Homozygosity for rs738409:G in PNPLA3 is associated with increased mortality following an episode of severe alcoholic hepatitis

Serum aryl hydrocarbon receptor activity is associated with survival in patients with alcohol-associated hepatitis

BACKGROUND AND AIMS

Patients with alcohol-associated hepatitis (AH) have an altered fecal metabolome, including reduced microbiota-derived tryptophan metabolites, which function as ligands for aryl hydrocarbon receptor (AhR). The aim of this study was to assess serum AhR ligand activity in patients with AH.

APPROACH AND RESULTS

The study included 74 controls without AUD, 97 patients with AUD, and 330 patients with AH from 2 different multicenter cohorts (InTeam: 134, AlcHepNet: 196). Serum AhR activity was evaluated using an AhR reporter assay with HepG2-Lucia cells incubated with serum for 24 hours. Serum AhR activity was significantly higher in patients with AH compared with both controls (1.59 vs. 0.96-fold change, p < 0.001) and patients with AUD (1.59 vs. 0.93, p < 0.001). In both AH cohorts, patients with AhR activity ≥ 2.09 had significantly lower cumulative survival rates at 30, 60, 90, and 180 days compared to those with AhR activity < 2.09. When serum AhR activity was used to further stratify patients with severe AH, the cumulative 30, 60, 90, and 180-day survival rates for patients with severe AH and the AhR activity ≥ 2.09 group were all significantly lower than those with an AhR activity < 2.09 group.

CONCLUSIONS

Serum AhR activity was significantly higher in patients with AH compared with controls and individuals with AUD, and this increased activity was associated with higher mortality. Consequently, serum AhR activity holds potential as a prognostic marker.

Non-Invasive Biomarkers for Differentiating Alcohol Associated Hepatitis from Acute Decompensation in Patients with ALD

Alcohol-associated hepatitis (AH) is the most severe form of alcohol-related liver disease. The natural course of alcohol-related liver disease is influenced by heavy alcohol consumption and abstinence periods. Differentiating between AH and decompensated cirrhosis (DC) could be extremely challenging in clinical practice due to clinical and bioclinical similarities. The severity of AH is made on bioclinical grounds, the severe form necessitating corticotherapy treatment. Liver biopsy is still the standard of care for establishing the diagnosis in atypical presentations. The pathogenesis of AH is an interplay between gene expression, cytokine dysregulation, the immune system and the gut microbiota. Non-invasive tests are increasingly and widely used for the purpose of early diagnosis and reliable prognostication. The non-invasive tests are emerging in concordance with disease pathogenesis. In this review, we describe the non-invasive tools that can distinguish AH from DC. We outline the available cut-offs and their performance in diagnosis and prognosis, as well as in assessing the treatment response to corticotherapy. Promising circulating biomarkers like keratin 18, microRNAs and sphingolipids will be in the review.

ACG Clinical Guideline: Alcohol-Associated Liver Disease

ABSTRACT

Alcohol-associated liver disease (ALD) is the most common cause of advanced hepatic disease and frequent indication for liver transplantation worldwide. With harmful alcohol use as the primary risk factor, increasing alcohol use over the past decade has resulted in rapid growth of the ALD-related healthcare burden. The spectrum of ALD ranges from early asymptomatic liver injury to advanced disease with decompensation and portal hypertension. Compared with those with other etiologies of liver disease, patients with ALD progress faster and more often present at an advanced stage. A unique phenotype of advanced disease is alcohol-associated hepatitis (AH) presenting with rapid onset or worsening of jaundice, and acute on chronic liver failure in severe forms conveying a 1-month mortality risk of 20%-50%. The model for end stage disease score is the most accurate score to stratify AH severity (>20 defined as severe disease). Corticosteroids are currently the only available therapeutic with proven efficacy for patients with severe AH, providing survival benefit at 1 month in 50%-60% of patients. Abstinence of alcohol use, a crucial determinant of long-term outcomes, is challenging to achieve in ALD patients with concurrent alcohol use disorder (AUD). As patients with ALD are rarely treated for AUD, strategies are needed to overcome barriers to AUD treatment in patients with ALD and to promote a multidisciplinary integrated care model with hepatology, addiction medicine providers, and social workers to comprehensively manage the dual pathologies of liver disease and of AUD. Liver transplantation, a definitive treatment option in patients with advanced cirrhosis, should be considered in selected patients with AH, who are unresponsive to medical therapy and have a low risk of relapse to posttransplant alcohol use. Level of evidence and strength of recommendations were evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations system. This guideline was developed under the American College of Gastroenterology Practice Parameters Committee.

Advances in the understanding and management of alcohol-related liver disease

Alcohol-related liver disease (ALD) is a major cause of liver-related morbidity and mortality. Epidemiological trends indicate recent and predicted increases in the burden of disease. Disease progression is driven by continued alcohol exposure on a background of genetic predisposition together with environmental cofactors. Most individuals present with advanced disease despite a long history of excessive alcohol consumption and multiple missed opportunities to intervene. Increasing evidence supports the use of non-invasive tests to screen for and identify disease at earlier stages. There is a definite role for public health measures to reduce the overall burden of disease. At an individual level, however, the ability to influence subsequent disease course by modifying alcohol consumption or the underlying pathogenic mechanisms remains limited due to a comparative lack of effective, disease-modifying medical interventions. Abstinence from alcohol is the key determinant of outcome in established ALD and the cornerstone of clinical management. In those with decompensated ALD, liver transplant has a clear role. There is consensus that abstinence from alcohol for an arbitrary period should not be the sole determinant in a decision to transplant. An increasing understanding of the mechanisms by which alcohol causes liver disease in susceptible individuals offers the prospect of new therapeutic targets for disease-modifying drugs. Successful translation will require significant public and private investment in a disease area which has traditionally been underfunded when compared to its overall prevalence.

Genomic approaches to explore susceptibility and pathogenesis of alcohol use disorder and alcohol-associated liver disease

Excessive alcohol use is a major risk factor for the development of an alcohol use disorder (AUD) and contributes to a wide variety of other medical illnesses, including alcohol-associated liver disease (ALD). Both AUD and ALD are complex and causally interrelated diseases, and multiple factors other than alcohol consumption are implicated in the disease pathogenesis. While the underlying pathophysiology of AUD and ALD is complex, there is substantial evidence for a genetic susceptibility of both diseases. Current genome-wide association studies indicate that the genes associated with clinical AUD only poorly overlap with the genes identified for heavy drinking and, in turn, neither overlap with the genes identified for ALD. Uncovering the main genetic factors will enable us to identify molecular drivers underlying the pathogenesis, discover potential targets for therapy, and implement patient care early in disease progression. In this review, we described multiple genomic approaches and their implications to investigate the susceptibility and pathogenesis of both AUD and ALD. We concluded our review with a discussion of the knowledge gaps and future research on genomic studies in these 2 diseases.

