Development and prognostic relevance of a histologic grading and staging system for alcohol-related liver disease

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.

Histological characteristics in patients admitted to the hospital with alcoholic hepatitis complicated by acute-on-chronic liver failure

OBJECTIVES

Alcoholic hepatitis (AH) is a frequent precipitating event for the development of acute-on-chronic liver failure (ACLF), a syndrome characterised by organ failures due to immune dysfunction. The histological features of this complication are not well characterized. We investigated whether ACLF has specific histological characteristics.

METHODS

Prospective cohort study in consecutive adult patients admitted between 03-2008 and 04-2021 to a tertiary referral centre with suspected AH. Diagnosis of AH was based on clinical presentation and confirmed by transjugular liver biopsy. All biopsies were assessed by a dedicated liver pathologist, blinded for clinical data and outcome. Diagnosis of ACLF was based on EASL-CLIF criteria. Histological and clinical characteristics of patients with and without ACLF at baseline were compared.

RESULTS

184 patients with biopsy-proven AH were enrolled. Median time from hospital admission to transjugular biopsy was 4.5 days (IQR 2-8). At baseline, ACLF was present in 73 patients (39.7%). Out of the 110 patients without ACLF at baseline, 30 (27.3%) developed ACLF within 28 days (median 7.5 days (IQR 2-20)). At baseline, ductular bilirubinostasis (DB) was the only histological feature significantly more frequently present in patients with ACLF compared to patients without ACLF (50.7% vs. 30.6%, p = 0.003). No clear association between histological features and the development of ACLF later on could be demonstrated.

CONCLUSIONS

In this well-defined cohort of patients with biopsy-proven AH, DB was associated with the presence of ACLF. This finding fits with the pathophysiology of this syndrome, which is characterized by systemic inflammation and an increased risk of infections.

Validation of NIAAAm-CRP criteria to predict alcohol-associated steatohepatitis on liver histology

Background & Aims

In clinical practice, the diagnosis of alcohol-associated hepatitis (AH) is mostly based on non-invasive criteria, which were defined at a consensus conference by the National Institute on Alcohol Abuse and Alcoholism (NIAAA). These criteria were recently modified by adding C-reactive protein (CRP) and termed NIAAAm-CRP criteria, which showed superior diagnostic accuracy for presence of alcohol-associated steatohepatitis (ASH) on liver histology. The aim of our study was to validate the diagnostic accuracy of both original NIAAA criteria and NIAAAm-CRP criteria for presence of ASH on liver histology in an independent cohort.

Methods

Data from a large multinational cohort of 445 patients with alcohol-associated liver disease (ALD) that served to establish a novel grading and staging system of alcohol-associated liver disease were analyzed retrospectively. Diagnosis of ASH was based on presence of hepatocyte ballooning plus lobular neutrophil infiltration and established in virtual consensus meetings of multiple expert liver pathologists.

Results

Complete data including CRP values were available in 346 patients. Overall diagnostic accuracy for prediction of ASH was 73% for NIAAA criteria and 77% for NIAAAm-CRP criteria. In a subgroup with suspected severe AH (MELD >20, n = 123), overall diagnostic accuracy for prediction of ASH was 69% for NIAAA criteria and 74% for NIAAAm-CRP criteria.

Conclusion

Our findings confirm recent data on suboptimal diagnostic accuracy of original NIAAA criteria and validate slightly better but still suboptimal performance of NIAAAm-CRP criteria for presence of ASH.

Impact and Implications

Alcohol-associated steatohepatitis (ASH) is diagnosed on liver histology but liver biopsy is not always feasible. Non-invasive diagnosis based on clinical findings has been proposed using the National Institute on Alcohol Abuse and Alcoholism (NIAAA) criteria and recently improved using NIAAAm-CRP criteria. Our findings validate slightly better but still suboptimal performance of NIAAAm-CRP criteria for the presence of histological ASH. Clinical trials of novel drugs should focus on histologically proven ASH.

Clinical criteria accurately diagnose severe but not moderate alcohol-associated hepatitis: A systematic review and meta-analysis

BACKGROUND

The precision of clinical criteria and the utility of liver biopsy for diagnosis or prognosis remain unclear in patients with alcohol-associated hepatitis (AH). We systematically reviewed the literature to answer these questions.

METHODS

Four databases were searched for studies describing the precision of clinical criteria (National Institute on Alcohol Abuse and Alcoholism, European Association for Study of Liver, or classical) and the role of histology in AH. The precision(positive predictive value) of criteria was pooled through random-effects meta-analysis, and its variation was investigated through subgroups and meta-regression of study-level factors with their percent contribution to variation (R2). The risk of bias among studies was evaluated through the QUADAS2 tool (PROSPERO-ID-CRD4203457250).

