Alcoholic hepatitis: a clinician's guide

Loss of GCN5L1 exacerbates damage in alcoholic liver disease through ferroptosis activation

BACKGROUND AND AIMS

Iron overload, oxidative stress and ferroptosis are associated with liver injury in alcohol-associated liver disease (ALD), however, the crosstalk among these regulatory pathways in ALD development is unclear.

METHODS

ALD mouse model and general control of amino acid synthesis 5 like 1 (GCN5L1) liver knockout mice were generated to investigate the role of GCN5L1 in ALD development. Proteomic screening tests were performed to identify the key factors mediating GCN5L1 loss-induced ALD.

RESULTS

Gene Expression Omnibus data set analysis indicates that GCN5L1 expression is negatively associated with ALD progression. GCN5L1 hepatic knockout mice develop severe liver injury and lipid accumulation when fed an alcohol diet. Screening tests identified that GCN5L1 targeted the mitochondrial iron transporter CISD1 to regulate mitochondrial iron homeostasis in ethanol-induced ferroptosis. GCN5L1-modulated CISD1 acetylation and activity were crucial for iron accumulation and ferroptosis in response to alcohol exposure.

CONCLUSION

Pharmaceutical modulation of CISD1 activity is critical for cellular iron homeostasis and ethanol-induced ferroptosis. The GCN5L1/CISD1 axis is crucial for oxidative stress and ethanol-induced ferroptosis in ALD and is a promising avenue for novel therapeutic strategies.

High-Acuity Alcohol-Related Complications During the COVID-19 Pandemic

Importance

Research has demonstrated an association between the COVID-19 pandemic and increased alcohol-related liver disease hospitalizations and deaths. However, trends in alcohol-related complications more broadly are unclear, especially among subgroups disproportionately affected by alcohol use.

Objective

To assess trends in people with high-acuity alcohol-related complications admitted to the emergency department, observation unit, or hospital during the COVID-19 pandemic, focusing on demographic differences.

Design, Setting, and Participants

This longitudinal interrupted time series cohort study analyzed US national insurance claims data using Optum's deidentified Clinformatics Data Mart database from March 2017 to September 2021, before and after the March 2020 COVID-19 pandemic onset. A rolling cohort of people 15 years and older who had at least 6 months of continuous commercial or Medicare Advantage coverage were included. Subgroups of interest included males and females stratified by age group. Data were analyzed from April 2023 to January 2024.

Exposure

COVID-19 pandemic environment from March 2020 to September 2021.

Main Outcomes and Measures

Differences between monthly rates vs predicted rates of high-acuity alcohol-related complication episodes, determined using claims-based algorithms and alcohol-specific diagnosis codes. The secondary outcome was the subset of complication episodes due to alcohol-related liver disease.

Results

Rates of high-acuity alcohol-related complications were statistically higher than expected in 4 of 18 pandemic months after March 2020 (range of absolute and relative increases: 0.4-0.8 episodes per 100 000 people and 8.3%-19.4%, respectively). Women aged 40 to 64 years experienced statistically significant increases in 10 of 18 pandemic months (range of absolute and relative increases: 1.3-2.1 episodes per 100 000 people and 33.3%-56.0%, respectively). In this same population, rates of complication episodes due to alcohol-related liver disease increased above expected in 16 of 18 pandemic months (range of absolute and relative increases: 0.8-2.1 episodes per 100 000 people and 34.1%-94.7%, respectively).

Conclusions and Relevance

In this cohort study of a national, commercially insured population, high-acuity alcohol-related complication episodes increased beyond what was expected in 4 of 18 COVID-19 pandemic months. Women aged 40 to 64 years experienced 33.3% to 56.0% increases in complication episodes in 10 of 18 pandemic months, a pattern associated with large and sustained increases in high-acuity alcohol-related liver disease complications. Findings underscore the need for increased attention to alcohol use disorder risk factors, alcohol use patterns, alcohol-related health effects, and alcohol regulations and policies, especially among women aged 40 to 64 years.