Quality standards for the management of alcohol-related liver disease: consensus recommendations from the British Association for the Study of the Liver and British Society of Gastroenterology ARLD special interest group

OBJECTIVE

Alcohol-related liver disease (ALD) is the most common cause of liver-related ill health and liver-related deaths in the UK, and deaths from ALD have doubled in the last decade. The management of ALD requires treatment of both liver disease and alcohol use; this necessitates effective and constructive multidisciplinary working. To support this, we have developed quality standard recommendations for the management of ALD, based on evidence and consensus expert opinion, with the aim of improving patient care.

DESIGN

A multidisciplinary group of experts from the British Association for the Study of the Liver and British Society of Gastroenterology ALD Special Interest Group developed the quality standards, with input from the British Liver Trust and patient representatives.

RESULTS

The standards cover three broad themes: the recognition and diagnosis of people with ALD in primary care and the liver outpatient clinic; the management of acutely decompensated ALD including acute alcohol-related hepatitis and the posthospital care of people with advanced liver disease due to ALD. Draft quality standards were initially developed by smaller working groups and then an anonymous modified Delphi voting process was conducted by the entire group to assess the level of agreement with each statement. Statements were included when agreement was 85% or greater. Twenty-four quality standards were produced from this process which support best practice. From the final list of statements, a smaller number of auditable key performance indicators were selected to allow services to benchmark their practice and an audit tool provided.

CONCLUSION

It is hoped that services will review their practice against these recommendations and key performance indicators and institute service development where needed to improve the care of patients with ALD.

Alcohol-Related Liver Disease: Is There a Safe Alcohol Consumption Limit for Liver Disease?

This review is to evaluate how much alcohol is safe in the context of alcohol-related liver disease (ALD). In patients without an established diagnosis of ALD consuming alcohol at quantities below 12 to 20 g daily with alcohol-free days is associated with a very low risk of developing disease. This risk is mediated by the presence of cofactors such as sex, medical comorbidity, obesity, and genetic factors. A threshold effect below which liver disease will not occur is not seen, instead a dose-response relationship where risk ranges from low to high. Once ALD is present, natural history studies confirm that continued alcohol consumption is clearly associated with an increased risk of ill health and premature death. In conclusion, low-level alcohol consumption in the absence of liver disease is associated with a very small risk of developing ALD, but once ALD is present patients should be supported to achieve complete abstinence from alcohol.

Current and future treatment for alcoholic-related liver diseases

The socioeconomic burden of alcohol-related liver disease has been increasing worldwide. Its prevalence is underestimated, and patients with alcohol-related liver disease are rarely diagnosed in the earlier phase of the disease spectrum. Alcoholic hepatitis is a distinct syndrome with life-threatening signs of systemic inflammation. In severe alcoholic hepatitis, prednisolone is indicated as the first-line treatment even with the possibility of various complications. Early liver transplantation can be another option for highly selected patients with a null response to prednisolone. Most importantly, abstinence is the mainstay of long-term care, but relapse is frequent among patients. Recent findings on the pathogenesis of alcoholic hepatitis have enabled us to discover new therapeutic targets. Preventing hepatic inflammation, reducing oxidative stress, improving gut dysbiosis, and enhancing liver regeneration are the main targets of emerging therapies. Herein, we review the pathogenesis, current treatment, and barriers to successful clinical trials of alcoholic hepatitis. Additionally, clinical trials for alcoholic hepatitis, either ongoing or recently completed, will be briefly introduced.

Acute alcohol-associated hepatitis: Latest findings in non-invasive biomarkers and treatment

Acute alcohol-associated hepatitis (AH) is a syndrome that occurs in heavy and long-term drinkers and results in severe jaundice and liver failure. The mortality rate in severe cases is 20%-50% at 28 days, and in cases that do not improve despite appropriately timed corticosteroid therapy, the mortality rate reaches 70% at 6 months. The only curative treatment is early liver transplantation, but less than 2% of patients with severe AH are eligible. In order to improve the prognosis, diagnostic tools are needed to detect appropriate cases at risk of severe conditions, and new therapies need to be developed that can replace corticosteroids. Recent research has revealed that the pathogenesis of AH involves a complex of factors, including changes in the gut microbiota, inflammatory and cytokine signalling, oxidative stress and mitochondrial dysfunction, and abnormalities in the hepatic regenerative capacity. Non-invasive diagnostic tools focusing on these specific pathologies have been reported in recent years. In addition, several novel agents targeting specific pathways are currently being developed and tested in clinical trials. This review will provide an overview of alcohol-associated hepatitis and focus on the latest diagnostic tools, particularly non-invasive biomarkers, and novel therapies.

Acute Kidney Injury (AKI) at Admission Predicts Mortality in Patients With Severe Alcoholic Hepatitis (SAH)

Background & aims

Severe alcoholic hepatitis (SAH) is a grave condition, and the presence of acute kidney injury (AKI) further jeopardizes patient survival. However, the impact of AKI on survival in SAH has not been assessed from this region of Asia.

Materials and methods

This study was conducted on consecutive alcohol-associated liver disease (ALD) patients hospitalized in Gastroenterology Department, SCB Medical College, Cuttack, India, between October 2016 and December 2018. On diagnosis of SAH (mDF score ≥32), demographic, clinical, and laboratory parameters were recorded, and survival was compared between patients with and without AKI (AKIN criteria). In addition, survival was compared among SAH patients defined by other criteria and prognostic models in the presence and absence of AKI.

Results

309 (70.71%) of ALD patients had SAH, and 201 (65%) of them had AKI. SAH patients with AKI had higher total leucocyte count, total bilirubin, serum creatinine, serum urea, INR, MELD (UNOS), MELD (Na+), CTP score, mDF score, Glasgow score, ABIC score, and increased prevalence of acute on chronic liver failure (ACLF) as per EASL-CLIF Consortium criteria (P < 0.001). Further, they had prolonged hospital stay, and increased death during hospitalization, at 28 days as well as 90 days (P < 0.001). Significant differences in survival were also seen in SAH (as per MELD, ABIC, and GAHS criteria) patients above the marked cut offs in respect to AKI.

Conclusions

Over two-thirds of ALD patients had SAH, and about two-thirds had AKI. Patients with SAH and AKI had an increased prevalence of ACLF, longer hospital stay, and increased mortality during hospitalization at 28 days and 90 days.

