Differences in the Synthesis and Elimination of Phosphatidylethanol 16:0/18:1 and 16:0/18:2 After Acute Doses of Alcohol

Utilising paired measurements of phosphatidylethanol to monitor early success in alcohol abstinence

INTRODUCTION

Phosphatidylethanol (PEth) is a specific and persisting marker of ethanol (alcohol) consumption. Early success of medically necessary abstinence can be assessed by monitoring PEth disappearance at a biologically plausible rate. This requires an understanding of PEth elimination, its variability and its determinants. To achieve this, we characterised PEth elimination in drinkers who voluntarily abstained. We aimed to derive a nomogram from the data to assist practitioners in recognising abstinence.

METHODS

Twenty-nine usual drinkers who were prepared to abstain from alcohol consumption for 4 weeks were recruited. Erythrocyte PEth was measured weekly. A population pharmacokinetic model for PEth was developed, describing the time-course of PEth elimination. Estimates were derived for population average, inter-individual variability in PEth half-life and any covariate influences. These estimates informed a nomogram of PEth elimination that incorporated a boundary separating continued abstinence from resumed drinking. The nomogram was tested to identify drinking events among participants.

RESULTS

The model estimated a population average elimination rate constant (k) of 0.088 day-1, corresponding to a half-life of 7.9 days with a residual coefficient of variation of 8.5%. Elimination was first order and no covariate influences were identified. The nomogram was internally assessed as predictively accurate for 21 successfully abstinent participants and in detecting alcohol consumption in 2 further participants, using a 99.9% prediction interval.

DISCUSSION AND CONCLUSIONS

The value of PEth in distinguishing alcohol abstinence from consumption is enhanced by using a nomogram to confirm abstinence within weeks of its medically necessary imposition. Further work will establish the value of this approach in clinical practice.

Evaluation and comparison of sensitivity of alcohol biomarkers PEth, EtG and EtPa in civil cases in England 2022-2023

This study details trends in direct alcohol biomarker concentrations from civil cases within the United Kingdom (UK). Our subject cohort in this study related to family law litigation, where an individual was subject to an alcohol monitoring order by the court. This monitoring was conducted by quantification of alcohol biomarkers Phosphatidlyethanol (PEth) in dried blood spots (DBS) and Ethyl Glucuronide (EtG) and Ethyl Palmitate (EtPa) from hair segments. In total 298 PEth cases predominantly from the South East of England during the period July 2022 to August 2023 were analysed for alcohol biomarkers in DBS and hair. Subjects alcohol intake was classified as abstinence/low alcohol consumption, moderate or excessive alcohol consumption, based on a combination of Society for Hair Testing and PEth Net guidelines. Our results indicate that 33 % of PEth concentrations were consistent with excessive alcohol use (>200 ng/mL DBS), with 36 % consistent with social or moderate alcohol use (20-200 ng/mL DBS). In relation to EtG and EtPa 23 % and 31 % of subjects were classified as excessive alcohol users respectively. This study indicates that DBS sampling of PEth is a more sensitive predictor of alcohol use, in particular, at differentiating between moderate and excessive alcohol use compared to EtG and EtPa testing in hair. The authors suggest that increased frequency in the sampling of PEth in DBS (multiple occasions per month) may provide a more accurate assessment and simplification of the interpretation criteria of alcohol patterns rather than the combined hair testing and DBS sampling that are typically requested by UK courts.

Phosphatidylethanol is a promising tool for screening alcohol consumption during pregnancy

BACKGROUND

Prenatal alcohol exposure (PAE) is one of the leading causes of preventable developmental disabilities. A lack of objective screening methods results in an under-recognition of the phenomenon. Phosphatidylethanol (PEth) is a specific ethanol biomarker that reveals alcohol intake up to several weeks after alcohol use. So far, PEth has mostly been a tool for detecting moderate and heavy drinking. With lower PEth cut-offs, revealing even minor prenatal alcohol consumption is possible. We aimed to find out if a sensitive method for PEth analysis would give additional information about PAE and to assess the cut-off value for a positive alcohol result in prenatal screening.

METHODS

The study was an observational study of 3000 anonymous blood samples collected from the Helsinki University Hospital Diagnostic Center between June and September 2023. The Finnish Red Cross Blood Service received the samples originally for blood group typing and antibody screening as part of the prenatal blood screening program. We developed a sensitive PEth 16:0/18:1 analysis method using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) equipment after liquid-liquid extraction of PEth from whole blood. The lower limit of quantification was 1 ng/mL.

RESULTS

PEth was ≥2 ng/mL in 5.2% of the cases, ≥8 ng/mL in 2.0%, and ≥20 ng/mL in 1.0%. The detection time of PEth can be several weeks, especially with low PEth concentrations and after heavy alcohol consumption. It remained unknown whether the positive PEth tests resulted from drinking deliberately during pregnancy or before pregnancy recognition.

CONCLUSIONS

We suggest adding PEth 16:0/18:1 to a routine prenatal blood screening program with a cut-off of 2 ng/mL-and in positive cases, clinical evaluation and retesting in 2-4 weeks. In clinical settings, information on gestational week and alcohol consumption before pregnancy is relevant and needs to be considered when interpreting low PEth concentrations.

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.

Storage stability of phosphatidylethanol homologues in whole blood and dried blood spots of nonalcoholics at different temperatures over 60 days

Phosphatidylethanol (PEth) has recently become a popular direct alcohol marker for evaluating drinking behavior. This study aimed at gaining further information on the long-term stability of five PEth homologues (16:0/18:1, 16:0/18:2, 16:0/20:4, 18:0/18:1, 18:0/18:2) in whole blood (WB) and dried blood spots (DBS) stored at -80°C, 4°C, and room temperature (18°C) over a period of 60 days. Venous blood was taken from 10 volunteers (five females and five males, aged 21-40 years) with a moderate drinking behavior and a negative breath alcohol test at the time of collection. 100 μL aliquots of WB were prepared in addition to 20 μL DBS samples. The initial PEth concentrations were determined on the day of the blood collection. On days 1, 3, 5, 7, 11, 17, 40, and 60, DBS were analyzed in triplicate by means of LC-MS/MS. On these days, WB aliquots having been stored until that time were used to create further DBS in triplicate, which were subsequently stored at 18°C and analyzed in a single batch after day 60. All homologues, except PEth 16:0/20:4, were stable at -80°C in DBS and WB for 60 days. The initial PEth 16:0/18:1 concentrations remained stable in both DBS and WB in all but one volunteer's specimen at 4 and 18°C. Apart from this exception, simultaneously detected PEth homologues 16:0/18:2, 18:0/18:1, and 18:0/18:2 remained stable over at least 40 days in DBS. Nevertheless, the storage time between sample collection and analysis should be kept as short as possible if an ethanol-free sample cannot be ensured.

