A phase II, multicenter, open-label, randomized trial of pegfilgrastim for patients with alcohol-associated hepatitis

Inflammation in Alcohol-Associated Hepatitis: Pathogenesis and Therapeutic Targets

Alcohol-associated hepatitis (AH) is an acute-on-chronic liver injury that occurs in patients with chronic alcohol-associated liver disease (ALD). Patients with severe AH have high short-term mortality and lack effective pharmacologic therapies. Inflammation is believed to be one of the key factors promoting AH progression and has been actively investigated as therapeutic targets over the last several decades, but no effective inflammatory targets have been identified so far. In this review, we discuss how inflammatory cells and the inflammatory mediators produced by these cells contribute to the development and progression of AH, with focus on neutrophils and macrophages. The crosstalk between inflammatory cells and liver nonparenchymal cells in the pathogenesis of AH is elaborated. We also deliberate the application of recent cutting-edge technologies in characterizing liver inflammation in AH. Finally, the potential therapeutic targets of inflammatory mediators for AH are briefly summarized.

Steroid responsiveness in alcohol-associated hepatitis is linked to glucocorticoid metabolism, mitochondrial repair, and heat shock proteins

BACKGROUND

Alcohol-associated hepatitis (AH) is one of the clinical presentations of alcohol-associated liver disease. AH has poor prognosis, and corticosteroids remain the mainstay of drug therapy. However, ~40% of patients do not respond to this treatment, and the mechanisms underlying the altered response to corticosteroids are not understood. The current study aimed to identify changes in hepatic protein expression associated with responsiveness to corticosteroids and prognosis in patients with AH.

METHODS

Patients with AH were enrolled based on the National Institute on Alcohol Abuse and Alcoholism inclusion criteria for acute AH and further confirmed by a diagnostic liver biopsy. Proteomic analysis was conducted on liver samples acquired from patients with AH grouped as nonresponders (AH-NR, n = 7) and responders (AH-R, n = 14) to corticosteroids, and nonalcohol-associated liver disease controls (n = 10). The definition of responders was based on the clinical prognostic model, the Lille Score, where a score < 0.45 classified patients as AH-R and a score > 0.45 as AH-NR. Primary outcomes used to assess steroid response were Lille Score (eg, improved liver function) and survival at 24 weeks.

RESULTS

Reduced levels of the glucocorticoid receptor and its transcriptional co-activator, glucocorticoid modulatory element-binding protein 2, were observed in the hepatic proteome of AH-NR versus AH-R. The corticosteroid metabolizing enzyme, 11-beta-hydroxysteroid dehydrogenase 1, was increased in AH-NR versus AH-R along with elevated mitochondrial DNA repair enzymes, while several proteins of the heat shock pathway were reduced. Analysis of differentially expressed proteins in AH-NR who survived 24 weeks relative to AH-NR nonsurvivors revealed several protein expression changes, including increased levels of acute phase proteins, elevated coagulation factors, and reduced mast cell markers.

CONCLUSIONS

This study identified hepatic proteomic changes that may predict responsiveness to corticosteroids and mortality in patients with AH.

Alcohol-associated liver disease

Alcohol-associated liver disease (ALD) is a major cause of chronic liver disease worldwide, and comprises a spectrum of several different disorders, including simple steatosis, steatohepatitis, cirrhosis, and superimposed hepatocellular carcinoma. Although tremendous progress has been made in the field of ALD over the last 20 years, the pathogenesis of ALD remains obscure, and there are currently no FDA-approved drugs for the treatment of ALD. In this Review, we discuss new insights into the pathogenesis and therapeutic targets of ALD, utilizing the study of multiomics and other cutting-edge approaches. The potential translation of these studies into clinical practice and therapy is deliberated. We also discuss preclinical models of ALD, interplay of ALD and metabolic dysfunction, alcohol-associated liver cancer, the heterogeneity of ALD, and some potential translational research prospects for ALD.

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.

Past, Present, and Future Therapies for Alcohol-associated Hepatitis

PURPOSE

Alcohol-associated hepatitis (AH) is a unique presentation of cholestatic steatohepatitis with liver dysfunction and malaise preceded by heavy alcohol intake. Although AH exists on a spectrum, in its most severe form, 28-day mortality approaches 50%. Clinical trials of therapeutic interventions over the last 50 years have yielded few durable therapies, none of which convey benefit beyond the short term.

METHODS

A qualitative systematic review was performed via searches of PubMed, the International Clinical Trials Registry Platform, and ClinicalTrials.gov for therapeutic interventions for AH.

FINDINGS

Prior to 2005, clinical trial results for AH were identified within PubMed. From 2005 to the present, trials were well catalogued within online registries and included information regarding trial status (eg, complete, terminated, actively enrolling). Most clinical trials for AH have used existing medications broadly targeting pathogenic themes of AH (eg, inflammation, cell death) in an off-label manner. The trend of initially promising pilot studies answered by larger trials showing lack of efficacy or safety signals have ended the hopes of many new therapeutics. The emergence of theragnostics to identify patients who may benefit from existing therapies and trials of agents with novel mechanisms of action, including epigenetic modifications and hyaluronic acid signaling targeted to AH pathogenesis, are currently under investigation.

IMPLICATIONS

This review of AH treatments details the historical interventions and clinical trials that have led to the current treatment algorithm and active studies shaping the therapeutic pipeline for AH.

The role of neutrophils in alcohol-related hepatitis

Alcohol-related liver disease is a major cause of liver disease-associated mortality, with inpatient care being a major contributor to its clinical and economic burden. Alcohol-related hepatitis (AH) is an acute inflammatory form of alcohol-related liver disease. Severe AH is associated with high short-term mortality, with infection being a common cause of death. The presence of AH is associated with increased numbers of circulating and hepatic neutrophils. We review the literature on the role of neutrophils in AH. In particular, we explain how neutrophils are recruited to the inflamed liver and how their antimicrobial functions (chemotaxis, phagocytosis, oxidative burst, NETosis) may be altered in AH. We highlight evidence for the existence of 'high-density' and 'low-density' neutrophil subsets. We also describe the potentially beneficial roles of neutrophils in the resolution of injury in AH through their effects on macrophage polarisation and hepatic regeneration. Finally, we discuss how manipulation of neutrophil recruitment/function may be used as a therapeutic strategy in AH. For example, correction of gut dysbiosis in AH could help to prevent excess neutrophil activation, or treatments could aim to enhance miR-223 function in AH. The development of markers that can reliably distinguish neutrophil subsets and of animal models that accurately reproduce human disease will be crucial for facilitating translational research in this important field.

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.

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.