Lay summary

SAH is a critical condition, and the presence of AKI negatively affects their survival. Hence, early identification of SAH and AKI, as well as early initiation of treatment, is crucial for better survival. Our study from the coastal part of eastern India is the first to demonstrate the prevalence of SAH among patients with ALD along with the prevalence of AKI among SAH patients in this region. This knowledge will be helpful in managing these patients from this region of world.

Emerging Biomarkers in Alcohol-associated Hepatitis

Alcohol-associated hepatitis (AH) is a clinical syndrome of jaundice, abdominal pain, and anorexia due to prolonged heavy alcohol intake. AH is associated with changes in gene expression, cytokines, immune response, and the gut microbiome. There are limited biomarkers to diagnose and prognosticate in AH, but several non-invasive biomarkers are emerging. In this review, clinical risk-stratifying algorithms, promising AH biomarkers like cytokeratin-18 fragments, genetic polymorphisms, and microRNAs will be reviewed.

PNPLA3 allele frequency has no impact on biliary bile acid composition or disease course in patients with primary sclerosing cholangitis

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease that leads to bile duct strictures, cholestasis, and biliary cirrhosis. PNPLA3 (patatin-like phospholipase domain containing 3), regulates cellular lipid synthesis by converting lysophosphatidic acid into phosphatidic acid. Isoleucine mutation to methionine at position 148 (I148M) causes a loss of this function. Only two studies, with contradictory results, have evaluated the role of PNPLA3 in PSC. The rs738409(G) variant of PNPLA3 has been associated with an increased risk for transplantation in male patients with dominant strictures (DS). The study aimed to evaluate the PNPLA3 allele frequency effect on the clinical outcomes, progression, and prognosis of PSC. Furthermore, we analyzed the impact of PNPLA3 on phospholipid and bile acid composition to evaluate the effect of the PNPLA3 status on UDCA response.

PATIENTS AND METHODS

We recruited 560 patients prospectively and collected clinical and laboratory data as well as liver histology and imaging findings. PNPLA3 (CC, CG, GG) alleles were analyzed with TaqManTM. We also analyzed bile acids (BA), cholesterol and phospholipids and individual BA from a sample aspirated during endoscopic retrograde cholangiography (ERC).

RESULTS

Among the recruited patients, 58.4%, 35.7% and 5.9% had the wild (CC), heterozygous (CG) and homozygous (GG) alleles, respectively. The PNPLA3 haplotype did not impact bile composition or individual BA. In addition, we found no differences in age at diagnosis, disease progression, liver fibrosis or survival between the cohorts.

CONCLUSIONS

The PNPLA3 I148M variant had no significant impact on on bile composition, including UDCA content, clinical outcomes, progression of liver fibrosis, hepatobiliary cancer risk, liver transplantation, or overall survival.

Natural History of Alcohol-Associated Liver Disease: Understanding the Changing Landscape of Pathophysiology and Patient Care

Alcohol use and consequent liver disease are major burdens that have worsened during the COVID-19 pandemic. There are several facets to the pathophysiology and clinical consequences of alcohol-use disorder (AUD) and progression to alcohol-associated liver disease (ALD) that require a concerted effort by clinicians and translational and basic science investigators. Several recent advances from bedside to bench and bench to bedside have been made in ALD. We focused this review on a case-based approach that provides a human context to these important advances across the spectrum of ALD.

The MELD Score Is Superior to the Maddrey Discriminant Function Score to Predict Short-Term Mortality in Alcohol-Associated Hepatitis: A Global Study

INTRODUCTION

Several scoring systems predict mortality in alcohol-associated hepatitis (AH), including the Maddrey discriminant function (mDF) and model for end-stage liver disease (MELD) score developed in the United States, Glasgow alcoholic hepatitis score in the United Kingdom, and age, bilirubin, international normalized ratio, and creatinine score in Spain. To date, no global studies have examined the utility of these scores, nor has the MELD-sodium been evaluated for outcome prediction in AH. In this study, we assessed the accuracy of different scores to predict short-term mortality in AH and investigated additional factors to improve mortality prediction.

METHODS

Patients admitted to hospital with a definite or probable AH were recruited by 85 tertiary centers in 11 countries and across 3 continents. Baseline demographic and laboratory variables were obtained. The primary outcome was all-cause mortality at 28 and 90 days.

RESULTS

In total, 3,101 patients were eligible for inclusion. After exclusions (n = 520), 2,581 patients were enrolled (74.4% male, median age 48 years, interquartile range 40.9-55.0 years). The median MELD score was 23.5 (interquartile range 20.5-27.8). Mortality at 28 and 90 days was 20% and 30.9%, respectively. The area under the receiver operating characteristic curve for 28-day mortality ranged from 0.776 for MELD-sodium to 0.701 for mDF, and for 90-day mortality, it ranged from 0.773 for MELD to 0.709 for mDF. The area under the receiver operating characteristic curve for mDF to predict death was significantly lower than all other scores. Age added to MELD obtained only a small improvement of AUC.

DISCUSSION

These results suggest that the mDF score should no longer be used to assess AH's prognosis. The MELD score has the best performance in predicting short-term mortality.

Liver Biopsy in Patients With Alcohol-Associated Liver Disease With Acute-on-Chronic Liver Failure

Patients with alcohol-associated liver disease may develop severe forms of presentation of acute-on-chronic liver failure, with a high risk for short-term mortality. Alcoholic hepatitis should be suspected among patients with alcohol-associated liver disease who present with acute-on-chronic liver failure. In this review, we discuss the need and feasibility of liver biopsy in the diagnosis of alcoholic hepatitis and predicting its prognosis among decompensated patients with alcohol-associated liver disease and acute-on-chronic liver failure.

PNPLA3 is the dominant SNP linked to liver disease severity at time of first referral to a tertiary center

BACKGROUND

Single nucleotide polymorphisms (SNPs) in genes including PNPLA3, TM6SF2, HSD17B13 and SERPINA1 have been identified as risk modifiers of progression in chronic liver disease (CLD). However, it is unclear whether genotyping for these risk variants is useful in clinical routine.

METHODS

Liver disease severity was assessed by liver stiffness measurement (LSM) and by presence of clinical manifestations of advanced-chronic liver disease (ACLD) in 779 consecutive CLD patients at the time of referral to a tertiary center. The associations of risk variants with CLD severity were calculated individually and in a combined model using a polygenic risk-score.

