Active alcohol consumption is associated with acute-on-chronic liver failure in Hispanic patients

Review article: Current indications and selection criteria for early liver transplantation in severe alcohol-associated hepatitis

BACKGROUND

Alcohol-associated hepatitis (AH) is a severe inflammatory form of alcohol-associated liver disease (ALD) that carries a high mortality rate. Early liver transplantation for severe AH is increasingly available. However, specific criteria for referral and selection remain a subject of debate.

AIMS

To provide a narrative review of the natural history, diagnostic criteria and indications for referral for early liver transplantation for severe AH.

METHODS

We searched PubMed for articles published through August 2023. Key search terms were 'alcoholic hepatitis,' 'alcohol-associated hepatitis,' 'abstinence,' 'alcohol relapse,' and 'liver transplantation.'

RESULTS

Previously, a six-month period of alcohol abstinence was required before patients with ALD were considered for liver transplantation. However, studies in recent years have demonstrated that, among carefully selected patients, patients who received early transplants have much higher survival rates than patients with similarly severe disease who did not undergo transplants (77% vs. 23%). Despite these successes, early liver transplantation remains controversial, as these patients have typically not undergone treatment for alcohol use disorder, with the ensuing risk of returning to alcohol use.

CONCLUSIONS

While early liver transplantation for AH has survival benefits, many patients would not have received treatment for alcohol use disorder. An integrated approach to evaluating candidacy for early liver transplantation is needed.

New insights into the molecular basis of alcohol abstinence and relapse in alcohol-associated liver disease

Alcohol use disorder remains a significant public health concern, affecting around 5% of adults worldwide. Novel pathways of damage have been described during the last years, providing insight into the mechanism of injury due to alcohol misuse beyond the direct effect of ethanol byproducts on the liver parenchyma and neurobehavioral mechanisms. Thus, the gut-liver-brain axis and immune system involvement could be therapeutic targets for alcohol use disorder. In particular, changes in gut microbiota composition and function, and bile acid homeostasis, have been shown with alcohol consumption and cessation. Alcohol can also directly disrupt intestinal and blood-brain barriers. Activation of the immune system can be triggered by intestinal barrier dysfunction and translocation of bacteria, pathogen-associated molecular patterns (such as lipopolysaccharide), cytokines, and damage-associated molecular patterns. These factors, in turn, promote liver and brain inflammation and the progression of liver fibrosis. Other involved mechanisms include oxidative stress, apoptosis, autophagy, and the release of extracellular vesicles and miRNA from hepatocytes. Potential therapeutic targets include gut microbiota (probiotics and fecal microbiota transplantation), neuroinflammatory pathways, as well as neuroendocrine pathways, for example, the ghrelin system (ghrelin receptor blockade), incretin mimetics (glucagon-like peptide-1 analogs), and the mineralocorticoid receptor system (spironolactone). In addition, support with psychological and behavioral treatments is essential to address the multiple dimensions of alcohol use disorder. In the future, a personalized approach considering these novel targets can contribute to significantly decreasing the alcohol-associated burden of disease.