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Most patients with alcohol-associated liver disease (ALD) engage in heavy drinking defined as 4 or more drinks per day (56 g) or 8 (112 g) or more drinks per week for women and 5 or more drinks per day (70 g) or 15 (210 g) or more drinks per week for men. Although abstinence from alcohol after diagnosis of ALD improves life expectancy and reduces the risk of decompensation of liver disease, few studies have evaluated whether treatment of alcohol use disorders will reduce progression of liver disease and improve liver-related outcomes. In November 2021, the National Institute of Alcohol Abuse and Alcoholism commissioned a task force that included hepatologists, addiction medicine specialists, statisticians, clinical trialists and members of regulatory agencies to develop recommendations for the design and conduct of clinical trials to evaluate the effect of alcohol use, particularly treatment to reduce or eliminate alcohol use in patients with ALD. The task force conducted extensive reviews of relevant literature on alcohol use disorders and ALD. Findings were presented at one in-person meeting and discussed over the next 16 months to develop the final recommendations. As few clinical trials directly address this topic, the 28 recommendations approved by all members of the task force represent a consensus of expert opinions., (© 2024. Springer Nature Limited.)

Background/aims: Alcohol-associated hepatitis (AH) mortality and risk factors have not been carefully studied in real-world settings. We examined the rate, temporal trend, and risk factors of mortality in AH., Methods: We conducted a cohort study of individuals with AH diagnoses using medical claims data from Optum's Clinformatics® Data Mart (CDM). Participants were individuals covered by Medicare Advantage and commercial insurance policies. Cases were identified using diagnostic codes. Cox regressions were used to estimate 90 and 180-day mortality rates by hospitalization status., Results: The cohort included 32,001 patients (72% men) who had at least one year of continuous insurance coverage prior to AH diagnoses. Of these, 20,912 were hospitalized within seven days of diagnosis. Ninety and 180-day mortality rates were 12.0% (95% CI [11.6%, 12.5%]) and 16.0% (95% CI [15.4%, 16.5%]), respectively, for the hospitalized patients and 3.1% (95% CI [2.8%, 3.4%]) and 5.1% (95% CI [4.6%, 5.5%]) for the non-hospitalized patients. Pre-existing liver disease, even in a mild form, was associated with an increased risk of death. In hospitalized patients, a history of mild liver disease was associated with a 24% increase in 180-day mortality risk (HR = 1.24, 95% CI: [1.14, 1.36]). Moderate-to-severe liver disease was associated with a more than doubled risk (HR = 2.33, 95% CI: [2.12, 2.56])., Conclusions: History of liver disease was associated with significantly increased AH mortality. The finding highlights the chronic disease context of AH and suggests that prior diagnosis of liver disease should be considered for prognosis and targeted prevention., Competing Interests: Declaration of competing interest Dr. Gawrieh is a consultant to TransMedics, Pfizer. He received research grant support from Viking, Sonic Incytes, and Zydus. None of the other authors had conflicts of interest to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background & Aims: Severe alcohol-associated hepatitis (SAH) is associated with high 90-day mortality. Glucocorticoid therapy for 28 days improves 30- but not 90-day survival. We assessed the efficacy and safety of a combination of anakinra, an IL-1 antagonist, plus zinc (A+Z) compared to prednisone using the Day-7 Lille score as a stopping rule in patients with SAH., Methods: In this phase IIb double-blind randomized trial in adults with SAH and MELD scores of 20-35, participants were randomized to receive either daily anakinra 100 mg subcutaneously for 14 days plus daily zinc sulfate 220 mg orally for 90 days, or daily prednisone 40 mg orally for 30 days. Prednisone or prednisone placebo was stopped if Day-7 Lille score was >0.45. All study drugs were stopped for uncontrolled infection or ≥5 point increase in MELD score. The primary endpoint was overall survival at 90 days., Results: Seventy-three participants were randomized to prednisone and 74 to A+Z. The trial was stopped early after a prespecified interim analysis showed prednisone was associated with higher 90-day overall survival (90% vs. 70%; hazard ratio for death = 0.34, 95% CI 0.14-0.83, p = 0.018) and transplant-free survival (88% vs. 64%; hazard ratio for transplant or death = 0.30, 95% CI 0.13-0.69, p = 0.004) than A+Z. Acute kidney injury was more frequent with A+Z (45%) than prednisone (22%) (p = 0.001), but rates of infection were similar (31% in A+Z vs. 27% in prednisone, p = 0.389)., Conclusions: Participants with SAH treated with prednisone using the Day-7 Lille score as a stopping rule had significantly higher overall and transplant-free 90-day survival and lower incidence of acute kidney injury than those treated with A+Z., Impact and Implications: There is no approved treatment for severe alcohol-associated hepatitis (SAH). In this double-blind randomized trial, patients with SAH treated with prednisone using the Lille stopping rule on Day 7 had higher 90-day overall and transplant-free survival and lower rates of acute kidney injury compared to patients treated with a combination of anakinra and zinc. The data support continued use of glucocorticoids for patients with SAH, with treatment discontinuation for those with a Lille score >0.45 on Day 7., Trial Registration: NCT04072822., (Copyright © 2024 European Association for the Study of the Liver. All rights reserved.)