RESULTS

Non-alcoholic fatty liver disease (NAFLD) was the most common etiology (n = 511, 65.6%), and ACLD was present in 217 (27.9%) patients. The PNPLA3-G-allele remained independently associated with higher LSM (adjusted-B: 2.508 [95%CI: 0.887-4.130], P = 0.002) or the presence of ACLD (aOR: 1.562 [95%CI: 1.097-2.226], P = 0.013). SERPINA1-Z-allele was also independently associated with LSM (adjusted-B: 4.558 [95%CI: 1.182-7.934], P = 0.008), while the other risk alleles did not attain statistical significance. Combining these risk alleles into a polygenic risk-score was significantly associated with LSM (adjusted-B: 0.948 [95%CI: 0.153-1.743], P = 0.020).

CONCLUSION

PNPLA3 risk-variants are linked to liver disease severity at the time of first referral to an outpatient hepatology clinic.

Current and Future Biomarkers in Alcoholic Hepatitis

Alcoholic hepatitis (AH) is a clinical syndrome of jaundice, abdominal pain, and anorexia due to prolonged heavy alcohol intake, and is associated with alterations in gene expression, cytokines, immune response, and the gut microbiome. Currently, we have limited biomarkers to diagnose and prognosticate in AH, but there are many novel noninvasive biomarkers under development. We evaluate the currently used algorithms to risk-stratify in AH (such as the Maddrey modified discriminant function), and discuss novel biomarkers in development, such as breath biomarkers, microRNAs, cytokeratin-18 fragments, and the AshTest. We also review the characteristics of an ideal biomarker in AH.

Diagnosis of Alcohol-Associated Hepatitis: When Is Liver Biopsy Required?

Alcohol-associated hepatitis (AH) is a unique clinical syndrome in patients with excessive and prolonged alcohol consumption, and negatively impacts the patient outcomes. Among patients with asymptomatic alcohol-associated liver disease with elevated liver enzymes and/or steatosis, liver biopsy is required to diagnose AH. Noninvasive assessment should be performed in these patients to determine risk of advanced fibrosis. In symptomatic patients with jaundice, liver biopsy is required when the clinical diagnosis is uncertain. Liver biopsy is not recommended to determine prognosis of patients with AH. Noninvasive biomarkers are emerging for diagnosis of and determining prognosis of patients with AH.

Genetic and Environmental Susceptibility to Alcoholic Hepatitis

Constitutional, environmental, and genetic risk factors influence the development of alcohol-related cirrhosis. The amount of alcohol consumed and whether excessive drinking continues after the identification of pre-cirrhotic liver damage are key risk factors. Female sex, ethnicity, obesity, coffee consumption, cigarette smoking, and exposure to other causes of liver injury also influence the risk of disease development. More recently several genetic loci have been robustly associated with the risk for developing significant alcohol-related liver disease. It remains unclear whether additional risk factors are involved in the development of the clinical syndrome of alcoholic hepatitis, but the genetic evidence is suggestive.

Prevention of First Decompensation in Advanced Chronic Liver Disease

The first occurrence of decompensation constitutes a watershed moment in the natural history of chronic liver disease; it denotes a point of no return in a relevant proportion of patients. Preventive strategies may profoundly decrease cirrhosis-related morbidity and mortality. Removing the primary etiologic factor and cofactors, is key; however, a considerable proportion of patients require additional etiology-independent treatment strategies that target important pathomechanisms promoting decompensation (ie, portal hypertension and systemic inflammation). This article explains the importance of preventing first decompensation and summarizes the evidence for etiologic and etiology-independent (most important, nonselective beta-blockers and statins) therapies.

Influence of Genetic Variants on Disease Regression and Outcomes in HCV-Related Advanced Chronic Liver Disease after SVR

Genetic variants including PNPLA3-rs738409 C>G, TM6SF2-rs58542926 C>T, MBOAT7-rs641738 C>T, and HSD17B13-rs72613567 T>TA have been shown to influence progression to advanced chronic liver disease (ACLD) in patients with chronic hepatitis C (CHC). We aimed to investigate their impact on disease regression (i.e., changes in hepatic venous pressure gradient [HVPG] and non-invasive surrogates [liver stiffness measurement (LSM), von Willebrand factor (VWF), and VWF/platelet count ratio (VITRO)]) and clinical outcomes after CHC cure in 346 patients with pre-treatment ACLD. Patients carrying the PNPLA3 minor allele had more advanced liver disease prior to antiviral therapy, confirming its impact on liver disease progression. In a subgroup of 88 patients who underwent paired HVPG-measurements and were genotyped for all SNP/indels, PNPLA3/TM6SF2/MBOAT7/HSD17B13 genotypes were not associated with changes in HVPG. In line, changes in non-invasive surrogates of portal hypertension (LSM/VWF/VITRO) were comparable between carriers and non-carriers of the PNPLA3 G-allele in the overall cohort. Finally, carriage of PNPLA3 G-allele was not associated with the development of hepatic decompensation, de-novo hepatocellular carcinoma, or transplant-free mortality during a median follow-up of 42 months after the end of antiviral treatment. Therefore, genetic variants in PNPLA3/TM6SF2/MBOAT7/HSD17B13 do not impact the regression of portal hypertension and clinical outcomes in patients with pre-treatment ACLD after CHC cure.

Genetic predisposition similarities between NASH and ASH: Identification of new therapeutic targets

Fatty liver disease can be triggered by a combination of excess alcohol, dysmetabolism and other environmental cues, which can lead to steatohepatitis and can evolve to acute/chronic liver failure and hepatocellular carcinoma, especially in the presence of shared inherited determinants. The recent identification of the genetic causes of steatohepatitis is revealing new avenues for more effective risk stratification. Discovery of the mechanisms underpinning the detrimental effect of causal mutations has led to some breakthroughs in the comprehension of the pathophysiology of steatohepatitis. Thanks to this approach, hepatocellular fat accumulation, altered lipid droplet remodelling and lipotoxicity have now taken centre stage, while the role of adiposity and gut-liver axis alterations have been independently validated. This process could ignite a virtuous research cycle that, starting from human genomics, through omics approaches, molecular genetics and disease models, may lead to the development of new therapeutics targeted to patients at higher risk. Herein, we also review how this knowledge has been applied to: a) the study of the main PNPLA3 I148M risk variant, up to the stage of the first in-human therapeutic trials; b) highlight a role of MBOAT7 downregulation and lysophosphatidyl-inositol in steatohepatitis; c) identify IL-32 as a candidate mediator linking lipotoxicity to inflammation and liver disease. Although this precision medicine drug discovery pipeline is mainly being applied to non-alcoholic steatohepatitis, there is hope that successful products could be repurposed to treat alcohol-related liver disease as well.

