. We calculated operating characteristics and agreement between TLFB (> 1 and > 2 average drinks/day), AUDIT-C ≥ 4 and PEth ≥ 20 among 275 men with HIV. Median age was 57 years, 80% were African-American; and 17% white. Sixty-eight percent had PEth ≥ 20, 46% reported > 2 average drinks/day on TLFB, 61% reported > 1 average drinks/day on TLFB, and 72% had an AUDIT-C ≥ 4. Relative to PEth, sensitivity for AUDIT-C ≥ 4 was 84% (kappa = 0.36), and for TLFB > 1 average drink/day was 76% (kappa = 0.44). Change in alcohol use appeared greater using TLFB measures than PEth. Strategies to robustly assess alcohol use in PWH may require both self-report and biomarkers.

Phosphatidylethanol in patients with liver diseases of different etiologies: Analysis of six homologues and comparison with other alcohol markers

BACKGROUND AND AIMS

Phosphatidylethanol (PEth) is a direct alcohol biomarker. Aim of the study was to evaluate the performance of six homologues of PEth in comparison to other alcohol markers in patients with liver diseases.

METHODS

The study included 234 patients with liver disease, who gave statements about alcohol consumption during the three months prior to the doctor's appointment. Ethylglucuronide in urine (uEtG) and in hair (hEtG) and carbohydrate-deficient transferrin (CDT) were analyzed in addition to PEth.

RESULTS

Of all patients 47% stated to have drunk alcohol during the past three months. UEtG, hEtG and CDT showed a sensitivity of 29% and a specificity of 92% together for ingestion of at least two standard drinks (24 g) per week. With PEth 16:0/18:1 in addition, sensitivity increased to 59%. For consumption in the last week uEtG's sensitivity and specificity was 28% and 100%, respectively. PEth's was 75% and 93%. When looking at patients who consumed at least two standard drinks per week during the past three months and of which a hair sample could be obtained, hEtG's sensitivity was 37% and specificity 90%. PEth had a sensitivity of 53% and specificity of 100%. Quotients of PEth 16:0/18:1 with 16:0/18:2, 16:0/20:4 and 18:0/18:2 were smaller when alcohol had been consumed more recently.

CONCLUSION

Despite the rather poor overall sensitivity of alcohol biomarkers in this study, PEth showed best sensitivity for all time periods of alcohol consumption.

Phosphatidylethanol, ethyl glucuronide and ethanol in blood as complementary biomarkers for alcohol consumption

Alcohol biomarkers can monitor both recent and long-term drinking and provide information about drinking habits as a complement to self-reporting. Ethyl glucuronide (EtG) and phosphatidylethanol (PEth) are the most sensitive available biomarkers for this purpose. The present study aimed to collect data on both PEth and EtG in the same blood sample, in addition to ethanol, in order to evaluate the combined use of these biomarkers. Venous EDTA blood samples (n = 1149) sent to the laboratory as part of a clinical routine service for measuring PEth were investigated. PEth and EtG concentrations were analyzed using liquid chromatography-mass spectrometry methods and ethanol with an enzymatic method. Of the 1149 samples, 95 were positive for ethanol (range 0.11-3.12 g/L), 454 for EtG (1.0-9739 ng/mL), 635 for PEth (0.014-6.0 µmol/L), 534 for PEth ≥ 0.050 µmol/L, and 315 for PEth ≥ 0.30 µmol/L. EtG and PEth concentrations seemed largely independent as the coefficient of determination (r²) between PEth and EtG concentrations was 0.15. However, when the EtG concentrations were evaluated for different subgroups depending on ethanol or PEth concentrations a statistically significant difference between successive higher concentrations was observed. EtG and PEth are independent measures of recent alcohol drinking reflecting different time windows. Their combined measurement in the same blood sample is possible and will provide valuable information regarding recent alcohol consumption as a complement to self-reporting.

Investigating the use of PEth, CDT and MCV to evaluate alcohol consumption in a cohort of homeless individuals- A comparison of different alcohol biomarkers