Targeting Endoplasmic Reticulum Stress as an Effective Treatment for Alcoholic Pancreatitis

Pancreatitis and alcoholic pancreatitis are serious health concerns with an urgent need for effective treatment strategies. Alcohol is a known etiological factor for pancreatitis, including acute pancreatitis (AP) and chronic pancreatitis (CP). Excessive alcohol consumption induces many pathological stress responses; of particular note is endoplasmic reticulum (ER) stress and adaptive unfolded protein response (UPR). ER stress results from the accumulation of unfolded/misfolded protein in the ER and is implicated in the pathogenesis of alcoholic pancreatitis. Here, we summarize the possible mechanisms by which ER stress contributes to alcoholic pancreatitis. We also discuss potential approaches targeting ER stress and UPR in developing novel therapeutic strategies for the disease.

Liver and Biliary Disease of Pregnancy and Anesthetic Implications: A Review

Liver and biliary disease complicates pregnancy in varying degrees of severity to the mother and fetus, and anesthesiologists may be asked to assist in caring for these patients before, during, and after birth of the fetus. Therefore, it is important to be familiar with how different liver diseases impact the pregnancy state. In addition, knowing symptoms, signs, and laboratory markers in the context of a pregnant patient will lead to faster diagnosis and treatment of such patients. This review article discusses changes in physiology of parturients, patients with liver disease, and parturients with liver disease. Next, general treatment of parturients with acute and chronic liver dysfunction is presented. The article progresses to specific liver diseases with treatments as they relate to pregnancy. And finally, important aspects to consider when anesthetizing parturients with liver disease are discussed.

Experimental models of metabolic and alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multi-systemic disease that is considered the hepatic manifestation of metabolic syndrome (MetS). Because alcohol consumption in NAFLD patients is common, there is a significant overlap in the pathogenesis of NAFLD and alcoholic liver disease (ALD). Indeed, MetS also significantly contributes to liver injury in ALD patients. This “syndrome of metabolic and alcoholic steatohepatitis” (SMASH) is thus expected to be a more prevalent presentation in liver patients, as the obesity epidemic continues. Several pre-clinical experimental models that couple alcohol consumption with NAFLD-inducing diet or genetic obesity have been developed to better understand the pathogenic mechanisms of SMASH. These models indicate that concomitant MetS and alcohol contribute to lipid dysregulation, oxidative stress, and the induction of innate immune response. There are significant limitations in the applicability of these models to human disease, such as the ability to induce advanced liver injury or replicate patterns in human food/alcohol consumption. Thus, there remains a need to develop models that accurately replicate patterns of obesogenic diet and alcohol consumption in SMASH patients.

Acute-on-chronic liver failure: to admit to intensive care or not?

Acute-on-chronic liver failure is used to describe an acute decline in liver function in a patient with existing liver disease combined with other organ failure. Acute-on-chronic liver failure is associated with high short-term mortality, and the greater the number and severity of organ failures, the higher the mortality. The most commonly identified precipitants of acute-on-chronic liver failure include bacterial infection, gastrointestinal haemorrhage, viral hepatitis and recent excessive alcohol intake. Since some of these aetiologies are treatable, organ failure may return to pre-decompensation levels in up to 55% of patients. As a result, a trial of critical care treatment may be appropriate for many of these patients. Clinical scoring tools may help clinicians recognise futility, allowing timely withdrawal of organ support and shifting the focus of care toward palliation.

Label‑free quantitative proteomics and bioinformatics analyses of alcoholic liver disease in a chronic and binge mouse model

As a significant cause of mortality and morbidity, alcoholic liver disease (ALD) has been widely investigated. However, little is known about the underlying metabolic mechanisms involved in the complicated pathological processes of ALD. The present study used label‑free quantitative proteomics and bioinformatics analyses to investigate the differentially expressed proteins (DEPs) and their functions in the livers of alcohol‑feed (AF) and control pair‑feed (PF) mice. As a result, 87 upregulated DEPs and 133 downregulated DEPs were identified in AF liver tissues compared with PF livers. Gene ontology and Kyoto encyclopedia of genes and genomes bioinformatics analyses demonstrated that the DEPs were significantly enriched in 'protein binding', 'metabolism', 'signal conduction' and 'immune response'. The expression of several core proteins including thyroid hormone receptor interactor 12 (TRIP12), NADH dehydrogenase (ubiquinone)1 α subcomplex, assembly factor 3 (NDUFAF3) and guanine monophosphate synthetase (GMPS) was validated by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) in a larger series of samples. The RT‑qPCR results confirmed that TRIP12, NDUFAF3 and GMPS genes were significantly differentially expressed in between the AF and PF samples. These results extend our understanding of the molecular mechanisms underlying the occurrence and development of ALD. The present study indicated that the majority of DEPs serve vital roles in multiple metabolic pathways and this extends our knowledge of the molecular mechanisms involved in the occurrence and progression of ALD.