Characterization of the alcohol biomarker phosphatidylethanol in donor whole blood and apheresis red blood cells: Implications for transfusion recipients

INTRODUCTION

Phosphatidylethanol (PEth) is a long-term marker of alcohol consumption used frequently in clinical scenarios such as liver transplant evaluation. Recent cases have demonstrated that packed red blood cell (pRBC) transfusion creates the potential for artificial elevation or decrease of observed PEth concentrations in recipients. Very little is known about the prevalence or stability of PEth in pRBCs.

METHODS

Apheresis and whole-blood (WB) donations were tested for PEth using liquid chromatography - tandem mass spectrometry with limit of quantitation 10 ng/mL. Units were stored under routine blood bank conditions to evaluate the stability of PEth and the impact of irradiation.

RESULTS

Over 40% of apheresis and WB donors had PEth ≥10 ng/mL (maximum observed 587 ng/mL). As WB units were processed into component pRBCs, PEth concentrations increased and were higher than donor WB levels (EDTA sample) prior to collection (maximum observed 711 ng/mL). Storage for up to 5 weeks post donation resulted in mean 17.3% decrease in PEth-positive units; in contrast to a prior report, we observed no PEth formation in units with negative (<10 ng/mL) baseline concentrations. Irradiation of pRBCs did not substantially affect PEth concentrations in either PEth-positive or PEth-negative units.

DISCUSSION

PEth concentrations in healthy blood donors may potentially confound alcohol use or abstinence assessment in pRBC recipients. Transfusion medicine services and clinical practices such as transplantation and behavioral medicine should recognize this phenomenon and collaborate on testing protocols to appropriately interpret PEth in pRBC recipients.

Mental Manifestations and Biomarkers of Alcohol Consumption

The purpose of this study is to examine healthcare usage, morbidities, and alcohol consumption monitoring in patients before a diagnosis of mental manifestations to assist in the early identification of individuals at risk. Biological markers of alcoholism are separated into two groups: those biological variables that highlight with great confidence and validate the presence of a predisposition to alcoholism, also called trait markers, or those that highlight alcohol consumption, called markers of alcoholism ("status markers"). Biomarkers are the true "gold standard" for the diagnosis of alcoholism. They are valuable for tracking evolution and progress during biological and psychological therapy and for highlighting relapse. This review compiles the existing data from research on healthcare utilization, comorbidities, and alcohol consumption monitoring in patients before a diagnosis of mental manifestations to aid in the early identification of individuals at risk. This documentary study took place over three to four months by searching for terms on the Science Direct platform, PubMed, Web of Science, and Google Scholar such as alcoholism, alcohol use disorders, alcohol abuse, and biomarkers. Studies reporting on the development, characteristics, and utilization of blood biomarkers for alcohol consumption were included in the search. The initial search included a number of 11.019 articles that contained the keywords biomarkers and alcohol. Finally, a total of 50 research articles were considered. I am involved in clinical studies, meta-analyses, reviews, and case studies regarding alcohol consumption detection, as well as potential alcohol markers.

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.

Monitoring of phosphatidylethanol in dried blood spots and of ethyl glucuronide in hair over 6 months of alcohol consumption

The aim of this study was to monitor seven phosphatidylethanol (PEth) homologues in dried blood spots (DBS) and ethyl glucuronide in hair (EtGH) over a 6-month period of drinking while documenting the daily drinks (amount and type) of alcohol via app. A total of 23 volunteers (12 males and 11 females) aged 19-54 years were enrolled. At four-weekly intervals, capillary blood to create DBS and after 3 and 6 months, respectively, a strand of hair (proximal, 3 cm) was collected. Analyses of EtGH and PEth homologues were performed using liquid chromatography-tandem mass spectrometry. All participants consumed alcohol during the 6 months. Only one participant tested negative for both PEth and EtGH. Eight participants had PEth 16:0/18:1 concentrations between 20 and <210 ng/mL (mean: 45.6 ng/mL) but EtGH concentrations below 5 pg/mg. PEth 16:0/18:1 concentrations between 20 and <210 ng/mL and EtGH concentrations between 5 and <30 pg/mg were assigned to eight subjects, uniformly matching them in the category of socially accepted drinking behavior. Four test subjects exceeded the cutoff for social drinking behavior in both PEth 16:0/18:1 (mean: 528 ng/mL) and EtGH (mean: 84.5 pg/mg). Two participants exceeded the threshold for PEth 16:0/18:1 of 210 ng/mL in blood but remained below 30 pg EtG/mg hair. PEth showed a higher detection rate for alcohol consumption than EtGH did. Moreover, PEth concentrations reacted quickly to changes in drinking behavior, whereas EtGH concentrations remained similar over time.

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.

Feasibility of a telehealth-based contingency management intervention for alcohol use disorders using the phosphatidylethanol (PEth) 16:0/18:1 alcohol biomarker: a pilot randomized trial

Background: Phosphatidylethanol (PEth) is a blood-based biomarker for alcohol consumption that can be self-collected and has high sensitivity, specificity, and a longer detection window compared to other alcohol biomarkers.Objectives: We evaluated the feasibility and acceptability of a telehealth-based contingency management (CM) intervention for alcohol use disorder (AUD) using the blood-based biomarker PEth to assess alcohol consumption.Methods: Sixteen adults (7 female, 9 male) with AUD were randomized to Control or CM conditions. Control participants received reinforcers regardless of their PEth levels. CM participants received reinforcers for week-to-week decreases in PEth (Phase 1) or maintenance of PEth consistent with abstinence (<20 ng/mL, Phase 2). Blood samples were self-collected using the TASSO-M20 device. Acceptability was assessed by retention in weeks. Satisfaction was assessed with the Client Satisfaction Questionnaire (CSQ-8) and qualitative interviews. The primary efficacy outcome was PEth-defined abstinence. Secondary outcomes included the proportion of visits with PEth-defined heavy alcohol consumption, negative urine ethyl glucuronide results, and self-reported alcohol use.Results: Retention averaged 18.6 ± 8.8 weeks for CM participants. CM participants reported high levels of satisfaction (CSQ-8, Mean = 30.3 ± 1.5). Interview themes included intervention positives, such as staff support, quality of life improvement, and accountability. 72% of PEth samples from CM participants were consistent with abstinence versus 34% for Control participants (OR = 5.0, p = 0.007). PEth-defined heavy alcohol consumption was detected in 28% of CM samples and 52% of Control samples (OR = 0.36, p = 0.159). CM participants averaged 1.9 ± 1.7 drinks/day versus 4.2 ± 6.3 for Control participants (p = 0.304).Conclusion: Results support the acceptability and satisfaction of a telehealth PEth-based CM intervention, though a larger study is needed to assess its efficacy [NCT04038021].