In a cohort including individuals with suspected high alcohol consumption, the concentrations of the indirect alcohol biomarkers carbohydrate-deficient transferrin (CDT) and mean corpuscular volume (MCV) and the direct alcohol biomarker phosphatidylethanol (PEth) were investigated. Blood alcohol concentration (BAC) was analysed as a marker for acute alcohol ingestion. In addition to questions about subjective alcohol consumption behaviour, 147 homeless persons underwent a physical examination with blood sampling. BAC, PEth, CDT and MCV were determined in the blood samples. Special focus was on the comparison of PEth and CDT for indicating excessive alcohol consumption. BAC was measured above 0.1‰ in 39 blood samples (0.1-2.5‰, median 0.75‰). PEth was detected in all of them. Overall, PEth was positive (≥10 ng/ml) in 104 samples (71%) (11-5687 ng/ml, median 650 ng/ml) with 68 (46%) being above the cut-off for excessive alcohol consumption (210 ng/ml). In 26 subjects PEth was the only positive alcohol biomarker. CDT was ≥ 1.7% in 66 cases (47%) (1.8-22.2%, median 4.4%) and ≥ 2.5% in 52 (35%) cases. MCV was elevated (≥95 fl) in 58 subjects (39%). CDT and PEth concentrations showed a significant positive correlation (spearman's correlation coefficient ρ = 0.77, p < 0.001). PEth concentrations were significantly higher in samples that were also CDT positive than solely PEth positive (p = 0.004). PEth did not indicate excessive alcohol consumption (< 210 ng/ml) in eight and two cases in which CDT was ≥ 1.7% and ≥ 2.5%, respectively. On the other hand, CDT was< 1.7% and< 2.5% in ten and 18 cases, respectively, in which PEth was above cut-off for excessive alcohol consumption. Taking the self-reports of the participants into consideration, PEth's sensitivity for detecting excessive alcohol consumption was 100% (10 ng/ml) and 94% (210 ng/ml) and CDT's was 88% (1.7%) and 75% (2.5%). In individuals of the investigated cohort unusually high concentrations of the alcohol consumption markers PEth and CDT were quantified, which proves the assumption of chronic excessive alcohol consumption in parts of the cohort. PEth was the marker that was positive most often and was more sensitive for excessive alcohol consumption than CDT.

Factors associated with phosphatidylethanol (PEth) sensitivity for detecting unhealthy alcohol use: An individual patient data meta-analysis

BACKGROUND

Objective measurement of alcohol consumption is important for clinical care and research. Adjusting for self-reported alcohol use, we conducted an individual participant data (IPD) meta-analysis to examine factors associated with the sensitivity of phosphatidylethanol (PEth), an alcohol metabolite, among persons self-reporting unhealthy alcohol consumption.

METHODS

We identified 21 eligible studies and obtained 4073 observations from 3085 participants with Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) positive scores (≥3 for women and ≥4 for men) and PEth measurements. We conducted 1-step IPD meta-analysis using mixed effects models with random intercepts for study site. We examined the associations between demographic (sex, race/ethnicity, and age) and biologic (body mass index-BMI, hemoglobin, HIV status, liver fibrosis, and venous versus finger-prick blood collection) variables with PEth sensitivity (PEth≥8 ng/ml), adjusting for the level of self-reported alcohol use using the AUDIT-C score.

RESULTS

One third (31%) of participants were women, 32% were African, 28% African American, 28% White, and 12% other race/ethnicity. PEth sensitivity (i.e., ≥8 ng/ml) was 81.8%. After adjusting for AUDIT-C, we found no associations of sex, age, race/ethnicity, or method of blood collection with PEth sensitivity. In models that additionally included biologic variables, those with higher hemoglobin and indeterminate and advanced liver fibrosis had significantly higher odds of PEth sensitivity; those with higher BMI and those living with HIV had significantly lower odds of PEth sensitivity. African Americans and Africans had higher odds of PEth sensitivity than whites in models that included biologic variables.

CONCLUSIONS

Among people reporting unhealthy alcohol use, several biological factors (hemoglobin, BMI, liver fibrosis, and HIV status) were associated with PEth sensitivity. Race/ethnicity was associated with PEth sensitivity in some models but age, sex, and method of blood collection were not. Clinicians should be aware of these factors, and researchers should consider adjusting analyses for these characteristics where possible.

Phosphatidylethanol as Blood Biomarker of Alcohol Consumption in Early Pregnancy: An Observational Study in 4,067 Pregnant Women

BACKGROUND

The teratogenic effects of alcohol are well documented, but there is a lack of screening methods to detect alcohol use during pregnancy. Phosphatidylethanol 16:0/18:1 (PEth) is a specific and sensitive biomarker reflecting alcohol intake up to several weeks after consumption. The aim of this study was to investigate the prevalence of positive PEth values as an indicator of early prenatal alcohol exposure in a general population of pregnant women.

METHODS

Rhesus typing is routinely performed in Norway in all pregnancies around gestational week 12. Rhesus-negative women have an additional test taken around week 24. Blood samples submitted to St. Olav University Hospital in Trøndelag, Norway, for Rhesus typing during the period September 2017 to October 2018 were collected. A total of 4,533 whole blood samples from 4,067 women were analyzed for PEth (limit of quantification of 0.003 µM).

RESULTS

Fifty-eight women had a positive PEth sample. Of these, 50 women were positive around gestational week 12, 3 women were positive around week 24, and in 5 cases, the timing was unknown. There were no significant differences in proportions of women with positive PEth values related to age, or rural versus urban residency.