Rodent Models of Alcoholic Liver Disease: Role of Binge Ethanol Administration

Both chronic and acute (binge) alcohol drinking are important health and economic concerns worldwide and prominent risk factors for the development of alcoholic liver disease (ALD). There are no FDA-approved medications to prevent or to treat any stage of ALD. Therefore, discovery of novel therapeutic strategies remains a critical need for patients with ALD. Relevant experimental animal models that simulate human drinking patterns and mimic the spectrum and severity of alcohol-induced liver pathology in humans are critical to our ability to identify new mechanisms and therapeutic targets. There are several animal models currently in use, including the most widely utilized chronic ad libitum ethanol (EtOH) feeding (Lieber–DeCarli liquid diet model), chronic intragastric EtOH administration (Tsukamoto–French model), and chronic-plus-binge EtOH challenge (Bin Gao—National Institute on Alcohol Abuse and Alcoholism (NIAAA) model). This review provides an overview of recent advances in rodent models of binge EtOH administration which help to recapitulate different features and etiologies of progressive ALD. These models include EtOH binge alone, and EtOH binge coupled with chronic EtOH intake, a high fat diet, or endotoxin challenge. We analyze the strengths, limitations, and translational relevance of these models, as well as summarize the liver injury outcomes and mechanistic insights. We further discuss the application(s) of binge EtOH models in examining alcohol-induced multi-organ pathology, sex- and age-related differences, as well as circadian rhythm disruption.

Pathogenesis of Alcoholic Liver Disease

Alcoholic liver disease includes a broad clinical-histological spectrum from simple steatosis, cirrhosis, acute alcoholic hepatitis with or without cirrhosis to hepatocellular carcinoma as a complication of cirrhosis. The pathogenesis of alcoholic liver disease can be conceptually divided into (1) ethanol-mediated liver injury, (2) inflammatory immune response to injury, (3) intestinal permeability and microbiome changes. Corticosteroids may improve outcomes, but this is controversial and probably only impacts short-term survival. New pathophysiology-based therapies are under study, including antibiotics, caspase inhibition, interleukin-22, anakinra, FXR agonist and others. These studies provide hope for better future outcomes for this difficult disease.

Diagnosis of Alcoholic Liver Disease: Key Foundations and New Developments

Alcoholic liver disease is a spectrum of conditions that include alcoholic fatty liver disease, alcoholic hepatitis, and chronic alcoholic liver disease. The diagnosis of alcoholic liver disease remains founded in an accurate patient history and detailed physical examination. Concurrent with the physical examination, objective data from laboratory, imaging, and histologic studies are helpful to confirm a diagnosis of alcoholic liver disease. Novel biomarkers, scoring systems, and imaging modalities are improving the ability to diagnose and manage alcoholic liver disease, but for most practicing clinicians, these have not been adopted widely because of their cost, but also because of limitations and uncertainty in their performance characteristics.

Model for end-stage liver disease-Na score or Maddrey discrimination function index, which score is best?

AIM: To compare the ability of model for end-stage liver disease (MELD)-Na and Maddrey discrimination function index (DFI) to predict mortality at 30 and 90 d in patients with alcoholic hepatitis (AH).

METHODS: We prospectively assessed 52 patients with AH. Demographic, clinical and laboratory parameters were obtained. MELD-Na and Maddrey DFI were calculated on admission. Short-term mortality was assessed at 30 and 90 d. Receiver operating characteristic curve analysis was performed.