Background: Recruitment and retention are critical in clinical studies but there are limited objective metrics of trial performance. We tested if development of trial performance metrics will allow for objective evaluation of study quality. Performance metrics were developed using data from the observational cohort (OBS) and randomized clinical trial (RCT) arms of the prospective Alcoholic Hepatitis Network., Methods: Yield-rate (%YR; eligible/screened), recruitment index (RI; mean recruitment time/patient), completion index (CI; average number of days to complete the follow-up/patient), and protocol adherence index (AI; average number of deviations/subject recruited) were determined., Results: 2250 patients (1168 for OBS; 1082 for RCT) were screened across 8 sites. Recruitment in the RCT (57% target) was similar to that in the OBS (59% target). Of those screened, 743 (63.6%) subjects in the OBS and 147 (13.6%) subjects in the RCT were enrolled in the study. In OBS study, 253 (34.1%) subjects, and in the RCT, 68 (46.3%) subjects, completed the study or reached a censoring event. Across all sites (range), YR for OBS was 63.6% (41.3-98.3%) and for RCT was 13.6% (5.5-92.6%); RI for OBS was 1.66 (8.79-19.85) and for RCT was 4.05 (19.76-36.43); CI for OBS was 4.87 (22.6-118.3) and for RCT was 8.75 (27.27-161.5); and AR for OBS was 0.56 (0.08-1.04) and for RCT was 1.55 (0.39-3.21. Factors related to participants, research design, study team, and research sponsors contributed to lower performance metrics., Conclusions: Objective measures of clinical trial performance allow for strategies to enhance study quality and development of site-specific improvement plans., Trial Registration Number: ClinicalTrials.gov NCT4072822 NCT03850899., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Severe alcoholic hepatitis (AH) has a high short-term mortality rate. The MELD assesses disease severity and mortality; however, it is not specific for AH. We screened plasma samples from patients with severe AH for biomarkers of multiple pathological processes and identified predictors of short-term mortality., Methods: Plasma was collected at baseline from 85 patients with severe AH (MELD≥20, Maddrey's discriminant function≥32) enrolled in the Defeat Alcoholic Steatohepatitis clinical trial (investigating IL-1 receptor antagonist+pentoxifylline+zinc vs. methylprednisolone+placebo). Samples were analyzed for 43 biomarkers and the markers' association with 28- and 90-day mortalities was assessed., Results: Thirty-one (36.5%) patients died during the 90-day follow-up with similar ratios in the treatment groups. Eight biomarkers showed an association with mortality. IL-6, IL-22, interferon-α2, soluble TNF receptor 1, lipocalin-2, and α-fetoprotein levels were associated with 28-day mortality, while IL-6, IL-13, and endotoxin levels with 90-day mortality. In multivariable Cox regression, encephalopathy, lipocalin-2, and α-fetoprotein levels were independent predictors of 28-day mortality, and IL-6, IL-13, international normalized ratio levels, and age were independent predictors of 90-day mortality. The combination of IL-13 and age had superior performance in predicting 90-day mortality compared with MELD in the total cohort and the individual treatment groups., Conclusions: We identified predictors of short-term mortality in a cohort exclusively involving patients with severe AH. We created a composite score of IL-13 and age that predicts 90-day mortality regardless of the treatment type with a performance superior to MELD in severe AH., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Study of Liver Diseases.)