PNPLA3 and SERPINA1 Variants Are Associated with Severity of Fatty Liver Disease at First Referral to a Tertiary Center

Single nucleotide polymorphisms (SNPs), including PNPLA3 rs738409 and SERPINA1 rs17580, have been identified as risk modifiers in the progression fatty liver disease (alcoholic (ALD) or non-alcoholic (NAFLD)). While PNPLA3 has been studied in various settings, the value of both SNPs has so far not been addressed in a real-world cohort of subjects referred for a diagnostic work-up of liver disease. Thus, liver disease severity was assessed in 1257 consecutive patients with suspected ALD or NAFLD at the time of referral to a tertiary center. Advanced chronic liver disease (ACLD) was present in 309 (24.6%) patients and clinically significant portal hypertension (CSPH) was present in 185 (14.7%) patients. The PNPLA3 G-allele was independently associated with a higher liver stiffness measurement (LSM; adjusted B: 2.707 (1.435–3.979), p < 0.001), and higher odds of ACLD (adjusted odds ratio (aOR): 1.971 (1.448–2.681), p < 0.001) and CSPH (aOR: 1.685 (1.180–2.406), p = 0.004). While the SERPINA1 Z-allele was not associated with a higher LSM or the presence of ACLD, it was independently associated with higher odds of CSPH (aOR: 2.122 (1.067–4.218), p = 0.032). Associations of the PNPLA3 G-allele and the SERPINA1 Z-allele with CSPH were maintained independently of each other. The presence of both risk variants further increased the likelihood of ACLD and CSPH.

Interferon lambda 4 genotype and pathway in alcoholic hepatitis

OBJECTIVES

Single nucleotide polymorphisms within the interferon lambda 4 (IFNL4) gene influence liver inflammation and fibrosis in chronic liver disease. We investigated whether this is also the case during acute liver disease, alcoholic hepatitis. We, therefore, related variants within the IFNL4 gene to the clinical course of acute alcoholic hepatitis, and characterized the activation state of the IFN lambda system in these patients.

METHODS

In this pilot study, 58 patients with alcoholic hepatitis were genotyped for the rs368234815IFNL4 single nucleotide polymorphism (deltaG, deltaG/TT: IFN lambda 4 positive, TT/TT: IFN lambda 4 negative). The genotypes were related to mortality, infection and inflammation and expression of the IFNL receptor 1 and IFN inducible genes were measured in liver and peripheral leukocytes.

RESULTS

Amongst the alcoholic hepatitis patients who died, the IFN negative patients live longer after diagnosis, and also the IFN negative patients tended to have an overall short-term survival benefit compared to IFN lambda positive patients (p = .058). The IFN lambda 4 negative patients at diagnosis had fewer circulating monocytes and lower plasma soluble CD163. The patients with alcoholic hepatitis had reduced expression of the IFNL receptor 1in both liver and blood compared with healthy controls. In blood, the expression of IFN stimulated genes was lower than in healthy controls and most so in the patients, who died.

CONCLUSIONS

The IFN lambda 4 pathway seems involved in the acute disease processes of alcoholic hepatitis and patients without IFN lambda expression seem to have a short-term survival benefit.

Role of candidate gene variants in modulating the risk and severity of alcoholic hepatitis

BACKGROUND

Alcoholic hepatitis (AH) is a severe and life-threatening alcohol-associated liver disease. Only a minority of heavy drinkers acquires AH and severity varies among affected individuals, suggesting a genetic basis for the susceptibility to and severity of AH.

METHODS

A cohort consisting of 211 patients with AH and 176 heavy drinking controls was genotyped for five variants in five candidate genes that have been associated with chronic liver diseases: rs738409 in patatin-like phospholipase domain-containing protein 3 (PNPLA3), rs72613567 in hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13), rs58542926 in transmembrane 6 superfamily member 2 (TM6SF2), rs641738 in membrane bound O-acyltransferase domain containing 7 (MBOAT7), and a copy number variant in the haptoglobin (HP) gene. We tested the effects of individual variants and the combined/interacting effects of variants on AH risk and severity.

RESULTS

We found significant associations between AH risk and the risk alleles of rs738409 (p = 0.0081) and HP (p = 0.0371), but not rs72613567 (p = 0.3132), rs58542926 (p = 0.2180), or rs641738 (p = 0.7630), after adjusting for patient's age and sex. A multiple regression model indicated that PNPLA3 rs738409:G [OR = 1.59 (95% CI: 1.15-2.22), p = 0.0055] and HP*2 [OR = 1.38 (95% CI: 1.04-1.82), p = 0.0245], when combined and adjusted for age and sex also had a large influence on AH risk among heavy drinkers. In the entire cohort, variants in PNPLA3 and HP were associated with increased total bilirubin and Model for End-stage Liver Disease (MELD) score, both measures of AH severity. The HSD17B13 rs72613567:AA allele was not found to reduce risk of AH in patients carrying the G allele of PNPLA3 rs738409 (p = 0.0921).

CONCLUSION

PNPLA3 and HP genetic variants increase AH risk and are associated with total bilirubin and MELD score, surrogates of AH severity.

PNPLA3 gene polymorphism and overall and cardiovascular mortality in the United States

BACKGROUND AND AIM

The association between palatin-like phospholipase domain-containing 3 (PNPLA3) I148M (rs738409) polymorphism and mortality is not well understood. We investigated the impact of PNPLA3 I148M (rs738409) polymorphism on overall and cardiovascular mortality based on the presence of nonalcoholic fatty liver disease (NAFLD).

METHODS

The third National Health and Nutrition Examination Survey (NHANES) from 1991 to 1994 and National Health and Nutrition Examination Survey III-linked mortality data through 31 December 2015 were utilized in this study.

RESULTS

Of 4814 participants, 50.7% were homozygous for the C-allele and 12.6% were homozygous for the G-allele. During a follow up of 20 years, there were a total of 1255 deaths, 422 attributed to cardiovascular disease. There was a significant association with overall mortality among those with the PNPLA3 I148M (rs738409) GG genotype (hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.02-1.77) or G-allele (HR 1.22, 95% CI 1.09-1.36) in the general population. NAFLD with homozygous PNPLA3 I148M (rs738409) GG genotype had higher overall mortality after adjusting for multiple metabolic risk factors (HR 1.45, 95% CI 1.01-2.08). The PNPLA3 I148M (rs738409) G-allele had a tendency of increased cardiovascular mortality in the total population. This association was not noted in those with NAFLD.

CONCLUSIONS

The homozygous PNPLA3 I148M (rs738409) GG genotype showed an increase in overall mortality in the general population and NAFLD independent of multiple metabolic risk factors.