RESULTS: Thirty-day and 90-d mortality was 44% and 58%, respectively. In the univariate analysis, sodium levels was associated with mortality at 30 and 90 d (P = 0.001 and P = 0.03). Child stage, encephalopathy, ascites, or types of treatment were not associated with mortality. MELD-Na was the only predictive factor for mortality at 90 d. For 30-d mortality area under the curve (AUC) was 0.763 (95%CI: 0.63-0.89) for Maddrey DFI and 0.784 for MELD-Na (95%CI: 0.65-0.91, P = 0.82). For 90-d mortality AUC was 0.685 (95%CI: 0.54-0.83) for Maddrey DFI and 0.8710 for MELD-Na (95%CI: 0.76-0.97, P = 0.041).

CONCLUSION: AH is associated with high short-term mortality. Our results show that MELD-Na is a more valuable model than DFI to predict short-term mortality.

Osteopontin deficiency does not prevent but promotes alcoholic neutrophilic hepatitis in mice

Alcoholic hepatitis (AH) is a distinct spectrum of alcoholic liver disease (ALD) with intense neutrophilic (polymorphonuclear; PMN) inflammation and high mortality. Although a recent study implicates osteopontin (SPP1) in AH, SPP1 is also shown to have protective effects on experimental ALD. To address this unsettled question, we examined the effects of SPP1 deficiency in male mice given 40% calories derived from ad libitum consumption of the Western diet high in cholesterol and saturated fat and the rest from intragastric feeding of alcohol diet without or with weekly alcohol binge. Weekly binge in this new hybrid feeding model shifts chronic ASH with macrophage inflammation and perisinusoidal and pericellular fibrosis to AH in 57% (15 of 26) of mice, accompanied by inductions of chemokines (Spp1, Cxcl1, and interleukin [Il]-17a), progenitor genes (Cd133, Cd24, Nanog, and epithelial cell adhesion molecule), PMN infiltration, and clinical features of AH, such as hypoalbuminemia, bilirubinemia, and splenomegaly. SPP1 deficiency does not reduce AH incidence and inductions of progenitor and fibrogenic genes, but rather enhances the Il-17a induction and PMN infiltration in some mice. Furthermore, in the absence of SPP1, chronic ASH mice without weekly binge begin to develop AH.

CONCLUSION

These results suggest that SPP1 has a protective, rather than causal, role for experimental AH reproduced in our model.

Alcoholic hepatitis: current challenges and future directions

Alcoholic hepatitis is a distinct clinical syndrome among people with chronic and active alcohol abuse, with a potential for 30%-40% mortality at 1 month among those with severe disease. Corticosteroids or pentoxifylline are the current pharmacologic treatment options, but they provide only about 50% survival benefit. These agents are recommended for patients with modified discriminant function (mDF) ≥ 32 or Model for End-Stage Liver Disease score ≥ 18. The Lille score is used to determine response to steroids. Currently, a minimum of 6 months of abstinence from alcohol use is required for patients to receive a liver transplant, a requirement that cannot be met by patients with severe alcoholic hepatitis nonresponsive to steroids (Lille score ≥ 0.45). Data are emerging on the benefit of liver transplantation in select patients with first episode of severe alcoholic hepatitis. This review also focuses on recent treatment trials in alcoholic hepatitis including liver transplantation and its associated controversies, as well as possible future targets and pharmacologic treatment options for patients with alcoholic hepatitis that are being pursued through upcoming consortium studies.

Pharmacotherapy of acute alcoholic hepatitis in clinical practice

Severe alcoholic hepatitis (AH) is an acute form of alcohol induced liver disease with a poor prognosis that is seen in the patients who consume large quantities of alcohol. The diagnosis of AH is based on the appropriate alcohol intake history and is supported with clinical and histological features, and several scoring systems. Glucocorticoids are the mainstay for treating severe AH with pentoxifylline used as an alternative to steroids in addition to total alcohol abstinence. Liver transplantation is a possible therapeutic option for severe AH. Among the anti-craving medications able to improve abstinence rate, baclofen seems to be effective and safe in the alcoholic patients affected by severe liver damage.