A randomized, double-blind, placebo-controlled, multicentre trial on the efficacy of varenicline and bupropion in combination and alone for treatment of alcohol use disorder: Protocol for the COMB study

BACKGROUND

Alcohol Use Disorder (AUD) is a major cause of premature death, disability and suffering. Available treatments are of modest efficacy and under-prescribed so there is a pressing need for a well-tolerated and effective treatment option for AUD. Dopamine is hypothesized to be involved in the development of alcohol dependence. To challenge the low-dopamine hypothesis of addiction, this randomized, double-blind, placebo-controlled, 13-week, multicentre clinical trial with four parallel arms is designed to evaluate the efficacy of two substances raising dopamine levels, varenicline and bupropion, alone and in combination vs. placebo on alcohol consumption in AUD. Varenicline, a partial agonist at brain nicotinic acetylcholine receptors increases dopamine release, whereas bupropion is a centrally-acting, norepinephrine-dopamine reuptake inhibitor. Varenicline is previously shown to reduce alcohol intake in individuals with AUD. We hypothesize that the effect size of a combination of two drugs affecting dopamine levels in the brain will exceed that of approved AUD therapies.

METHODS

Consenting individuals with AUD will be recruited via media advertisements. Those fulfilling the eligibility criteria (N = 380) will be randomized to one of four interventions (n = 95 per arm). Treatment will comprise one week of titration (varenicline 0.5‒2 mg; bupropion SR 150‒300 mg) plus 12 weeks at steady state. Efficacy will be evaluated using two primary endpoints of alcohol consumption: Heavy Drinking Days and blood levels of phosphatidylethanol. Secondary objectives, exploratory and subgroup analyses will be also performed. The modified Intention-to-Treat and Per Protocol datasets will be evaluated using Analysis of Covariance. Last patient out is estimated to occur in December, 2022.

DISCUSSION

The COMB Study aims to evaluate the efficacy of the combination of varenicline and bupropion, two drugs affecting dopamine, on alcohol consumption, and to challenge the low-dopamine hypothesis of addiction. Study Code COMB-BO8, EudraCT 2018-000048-24, Version 3.2, Lidö & deBejczy, 2020-06-16; https://clinicaltrials.gov identifier NCT04167306.

Formation of phosphatidylethanol and ethylglucuronide after low to moderate alcohol consumption in volunteers with a previous three-week alcohol abstinence

AIMS

Phosphatidylethanol (PEth) is only formed when ethanol is present in blood. This direct alcohol marker has been widely discussed, including the minimum amount of ethanol being necessary to form as much PEth as to exceed the threshold of 20 ng/mL in previously PEth negative subjects. In order to corroborate hitherto existing results, a drinking study including 18 participants after a 3-week alcohol abstinence was performed.

METHODS

They consumed a pre-calculated amount of ethanol to reach a blood alcohol concentration (BAC) of at least 0.6 g/kg. Blood was drawn before and periodically seven times after alcohol administration on day 1. Blood and urine were also collected the next morning. Dried blood spots (DBS) were prepared immediately from collected venous blood. BAC was determined by head space gas chromatography and the concentrations of both PEth (16:0/18:1, 16:0/18:2 and five additional homologues) and ethyl glucuronide (EtG) were analysed using liquid chromatography-tandem mass spectrometry.

RESULTS

Out of 18, 5 participants had concentrations of PEth 16:0/18:1 above the threshold of 20 ng/mL, and 11 out of the 18 subjects had concentrations between 10 and 20 ng/mL. In addition, four persons had PEth 16:0/18:2 concentrations above 20 ng/mL the following morning. All test subjects tested positive for EtG in DBS (≥ 3 ng/mL) and urine (≥100 ng/mL) upon 20-21 h after alcohol administration.

CONCLUSION

By combining both a lower cutoff of 10 ng/mL and the homologue PEth 16:0/18:2, the sensitivity to detect a single alcohol intake after a 3-week abstinence increases to 72.2%.

Confounders of Serum Phosphatidylethanol: Role of Red Blood Cell Turnover and Cirrhosis

Purpose

Ethyl glucuronide (EtG), ethyl sulfate (EtS) and phosphatidylethanol (PEth) are considered specific direct biomarkers for detecting alcohol consumption. However, PEth, which is produced in red blood cells (RBC), varies considerably between patients for unknown reasons. We here studied various confounders of PEth elimination including fibrosis after alcohol withdrawal.

Patients and Methods

EtG, EtS and PEth together with routine laboratory and clinical parameters were studied in 100 Caucasian heavy drinkers prior and after alcohol detoxification. In addition, fibrosis stage and degree of steatosis were assessed by transient elastography (Fibroscan, Echosens, Paris).

Results

All three biomarkers were highly correlated (0.61-0.72) with initial serum alcohol levels, but only PEth correlated with daily alcohol consumption. After alcohol withdrawal, PEth significantly decreased within 6.1 days from 1708 to 810 ng/mL (half-life varied from 1.6 to 15.2 days). Both levels of serum alcohol but also EtG and EtS were higher in patients with liver cirrhosis as compared to patients without fibrosis despite comparable alcohol consumption suggesting a decreased alcohol elimination in patients with cirrhosis. PEth was also elevated in cirrhosis but not significantly. In contrast, PEth elimination rate was significantly higher in patients with enhanced RBC turnover and signs of alcohol-mediated hemolytic anemia with elevated ferritin, LDH and increased mean corpuscular volume (MCV).

Conclusion

We here demonstrate that alcohol elimination is decreased in patients with liver cirrhosis. In patients with cirrhosis, PEth levels are both affected in opposite directions by enhanced red blood cell turnover and elevated alcohol levels. Our data have important implications for the use and interpretation of PEth in the clinical setting.

An accurate and precise liquid chromatography-tandem mass spectrometry method for the determination of six phosphatidylethanol homologues in whole blood with phospholipid interferences minimized

Alcohol consumption is associated with a wide risk of different diseases, injury and death, and has significant social and economic consequences worldwide. Phosphatidylethanol (PEth) is a group of promising direct alcohol biomarkers, with a significantly longer half-life in blood than ethanol, which can be measured to predict different drinking patterns, such as heavy- and social drinking. This study aimed to develop and validate an accurate and precise LC-MS/MS method for the determination of six PEth homologues in whole blood with minimal interference from unwanted phospholipids. Different organic solvent mixtures for liquid-liquid extraction were investigated to obtain satisfactory recovery of PEth homologues and removal of the lyso-phospholipids and other early eluting phospholipids. The mixture of heptane/2-propanol (80:20, v:v) gave lower phospholipid background and better signal/noise values for the PEth peaks. An LC-MS/MS TQ-S system from Waters was used for the instrumental analysis. The main part of unwanted phospholipids were separated from the PEth homologues on an Acquity BEH C18 column (50 × 2.1 mm ID, 1.7 µm particles) using a buffer-free mobile phase of 0.025 % ammonia in Type 1 water, pH 10.7, as solvent A and methanol as solvent B. Validation and quantification of 22 authentic blood samples showed that the developed LC-MS/MS method is sensitive, precise and accurate for the determination of the six PEth homologues in whole blood. Lower limit of quantification was 10 nM for all compounds. No matrix effects were observed, possibly due to the successful strategies incorporated to avoid the influence of unwanted phospholipids.