RESULTS

Of 4320 studies, 18 in the systematic review and 15 (10/5: low/high risk of bias, N=1639) were included in the meta-analysis. The pooled precision of clinical criteria was 80.2% (95% CI: 69.7-89.7, I2:93%, p < 0.01), higher in studies with severe AH (mean-Model for End-Stage Liver Disease > 20) versus moderate AH (mean-Model for End-Stage Liver Disease < 20): 92% versus 67.1%, p < 0.01, and in studies with serum bilirubin cutoff 5 versus 3 mg/dL (88.5% vs.78.8%, p = 0.01). The factors contributing to variation in precision were Model for End-Stage Liver Disease (R2:72.7%), upper gastrointestinal bleed (R2:56.3%), aspartate aminotransferase:aspartate aminotransferase ratio (R2:100%), clinical criteria (R2:40.9%), bilirubin (R2:22.5%), and Mallory body on histology (R2:19.1%).The net inter-pathologist agreement for histologic findings of AH was variable (0.33-0.97), best among 2 studies describing AH through simple and uniform criteria, including steatosis, ballooning, and neutrophilic inflammation. Few studies reported the utility of histology in estimating steroid responsiveness (N = 1) and patient prognosis (N = 4); however, very broad septa, pericellular fibrosis, and cholestasis were associated with mortality. Bilirubinostasis was associated with infection in 1 study.

CONCLUSIONS

Clinical criteria are reasonably precise for diagnosing severe AH, while there is an unmet need for better criteria for diagnosing moderate AH. Histologic diagnosis of AH should be simple and uniform.

Alcoholic Foamy Degeneration, an Entity Resembling Alcohol-Associated Hepatitis: Diagnosis, Prognosis, and Molecular Profiling

BACKGROUND & AIMS

Alcoholic foamy degeneration (AFD) is a condition with similar clinical presentation to alcohol-associated hepatitis (AH), but with a specific histologic pattern. Information regarding the prevalence and prognosis of AFD is scarce and there are no tools for a noninvasive diagnosis.

METHODS

A cohort of patients admitted to the Hospital Clinic of Barcelona for clinical suspicion of AH who underwent liver biopsy was included. Patients were classified as AFD, AH, or other findings, according to histology. Clinical features, histology, and genetic expression of liver biopsy specimens were analyzed. The accuracy of National Institute on Alcohol Abuse and Alcoholism criteria and laboratory parameters for differential diagnosis were investigated.

RESULTS

Of 230 patients with a suspicion of AH, 18 (8%) met histologic criteria for AFD, 184 (80%) had definite AH, and 28 (12%) had other findings. In patients with AFD, massive steatosis was more frequent and the fibrosis stage was lower. AFD was characterized by down-regulation of liver fibrosis and inflammation genes and up-regulation of lipid metabolism and mitochondrial function genes. Patients with AFD had markedly better long-term survival (100% vs 57% in AFD vs AH; P = .002) despite not receiving corticosteroid treatment, even in a model for end-stage liver disease-matched sensitivity analysis. Serum triglyceride levels had an area under the receiver operating characteristic of 0.886 (95% CI, 0.807-0.964) for the diagnosis of AFD, whereas the National Institute on Alcohol Abuse and Alcoholism criteria performed poorly. A 1-step algorithm using triglyceride levels of 225 mg/dL (sensitivity, 0.77; specificity, 0.90; and Youden index, 0.67) is proposed for differential diagnosis.

CONCLUSIONS

AFD in the setting of suspicion of AH is not uncommon. A differential diagnosis is important because prognosis and treatment differ largely. Triglyceride levels successfully identify most patients with AFD and may be helpful in decision making.

Alcohol-associated liver disease: Epidemiology and management

Alcohol is the leading cause of preventable liver morbidity and mortality worldwide, as it is also the most frequent cause of advanced liver disease. Alcohol-associated liver disease (ALD) covers different phenotypes ranging from steatosis to the development of inflammation (steatohepatitis), fibrosis and ultimately, in a proportion of patients, the development of liver cirrhosis and its associated complications. ALD has a complex pathogenesis that includes the interplay of both genetic and environmental factors, yet the precise mechanisms are largely unknown. Alcohol-associated hepatitis (AH) is a severe clinical presentation of ALD, which is characterized by abrupt jaundice and clinical decompensations of liver disease. AH occurs in a percentage of patients with underlying ALD and active alcohol consumption. Currently, there are no approved targeted therapies able to interfere in the pathogenesis of ALD and halt the progression of the disease, therefore alcohol abstinence is the most effective measure to improve prognosis in this patient population. In this regard, alcohol cessation remains the first-line treatment in all stages of alcohol disease. In patients with advanced ALD nonresponding to medical therapy, liver transplantation is the only approach that improves prognosis, and it should be considered in patients with decompensated cirrhosis. In the last years, AH has emerged as a new indication of early liver transplantation in non-responders to medical therapy, with promising results in highly selected patients. In this review, we provide an update on the epidemiology, risk factors, natural history, diagnosis, pathogenesis, and current treatments for ALD, taking into account the importance of assessing and managing alcohol consumption as the etiological factor and the main driver of prognosis in patients with ALD.