CONCLUSION

In an unselected pregnant population in Norway, 1.4% had a positive PEth sample around gestational week 12, whereas 0.4% had a positive sample around week 24. The use of PEth as an alcohol biomarker should be further investigated as a diagnostic tool in the antenatal setting.

The Association between the Alcohol Biomarker Phosphatidylethanol (PEth) and Self-Reported Alcohol Consumption among Russian and Norwegian Medical Patients

Aims

Valid measures to identify harmful alcohol use are important. Alcohol Use Disorders Identification Test (AUDIT) is a validated questionnaire used to self-report harmful drinking in several cultures and settings. Phosphatidylethanol 16:0/18:1 (PEth) is a direct alcohol biomarker measuring alcohol consumption levels. The aim of this study was to investigate how PEth levels correlate with AUDIT-QF and weekly grams of alcohol consumed among patients in two urban hospitals. In addition, we wanted to investigate the predictive value of PEth in identifying harmful alcohol use as defined by AUDIT-QF and weekly grams of alcohol cutoffs.

Methods

A cross-sectional study comprising acute medically ill patients with measurable PEth levels (≥0.030 μM) admitted to two urban hospitals in Oslo, Norway (N = 931) and Moscow, Russia (N = 953) was conducted using PEth concentrations in whole blood, sociodemographic data and AUDIT-QF questionnaires.

Results

PEth levels from patients with measurable PEth were found to be positively correlated with AUDIT-QF scores, with PEth cutpoints of 0.128 μM (Oslo) and 0.270 μM (Moscow) providing optimal discrimination for harmful alcohol use defined by AUDIT-QF (the difference between cities probably reflecting different national drinking patterns in QF). When converting AUDIT-QF into weekly grams of alcohol consumed, the predictive value of PEth improved, with optimal PEth cutpoints of 0.327 (Oslo) and 0.396 (Moscow) μM discriminating between harmful and non-harmful alcohol use as defined in grams (≥350 grams/week).

Conclusions

By using PEth levels and converting AUDIT-QF into weekly grams of alcohol it was possible to get an improved rapid and sensitive determination of harmful alcohol use among hospitalized patients.

Measurement of the alcohol biomarker phosphatidylethanol (PEth) in dried blood spots and venous blood-importance of inhibition of post-sampling formation from ethanol

Phosphatidylethanol (PEth) is a group of phospholipids formed in cell membranes following alcohol consumption by action of the enzyme phospholipase D (PLD). PEth measurement in whole blood samples is established as a specific alcohol biomarker with clinical and forensic applications. However, in blood specimens containing ethanol, formation of PEth may continue after sampling leading to falsely elevated concentrations. This study evaluated the use of dried blood spot (DBS) and microsampling specimens to avoid post-sampling formation of PEth. Filter paper cards and three commercial devices for volumetric microsampling of finger-pricked blood were assessed, using PEth-negative and PEth-positive whole blood fortified with 2 g/L ethanol. PEth (16:0/18:1) was measured by LC–MS/MS. Post-sampling formation of PEth occurred in wet blood and in the volumetric devices, but not filter paper cards, when stored at room temperature for 48 h. Addition of an inhibitor of PLD, sodium metavanadate (NaVO₃), eliminated post-sampling formation during storage and drying. In conclusion, the present study confirmed previous observations that PEth can be formed in blood samples after collection, if the specimen contains ethanol. The results further demonstrated that post-sampling formation of PEth from ethanol also occurred with commercial devices for volumetric dried blood microsampling. In order for a PEth result not to be questioned, it is recommended to use a PLD inhibitor, whether venous blood is collected in a vacutainer tube or finger-pricked blood is obtained using devices for dried blood microsampling.

Secondary Analysis of a Randomized Clinical Trial of Naltrexone Among Women Living With HIV: Correlations Between Reductions in Self-Reported Alcohol Use and Changes in Phosphatidylethanol

BACKGROUND

Direct biomarkers such as phosphatidylethanol (PEth) have the capability to detect heavy alcohol use, but it is unclear how strongly self-reported reduction in alcohol use correlates with reduction in PEth. We sought to explore the strength of correlation between reductions in self-reported alcohol use and change in PEth among a sample of women living with HIV (WLWH) who participated in a clinical trial to reduce heavy alcohol use. We also sought to determine whether this correlation was stronger in women with lower body mass index (BMI) and women without an alcohol use disorder (AUD).