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.

Development of an LC-MS/MS assay with automated sample preparation for phosphatidylethanol (PEth)- Not your typical clinical marker

Phosphatidylethanol (PEth) is a group of phospholipids formed exclusively in the presence of ethanol on the erythrocyte membrane, making it a direct biomarker for long-term ethanol consumption for which a clinical reference interval has been established. Here, we describe an assay for quantitation for two most abundant PEth homologues, PEth 16:0/18:1 and PEth 16:0/18:2, from human whole blood, and present challenges overcome throughout the development process. Since PEth is localized within erythrocyte membranes, a reliable sample preparation technique is an important aspect of PEth analysis. Therefore, various erythrocyte lysing agents for recovery of exogenously spiked standards and controls were evaluated to identify one that performed comparably to the recovery of endogenous analytes found in authentic samples. A supported liquid extraction (SLE) technique was employed for sample cleanup and enrichment which together with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis enabled automated sample preparation, appropriate chromatographic resolution, and minimal system carryover. This resulted in a laboratory developed test with an analytical measurement range (AMR) of 10-1000 ng/mL (slope = 0.9902-1.0138, R2 = 0.9958-0.9972), that was precise (intra-day precision: 3.4-4.1%; inter-day precision: 4.4-8.2% over the AMR), accurate when compared with an available external laboratory test (slope = 0.9943-1.0206, R2 = 0.9635-0.9678, no lower decision point interpretation changes), with effective analyte recovery (77.2-83.5%), and established stability characteristics, while chromatographically separating the analytes to ensure no additive effects due to the isotopic distribution of the opposing analyte.

Phosphatidylethanol (PEth) in Blood as a Marker of Unhealthy Alcohol Use: A Systematic Review with Novel Molecular Insights

The Alcohol Use Disorders Identification Test (AUDIT) and its short form, the AUDIT-C, the main clinical instruments used to identify unhealthy drinking behaviors, are influenced by memory bias and under-reporting. In recent years, phosphatidylethanol (PEth) in blood has emerged as a marker of unhealthy alcohol use. This systematic review aims to investigate the molecular characteristics of PEth and summarize the last ten years of published literature and its use compared to structured questionnaires. A systematic search was performed, adhering to PRISMA guidelines, through "MeSH" and "free-text" protocols in the databases PubMed, SCOPUS, and Web of Science. The inclusion criteria were as follows: PEth was used for detecting unhealthy alcohol consumption in the general population and quantified in blood through liquid chromatography coupled to mass spectrometry, with full texts in the English language. Quality assessment was performed using the JBI critical appraisal checklist. Twelve papers were included (0.79% of total retrieved records), comprising nine cross-sectional studies and three cohort studies. All studies stratified alcohol exposure and quantified PEth 16:0/18:1 through liquid chromatography coupled to mass spectrometry (LC-MS) in liquid blood or dried blood spots (DBS) with lower limits of quantitation (LLOQ) ranging from 1.7 ng/mL to 20 ng/mL. A correlation between blood PEth level and the amount of alcohol ingested in the previous two weeks was generally observed. PEth interpretative cut-offs varied greatly among the included records, ranging from 4.2 ng/mL to 250 ng/mL, with sensitivity and specificity in the ranges of 58-100% and 64-100%, respectively. Although the biomarker seems promising, further research elucidating the variability in PEth formation and degradation, as well as the molecular mechanisms behind that variability, are necessary.

Predictive risk markers in alcoholism

The medical disorders of alcoholism rank among the leading public health problems worldwide and the need for predictive and prognostic risk markers for assessing alcohol use disorders (AUD) has been widely acknowledged. Early-phase detection of problem drinking and associated tissue toxicity are important prerequisites for timely initiations of appropriate treatments and improving patient's committing to the objective of reducing drinking. Recent advances in clinical chemistry have provided novel approaches for a specific detection of heavy drinking through assays of unique ethanol metabolites, phosphatidylethanol (PEth) or ethyl glucuronide (EtG). Carbohydrate-deficient transferrin (CDT) measurements can be used to indicate severe alcohol problems. Hazardous drinking frequently manifests as heavy episodic drinking or in combinations with other unfavorable lifestyle factors, such as smoking, physical inactivity, poor diet or adiposity, which aggravate the metabolic consequences of alcohol intake in a supra-additive manner. Such interactions are also reflected in multiple disease outcomes and distinct abnormalities in biomarkers of liver function, inflammation and oxidative stress. Use of predictive biomarkers either alone or as part of specifically designed biological algorithms helps to predict both hepatic and extrahepatic morbidity in individuals with such risk factors. Novel approaches for assessing progression of fibrosis, a major determinant of prognosis in AUD, have also been made available. Predictive algorithms based on the combined use of biomarkers and clinical observations may prove to have a major impact on clinical decisions to detect AUD in early pre-symptomatic stages, stratify patients according to their substantially different disease risks and predict individual responses to treatment.

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.

Validation of the quantification of phosphatidylethanol 16:0/18:1 concentrations in TASSO-M20 devices

BACKGROUND

Phosphatidylethanol 16:0/18:1 (PEth), found in whole blood, is a biomarker for alcohol consumption with high sensitivity, specificity, and a long detection window. The TASSO-M20 device is used to self-collect capillary blood from the upper arm and has advantages over finger stick methods. The purpose of this study was to (1) validate PEth measurement using the TASSO-M20 device, (2) describe the TASSO-M20 for blood self-collection during a virtual intervention, and (3) characterize PEth, urinary ethyl glucuronide (uEtG) and self-reported alcohol in a single participant over time.

METHODS

PEth levels in blood samples dried on TASSO-M20 plugs were compared to those in (1) liquid whole blood (N = 14) and (2) dried blood spot cards (DBS; N = 23). Additionally, the self-reported drinking, positive or negative uEtG results (dip card cutoff ≥300 ng/mL), and observed self-collection of blood with TASSO-M20 devices for PEth levels were obtained over time during virtual interviews of a single contingency management participant. High-performance liquid chromatography with tandem mass spectrometry detection was used to measure PEth levels for both preparations.

RESULTS

PEth concentrations from dried blood on TASSO-M20 plugs and liquid whole blood were correlated (0 to 1700 ng/mL; N = 14; r2  = 0.988; slope = 0.951) and in a subgroup of samples with lower concentrations (N = 7; 0 to 200 ng/mL; r2  = 0.944, slope = 0.816). PEth concentrations from dried blood on TASSO-M20 plugs and DBS were correlated (0 to 2200 ng/mL; N = 23; r2  = 0.927; slope = 0.667) and in a subgroup of samples with lower concentrations (N = 16; 0 to 180 ng/mL; r2  = 0.978, slope = 0.749). Results of the contingency management participant indicate that changes in PEth levels (TASSO-M20) and uEtG concentrations were consistent with each other and with changes in self-reported alcohol use.