Human Precision-Cut Liver Slices: A Potential Platform to Study Alcohol-Related Liver Disease

Alcohol-related liver disease (ALD) encompasses a range of pathological conditions that are complex to study at the clinical and preclinical levels. Despite the global burden of ALD, there is a lack of effective treatments, and mortality is high. One of the reasons for the unsuccessful development of novel therapies is that experimental studies are hindered by the challenge of recapitulating this multifactorial disorder in vitro, including the contributions of hepatotoxicity, impaired lipid metabolism, fibrosis and inflammatory cytokine storm, which are critical drivers in the pathogenesis of ALD in patients and primary targets for drug development. Here, we present the unique characteristics of the culture of human precision-cut liver slices (PCLS) to replicate key disease processes in ALD. PCLS were prepared from human liver specimens and treated with ethanol alone or in combination with fatty acids and lipopolysaccharide (FA + LPS) for up to 5 days to induce hepatotoxic, inflammatory and fibrotic events associated with ALD. Alcohol insult induced hepatocyte death which was more pronounced with the addition of FA + LPS. This mixture showed a significant increase in the cytokines conventionally associated with the prototypical inflammatory response observed in severe ALD, and interestingly, alcohol alone exhibited a different effect. Profibrogenic activation was also observed in the slices and investigated in the context of slice preparation. These results support the versatility of this organotypic model to study different pathways involved in alcohol-induced liver damage and ALD progression and highlight the applicability of the PCLS for drug discovery, confirming their relevance as a bridge between preclinical and clinical studies.

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.

Hepatocyte-derived biomarkers predict liver-related events at 2 years in Child-Pugh class A alcohol-related cirrhosis

BACKGROUND & AIMS

In patients with compensated alcohol-related cirrhosis, reliable prognostic biomarkers are lacking. Keratin-18 and hepatocyte-derived large extracellular vesicle (lEV) concentrations reflect disease activity, but their ability to predict liver-related events is unknown.

METHODS

We measured plasma keratin-18 and hepatocyte lEV concentrations in 500 patients with Child-Pugh class A alcohol-related cirrhosis. The ability of these hepatocyte-derived biomarkers, alone or combined with model for end-stage liver disease (MELD) and FibroTest scores, to predict liver-related events at 2 years was analyzed, taking into account the alcohol consumption at inclusion and during follow-up.

RESULTS

Keratin-18 and hepatocyte lEV concentrations increased with alcohol consumption. In patients without active alcohol consumption at enrollment (n = 419), keratin-18 concentration predicted liver-related events at 2 years, independently of FibroTest and MELD. Patients with both keratin-18 concentrations >285 U/L and FibroTest >0.74 had a 24% cumulative incidence of liver-related events at 2 years, vs. 5% to 14% in other groups of patients. Similar results were obtained when combining keratin-18 concentrations >285 U/L with MELD >10. In patients with active alcohol consumption at enrollment (n = 81), hepatocyte lEVs predicted liver-related events at 2 years, independently of FibroTest and MELD. Patients with both hepatocyte lEV concentrations >50 U/L and FibroTest >0.74 had a 62% cumulative incidence of liver-related events at 2 years, vs. 8% to 13% in other groups of patients. Combining hepatocyte lEV concentrations >50 U/L with MELD >10 had a lower discriminative ability. Similar results were obtained when using decompensation of cirrhosis, defined according to Baveno VII criteria, as an endpoint.

CONCLUSION

In patients with Child-Pugh class A alcohol-related cirrhosis, combining hepatocyte-derived biomarkers with FibroTest or MELD scores identifies patients at high risk of liver-related events, and could be used for risk stratification and patient selection in clinical trials.

IMPACT AND IMPLICATIONS

In patients with compensated alcohol-related cirrhosis, reliable predictors of outcome are lacking. In patients with Child-Pugh class A alcohol-related cirrhosis, combining hepatocyte-derived biomarkers (keratin-18 and hepatocyte-large extracellular vesicles) with FibroTest or MELD scores identifies those at high risk of liver-related events at 2 years. The identified patients at high risk of liver-related events are the target-of-choice population for intensive surveillance (e.g., referral to tertiary care centers; intensive control of risk factors) and inclusion in clinical trials.

