Applications and Challenges for the Use of Phosphatidylethanol Testing in Liver Disease Patients (Mini Review)

Substance Use Disorders and Interprofessional Management in the Pre and Post Liver Transplant Settings

Substance use disorders (SUDs) are rising in the general population and also in the transplant population. Alcohol use disorder leading to alcohol-associated liver disease is the most common of all SUDs in the liver transplantation setting. Uncontrolled SUDs and relapse after transplant can lead to graft loss and mortality, as well as reduce quality of life and patient functioning. SUDs can be treated effectively through integrated, interprofessional management by addiction and medical/surgical professional members of the transplant team. Teams should be aware of pitfalls in interprofessional teamwork and communication so that corrective steps could be implemented for improved efficiency.

Beyond the baseline: quantification of two phosphatidylethanol homologues in whole blood by LC-MS-MS and retrospective data analysis from a National Reference Laboratory

Alcohol is the most abused substance in Western society, resulting in major economic losses and negative health consequences. Therefore, there is a need for a selective and robust detection method for alcohol consumption in various clinical and forensic settings. This study aimed to validate a mass spectrometry method for quantifying phosphatidylethanol (PEth) and perform retrospective data analysis from the patient population of a national reference laboratory. Quantification of PEth in whole blood was accomplished using an LC-MS-MS assay. Isotopically labeled internal standard for the two PEth homologues was added to the whole-blood specimen, followed by protein precipitation with a mixture of acetonitrile and isopropyl alcohol. After centrifugation, an aliquot of the supernatant was buffered with ammonium acetate before LC-MS-MS analysis on an Agilent 6470 triple quadrupole mass spectrometer coupled to an Agilent 1260 Infinity II LC system. This LC-MS-MS assay was validated for clinical use in accordance with Clinical & Laboratory Standards Institute guidelines. The analytical measurement range, 10-2000 ng/mL, was linear with R2 of 0.999. The within-run and total imprecision was < 5% CV for the low (20 ng/mL), medium (200 ng/mL), and high QC (1000 ng/mL). Results from accuracy and method comparison experiments met the bias criteria of ±15%. Retrospective data analysis showed ∼27% of patients had PEth concentrations <20 ng/mL. Males and females had similar positivity rates for PEth and the positivity rate of women of reproductive age (15-44 years old) was 35% in comparison to 25% in women 45-89 years old. This study's LC-MS-MS method showed acceptable analytical performance in quantifying PEth as a sensitive and specific biomarker for evaluating alcohol consumption. Results from this study may provide an opportunity to educate women of reproductive age on drinking during pregnancy and the long-term effects of alcohol use.

Lipidomic profiling of serum and liver tissue reveals hepatoprotective mechanism of taxifolin in rats with CCl4-induced subacute hepatic injury based on LC-MS/MS

Currently, the hepatoprotective activity of taxifolin, a flavonoid isolated from Pseudotsuga taxifolia, has been reported in many animal models. However, whether the protective effect of taxifolin on the liver is related to its effect on lipidomics is unclear. Based on the significant therapeutic effect of taxifolin on CCl4 induced subacute hepatic injury, we observed the intervention of taxifolin by lipidomics. The results demonstrate that taxifolin can effectively reverse the damage caused by CCl4, which including hepatocyte vacuolization and necrosis. Lipomic profiling based on liquid chromatography-mass spectrometry showed that taxifolin was able to restore lipidomic changes caused by CCl4, including the levels of lysophosphatidylserine (LPS), phosphatidylcholine (PC), coenzyme (Co), phosphatidylglyceride (PG), phosphatidylserine (PS), dimethylphosphatidylethanolamine (dMePE), ceramide (Cer), sphingosine (So), triglycerides (TG), and monogalactosyl diacylglycerol (MGDG) in the rat liver, and phosphatidylcarbinol (PMe) and phosphatidylethanolamine (PE), plant sphingosine (phSM), glucose ceramide (CerG1), TG, and diglycerides (DG) in serum. Spearman's correlation analysis showed that CerG1, phSM, PE, and PMe in serum, and Cer, dMePE, PG, PS, So, TG, and MGDG in liver were positively correlated with serum levels of aspartate transaminase, alanine transaminase, and liver index; while TG, DG in serum, and Co, LPS, PC in liver were negatively correlated with the parameters. In total, 43 and 34 lipid molecules were altered by taxifolin treatment in the liver and serum, respectively, mainly including glycerophosphoglycerols, glycerophosphocholines, glycerophosphoethanolamines, and linoleic acids and derivatives. Our findings help to provide novel insights into the mechanism of the hepatoprotective effect of taxifolin from a lipidomics approach.