CONCLUSIONS

Our data support the utility, accuracy, and feasibility of using the TASSO-M20 device for blood self-collection during a virtual study. The TASSO-M20 device had multiple advantages over the typical finger stick method, including consistent blood collection, participant acceptability, and less discomfort as indicated by acceptability interviews.

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.

Blood Phosphatidylethanol (PEth) Concentrations following Intensive Use of an Alcohol-based Hand Sanitizer

Alcohol use disorders are prevalent in the USA and throughout the world. Monitoring for alcohol abstinence is useful in several clinical and forensic contexts. The direct alcohol biomarkers have the requisite sensitivity and specificity for abstinence monitoring. The relatively new direct biomarker phosphatidylethanol (PEth), measured in blood, is gaining increasing acceptance in monitoring abstinence from beverage alcohol consumption, but there remains little research addressing the potential for PEth formation consequent to incidental alcohol exposures. In the midst of the coronavirus disease 2019 pandemic, high-alcohol content hand sanitizer is a particularly important source of nonbeverage alcohol exposure. To assess the extent of alcohol absorption and subsequent formation of blood PEth related to intensive use of high alcohol content hand sanitizer, we recruited 15 participants to use a 70% ethyl alcohol-based hand sanitizer 24-100 times daily, for 12-13 consecutive days. Blood was analyzed for PEth 16:0/18:1 by liquid chromatography--tandem mass spectrometry. Our hypothesis that blood PEth concentrations would fail to reach a 20 ng/mL threshold was confirmed. This work adds to the nascent literature on the effects of incidental alcohol exposures on blood PEth formation.

Can PEth be Detected with a Cutoff of 20 ng/mL after Single Alcohol Consumption?

Phosphatidylethanol (PEth) can be determined in capillary blood collected as dried blood spots (DBS) and is a promising direct alcohol biomarker for the determination of drinking habits. Its use for abstinence monitoring needs to be evaluated. Studies with patients undergoing alcohol withdrawal have shown that the elimination of PEth can take up to 2 months. For the determination of PEth 16:0/18:1, a cutoff of 20 ng/mL has been agreed upon in the major US laboratories. However, it is not yet clear what minimum blood alcohol concentrations (BACs) have to be achieved by a single drinking episode to result in PEth concentrations above this cutoff after previous long-term abstinence. To determine whether low drinking amounts can result in a positive PEth concentration above 20 ng/mL, we recruited 12 participants ('social' drinkers). After 4 weeks of abstinence, alcohol was consumed at two separate drinking events with target BACs of 0.5 and 0.3 g/kg, resulting in maximum BACs in the ranges of 0.30-0.63 g/kg and 0.10-0.28 g/kg, respectively. Capillary blood was collected at different time points of the drinking experiment, and PEth was extracted from DBS and analyzed by liquid chromatography-tandem mass spectrometry. Despite drinking doses up to 0.58 g ethanol per kg body weight and reaching BACs of up to 0.63 g/kg, PEth 16:0/18:1 and PEth 16:0/18:2 could not be detected at or above the 20 ng/mL cutoff in any participant at any time after the drinking events. We conclude that after long-term abstinence the cutoff of 20 ng/mL for single alcohol consumption leading to BACs up to 0.63 g/kg is not exceeded.

Assessing the sensitivity and specificity of phosphatidylethanol (PEth) cutoffs to identify alcohol exposed pregnancies

In the literature on alcohol use biomarkers, there has been debate as to what a valid and/or utilitarian cut off level should be for various research applications. In this manuscript, we assessed the sensitivity and specificity of multiple cutoff values for phosphatidylethanol (PEth) from bloodspots relative to self-report, the Alcohol Use Disorder Identification Test (AUDIT) scores, and another alcohol use biomarker ethyl glucuronide (EtG) from fingernails in a sample of 222 pregnant women in the Western Cape Province of South Africa. Receiver operating characteristic (ROC) curves were used to assess the area under the curve (AUC) and assess PEth cutoff values of ≥2, ≥4, ≥8, ≥14, and ≥20 nanograms per milliliter (ng/ml). The highest AUC value was attained when PEth was compared to an AUDIT score of 1 or more. Depending on the cutoff used to determine alcohol consumption, PEth identified 47%-70% of the individuals as alcohol-consuming while 62.6%-75.2% were identified by self-reported measures, and 35.6% were identified by EtG. In this sample, sensitivity and accuracy were highest at less stringent PEth cutoffs when compared to self-report, AUDIT score of 1 or more, 5 or more, 8 or more, and EtG ≥ 8 picograms per milligram (pg/mg). For research purposes, less stringent cutoffs, such as PEth ≥ 8 ng/ml, may be considered a valid, positive cutoff for identifying women who consume alcohol during pregnancy in this population. A cutoff of PEth ≥ 20 ng/ml may miss individuals who reported consuming alcohol (false negatives).

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.

Screening for hazardous alcohol use in the Emergency Department: Comparison of phosphatidylethanol with the Alcohol Use Disorders Identification Test and the Timeline Follow-back

BACKGROUND

Up to 15% of all visits to the Emergency Department (ED) are alcohol related. Identification of problematic alcohol use is important in this setting because it allows for intervention and prevention efforts. This study investigated the correlation between the objective phosphatidylethanol (PEth) marker and the subjective Alcohol Use Disorders Identification Test (AUDIT) and Timeline Followback Questionnaire (TLFB) as screening methods for hazardous alcohol use in the general ED population.

METHODS

This prospective cohort study included 301 ED patients (57% male) who were seen in the ED and required to give a blood sample. The correlation between the values of PEth (PEth 16:0/18:1 and PEth 16:0/18:2) and the scores on the AUDIT and TLFB were analyzed using Spearman's rank correlation coefficient. Differences between risk categories of PEth and AUDIT were also examined.

RESULTS

The Spearman correlation coefficients between PEth 16:0/18:1|PEth 16:0/18:2 values and the AUDIT scores were moderate (PEth 16:0/18:1: 0.67, p < 0.001; PEth 16:0/18:2: 0.67, p < 0.001). Of the patients who scored 'low risk drinking/abstinence' according to the AUDIT questionnaire, respectively 1% and 4% had PEth 16:0/18:1|PEth 16:0/18:2 values indicating excessive alcohol use, and another 10% and 12% had PEth 16:0/18:1|PEth 16:0/18:2 values indicating moderate alcohol consumption. Of the 12 (PEth 16:0/18:1) and 25 (PEth 16:0/18:2) patients with high-risk values, respectively 25% and 40% scored in the lowest risk category on the AUDIT questionnaire. Spearman correlation coefficients between PEth 16:0/18:1|PEth 16:0/18:2 values and TLFB two-week scores were high (PEth 16:0/18:1: 0.74, p < 0.001; PEth 16:0/18:2: 0.82, p < 0.001).

CONCLUSIONS

AUDIT scores were moderately correlated with PEth values in the general ED population. In almost all cases where there was not a good correlation, patients had high PEth values with low AUDIT scores. We conclude that PEth identifies patients with problematic alcohol use who are missed by the AUDIT questionnaire and therefore PEth could be used as an additional screening method for hazardous alcohol use in this population.