Management of alcoholic hepatitis: A clinical perspective

Alcohol-associated liver disease is the primary cause of liver-related mortality worldwide and one of the most common indications for liver transplantation. Alcoholic hepatitis represents the most acute and severe manifestation of alcohol-associated liver disease and is characterized by a rapid onset of jaundice with progressive inflammatory liver injury, worsening of portal hypertension, and an increased risk for multiorgan failure in patients with excessive alcohol consumption. Severe alcoholic hepatitis is associated with a poor prognosis and high short-term mortality. During the COVID-19 pandemic, rates of alcohol-associated hepatitis have increased significantly, underscoring that it is a serious and growing health problem. However, adequate management of alcohol-associated hepatitis and its complications in everyday clinical practice remains a major challenge. Currently, pharmacotherapy is limited to corticosteroids, although these have only a moderate effect on reducing short-term mortality. In recent years, translational studies deciphering key mechanisms of disease development and progression have led to important advances in the understanding of the pathogenesis of alcoholic hepatitis. Emerging pathophysiology-based therapeutic approaches include anti-inflammatory agents, modifications of the gut-liver axis and intestinal dysbiosis, epigenetic modulation, antioxidants, and drugs targeting liver regeneration. Concurrently, evidence is increasing that early liver transplantation is a safe treatment option with important survival benefits in selected patients with severe alcoholic hepatitis not responding to medical treatment. This narrative review describes current pathophysiology and management concepts of alcoholic hepatitis, provides an update on emerging treatment options, and focuses on the need for holistic and patient-centred treatment approaches to improve prognosis.

Molecular magnetic resonance imaging of liver inflammation using an oxidatively activated probe

Background & Aims

Many liver diseases are driven by inflammation, but imaging to non-invasively diagnose and quantify liver inflammation has been underdeveloped. The inflammatory liver microenvironment is aberrantly oxidising owing in part to reactive oxygen species generated by myeloid leucocytes. We hypothesised that magnetic resonance imaging using the oxidatively activated probe Fe-PyC3A will provide a non-invasive biomarker of liver inflammation.

Methods

A mouse model of drug-induced liver injury was generated through intraperitoneal injection of a hepatoxic dose of acetaminophen. A mouse model of steatohepatitis was generated via a choline-deficient, l-amino acid defined high-fat diet (CDAHFD). Images were acquired dynamically before and after intravenous injection of Fe-PyC3A. The contrast agent gadoterate meglumine was used as a non-oxidatively activated negative control probe in mice fed CDAHFD. The (post-pre) Fe-PyC3A injection change in liver vs. muscle contrast-to-noise ratio (ΔCNR) recorded 2 min post-injection was correlated with liver function test values, histologic scoring assigned using the NASH Clinical Research Network criteria, and intrahepatic myeloid leucocyte composition determined by flow cytometry.

Results

For mice receiving i.p. injections of acetaminophen, intrahepatic neutrophil composition correlated poorly with liver test values but positively and significantly with ΔCNR (r = 0.64, p <0.0001). For mice fed CDAHFD, ΔCNR generated by Fe-PyC3A in the left lobe was significantly greater in mice meeting histologic criteria strongly associated with a diagnosis NASH compared to mice where histology was consistent with likely non-NASH (p = 0.0001), whereas no differential effect was observed using gadoterate meglumine. In mice fed CDAHFD, ΔCNR did not correlate strongly with fractional composition of any specific myeloid cell subpopulation as determined by flow cytometry.

Conclusions

Magnetic resonance imaging using Fe-PyC3A merits further evaluation as a non-invasive biomarker for liver inflammation.

Impact and implications

Non-invasive tests to diagnose and measure liver inflammation are underdeveloped. Inflammatory cells such as neutrophils release reactive oxygen species which creates an inflammatory liver microenvironment that can drive chemical oxidation. We recently invented a new class of magnetic resonance imaging probe that is made visible to the scanner only after chemical oxidation. Here, we demonstrate how this imaging technology could be applied as a non-invasive biomarker for liver inflammation.

Ambiguous Pathogenic Roles of Macrophages in Alcohol-Associated Liver Diseases

Alcohol-associated liver disease (ALD) represents a major public health issue worldwide and is a leading etiology of liver cirrhosis. Alcohol-related liver injuries include a range of manifestations including alcoholic hepatitis (AH), simple steatosis, steatohepatitis, hepatic fibrosis, cirrhosis and liver cancer. Liver disease occurs from several pathological disturbances such as the metabolism of ethanol, which generates reactive oxygen species (ROS) in hepatocytes, alterations in the gut microbiota, and the immune response to these changes. A common hallmark of these liver affections is the establishment of an inflammatory environment, and some (broad) anti-inflammatory approaches are used to treat AH (eg, corticosteroids). Macrophages, which represent the main innate immune cells in the liver, respond to a wide variety of (pathogenic) stimuli and adopt a large spectrum of phenotypes. This translates to a diversity of functions including pathogen and debris clearance, recruitment of other immune cells, activation of fibroblasts, or tissue repair. Thus, macrophage populations play a crucial role in the course of ALD, but the underlying mechanisms driving macrophage polarization and their functionality in ALD are complex. In this review, we explore the various populations of hepatic macrophages in alcohol-associated liver disease and the underlying mechanisms driving their polarization. Additionally, we summarize the crosstalk between hepatic macrophages and other hepatic cell types in ALD, in order to support the exploration of targeted therapeutics by modulating macrophage polarization.