Background: Chronic alcohol consumption impairs gut barrier function and perturbs the gut microbiome. Although shifts in bacterial communities in patients with alcohol-associated liver disease (ALD) have been characterized, less is known about the interactions between host metabolism and circulating microbe-derived metabolites during the progression of ALD., Methods: A large panel of gut microbiome-derived metabolites of aromatic amino acids was quantified by stable isotope dilution liquid chromatography with online tandem mass spectrometry in plasma from healthy controls (n = 29), heavy drinkers (n = 10), patients with moderate (n = 16) or severe alcohol-associated hepatitis (n = 40), and alcohol-associated cirrhosis (n = 10)., Results: The tryptophan metabolites, serotonin and indole-3-propionic acid, and tyrosine metabolites, p-cresol sulfate, and p-cresol glucuronide, were decreased in patients with ALD. Patients with severe alcohol-associated hepatitis and alcohol-associated cirrhosis had the largest decrease in concentrations of tryptophan and tyrosine-derived metabolites compared to healthy control. Western blot analysis and interrogation of bulk RNA sequencing data from patients with various liver pathologies revealed perturbations in hepatic expression of phase II metabolism enzymes involved in sulfonation and glucuronidation in patients with severe forms of ALD., Conclusions: We identified several metabolites decreased in ALD and disruptions of hepatic phase II metabolism. These results indicate that patients with more advanced stages of ALD, including severe alcohol-associated hepatitis and alcohol-associated cirrhosis, had complex perturbations in metabolite concentrations that likely reflect both changes in the composition of the gut microbiome community and the ability of the host to enzymatically modify the gut-derived metabolites., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Study of Liver Diseases.)

Introduction: We investigated the effect of daily oral Lactobacillus rhamnosus GG (LGG) in reducing liver injury/severity and drinking in patients with alcohol use disorder and moderately severe alcohol-associated hepatitis., Methods: Forty-six male and female individuals with alcohol use disorder and moderate alcohol-associated hepatitis (12 ≤ model for end-stage liver disease score < 20, aged 21-67 years) received either LGG (n = 24) or placebo (n = 22). Data were collected/assessed at baseline and at 1, 3, and 6 months., Results: LGG treatment was associated with a significant reduction in liver injury after 1 month. Six months of LGG treatment reduced heavy drinking levels to social or abstinence levels., Discussion: LGG treatment was associated with an improvement in both liver injury and drinking., (Copyright © 2023 by The American College of Gastroenterology.)

Background Aims: Prolonged systemic inflammation contributes to poor clinical outcomes in severe alcohol-associated hepatitis (AH) even after the cessation of alcohol use. However, mechanisms leading to this persistent inflammation remain to be understood., Approach Results: We show that while chronic alcohol induces nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation in the liver, alcohol binge results not only in NLRP3 inflammasome activation but also in increased circulating extracellular apoptosis-associated speck-like protein containing a caspase recruitment domain (ex-ASC) specks and hepatic ASC aggregates both in patients with AH and in mouse models of AH. These ex-ASC specks persist in circulation even after the cessation of alcohol use. Administration of alcohol-induced-ex-ASC specks in vivo in alcohol-naive mice results in sustained inflammation in the liver and circulation and causes liver damage. Consistent with the key role of ex-ASC specks in mediating liver injury and inflammation, alcohol binge failed to induce liver damage or IL-1β release in ASC-deficient mice. Our data show that alcohol induces ex-ASC specks in liver macrophages and hepatocytes, and these ex-ASC specks can trigger IL-1β release in alcohol-naive monocytes, a process that can be prevented by the NLRP3 inhibitor, MCC950. In vivo administration of MCC950 reduced hepatic and ex-ASC specks, caspase-1 activation, IL-1β production, and steatohepatitis in a murine model of AH., Conclusions: Our study demonstrates the central role of NLRP3 and ASC in alcohol-induced liver inflammation and unravels the critical role of ex-ASC specks in the propagation of systemic and liver inflammation in AH. Our data also identify NLRP3 as a potential therapeutic target in AH., (Copyright © 2023 American Association for the Study of Liver Diseases.)