Chronic plus binge ethanol feeding synergistically induces neutrophil infiltration and liver injury in mice: a critical role for E-selectin

Chronic plus binge ethanol feeding acts synergistically to induce liver injury in mice, but the mechanisms underlying this phenomenon remain unclear. Here, we show that chronic plus binge ethanol feeding synergistically up-regulated the hepatic expression of interleukin-1β and tumor necrosis factor alpha and induced neutrophil accumulation in the liver, compared with chronic or binge feeding alone. In vivo depletion of neutrophils through administration of an anti-Ly6G antibody markedly reduced chronic-binge ethanol feeding-induced liver injury. Real-time polymerase chain reaction analyses revealed that hepatic E-selectin expression was up-regulated 10-fold, whereas expression of other neutrophil infiltration-related adhesion molecules (e.g., P-selectin, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1) was slightly up- or down-regulated in this chronic-binge model. The genetic deletion of E-selectin prevented chronic-binge ethanol-induced hepatic neutrophil infiltration as well as elevation of serum transaminases without affecting ethanol-induced steatosis. In addition, E-selectin-deficient mice showed reduced hepatic expression of several proinflammatory cytokines, chemokines, and adhesion molecules, compared to wild-type mice, after chronic-binge ethanol feeding. Finally, the expression of E-selectin was highly up-regulated in human alcoholic fatty livers, but not in alcoholic cirrhosis.

CONCLUSIONS

Chronic-binge ethanol feeding up-regulates expression of proinflammatory cytokines, followed by the induction of E-selectin. Elevated E-selectin plays an important role in hepatic neutrophil infiltration and injury induced by chronic-binge feeding in mice and may also contribute to the pathogenesis of early stages of human alcoholic liver disease.

Moderate, excessive or heavy alcohol consumption: each is significantly associated with increased mortality in patients with chronic hepatitis C

BACKGROUND

The impact of moderate alcohol consumption on long-term outcomes of chronic hepatitis C (CH-C) infected patients remains controversial.

AIM

To assess the impact of moderate alcohol consumption on long-term outcomes of CH-C patients using population-based data.

METHODS

Data were obtained from the Third National Health and Nutrition Examination Survey (NHANES III)-mortality linked files. Alcohol consumption was estimated as grams/day. Multivariate Cox proportional hazards model was utilized to assess the effects of CH-C and alcohol consumption on mortality (all causes, cardiovascular disease, and liver disease).

RESULTS

A total of 8985 participants were included as the study cohort. Of these, 218 had CH-C. The follow-up time was 162.95 months for CH-C and 178.27 months for controls. CH-C patients had increased risk for both overall mortality and liver-related mortality. CH-C patients with excessive alcohol consumption had even higher risks for overall mortality and liver-related mortality. The risk of overall mortality associated with CH-C increased with moderate alcohol consumption of 1-19 g/day and heavy alcohol consumption ≥30 g/day.

CONCLUSION

Although chronic hepatitis C is associated with increased risks for overall and liver-related mortality, these risks are even higher for patients consuming moderate and excessive amounts of alcohol.

Mouse model of chronic and binge ethanol feeding (the NIAAA model)

Chronic alcohol consumption is a leading cause of chronic liver disease worldwide, leading to cirrhosis and hepatocellular carcinoma. Currently, the most widely used model for alcoholic liver injury is ad libitum feeding with the Lieber-DeCarli liquid diet containing ethanol for 4-6 weeks; however, this model, without the addition of a secondary insult, only induces mild steatosis, slight elevation of serum alanine transaminase (ALT) and little or no inflammation. Here we describe a simple mouse model of alcoholic liver injury by chronic ethanol feeding (10-d ad libitum oral feeding with the Lieber-DeCarli ethanol liquid diet) plus a single binge ethanol feeding. This protocol for chronic-plus-single-binge ethanol feeding synergistically induces liver injury, inflammation and fatty liver, which mimics acute-on-chronic alcoholic liver injury in patients. This feeding protocol can also be extended to chronic feeding for longer periods of time up to 8 weeks plus single or multiple binges. Chronic-binge ethanol feeding leads to high blood alcohol levels; thus, this simple model will be very useful for the study of alcoholic liver disease (ALD) and of other organs damaged by alcohol consumption.