Steatotic Liver Disease: Metabolic Dysfunction, Alcohol, or Both?

Non-alcoholic fatty liver disease (NAFLD) and alcohol-related liver disease (ALD), both of them accounting for fatty liver disease (FLD), are among the most common chronic liver diseases globally, contributing to substantial public health burden. Both NAFLD and ALD share a similar picture of clinical presentation yet may have differences in prognosis and treatment, which renders early and accurate diagnosis difficult but necessary. While NAFLD is the fastest increasing chronic liver disease, the prevalence of ALD has seemingly remained stable in recent years. Lately, the term steatotic liver disease (SLD) has been introduced, replacing FLD to reduce stigma. SLD represents an overarching term to primarily comprise metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), as well as alcohol-related liver disease (ALD), and MetALD, defined as a continuum across which the contribution of MASLD and ALD varies. The present review discusses current knowledge on common denominators of NAFLD/MASLD and ALD in order to highlight clinical and research needs to improve our understanding of SLD.

Thermoneutral housing promotes hepatic steatosis in standard diet-fed C57BL/6N mice, with a less pronounced effect on NAFLD progression upon high-fat feeding

Introduction

Non-alcoholic fatty liver disease (NAFLD) can progress to more severe stages, such as steatohepatitis and fibrosis. Thermoneutral housing together with high-fat diet promoted NAFLD progression in C57BL/6J mice. Due to possible differences in steatohepatitis development between different C57BL/6 substrains, we examined how thermoneutrality affects NAFLD progression in C57BL/6N mice.

Methods

Male mice were fed standard or high-fat diet for 24 weeks and housed under standard (22°C) or thermoneutral (30°C) conditions.

Results

High-fat feeding promoted weight gain and hepatic steatosis, but the effect of thermoneutral environment was not evident. Liver expression of inflammatory markers was increased, with a modest and inconsistent effect of thermoneutral housing; however, histological scores of inflammation and fibrosis were generally low (<1.0), regardless of ambient temperature. In standard diet-fed mice, thermoneutrality increased weight gain, adiposity, and hepatic steatosis, accompanied by elevated de novo lipogenesis and changes in liver metabolome characterized by complex decreases in phospholipids and metabolites involved in urea cycle and oxidative stress defense.

Conclusion

Thermoneutrality appears to promote NAFLD-associated phenotypes depending on the C57BL/6 substrain and/or the amount of dietary fat.

Serum keratin 18-M65 levels detect progressive forms of alcohol-associated liver disease in early noncirrhotic stages

BACKGROUND AND AIMS

The progression of alcohol-associated liver disease (ALD) in its early precirrhotic stages can be a silent process. Serum keratin 18 levels (K18-M65) predict severe events and mortality in advanced stages of ALD, but data on this biomarker in early stages are scarce. We evaluated the diagnostic accuracy of K18-M65 levels in identifying early forms of ALD.

METHODS

We prospectively evaluated two cohorts of actively drinking patients with alcohol use disorder (AUD) following a rehabilitation program (training (n = 162) and validation (n = 78)) and matched healthy controls (n = 21). Clinical, laboratory, and imaging data were used to distinguish AUD patients with simple steatosis (minimal ALD) and steatohepatitis/fibrosis (early ALD). We measured serum K18-M65 levels and assessed their ability to predict early ALD.

RESULTS

High levels of K18-M65 characterized AUD patients with early ALD, while levels in the minimal ALD group were similar to those in healthy controls. K18-M65 levels distinguished minimal liver disease from early ALD (AUROC = 0.8704; p < 0.0001) with an optimal cutoff at 265.9 U/L. K18-M65 levels strongly correlated with transaminases and predicted early ALD (OR 25.81; 95% CI 3.166-336.1; p < 0.0001), controlled attenuation parameter, and liver stiffness independently from transaminases and other potential confounders. K18-M65 levels did not discriminate between fibrosis and steatohepatitis but correlated with histological signs of hepatocellular injury and inflammation (all p < 0.05). The K18-M65 cutoff detected early ALD in the validation cohort with high accuracy (sensitivity 86.67%, specificity 96.67%) and a very high positive likelihood ratio (28.6; 95% CI 4.14-197.73).

CONCLUSIONS

Serum K18-M65 levels can be used as a biomarker to detect early ALD stages with excellent predictive value.

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.

Toll-like receptor 2 activation in monocytes contributes to systemic inflammation and alcohol-associated liver disease in humans

BACKGROUND AND RATIONALE

In the context of gut leakiness and translocation of microbial products in alcohol-associated liver disease (ALD), it is possible that systemic and liver inflammation involve the activation of circulating monocyte through gut-derived factors. We explored the association between monocytes, microbial translocation, systemic inflammation, and ALD.