Clinical Utility and Impact of Phosphatidylethanol Testing in Liver Transplantation Evaluations

BACKGROUND

Phosphatidylethanol (PEth) is a serum biomarker that can detect alcohol use within the last 28 days with excellent sensitivity and specificity. Urinary ethyl glucuronide (uEtG) is commonly used in transplant settings to screen for alcohol use; however, it has several limitations relevant to liver transplantation. Transplant centers are beginning to regularly utilize PEth as part of the screening process for high-risk liver transplantation candidates although the clinical utility of uniform pre-transplant PEth testing is unclear.

METHODS

This was a retrospective chart review of all patients evaluated for liver transplantation from December 1, 2019, through May 31, 2022, at a large academic tertiary referral center utilizing uniform serum PEth and uEtG screening. Information regarding the patients' transplantation status, age, sex, race, Model for End-Stage Liver Disease score, and PEth levels was obtained. In those with a positive PEth, we examined if the result would have been detected with uEtG, identified a discrepancy from the documented patient report of last use, led to a change in the Psychosocial Assessment of Candidate for Transplantation score, or influenced the transplant selection committee's decision.

RESULTS

Our sample included 865 individuals (mean age = 55.20, 61.27% male and 82.54% white) with calculated Model for End-Stage Liver Disease-Sodium scores ranging from 6.43 to 50.65 (mean: 18.09; median: 16.46). Forty-eight patients were found to have a positive PEth (PEth range 20-1833); 75% of the sample had alcohol-associated liver disease. In 23 of 48 (47.91%) cases, the positive PEth identified alcohol use missed by a concomitant uEtG screen. A positive PEth test identified a discrepancy from patients' self-report in 29 (60.42%) cases and influenced the selection committee's decision in 28 cases (58.33%).

CONCLUSION

Uniform pretransplant PEth screening of liver transplant candidates at the time of initial evaluation identified alcohol use that would have been missed by uEtG testing, identified discrepancies from the patient's self-report, and influenced clinical decision-making in a significant number of cases. These findings support the use of uniform PEth screening in liver transplantation evaluations.

Alcohol use disorder in alcohol-associated liver disease: Two sides of the same coin

Alcohol-associated liver disease (ALD) has emerged as the leading indication for liver transplantation (LT) worldwide, with 40% of LTs in the United States performed for ALD in 2019. The ALD-related health care burden accelerated during the COVID-19 pandemic, especially in young individuals. Alcohol use disorder (AUD), which focuses on the negative effects of alcohol on psychosocial, physical, and mental health, is present in the majority of patients with ALD, with moderate to severe AUD in 75%-80%. During the last decade, early liver transplantation (eLT) has emerged as a lifesaving treatment for selected patients with alcohol-associated hepatitis; these patients may have a higher risk of using alcohol after LT. The risk of alcohol use recurrence may be reduced during the pretransplant or post-transplant period with AUD treatment using behavioral and/or pharmacological therapies and with regular monitoring for alcohol use (self-reported and complemented with biomarkers like phosphatidylethanol). However, AUD treatment in patients with ALD is challenging due to patient, clinician, and system barriers. An integrated model to provide AUD and ALD care by hepatologists and addiction experts in a colocated clinic starting from LT evaluation and selection to monitoring listed candidates and then to following up on recipients of LT should be promoted. However, the integration of addiction and hepatology teams in an LT program in the real world is often present only during evaluation and candidate selection for LT. Data are emerging to show that a multidisciplinary integrated AUD treatment within an LT program reduces recurrent alcohol use after LT. If we want to continue using early liver transplantation for patients with severe alcohol-associated hepatitis, LT programs should focus on building integrated multidisciplinary care teams for the integrated treatment of both AUD and ALD.