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'.

Identification of unhealthy alcohol use by self-report and phosphatidylethanol (PEth) blood concentrations in an acute psychiatric department

BACKGROUND

The use of standard screening methods could improve the detection rate of unhealthy alcohol use in patients admitted to psychiatric acute and emergency departments. The aim of the present study was to investigate the ability of the alcohol biomarker phosphatidylethanol (PEth) to identify patients with high levels of alcohol consumption prior to admission.

METHODS

The data were prospectively collected at admittance to an acute psychiatric department in the period January 2016 to June 2017. A blood sample for the analysis of PEth was available from 177 patients. We compared the PEth concentrations with the Alcohol Use Disorders Identification Test (AUDIT) scores during the hospital stay, and psychiatric diagnoses at discharge.

RESULTS

A total of 45.8% of the patients had a PEth concentration ≥ 0.03 μmol/L, indicating significant alcohol consumption. AUDIT scores consistent with unhealthy alcohol use were present in 51.7%. There was a significant positive correlation between PEth concentrations and AUDIT scores (r = 0.631, p < 0.001). PEth was above the detection limit of 0.03 μmol/L in 19% of those reporting an average daily intake of zero alcohol units per day during the last week before admission. PEth concentrations were significantly higher among those with an alcohol diagnosis than among those without such a diagnosis (0.82 μmol/L vs. 0.09 μmol/L, p = 0.001).

CONCLUSION

PEth provides supplementary information on recent alcohol consumption in a psychiatric population and would be particularly helpful in patients unable or unwilling to give such information at admission.

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.

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.

Blood Phosphatidylethanol Concentrations Following Regular Exposure to an Alcohol-Based Mouthwash

Direct biomarkers of ethanol are used to monitor individuals who are required to abstain from ethanol consumption. In recent years, blood phosphatidylethanol (PEth) has gained acceptance in clinical and forensic contexts as an abstinence marker. Its elimination half-life of several days provides a window of detection of days to weeks. However, there is no research addressing the extent of PEth formation related to extraneous ethanol exposures. To assess the degree of ethanol absorption and subsequent formation of blood PEth related a common extraneous exposure, regular use of an ethanol-containing mouthwash, we recruited 16 participants to gargle with an alcohol-based mouthwash (21.6% ethanol) 4 times daily, for 12 consecutive days. Blood was analyzed for PEth 16:0/18:1 by liquid chromatography-tandem mass spectrometry. Our hypothesis that blood PEth concentrations would not equal or exceed 20 ng/mL was confirmed. Although the data suggest that regular use of mouthwash is unlikely to result in suprathreshold PEth concentrations, this work highlights the importance of considering extraneous ethanol exposures in clinical decision-making and in future research.

Fully automated correction for the hematocrit bias of non-volumetric dried blood spot phosphatidylethanol analysis

The quantitative analysis of substances in dried blood spots (DBS) has gained vast popularity in the past decade. The World Anti-Doping Agency (WADA) also recently committed to implementing DBS. Currently, DBS sampling mainly has focused on various volumetric sampling devices such as Hemaxis, Capitainer, and Mitra. These devices are designed to collect a specific sample volume, independent of the hematocrit (HCT), to enable quantitative DBS analysis. Here, we present an automated solution that makes the necessity of volumetric sampling for quantitative DBS analysis obsolete. Combining automated reflectance-based HCT correction in combination with fully automated DBS LC-MS/MS analysis, the novel strategy permits high-throughput analysis in combination with HCT independence. Studying the model compound phosphatidylethanol 16:0/18:1, which is HCT-dependent due to incorporation into red blood cells, an implementation of DBS HCT normalization is presented. First, the performance of the automated HCT module with DBS is demonstrated compared to standardized HCT analysis from whole blood using a centrifuge. Second, the HCT dependency of fully automated PEth analysis from DBS is evaluated. Third, a solution to correct for the HCT dependency of PEth using the HCT scanner is presented. The study demonstrates that as soon as the HCT dependence of an analyte is known, a correction factor can be applied for the normalization of HCT levels. In the context of PEth, a linear increase in PEth concentration was observed, as the analyte is primarily located within the cellular fraction. Based on the obtained results, the use of a common correction factor for PEth DBS is possible.

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.

Objective assessment of alcohol consumption in early pregnancy using phosphatidylethanol: a cross-sectional study

Background

Alcohol consumption during pregnancy is associated with major birth defects and developmental disabilities. Questionnaires concerning alcohol consumption during pregnancy underestimate alcohol use while the use of a reliable and objective biomarker for alcohol consumption enables more accurate screening. Phosphatidylethanol can detect low levels of alcohol consumption in the previous two weeks. In this study we aimed to biochemically assess the prevalence of alcohol consumption during early pregnancy using phosphatidylethanol in blood and compare this with self-reported alcohol consumption.

Methods

To evaluate biochemically assessed prevalence of alcohol consumption during early pregnancy using phosphatidylethanol levels, we conducted a prospective, cross-sectional, single center study in the largest tertiary hospital of the Netherlands. All adult pregnant women who were under the care of the obstetric department of the Erasmus MC and who underwent routine blood testing at a gestational age of less than 15 weeks were eligible. No specified informed consent was needed.

Results

The study was conducted between September 2016 and October 2017. In total, we received 1,002 residual samples of 992 women. After applying in- and exclusion criteria we analyzed 684 samples. Mean gestational age of all included women was 10.3 weeks (SD 1.9). Of these women, 36 (5.3 %) tested positive for phosphatidylethanol, indicating alcohol consumption in the previous two weeks. Of women with a positive phosphatidylethanol test, 89 % (n = 32) did not express alcohol consumption to their obstetric care provider.

Conclusions

One in nineteen women consumed alcohol during early pregnancy with a high percentage not reporting this use to their obstetric care provider. Questioning alcohol consumption by an obstetric care provider did not successfully identify (hazardous) alcohol consumption. Routine screening with phosphatidylethanol in maternal blood can be of added value to identify women who consume alcohol during pregnancy.

Phosphatidylethanol in whole blood of rhesus monkeys correlates with ethanol consumption

BACKGROUND

Phosphatidylethanol (PEth) homologs are ethanol metabolites used to identify and monitor alcohol drinking in humans. In this study, we measured levels of the 2 most abundant homologs, PEth 16:0/18:1 and PEth 16:0/18:2, in whole blood samples from rhesus macaque monkeys that drank ethanol daily ad libitum to assess the relationship between PEth levels and recent ethanol exposure in this animal model.

METHODS

Blood samples were obtained from The Monkey Alcohol Tissue Research Resource. The monkeys were first induced to consume 4% (w/v) ethanol in water from a panel attached to their home cage. Then, monkeys were allowed to drink ethanol and water ad libitum 22 h daily for 12 months and the daily amount of ethanol each monkey consumed was measured. Whole, uncoagulated blood was collected from each animal at the end of the entire experimental procedure. PEth 16:0/18:1 and PEth 16:0/18:2 levels were analyzed by HPLC with tandem mass spectrometry, and the ethanol consumed during the preceding 14 days was measured. Combined PEth was the sum of the concentrations of both homologs.