METHODS

Patients with alcohol use disorder following a rehabilitation program were compared with healthy controls. We determined the circulating number and proportion of monocyte subsets by FACS. The activation of signaling pathways by gut-derived microbes was analyzed by quantitative PCR in isolated monocytes. Cytokines secretion by monocytes and phagocytosis were assessed in vitro. Serum microbial translocation markers and cytokines were measured by ELISA and multiplex assay, respectively. ALD severity and liver inflammatory responses were analyzed in liver biopsies by various methods.

RESULTS

In patients with alcohol use disorder, the number of blood monocytes increased compared with controls. Monocytes from patients with alcohol use disorder upregulated IL-1β and IL-8 together with toll-like receptor 2 and downstream AP-1, while fungal sensor CARD9 was downregulated. IL-1β and IL-8 were actively secreted upon stimulation in vitro with the toll-like receptor 2 ligand peptidoglycan. Exposure with Escherichia coli confirmed preserved bacterial phagocytic activity. In contrast, Candida albicans stimulation leads to downregulation of IL-1β and TNFα compared with controls. Systemic cytokines and monocyte changes correlated with microbial translocation. Hepatic IL-1β and IL-8 increased with ALD severity together with liver macrophage activation and upregulation of chemokines involved in monocyte attraction.

CONCLUSIONS

Our results point to the contribution of activated monocytes to systemic inflammation and ALD. Monocytes likely infiltrate the liver, transform into monocyte-derived macrophages and release IL-1β and IL-8 in response to peptidoglycan and toll-like receptor 2 activation.

Fatty Liver Disease, Metabolism and Alcohol Interplay: A Comprehensive Review

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide, and its incidence has been increasing in recent years because of the high prevalence of obesity and metabolic syndrome in the Western population. Alcohol-related liver disease (ArLD) is the most common cause of cirrhosis and constitutes the leading cause of cirrhosis-related deaths worldwide. Both NAFLD and ArLD constitute well-known causes of liver damage, with some similarities in their pathophysiology. For this reason, they can lead to the progression of liver disease, being responsible for a high proportion of liver-related events and liver-related deaths. Whether ArLD impacts the prognosis and progression of liver damage in patients with NAFLD is still a matter of debate. Nowadays, the synergistic deleterious effect of obesity and diabetes is clearly established in patients with ArLD and heavy alcohol consumption. However, it is still unknown whether low to moderate amounts of alcohol are good or bad for liver health. The measurement and identification of the possible synergistic deleterious effect of alcohol consumption in the assessment of patients with NAFLD is crucial for clinicians, since early intervention, advising abstinence and controlling cardiovascular risk factors would improve the prognosis of patients with both comorbidities. This article seeks to perform a comprehensive review of the pathophysiology of both disorders and measure the impact of alcohol consumption in patients with NAFLD.

The circadian rhythm gene Bmal1 ameliorates acute deoxynivalenol-induced liver damage

Deoxynivalenol (DON) is widely emerging in various grain crops, milk, and wine products, which can trigger different toxic effects on humans and animals by inhalation or ingestion. It also imposes a considerable financial loss on the agriculture and food industry each year. Previous studies have reported acute and chronic toxicity of DON in liver, and liver is not only the main detoxification organ for DON but also the circadian clock oscillator directly or indirectly regulates critical physiologically hepatic functions under different physiological and pathological conditions. However, researches on the association of circadian rhythm in DON-induced liver damage are limited. In the present study, mice were divided into four groups (CON, DON, Bmal1^OE, and Bmal1^OE + DON) and AAV8 was used to activate (Bmal1) expression in liver. Then mice were gavaged with 5 mg/kg bw/day DON or saline at different time points (ZT24 = 0, 4, 8, 12, 16, and 20 h) in 1 day and were sacrificed 30 min after oral gavage. The inflammatory cytokines, signal transducers, and activators of transcription Janus kinase/signal transducers and activator of transcription 3 (JAKs/STAT3) pathway and bile acids levels were detected by enzyme-linked immunosorbent assay (ELISA), western blotting, and target metabolomics, respectively. The DON group showed significantly elevated interleukin-1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) levels (P < 0.05 for both) and impaired liver function with rhythm disturbances compared to the CON and Bmal1^OE groups. At the molecular level, expressions of some circadian clock proteins were significantly downregulated (P < 0.05 for both) and JAKs/STAT3 pathway was activated during DON exposure, accompanied by indicated circadian rhythm disturbance and inflammatory damage. Importantly, Bmal1 overexpression attenuated DON-induced liver damage, while related hepatic bile acids such as cholic acid (CA) showed a decreasing trend in the DON group compared with the CON group. Our study demonstrates a novel finding that Bmal1 plays a critical role in attenuating liver damage by inhibiting inflammatory levels and maintaining bile acids levels under the DON condition. Therefore, Bmal1 may also be a potential molecular target for reducing the hepatotoxic effects of DON in future studies.