"But I didn't drink!": What to do with discordant phosphatidylethanol results

Liver transplantation (LT) teams must be adept at detecting, evaluating, and treating patients' alcohol use, given its prominence among psychological and behavioral phenomena which cause and contribute to liver diseases. Phosphatidylethanol (PEth) is a highly useful alcohol biomarker increasingly recommended for routine use in hepatology and LT. PEth is unique among alcohol biomarkers because of its wide detection window, high sensitivity and specificity, and the correlation of its numerical value with different patterns of alcohol use. Alongside myriad clinical opportunities in hepatology and LT, PEth also confers numerous challenges: little guidance exists about its clinical use; fearing loss of LT access and the reactions of their clinicians and families, candidates and recipients are incentivized to conceal their alcohol use; and liver clinicians report lack of expertise diagnosing and treating substance-related challenges. Discordance between patient self-reported alcohol use and toxicology is yet another common and particularly difficult circumstance. This article discusses the general toxicological properties of PEth; explores possible scenarios of concordance and discordance among PEth results, patient history, and self-reported drinking; and provides detailed clinical communication strategies to explore discordance with liver patients, a key aspect of its use.

Closing the Care Gap: Management of Alcohol Use Disorder in Patients with Alcohol-associated Liver Disease

Alcohol-associated liver disease (ALD)-related morbidity and mortality are rising in the United States. Although effective medications and behavioral interventions are available for the treatment of patients with alcohol use disorder (AUD), patients with ALD are profoundly undertreated for AUD. This article reviews the management of AUD in patients with ALD, with a focus on appropriate screening and diagnosis, management of alcohol withdrawal syndrome, pharmacotherapy for AUD, alcohol biomarkers, and behavioral interventions. Expanding access to AUD treatment is imperative for improving health outcomes in patients with ALD.

GPs' experiences of phosphatidylethanol in treatment of hypertension: a qualitative study

BACKGROUND

Hazardous alcohol use increases the risk of hypertension but is underdetected in primary healthcare (PHC) patients. Use of the biomarker phosphatidylethanol (PEth), which reflects the last 2-3 weeks of alcohol consumption, is increasing in Swedish PHC, but studies exploring its use for hypertension are scarce or missing.

AIM

To explore GPs' experiences of using PEth to identify hazardous alcohol use in the context of managing hypertension.

DESIGN & SETTING

A qualitative study of GPs (n = 12) experienced in using PEth in hypertension management who were recruited at Swedish primary healthcare centres (PHCC) in 2021.

METHOD

The GPs participated in five focus group interviews. A questioning route was used. The interviews were audio-recorded, transcribed verbatim, and analysed with inductive qualitative content analysis.

RESULTS

'I don't hesitate anymore' was the overall theme, which reflected both the disappearance of GPs' fear that the PEth result might upset the patient, as this rarely occurred, and that the positive effects of PEth predominated in the findings. The theme is underpinned by the following four sub-themes: serving as an eye-opener; improving the dialogue; using with care; and learning by doing.

CONCLUSION

PEth is a useful tool that changed GPs' routines for addressing alcohol and identifying hazardous alcohol use in patients with hypertension managed in PHC. The GPs advocated adopting PEth as a routine test in the treatment of hypertension. However, PEth needs to be used with care to maximise benefit and minimise harm.

Alcohol-Associated Liver Disease: Evolving Concepts and Treatments

Alcohol is a prominent cause of liver disease worldwide with higher prevalence in developed nations. The spectrum of alcohol-associated liver disease (ALD) encompasses a diverse range of clinical entities, from asymptomatic isolated steatosis to decompensated cirrhosis, and in some cases, acute or chronic liver failure. Consequently, it is important for healthcare practitioners to maintain awareness and systematically screen for ALD. The optimal evaluation and management of ALD necessitates a collaborative approach, incorporating a multidisciplinary team and accounting for concurrent medical conditions. A repertoire of therapeutic interventions exists to support patients in achieving alcohol cessation and sustaining remission, with complete abstinence being the ultimate objective. This review explores the existing therapeutic options for ALD acknowledging geographical discrepancies in accessibility. Recent innovations, including the inclusion of alcohol consumption biomarkers into clinical protocols and the expansion of liver transplantation eligibility to encompass severe alcohol-associated hepatitis, are explored.