METHODS

81 WLWH (mean age = 48.7, 80% Black) engaging in a randomized trial of naltrexone versus placebo with a positive baseline PEth (≥8 ng/ml), and alcohol use data at baseline, 2, and 7 months were included in this analysis. Spearman correlation coefficients were compared to measure the correlation between baseline PEth and number of drinks per week by demographic, biological, and alcohol use factors. Mini-International Neuropsychiatric Interview was used to screen for AUD. Further analyses were stratified by BMI and AUD. Spearman correlation coefficients were calculated for the change in PEth and the change in number of drinks per week over 7 months, including 3 time-points: baseline, 2, and 7 months.

RESULTS

At baseline, the correlation between baseline PEth and the number of drinks per week was significantly stronger for those with a BMI ≤25 compared to those with a BMI > 25 (r = 0.66; r = 0.26, respectively). Similarly, the correlation between baseline PEth and number of drinks was stronger for those who did not screen positive for AUD compared with those who did (r = 0.66; r = 0.25, respectively). When stratifying by BMI, a low-to-moderate correlation (r = 0.32, p = 0.02) was present for persons with a BMI > 25; when stratifying by AUD, a moderate correlation (r = 0.50, p < 0.01) was present for persons without an AUD between 0 and 2 months only.

CONCLUSIONS

In this sample of WLWH, BMI and AUD affected the strength of correlation between PEth and drinks per week. Future work examining changes in PEth over time in broader populations is needed, particularly to understand the sex differences in PEth levels.

Relationship of Phosphatidylethanol Biomarker to Self-Reported Alcohol Drinking Patterns in Older and Middle-Age Adults

BACKGROUND

Risky alcohol consumption is on the rise among older adults. Biomarkers such as phosphatidylethanol (PEth) have been used to evaluate the correspondence between an objective, laboratory-based biomarker and self-report of alcohol consumption. This study examined the relationship between PEth, self-report of alcohol consumption, and health indices in a sample of community-dwelling older to middle-age adults (aged 35 to 89) with healthy and risky levels of alcohol consumption.

METHODS

Self-reports of alcohol consumption were collected using the Alcohol Use Disorders Identification Test (AUDIT) and Form 30. In addition, indices of health along with a blood sample to determine PEth values were collected (N = 183).

RESULTS

PEth was correlated with age, AUDIT-C, AUDIT total, alcohol consumption, mood, and liver function measures but not with medical comorbidity or body mass index (J Gerontol B Psychol Sci Soc Sci 73, 2018, 633). Alcohol consumption over the past 30 days measured with Form 30 was the strongest predictor of PEth levels for both middle-age and older adults, with age a small contributing predictor. General alcohol consumption patterns for amount of alcohol consumed over a 30-day period revealed middle-age adults consumed larger amounts of alcohol compared with older adults, but older adults consumed alcohol on more days than middle-age adults. Middle-age participants evidenced higher PEth levels than older adults at comparable drinking rates.

CONCLUSIONS

Overall, findings suggest a strong relationship between alcohol consumption and PEth levels with age a small but contributing factor to predicting PEth levels.

Performance of PEth Compared With Other Alcohol Biomarkers in Subjects Presenting For Occupational and Pre-Employment Medical Examination

Aims

To compare the performance of short- and long-term alcohol biomarkers for the evaluation of alcohol drinking in employment-related health controls.

Methods

The 519 blood samples originated from 509 patients (80% men) presenting at occupational health units and medical centers at employment agencies for the evaluation of risky drinking. The laboratory investigation comprised the measurement of phosphatidylethanol (PEth 16:0/18:1), carbohydrate-deficient transferrin (CDT; % disialotransferrin), gamma-glutamyl transferase (GGT), mean corpuscular volume (MCV), ethanol and ethyl glucuronide (EtG).

Results

Many samples tested positive for acute (57%) and chronic (69%) alcohol biomarkers. PEth was the single most positive biomarker (64%; cut-off 0.05 μmol/l or 35 μg/l) and the only positive chronic biomarker in 100 cases. The highest PEth concentrations were seen in samples positive for all chronic biomarkers, followed by those also being CDT positive (cut-off 2.0%). All 126 CDT-positive samples were positive for PEth using the lower reporting limit (≥0.05 μmol/l) and for 114 cases (90%) also using the higher limit (≥0.30 μmol/l or 210 μg/l). In the CDT-positive cases, the PEth median concentration was 1.71 μmol/l, compared with 0.45 μmol/l for the CDT-negative cases (P < 0.0001). PEth and CDT values were correlated significantly (r = 0.63, P < 0.0001). Among the EtG-positive cases (≥1.0 ng/ml), 95% were also PEth positive, and all ethanol-positive cases (≥0.10 g/l) were also PEth positive.

Conclusions

For optimal detection of drinking habits, using a combination of short- and long-term alcohol biomarkers provided best information. PEth was the single most positive alcohol biomarker, whereas GGT and MCV offered little additional value over PEth and CDT.