Patients with a History of Bariatric Surgery Are 8 Years Younger at Presentation with Severe Alcoholic Hepatitis

PURPOSE

Patients with prior bariatric surgery (BS) are at risk to develop alcohol use disorder (AUD) and alcohol-related liver disease (ALD). Severe alcoholic hepatitis (sAH) is one of the most severe manifestations of ALD with a 28-day mortality of 20-50%. The impact of prior BS on patients presenting with sAH was assessed.

METHODS

From 01/2008 to 04/2021, consecutive patients admitted to a tertiary referral center with biopsy-proven sAH were included in a database.

RESULTS

One hundred fifty-eight sAH patients of which 28 patients had a history of BS (BS group) were identified. Of this BS group, 24 patients underwent a Roux-en-Y gastric bypass (RYGB), 3 a biliopancreatic diversion, 1 an adjustable gastric band, and no patients a sleeve gastrectomy. The proportion of patients with BS increased threefold over time during the study period. Patients in the BS group were significantly younger at diagnosis of sAH (44.3 years vs 52.4 years), were more frequently female, and had a higher body mass index and a higher grade of steatosis on liver biopsy. The correlation between BS and a younger age at diagnosis remained significant in a multivariate regression analysis. There were no differences in disease severity between both groups. Furthermore, there were no differences in corticosteroid response, 28-day, 90-day, or 1-year survival.

CONCLUSION

Prior BS is independently associated with a younger age of presentation with sAH, but is not independently associated with a different disease severity or outcome. These findings support the need for early detection of AUD in patients who underwent BS, in particular RYGB.

Spectrum, Screening, and Diagnosis of Alcohol-related Liver Disease

Alcohol-related liver disease (ALD) represents one of the leading causes of chronic liver disease and is a major cause of liver-related deaths worldwide. ALD encompasses a range of disorders including simple steatosis, alcoholic steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Patients with underlying ALD and continued heavy alcohol consumption can also develop an episode of acute-on-chronic liver injury called alcohol-associated hepatitis, the most severe form of the disease, which portends a poor prognosis. The most important risk factor for the development of ALD is the amount of alcohol consumed. Individual susceptibility to progression to advanced fibrosis among heavy drinkers is likely determined by a combination of behavioral, environmental, genetic, and epigenetic factors, but the mechanisms are largely unknown. The only effective therapy for ALD is prolonged alcohol abstinence. Diagnosis of ALD involves assessing patients for alcohol use disorder and signs of advanced liver disease. In clinical practice, the histological assessment for ALD diagnosis is uncommon, and it is usually based on the medical history, clinical manifestations, and laboratory and imaging tests. Several promising biomarkers that can have both diagnostic and prognostic value in patients with ALD have been identified in recent years. This review provides an overview of the clinical spectrum of ALD, the diagnostic approach of the disease from different perspectives as well as current diagnostic and prognostic biomarkers.

Subclinical versus advanced forms of alcohol-related liver disease: Need for early detection

Alcohol-related liver disease (ALD) consists of a wide spectrum of clinical manifestations and pathological features, ranging from asymptomatic patients to decompensated cirrhosis and hepatocellular carcinoma. Patients with heavy alcohol intake and advanced fibrosis often develop a subacute form of liver failure called alcohol-induced hepatitis (AH). Globally, most patients with ALD are identified at late stages of the disease, limiting therapeutic interventions. Thus, there is a need for early detection of ALD patients, which is lacking in most countries. The identification of alcohol misuse is hampered by the existence of alcohol underreporting by many patients. There are useful biomarkers that can detect recent alcohol use. Moreover, there are several non-invasive techniques to assess the presence of advanced fibrosis among patients with alcohol misuse, which could identify patients at high risk of liver related events or early death. In this review, we discuss differences between early stages of ALD and AH as the cornerstone of advanced forms. A global overview of epidemiological, anthropometric, clinical, analytical, histological, and molecular differences is summarized in this article. We propose that campaigns aimed at identifying patients with subclinical forms can prevent the development of life-threatening forms.

Screening for Liver Fibrosis in the General Population: Where Do We Stand in 2022?

Approximately 30% of the worldwide population has at least one risk factor for liver disease. Identifying advanced liver disease before the occurrence of complications remains a difficult challenge in clinical practice, where diagnosis comes too late for many patients, at the time of liver decompensation or palliative hepatocellular carcinoma, with poor short-term prognosis. Noninvasive, blood- or elastography-based tests of liver fibrosis (NITs) have been developed for the early diagnosis of advanced liver fibrosis. Recent population-based studies evaluating the screening of liver fibrosis with these NITs have provided important information on at-risk groups that should be targeted. New measures based on the sequential use of NITs help to better organize the referral of at-risk patients to the liver specialist. However, energizing these measures will require increased awareness of both chronic liver diseases and the use of NITs among non-specialists.