A proposal from the liver forum for the management of comorbidities in non-alcoholic steatohepatitis therapeutic trials

The current document has been developed by the Liver Forum who mandated the NAFLD-Associated Comorbidities Working Group - a multistakeholder group comprised of experts from academic medicine, industry and patient associations - to identify aspects of diverse comorbidities frequently associated with non-alcoholic steatohepatitis (NASH) that can interfere with the conduct of therapeutic trials and, in particular, impact efficacy and safety results. The objective of this paper is to propose guidance for the management of relevant comorbidities in both candidates and actual participants in NASH therapeutic trials. We relied on specific guidelines from scientific societies, when available, but adapted them to the particulars of NASH trials with the aim of addressing multiple interacting requirements such as maintaining patient safety, reaching holistic therapeutic objectives, minimising confounding effects on efficacy and safety of investigational agents and allowing for trial completion. We divided the field of action into: first, analysis and stabilisation of the patient's condition before inclusion in the trial and, second, management of comorbidities during trial conduct. For the former, we discussed the concept of acceptable vs. optimal control of comorbidities, defined metabolic and ponderal stability prior to randomisation and weighed the pros and cons of a run-in period. For the latter, we analysed non-hepatological comorbid conditions for changes or acute events possibly occurring during the trial, including changes in alcohol consumption, in order to detail when specific interventions are necessary and how best to manage concomitant drug intake in line with methodological constraints. These recommendations are intended to act as a guide for clinical trialists and are open to further refinement when additional data become available.

Utility of phosphatidylethanol testing as an objective measure of alcohol use during the preoperative evaluation for bariatric surgery

BACKGROUND

The risk of alcohol use disorder increases after bariatric surgery. Preoperative alcohol use is a risk factor, and this is evaluated during the routine preoperative psychosocial evaluation. However, it is not clear whether patients accurately report their alcohol use.

OBJECTIVE

To determine whether an objective measure of alcohol use, phosphatidylethanol (PEth) testing, offers utility beyond self-reported alcohol use during the preoperative evaluation for bariatric surgery.

SETTING

Single healthcare system.

METHODS

PEth testing was included as part of the routine laboratory work for 139 patients undergoing evaluation for bariatric surgery. PEth testing results were compared with self-reported alcohol use and scores on the Alcohol Use Disorders Identification Test-Concise (AUDIT-C) questionnaire obtained during the preoperative psychosocial evaluation. PEth testing results were categorized into abstinent, light use, moderate use, or heavy use. There were 85 patients who completed both PEth testing and a preoperative psychosocial evaluation.

RESULTS

There were 25 participants (29.4%) who had a positive PEth test; about half had moderate or heavy use values (15.3% of the total sample). The majority of participants with a positive PEth test (82.6%) denied recent alcohol use. Of those with PEth values indicating moderate or heavy use, 61.5% did not have an elevated AUDIT-C score.

CONCLUSIONS

Patients appeared to underreport their alcohol use during the preoperative psychosocial evaluation. There appears to be utility for routine PEth testing as part of the evaluation process to identify those with risky drinking patterns. Patients with preoperative risky drinking could be educated about their risk and/or referred to programs to mitigate the development of preoperative alcohol misuse.

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'.

Management of alcohol use disorder in patients with cirrhosis in the setting of liver transplantation

The prevalence of alcohol use disorder (AUD) has been steadily increasing over the past decade. In parallel, alcohol-associated liver disease (ALD) has been increasing at an alarming rate, especially among young patients. Data suggest that most patients with ALD do not receive AUD therapy. Although liver transplantation is the only curative therapy for end-stage ALD, transplant candidacy is often a matter of debate given concerns about patients being under-treated for AUD and fears of post-transplantation relapse affecting the allograft. In this Review, we discuss diagnosis, predictors and effects of relapse, behavioural therapies and pharmacotherapies, and we also propose an integrative, multidisciplinary and multimodality approach for treating AUD in patients with cirrhosis, especially in the setting of liver transplantation. Notably, this approach takes into account the utility of AUD pharmacotherapy in patients on immunosuppressive medications and those with renal impairment after liver transplantation. We also propose a comprehensive and objective definition of relapse utilizing contemporary biomarkers to guide future clinical trials. Future research using the proposed approach and definition is warranted with the goal of optimizing AUD treatment in patients with cirrhosis, the transplant selection process and post-transplantation care of patients with AUD.