Genetic variant rs72613567 of HSD17B13 gene reduces alcohol-related liver disease risk in Chinese Han population

BACKGROUND & AIMS

Recently, the variant rs72613567:TA in the 17-beta-hydroxysteroid dehydrogenase 13 (HSD17B13) has been associated with reduced levels of ALT and AST and a reduced risk of alcohol-related liver disease (ALD) in the European population. Therefore, the aim of this study was to investigate the association between the polymorphisms of HSD17B13 and ALD, liver serum markers and patatin-like phospholipase domain-containing protein 3 (PNPLA3) p.I148M in the Chinese Han population.

METHODS

A case-control study was performed from five centres and included 769 ALD patients and 767 healthy controls. Two SNPs (rs72613567 and rs6834314) in HSD17B13 were genotyped using the Sequenom MassArray system and allele association analysis was performed using PLINK 1.90 software.

RESULTS

HSD17B13 rs72613567:TA allele was associated with a reduced risk of ALD by 19% (95% confidence interval [CI]: 0.05-0.31, P = .01), uniformly, the G allele in the rs6834314 reduced the risk of ALD by 19% (95% CI: 0.05-0.31, P = 8.28 × 10^-3). And the genotypes of two SNPs were associated with reducing the risk of ALD in three genetic model analysis. In addition, we found that TA allele was associated with lower levels of serum ALT, AST and GGT (P = .005, .007 and .02, respectively), higher level of serum ALB (P = .02), but not associated with ALP. In this cohort, the interaction between HSD17B13 rs72613567 and the steatogenic allele PNPLA3 rs738409 was not validated.

CONCLUSION

The present study revealed that HSD17B13 rs72613567 was significantly associated with a reduced risk of ALD in Chinese Han population.

The knowns and unknowns of treatment for alcoholic hepatitis

Alcoholic hepatitis is an acute, inflammatory liver disease associated with high morbidity and mortality both in the short term and long term. Alcoholic hepatitis often arises in patients with a background of chronic liver disease and it is characterised by the rapid onset of jaundice and the development of myriad complications. Medical therapy for severe alcoholic hepatitis relies on corticosteroids, which have modest effectiveness. Abstinence from alcohol is critically important in patients with alcoholic hepatitis, but recidivism is high. Because of the absence of effective medical treatments for alcoholic hepatitis and alcohol dependency, there is a pressing need to develop new and effective therapeutics. Supported by promising preliminary and preclinical studies, many ongoing clinical trials of new therapies for alcoholic hepatitis are currently underway and are discussed further in this Series paper.

Impact of PNPLA3 (rs738409-G) polymorphism on post-transplant outcomes after liver transplantation for alcohol-related liver disease

INTRODUCTION

We aimed to evaluate the association between PNPLA3 polymorphism and post-liver transplantation (LT) outcomes related to alcohol relapse (AR).

METHOD

We retrospectively analyzed data from patients receiving LT for alcoholic liver disease (ALD) from 04/2014 to 12/2017. Liver-related clinical outcomes were assessed by the gamma-glutamyltransferase (GGT) level and alcohol-related liver failure (ARLF). Genotyping was performed using prospectively collected DNA samples in both donors and recipients.

RESULTS

A total of 83 recipients were enrolled. Post-LT AR occurred in 31 patients (37.3%). Thirty-one patients (14 AR, 9 abstainers) showed elevated GGT levels, and 3 AR patients experienced ARLF. In the multivariate analysis, rs738409 G allele carrier and heavy drinking (HRAR score ≥ 4) were independent risk factors for elevated GGT levels (odds ratio [OR] = 8.69, P < .01; OR = 13.07, P = .01) and ARLF (OR = 4.52, P = .04; OR = 19.62, P = .03). Among 15 heavy AR patients, being an rs738409 G allele carrier was related to GGT elevation (P = .03) and ARLF (P = .04), but it was not related to GGT elevation in mild drinkers (n = 16) or abstainers (n = 52).

CONCLUSION

PNPLA3 polymorphism of the recipient genotype can independently affect the post-LT prognosis of LT patients for ALD, especially in heavy AR patients. Therefore, strong abstinence education is recommended in patients with this single nucleotide polymorphism.

The natural history of alcohol-related liver disease

PURPOSE OF REVIEW

This review will describe the natural history of alcohol-related liver disease (ArLD) in light of recent data that have synthesized existing knowledge on this topic and described new research cohorts to improve our understanding of progression and outcomes in ArLD.

RECENT FINDINGS

ArLD occurs after a threshold of alcohol consumption, but this threshold is lowered by the presence of comorbid factors of which obesity is the most common. The most common stage of ArLD is alcohol-related steatosis: this is associated with a low rate of progression to cirrhosis (3%/year) and nonliver-related morbidity is more likely (4 versus 1%/year). In contrast, alcohol-related steatohepatitis or cirrhosis is more dangerous with higher rates of both nonliver and liver-related mortality. Hepatocellular carcinoma occurs at approximately 3%/year amongst people with ArLD cirrhosis.

SUMMARY

These data allow an understanding of ArLD to accurately counsel patients and also to guide public health policies. Awareness of the shortcomings of the available data, highlighted in a recent systematic review, will inform the design of further research in particular to describe the multiple interacting factors that may cause ArLD to regress or progress.

Recent advances in alcohol-related liver disease (ALD): summary of a Gut round table meeting

Alcohol-related liver disease (ALD), which includes a range of disorders of different severity and is one of the most prevalent types of liver disease worldwide, has recently regained increased attention. Among other reasons, the realisation that any alcohol intake, regardless of type of beverage represents a health risk, and the new therapeutic strategies tested in recently published or undergoing clinical trials spur scientific interest in this area.In April 2019, Gut convened a round table panel of experts during the European Association for the Study of the Liver International Liver Congress in Vienna to discuss critical and up-to-date issues and clinical trial data regarding ALD, its epidemiology, diagnosis, management, pathomechanisms, possible future treatments and prevention. This paper summarises the discussion and its conclusions.

Patatin-Like Phospholipase Domain-Containing Protein 3 I148M and Liver Fat and Fibrosis Scores Predict Liver Disease Mortality in the U.S. Population

BACKGROUND AND AIMS

Fatty liver causes premature death worldwide and requires long-term health care. We examined relationships of liver disease markers, including patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148M, with mortality in the U.S. National Health and Nutrition Examination Survey, 1988-1994, with 27 years of linked mortality data.