RESULTS

Our results show that (1) PEth accumulates in the blood of rhesus monkeys after ethanol consumption; (2) PEth homolog levels were correlated with the daily average ethanol intake during the 14-day period immediately preceding blood collection; (3) the application of established human PEth 16:0/18:1 cutoff concentrations indicative of light social or no ethanol consumption (<20 ng/ml), moderate ethanol consumption (≥ 20 and < 200 ng/ml) and heavy ethanol consumption (≥ 200 ng/ml) predicted significantly different ethanol intake in these animals. PEth homologs were not detected in ethanol-naïve controls.

CONCLUSIONS

This study confirms that PEth is a sensitive biomarker for ethanol consumption in rhesus macaque monkeys. This nonhuman primate model may prove useful in evaluating sources of variability previously shown to exist between ethanol consumption and PEth homolog levels among humans.

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.

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.

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.

Analysis of six different homologues of phosphatidylethanol from dried blood spots using liquid chromatography-tandem mass spectrometry

Phosphatidylethanol (PEth) is a direct biomarker for alcohol consumption consisting of a fraction of different ethanol-modified, homologue phospholipids. The aim of this study was to validate an ultra-high-performance liquid chromatography-tandem mass spectrometry method to quantitate six different homologues of PEth (16:0/18:1, 16:0/18:2, 16:0/20:4, 18:0/18:1, 18:0/18:2, and 18:1/18:1) from dried blood spots (DBSs). DBSs were prepared volumetrically (20 μL of whole blood) and extracted with 1 mL of methanol (0.02 ng/μL internal standards). PEth homologues were separated on a BEH C18 column (2.1 × 150 mm, 1.7 μm) using methanol and ammonium acetate buffer (25 mM) in a 7 min isocratic run. Multiple reaction monitoring mode was used for the detection of PEth and the internal standards. Calibrators (10-1000 ng/mL) and quality controls (40, 400, and 700 ng/mL) were prepared from spiked whole blood; external control samples were obtained from proficiency testing schemes. After a comprehensive validation of the method, quantitative patterns of the different homologues were investigated in PEth positive samples (n = 57) from patients in a transplant setting. Satisfactory chromatographic separation, sensitive detection, and reliable quantification of the PEth homologues in DBSs can be achieved using the liquid chromatography-tandem mass spectrometry (LC/MS/MS) procedure. Validation results, including accuracy, linearity, recovery, matrix effects, and in-process stability, complied with international standards, and the analytical performance of the procedure was not affected by the hematocrit of the blood samples. Different quantitative patterns of the investigated PEth homologues were observed in authentic samples from liver transplant patients. This method will enable the study of the kinetics of six PEth homologues simultaneously and investigate the meaning of the homologues' distribution in individuals.

Alcohol Use Is Associated With Intestinal Dysbiosis and Dysfunctional CD8+ T-Cell Phenotypes in Persons With Human Immunodeficiency Virus

BACKGROUND

Inflammation persists among persons with human immunodeficiency virus (PWH) despite effective antiretroviral therapy and may contribute to T-cell dysfunction. Alcohol use is prevalent among PWH and promotes intestinal leak, dysbiosis, and a proinflammatory milieu. Whether alcohol use is associated with T-cell late differentiation remains to be investigated.

METHODS

Data and samples from PWH (N = 359 of 365) enrolled in the New Orleans Alcohol Use in HIV Study were used. Alcohol use was assessed by self-report (Alcohol Use Disorders Identification Test; lifetime alcohol exposure; 30-day Alcohol Timeline Followback) and phosphatidylethanol (PEth) quantitation. In a subset of participants, fecal bacterial content was assessed by ribosomal 16S marker gene deep sequencing and quantitative polymerase chain reaction. Intestinal leak was assessed by fecal-to-plasma α-1-antitrypsin (A1AT) enzyme-linked immunosorbent assay ratio. Peripheral T-cell populations were quantified by flow cytometry.

RESULTS

Alcohol Use Disorder Identification Test scores were positively associated with activated-senescent, exhausted, and terminal effector memory CD45RA+CD8+ but not CD4+ T cells (cells/μL) after confounder adjustment (P < .050). Phosphatidylethanol was positively associated with A1AT (P < .050). The PEth and activated-senescent CD8+ were associated with bacterial β-diversity (P < .050) and positively associated with the relative abundance of coabundant Prevotellaceae members (q < .100).

CONCLUSIONS

Alcohol use among PWH is associated with CD8+ T-cell late differentiation, intestinal leak, and dysbiosis. Alcohol-associated dysbiosis is implicated in CD8+ T-cell senescence.

The roles of phosphatidylethanol, ethyl glucuronide, and ethyl sulfate in identifying alcohol consumption among participants in professionals health programs

Direct alcohol biomarkers, including urinary ethyl glucuronide (EtG), urinary ethyl sulfate (EtS), and blood phosphatidylethanol (PEth), are used to monitor alcohol abstinence in individuals who are mandated to abstain. In this consecutive case series study, we examined 1000 forensic reports of participants enrolled in a professionals health program who were contractually obligated to abstain from alcohol and who underwent recovery status evaluations. We identified 52 evaluations in which urinary EtG, EtS, and blood PEth were measured and which produced a positive result for at least one of these analytes. PEth, at a cutoff concentration of 20 ng/mL, revealed alcohol use more frequently than EtG or EtS at our laboratory's cutoff concentrations of 100 and 25 ng/mL, respectively. This was true, as well, at alternative EtG/EtS cutoff concentrations of 200/50, 300/75, and 400/100 ng/mL. PEth was more likely than EtG/EtS to be positive in participants previously diagnosed with alcohol use disorders (AUD), whereas EtG/EtS was more likely than PEth to be positive in participants without AUD. In this study, blood PEth was the most sensitive biomarker for evidencing alcohol use.

A Review of Efforts to Improve Lipid Stability during Sample Preparation and Standardization Efforts to Ensure Accuracy in the Reporting of Lipid Measurements

Lipidomics is a rapidly growing field, fueled by developments in analytical instrumentation and bioinformatics. To date, most researchers and industries have employed their own lipidomics workflows without a consensus on best practices. Without a community-wide consensus on best practices for the prevention of lipid degradation and transformations through sample collection and analysis, it is difficult to assess the quality of lipidomics data and hence trust results. Clinical studies often rely on samples being stored for weeks or months until they are analyzed, but inappropriate sampling techniques, storage temperatures, and analytical protocols can result in the degradation of complex lipids and the generation of oxidized or hydrolyzed metabolite artifacts. While best practices for lipid stability are sample dependent, it is generally recommended that strategies during sample preparation capable of quenching enzymatic activity and preventing oxidation should be considered. In addition, after sample preparation, lipid extracts should be stored in organic solvents with antioxidants at -20 °C or lower in an airtight container without exposure to light or oxygen. This will reduce or eliminate sublimation, and chemically and physically induced molecular transformations such as oxidation, enzymatic transformation, and photon/heat-induced degradation. This review explores the available literature on lipid stability, with a particular focus on human health and/or clinical lipidomic applications. Specifically, this includes a description of known mechanisms of lipid degradation, strategies, and considerations for lipid storage, as well as current efforts for standardization and quality insurance of protocols.