Bioactive Lipids in MSCs Biology: State of the Art and Role in Inflammation

Lipidomics is a lipid-targeted metabolomics approach that aims to the comprehensive analysis of lipids in biological systems in order to highlight the specific functions of lipid species in health and disease. Lipids play pivotal roles as they are major structural components of the cellular membranes and energy storage molecules but also, as most recently shown, they act as functional and regulatory components of intra- and intercellular signaling. Herein, emphasis is given to the recently highlighted roles of specific bioactive lipids species, as polyunsaturated fatty acids (PUFA)-derived mediators (generally known as eicosanoids), endocannabinoids (eCBs), and lysophospholipids (LPLs), and their involvement in the mesenchymal stem cells (MSCs)-related inflammatory scenario. Indeed, MSCs are a heterogenous population of multipotent cells that have attracted much attention for their potential in regulating inflammation, immunomodulatory capabilities, and reparative roles. The lipidomics of the inflammatory disease osteoarthritis (OA) and the influence of MSCs-derived lipids have also been addressed.

Quantitation of phosphatidylethanol in dried blood after volumetric absorptive microsampling

BACKGROUND

Stimulated by the increased recognition of phosphatidylethanol (PEth) as sensitive direct marker of alcohol intake, the Ghent University's Laboratory of Toxicology and the National Institute of Criminalistics and Criminology combined their efforts to develop a quantitative method. To facilitate implementation the focus was on the use of a sampling technique which allows quick and easy blood collection, without the need of dedicated personnel at any place/any time. In the meantime the cooperation of the two labs should also allow to initiate a Belgian network of laboratories capable of quantifying PEth.

METHODS

Dried blood microsamples were collected via volumetric absorptive microsampling (VAMS). PEth 16:0/18:1 was quantified after liquid-liquid extraction using two independent isotope dilution - liquid chromatography - tandem mass spectrometry methods. A systematic review of the entire process at both sites was performed before the final method comparison using samples from 59 routine toxicology cases collected within a one-year time interval.

RESULTS

Initial differences between both laboratories were solved by focusing on important methodological aspects: (i) trueness verification of the calibration protocol focusing on the primary material, preparation of the stock solutions and adequate equilibration of calibrators and QCs, and (ii) verification of comparability of results obtained with different m/z transitions. Several of these aspects could only be verified by critically assessing spiked and native samples. After a final validation good average comparability of the two methods was observed. The average bias was -0.4%, with 85% of the differences within 20%. Moreover, the methods proved to be reproducible and robust within a one-year time interval.

CONCLUSION

This study is the first to develop a quantitative volumetric absorptive microsampling based method for PEth measurements, in addition it is the first to perform a systematic comparison of PEth measurements between two laboratories. From the discussion on the encountered pitfalls it is clear that also on a global scale, more efforts are needed to improve interlaboratory agreement.

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.

Confronting the Crisis of Comorbid Alcohol Use Disorder and Alcohol-Related Liver Disease With a Novel Multidisciplinary Clinic

BACKGROUND

Alcohol-related liver disease (ALD) is prevalent and deadly and increasingly affects younger people and women. No single discipline is adequately equipped to manage its biopsychosocial complexity.

OBJECTIVES

Depict the scope of the ALD problem, provide a narrative review of other integrated care models, share our experience forming and maintaining a multidisciplinary ALD clinic for over a year, and provide recommendations for replication elsewhere.

METHODS

Critical evaluation of clinic implementation and its first year of operation.

RESULTS

The clinical rationale for multidisciplinary ALD treatment is clear and supported by the literature. Such models are feasible although surprisingly rare and vulnerable to various surmountable challenges.

CONCLUSIONS

Successful ALD clinics must be built by teams with solid personal and professional relationships, supported by institutional leadership, and must use a new kind of multidisciplinary paradigm and training. Consultation-liaison psychiatry is uniquely positioned to lead future efforts in the care and study of ALD.

Alcohol Use Disorders in Alcoholic Liver Disease

Alcohol use disorder (AUD) is common in alcoholic liver disease (ALD) and intrinsic to its pathophysiology. Optimal treatment requires a multidisciplinary team approach and a working alliance between patients and providers. Diagnosing AUD involves a combination of thorough history taking, physical examination, screening questionnaires, and alcohol biomarkers. Alcohol biomarkers have advantages and limitations of use of which clinicians should be aware. AUD treatment is effective, multifaceted, and can be tailored to each individual. Available treatment modalities are myriad: motivational enhancement therapy, cognitive behavior therapy, 12-step facilitation, group therapies, intensive outpatient programs, inpatient and residential treatment, and relapse prevention medications.