Noninvasive proteomic biomarkers for alcohol-related liver disease

Alcohol-related liver disease (ALD) is a major cause of liver-related death worldwide, yet understanding of the three key pathological features of the disease-fibrosis, inflammation and steatosis-remains incomplete. Here, we present a paired liver-plasma proteomics approach to infer molecular pathophysiology and to explore the diagnostic and prognostic capability of plasma proteomics in 596 individuals (137 controls and 459 individuals with ALD), 360 of whom had biopsy-based histological assessment. We analyzed all plasma samples and 79 liver biopsies using a mass spectrometry (MS)-based proteomics workflow with short gradient times and an enhanced, data-independent acquisition scheme in only 3 weeks of measurement time. In plasma and liver biopsy tissues, metabolic functions were downregulated whereas fibrosis-associated signaling and immune responses were upregulated. Machine learning models identified proteomics biomarker panels that detected significant fibrosis (receiver operating characteristic-area under the curve (ROC-AUC), 0.92, accuracy, 0.82) and mild inflammation (ROC-AUC, 0.87, accuracy, 0.79) more accurately than existing clinical assays (DeLong's test, P < 0.05). These biomarker panels were found to be accurate in prediction of future liver-related events and all-cause mortality, with a Harrell's C-index of 0.90 and 0.79, respectively. An independent validation cohort reproduced the diagnostic model performance, laying the foundation for routine MS-based liver disease testing.

Increase in Serum MMP-9 and TIMP-1 Concentrations during Alcohol Intoxication in Adolescents-A Preliminary Study

Background: Alcohol consumption by adolescents is responsible for a number of adverse health and social outcomes. Despite the well-established effect of alcohol use on the development of alcoholic liver disease, the relationship between the pattern of alcohol consumption and liver fibrosis is still unclear. This study is a follow-up to work on liver damage from alcohol intoxication. The aim of our study was to explore the early effects of alcohol intoxication on liver fibrosis in adolescents. Methods: The prospective study included 57 adolescents aged 14−17 years admitted to the emergency department (ED) from February 2017 to June 2018 due to acute alcohol intoxication. Serum levels of amino terminal propeptide of type III procollagen (PIIINP), type IV collagen, matrix metallopeptidase 9 (MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1) were determined by enzyme-linked immunosorbent assays. Results: There were significant differences in MMP-9 (p = 0.02) and TIMP-1 (p = 0.007) levels between the study and control groups. Liver parameters and selected markers of fibrosis were similar in groups in terms of blood alcohol concentrations (BAC). MMP-9 was positively correlated with alanine aminotransferase (ALT) (r = 0.38; p = 0.004) and total bilirubin (r = 0.39; p = 0.004). Positive significant correlations were also found between TIMP-1 and ALT (r = 0.47; p < 0.001), AST (r = 0.29; p = 0.03) and total bilirubin (r = 0.32; p = 0.02). In receiver operating characteristic (ROC) analysis, MMP-9 (AUC = 0.67, p = 0.02) and TIMP-1 (AUC = 0.69, p = 0.003) allowed for the differentiation of patients with and without alcohol intoxication. Conclusion: Our results show that even a single episode of alcohol intoxication in adolescents can lead to imbalance in markers of fibrosis.

The purinergic P2Y14 receptor links hepatocyte death to hepatic stellate cell activation and fibrogenesis in the liver

Fibrosis contributes to ~45% of deaths in western countries. In chronic liver disease, fibrosis is a major factor determining outcomes, but efficient antifibrotic therapies are lacking. Although platelet-derived growth factor and transforming growth factor-β constitute key fibrogenic mediators, they do not account for the well-established link between cell death and fibrosis in the liver. Here, we hypothesized that damage-associated molecular patterns (DAMPs) may link epithelial cell death to fibrogenesis in the injured liver. DAMP receptor screening identified purinergic receptor P2Y14 among several candidates as highly enriched in hepatic stellate cells (HSCs), the main fibrogenic cell type of the liver. Conversely, P2Y14 ligands uridine 5'-diphosphate (UDP)-glucose and UDP-galactose were enriched in hepatocytes and were released upon different modes of cell death. Accordingly, ligand-receptor interaction analysis that combined proteomic and single-cell RNA sequencing data revealed P2Y14 ligands and P2Y14 receptor as a link between dying cells and HSCs, respectively. Treatment with P2Y14 ligands or coculture with dying hepatocytes promoted HSC activation in a P2Y14-dependent manner. P2Y14 ligands activated extracellular signal-regulated kinase (ERK) and Yes-associated protein (YAP) signaling in HSCs, resulting in ERK-dependent HSC activation. Global and HSC-selective P2Y14 deficiency attenuated liver fibrosis in multiple mouse models of liver injury. Functional expression of P2Y14 was confirmed in healthy and diseased human liver and human HSCs. In conclusion, P2Y14 ligands and their receptor constitute a profibrogenic DAMP pathway that directly links cell death to fibrogenesis.

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.