Elimination Characteristics of the Alcohol Biomarker Phosphatidylethanol (PEth) in Blood during Alcohol Detoxification

Aims

The study documented elimination characteristics of three phosphatidylethanol (PEth) homologs in serially collected blood samples from 47 heavy drinkers during ~2 weeks of alcohol detoxification at hospital.

Methods

Venous whole blood and urine samples were collected every 1–2 days during treatment. Concentrations of PEth, and of urinary ethyl glucuronide (EtG) and ethyl sulfate (EtS) to detect relapse drinking, were measured using liquid chromatography-tandem mass spectrometry.

Results

When included in the study, negative or decreasing breath ethanol concentrations demonstrated that the patients were in the elimination phase. The EtG and EtS measurements further confirmed alcohol abstinence during the study, with three exceptions. On admission, all patients tested positive for PEth, the total concentration ranging 0.82–11.7 (mean 6.35, median 5.88) μmol/l. PEth 16:0/18:1, 16:0/18:2 and 16:0/20:4 accounted for on average ~42%, ~26% and ~9%, respectively, of total PEth in these samples. There were good correlations between total PEth and individual homologs (P < 0.0001). There was no significant difference in PEth values between male and female subjects. During abstinence, the elimination half-life values ranged 3.5–9.8 days for total PEth, 3.7–10.4 days for PEth 16:0/18:1, 2.7–8.5 days for PEth 16:0/18:2 and 2.3–8.4 days for PEth 16:0/20:4.

Conclusions

The results demonstrated a very high sensitivity (100%) of PEth as alcohol biomarker for recent heavy drinking, but considerable differences in the elimination rates between individuals and between different PEth forms. This indicates that it is possible to make only approximate estimates of the quantity and recency of alcohol intake based on a single PEth value.

Harmful alcohol use among acutely ill hospitalized medical patients in Oslo and Moscow: A cross-sectional study

BACKGROUND

The aim was to estimate the prevalence of harmful alcohol use in relation to socio-demographic characteristics among acutely ill medical patients, and examine identification measures of alcohol use, including the alcohol biomarker phosphatidylethanol 16:0/18:1 (PEth).

METHODS

A cross-sectional study, lasting one year at one hospital in Oslo, Norway and one in Moscow, Russia recruiting acute medically ill patients (≥ 18 years), able to give informed consent. Self-reported data on socio-demographics, mental distress (Symptom Check List-5), alcohol use (Alcohol Use Disorder Identification Test-4 (AUDIT-4) and alcohol consumption past 24 h were collected. PEth and alcohol concentration were measured in whole blood.

RESULTS

Of 5883 participating patients, 19.2% in Moscow and 21.1% in Oslo were harmful alcohol users, measured by AUDIT-4, while the prevalence of PEth-positive patients was lower: 11.4% in Oslo, 14.3% in Moscow. Men in Moscow were more likely to be harmful users by AUDIT-4 and PEth compared to men in Oslo, except of those being ≥ 71 years. Women in Oslo were more likely to be harmful users compared to those in Moscow by AUDIT-4, but not by PEth for those aged < 61 years.

CONCLUSIONS

The prevalence of harmful alcohol use was high at both study sites. The prevalence of harmful alcohol use was lower when assessed by PEth compared to AUDIT-4. Thus, self-reporting was the most sensitive measure in revealing harmful alcohol use among all groups except for women in Moscow. Hence, screening and identification with objective biomarkers and self-reporting might be a method for early intervention.

Long-term stability of the alcohol consumption biomarker phosphatidylethanol in erythrocytes at -80 °C

Phosphatidylethanol (PEth) is a recently introduced biomarker with high specificity, high sensitivity, and response correlating with alcohol consumption. It has the potential to be a valuable biomarker in population studies on the health effects of alcohol, however its stability in long-term stored blood is not known. We used LC-MS/MS to assess the stability of PEth-16:0/18:1 in blood samples (packed erythrocytes) that were stored between 1 and 19 years at -80 °C in a biobank from a large population survey. The participants answered a life-style questionnaire that included questions on alcohol consumption. For analysis, we selected blood samples from seven homogenous ethanol consumption cohorts collected at intervals from 1997 to 2015. Despite the narrow stated alcohol consumption range, 10-15 g/day, there were large differences in PEth values between individuals in the cohorts, from below the limit of detection of 0.005 µmol/L to 1.40 µmol/L. The median was 0.08 µmol/L. Neither generalized linear modeling, nor principal component analysis revealed a statistically significant association between time of storage and PEth levels. The PEth results indicate that the participants had, on average, under-reported their alcohol consumption several-fold. The findings suggest that PEth in blood has a sufficient long-term stability for use as an alcohol biomarker in prospective case-control studies. Analysis of blood stored in biobanks could significantly improve the validity of assessments exploring the health effects of alcohol.

Pharmacokinetics of Phosphatidylethanol 16:0/20:4 in Human Blood After Alcohol Intake

BACKGROUND

The purpose of this study was to characterize the pharmacokinetics of the phosphatidylethanol (PEth) 16:0/20:4 homolog in uncoagulated human blood samples taken from 18 participants in a clinical laboratory setting after consumption of 2 standard doses of ethanol (EtOH).

METHODS

Male and female participants received either 0.4 or 0.8 g/kg oral doses of EtOH during a 15-minute period. Blood samples were collected before and throughout 6 hours immediately after alcohol administration and then again at days 2, 4, 7, 11, and 14 of the follow-up period. PEth 16:0/20:4 levels were quantified by high-performance liquid chromatography with tandem mass spectrometry detection.

RESULTS

(i) The increase in PEth 16:0/20:4 from baseline to maximum concentration was less than that of PEth 16:0/18:1 or PEth 16:0/18:2 homologs during the 6-hour period after EtOH administration; (ii) the mean half-life of PEth 16:0/20:4 was 2.1 ± 3 (SD) days, which was shorter than the mean half-life of either PEth 16:0/18:1 or PEth 16:0/18:2, 7.6 ± 3 (SD) or 6.8 ± 4 (SD) days, respectively.

CONCLUSIONS

The pharmacokinetics of PEth 16:0/20:4 in whole blood samples is detectable after alcohol consumption and differs in amount synthesized and rate of elimination versus PEth 16:0/18:1 and 16:0/18:2. Measuring the concentrations of these 3 homologs has the potential to provide more information about the amount and time frame of alcohol consumption than any one alone.