APPROACH AND RESULTS

We studied 13,298 viral hepatitis negative adults who fasted at least 4 hours using the nonalcoholic fatty liver disease (NAFLD) liver fat score and NAFLD fibrosis score. PNPLA3 I148M was genotyped in a subgroup of participants from 1991 to 1994 (n = 5,640). Participants were passively followed for mortality, identified by death certificate underlying or contributing causes, by linkage to the National Death Index through 2015. During follow-up (median, 23.2 years), cumulative mortality was 33.2% overall and 1.1% with liver disease, including primary liver cancer. Increased liver disease mortality was associated with PNPLA3 I148M (hazard ratio [HR], 2.9; 95% confidence interval [CI], 0.9-9.8) and 148M genotypes (HR, 18.2; 95% CI, 3.5-93.8), an intermediate (HR, 3.8; 95% CI, 1.3-10.7) or high (HR, 12.6; 95% CI, 4.3-36.3) NAFLD liver fat score, and a high NAFLD fibrosis score (HR, 12.2; 95% CI, 1.9-80.6) adjusted for risk factors. Survival curves suggest that increased mortality risk with two 148M alleles was greatest beginning in the second decade of follow-up. Overall, but not cardiovascular disease, mortality was associated with the PNPLA3 148M allele, and both mortality outcomes were associated with higher fat and fibrosis scores.

CONCLUSIONS

In the U.S. population, PNPLA3 I148M and higher NAFLD liver fat and fibrosis scores were associated with increased liver disease mortality. Genetic variant PNPLA3 I148M may complement other liver disease markers for NAFLD surveillance.

Serum Transferrin Is an Independent Predictor of Mortality in Severe Alcoholic Hepatitis

OBJECTIVES

Severe alcoholic hepatitis (sAH) confers substantial mortality, but the disease course is difficult to predict. As iron parameters are attractive outcome predictors in other liver diseases, we tested their prognostic ability in sAH.

METHODS

Serum ferritin, transferrin, iron, transferrin saturation, nontransferrin-bound iron, soluble transferrin receptor, and hepcidin were measured in 828 patients with sAH recruited prospectively through the STOPAH trial. The cohort was randomly divided into exploratory (n = 200) and validation sets (n = 628).

RESULTS

Patients with sAH had diminished serum transferrin but increased transferrin saturation. Among iron parameters, baseline transferrin was the best predictor of 28-day (area under the receiver operated characteristic 0.72 [95% confidence interval 0.67-0.78]) and 90-day survival (area under the receiver operated characteristic 0.65 [0.61-0.70]). Transferrin's predictive ability was comparable with the composite scores, namely model of end-stage liver disease, Glasgow alcoholic hepatitis score, and discriminant function, and was independently associated with survival in multivariable analysis. These results were confirmed in a validation cohort. Transferrin did not correlate with markers of liver synthesis nor with non-transferrin-bound iron or soluble transferrin receptor (as markers of excess unbound iron and functional iron deficiency, respectively).

DISCUSSION

In patients with sAH, serum transferrin predicts mortality with a performance comparable with commonly used composite scoring systems. Hence, this routinely available parameter might be a useful marker alone or as a component of prognostic models.

Leveraging Human Genetics to Identify Potential New Treatments for Fatty Liver Disease

Fatty liver disease (FLD), including its more severe pathologies, namely steatohepatitis, hepatocarcinoma, and cirrhosis, is the most common cause of chronic liver disease worldwide and is projected to become the leading cause of hepatocellular carcinoma and end-stage liver disease. FLD is heterogeneous with multiple etiologies and diverse histological phenotypes, so therapies will ultimately need to be individualized for relevant targets. Inherited factors contribute to FLD, and most of the genetic variation influencing liver disease development and progression is derived from genes involved in lipid biology, including PNPLA3, TM6SF2, GCKR, MBOAT7, and HSD17B13. From this point of view, we focus in this perspective on how human molecular genetics of FLD have highlighted defects in hepatic lipid handling as a major common mechanism of its pathology and how this insight could be leveraged to treat and prevent its more serious complications.

How Would You Manage This Patient With Nonalcoholic Fatty Liver Disease?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center

Nonalcoholic fatty liver disease (NAFLD), a common diagnosis in the United States and other developed countries, has been increasing in prevalence. The American Association for the Study of Liver Diseases recently published updated practice guidelines for diagnosing and managing NAFLD, including the following recommendations: Routine screening for NAFLD in high-risk groups is not advised because of uncertainties surrounding test and treatment options, along with a lack of knowledge about cost-effectiveness and long-term benefits. Noninvasive studies, including biomarkers from laboratory tests and liver stiffness measured through elastography, are clinically useful tools for identifying advanced fibrosis in patients with NAFLD. Liver biopsy should be considered in patients with NAFLD who are at increased risk for nonalcoholic steatohepatitis (NASH) or advanced fibrosis. Weight loss of at least 3% to 5% generally reduces NASH, but greater weight loss (7% to 10%) is needed to improve most histopathologic features, including fibrosis. Pharmacologic therapies (such as pioglitazone and vitamin E) should be considered only in patients with biopsy-proven NASH. Patients with NAFLD should not consume heavy amounts of alcohol, although insufficient data exist to provide advice about other levels of alcohol use. Here, 2 clinicians with expertise in this area debate whether to screen for NAFLD in primary care, how to monitor patients with NAFLD, and what interventions should be used to manage this condition.

Polymorphism in the Promoter Region of NFE2L2 Gene Is a Genetic Marker of Susceptibility to Cirrhosis Associated with Alcohol Abuse

Alcoholic liver disease (ALD) is a highly prevalent spectrum of pathologies caused by alcohol overconsumption. Morbidity and mortality related to ALD are increasing worldwide, thereby demanding strategies for early diagnosis and detection of ALD predisposition. A potential candidate as a marker for ALD susceptibility is the transcription factor nuclear factor erythroid-related factor 2 (Nrf2), codified by the nuclear factor erythroid 2-related factor 2 gene (NFE2L2). Nrf2 regulates expression of proteins that protect against oxidative stress and inflammation caused by alcohol overconsumption. Here, we assessed genetic variants of NFE2L2 for association with ALD. Specimens from patients diagnosed with cirrhosis caused by ALD were genotyped for three NFE2L2 single nucleotide polymorphisms (SNP) (SNPs: rs35652124, rs4893819, and rs6721961). Hematoxylin & eosin and immunohistochemistry were performed to determine the inflammatory score and Nrf2 expression, respectively. SNPs rs4893819 and rs6721961 were not specifically associated with ALD, but analysis of SNP rs35652124 suggested that this polymorphism predisposes to ALD. Furthermore, SNP rs35652124 was associated with a lower level of Nrf2 expression. Moreover, liver samples from ALD patients with this polymorphism displayed more severe inflammatory activity. Together, these findings provide evidence that the SNP rs35652124 variation in the Nrf2-encoding gene NFE2L2 is a potential genetic marker for susceptibility to ALD.

Impact of patatin-like phospholipase domain containing 3 rs738409 G/G genotype on hepatic decompensation and mortality in patients with portal hypertension

BACKGROUND

The rs738409 C>G p.I148M variant in the patatin-like phospholipase domain containing 3 (PNPLA3)-gene promotes triglyceride accumulation in hepatocytes and hepatic stellate cell activation and has previously been linked to hepatic steatosis/liver fibrosis.

AIM

To investigate its impact on hepatic decompensation and (liver-related) mortality in patients who had already developed portal hypertension. Moreover, we assessed its link with hepatic steatosis as evaluated by controlled attenuation parameter.

METHODS

We performed a retrospective analysis in prospectively characterised patients with viral hepatitis/fatty liver disease-induced portal hypertension (hepatic venous pressure gradient [HVPG] ≥ 6 mm Hg) diagnosed at the Medical University of Vienna who underwent HVPG measurement (until 2013; n = 372; longitudinal study) or simultaneous HVPG and controlled attenuation parameter measurement (2014-2017; n = 153; cross-sectional study).

RESULTS

While survival was similar between PNPLA3-C/C and -C/G patients, we observed substantially increased mortality in PNPLA3-G/G patients. PNPLA3-G/G had no impact on mortality in the subgroup of patients with viral hepatitis; however, we observed a strong independent association between PNPLA3-G/G and hepatic decompensation (adjusted subdistribution hazard ratio [aSHR]: 2.1, 95% confidence interval [95% CI]: 1.1-4; P = 0.024) as well as mortality (overall: aSHR: 2.2, 95% CI: 1.22-3.98; P = 0.009; liver-related: aSHR: 2.2, 95% CI: 1.08-4.46; P = 0.029) in patients with fatty liver disease. Interestingly, even in the subgroup of patients who had already progressed to clinically significant portal hypertension (HVPG ≥ 10 mm Hg), PNPLA3-G/G substantially increased mortality (aSHR: 2.33, 95% CI: 1.27-4.29; P = 0.006). PNPLA3-genotype had no influence on controlled attenuation parameter or the prevalence of values ≥248 dB/m.

CONCLUSION

PNPLA3-G/G-genotype seems to double the risks of hepatic decompensation and (liver-related) mortality in patients with portal hypertension due to fatty liver disease. Further studies are warranted to investigate potential underlying pathophysiological mechanisms unrelated to hepatic steatosis.

Microbiota, a key player in alcoholic liver disease

Alcoholic liver disease (ALD) is a major cause of morbidity and mortality worldwide. Only 20% of heavy alcohol consumers develop alcoholic liver cirrhosis. The intestinal microbiota (IM) has been recently identified as a key player in the severity of liver injury in ALD. Common features of ALD include a decrease of gut epithelial tight junction protein expression, mucin production, and antimicrobial peptide levels. This disruption of the gut barrier, which is a prerequisite for ALD, leads to the passage of bacterial products into the blood stream (endotoxemia). Moreover, metabolites produced by bacteria, such as short chain fatty acids, volatile organic compounds (VOS), and bile acids (BA), are involved in ALD pathology. Probiotic treatment, IM transplantation, or the consumption of dietary fiber, such as pectin, which all alter the ratio of bacterial species, have been shown to improve liver injury in animal models of ALD and to be associated with an improvement in gut barrier function. Although the connections between the microbiota and the host in ALD are well established, the underlying mechanisms are still an active area of research. Targeting the microbiome through the use of prebiotic, probiotic, and postbiotic modalities could be an attractive new approach to manage ALD.

Noncholesterol Sterols as Surrogate Markers in Patients with Severe Alcoholic Hepatitis

Severe alcoholic hepatitis (AH) is a life-threatening condition lacking good serologic markers to tailor treatment and predict recovery. We examined the cholesterol metabolism in severe AH to explore prognostic markers and evaluate the profile of cholesterol precursors, cholestanol and phytosterols, in this context. We assessed serum cholesterol, cholesterol precursors, cholestanol, phytosterols, and biochemical markers in 24 patients with severe AH treated with prednisolone and randomized to ciprofloxacin in the ratio 1:1. Response to prednisolone was assessed with the Lille model. Evaluations were made between responders and nonresponders to corticosteroid treatment and during follow-up for 180 days. The findings were compared with those from patients with primary sclerosing cholangitis (PSC) (n = 156) and healthy individuals (n = 124). Responders to prednisolone had ~56-60% higher (p-value 0.032-0.044) serum ratios to cholesterol of phytosterols, while the lathosterol/campesterol ratio was ~76% (p = 0.031) lower compared to nonresponders. Stigmasterol/cholesterol predicted response to corticosteroid therapy. Surrogate markers of cholesterol synthesis (lathosterol and desmosterol) inversely reflected those of absorption (cholestanol and phytosterols) in PSC and controls (r-range -0.247 to -0.559, p < 0.01 for all), contrary to AH patients, among whom this reciprocal regulation was partially recovered on day 90 (lathosterol: r-range -0.733 to -0.952, p < 0.05 for all). AH patients had ~26% lower lathosterol/cholesterol, but 1.13-3.87-fold higher cholestanol/cholesterol and sitosterol/cholesterol compared to control groups (p < 0.05 for all). Median ferritin concentration at baseline was ~37% lower (p = 0.011) among the responders. Cholesterol precursors and phytosterols have a disease-specific profile in AH. Phytosterols and ferritin may serve as surrogate markers for short-term response.

PNPLA3 expression and its impact on the liver: current perspectives

A single-nucleotide polymorphism occurring in the sequence of the human patatin-like phospholipase domain-containing 3 gene (PNPLA3), known as I148M variant, is one of the best characterized and deeply investigated variants in several clinical scenarios, because of its tight correlation with increased risk for developing hepatic steatosis and more aggressive part of the disease spectrum, such as nonalcoholic steatohepatitis, advanced fibrosis and cirrhosis. Further, the I148M variant is positively associated with alcoholic liver diseases, chronic hepatitis C-related cirrhosis and hepatocellular carcinoma. The native gene encodes for a protein that has not yet a fully defined role in liver lipid metabolism and, according to recent observations, seems to be divergently regulated among distinct liver cells type, such as hepatic stellate cells. Therefore, the aim of this review is to collect the latest data regarding PNPLA3 expression in human liver and to analyze the impact of its genetic variant in human hepatic pathologies. Moreover, a description of the current biochemical and metabolic data pertaining to PNPLA3 function in both animal models and in vitro studies is summarized to allow a better understanding of the relevant pathophysiological role of this enzyme in the progression of hepatic diseases.