Background: Mortality is high for severe alcohol-associated hepatitis (AH). Corticosteroids are the standard of care for patients without contraindications. Recent data showed that interleukin-1β receptor antagonist anakinra attenuated inflammation and liver damage. We designed a multicenter, double-blind, randomized controlled trial to assess the safety and efficacy of anakinra compared to prednisone., Methods: Patients meeting the clinical and biochemical criteria for severe AH with MELD scores between 20 and 35 were recruited at eight clinical sites. Eligible patients enrolled in the study were randomized to anakinra, 100 mg subcutaneous injection for 14 days, plus zinc sulfate 220 mg for 90 days, vs. prednisone 40 mg PO daily for 30 days. Matching placebos for anakinra, zinc, and prednisone were provided to mask the treatment. Participants were followed for 180 days. The primary outcome was overall survival at 90 days. An unadjusted log-rank test was used to compare the survival of the two treatments in the first 90 days. Between July 10, 2020, and March 4, 2022, we screened 1082 patients with severe AH, and 147 eligible patients were enrolled and randomized. The average baseline MELD score was 25 [range 20-35], Maddrey discriminant function (MDF) was 59.4 [range 20.2-197.5]. The mean aspartate transaminase (AST)-to-alanine transaminase (ALT) ratio was 3.5. The baseline characteristics were not statistically different between the two treatment groups., Conclusions: The study provided a direct comparison of the survival benefits and safety profiles of anakinra plus zinc vs. prednisone in patients with severe AH., Competing Interests: Dr. Samer Gawrieh provides consulting services to TransMedics and Pfizer and he receives research grant support from Cirius, Viking, and Zydus. Dr. Vijay Shah serves on Advisory boards of Akaza Bioscience Ltd, AgomAb Therapeutics, Generon Shanghai, Intercept Pharmaceuticals, Inc, Mallinckrodt Pharmaceuticals, and Surrozen. He provides consulting services Ambys Medicines, Durect Corporation, HepaRegeniX, and Novartis Pharma AG. Dr. Mack Mitchell owns stocks in Amygdala Neuroscience and Advisory at Prodigy Biotech. Dr. Douglass Simonetto provides consulting services to BioVie and Mallinckrodt. Dr. Wanzhu Tu provides consulting services to Bayer. Dr. Gyongyi Szabo provides consulting services to Alnylam, Duret, Generon, Glympse Bio, Novartis, Quest Diagnostics, Surrozen, Terra Firma, and Zomagen. Dr. Arun Sanyal owns stocks in Sanyal Bio, Exhalenz, Conatus, Genfit, Duret, Indalo, and Tiziana. He provides consulting services to Conatus, Genfit, Gilead, Mallinckrodt Pharmaceuticals, Pfizer, BI, Novartis, Merck, Lilly, Novo Nordisk, Terns, Albireo, Sanofi, Jannsen, Takeda, Northsea, Poxel, 89Bio, NGM Bio, Amgen, Genentech, Roche, Madrigal, Inventiva, Covance, Prosciento, Histoindex, PathAI, and Biocellvia. Other authors declared no conflicts of interest., (© 2023 Published by Elsevier Inc.)

Background and Aims: Patients with severe alcohol-associated hepatitis (AH) have high mortality. Corticosteroids improve survival only for 30 days. We targeted inflammation, cellular injury, and gut leakiness in a randomized clinical trial comparing combination therapy to corticosteroids on 180-day survival., Approach and Results: Subjects with a clinical diagnosis of severe AH (Model for End-Stage Liver Disease [MELD] >20, Maddrey discriminant function [MDF] >32) were randomized to receive methylprednisolone (PRED; 28 days) or a combination of anakinra (14 days) plus pentoxifylline (28 days) plus zinc (COMB; 180 days). The primary endpoint was survival at 180 days. The study was designed in 2013, initiated in October 2014, and completed in March 2018. Five hundred patients were screened to randomize 104 subjects with a clinical diagnosis of AH with a MELD score >20. Fifty-three patients were randomized into the COMB and 50 to the PRED treatment; 1 dropped out of the study before randomization. Mean age was 45.3 ± 10.4 years; 60.6% were males, 92.3% White, and mean MELD 25.7 ± 3.9. Kaplan-Meier survival estimate at 180 days was 67.9% in COMB and 56% in PRED (HR = 0.69; p = 0.3001). Survival curves separated by 90 days (COMB, 69.8%; PRED, 58.0%; HR = 0.69; p = 0.28). Survival at 28 days was similar between the COMB (83.4%) and PRED groups (81.2%; HR = 0.91; p = 0.85). There were no unexpected serious adverse events, and incidence of infection was comparable between groups. MELD 20-25 and MELD >26 strata showed nonsignificant treatment effects in favor of COMB., Conclusions: A combination of anakinra, pentoxifylline plus zinc provides similar survival benefits compared to corticosteroid therapy in severe AH., (© 2022 American Association for the Study of Liver Diseases.)

There is mounting evidence that microbes residing in the human intestine contribute to diverse alcohol-associated liver diseases (ALD) including the most deadly form known as alcohol-associated hepatitis (AH). However, mechanisms by which gut microbes synergize with excessive alcohol intake to promote liver injury are poorly understood. Furthermore, whether drugs that selectively target gut microbial metabolism can improve ALD has never been tested. We used liquid chromatography tandem mass spectrometry to quantify the levels of microbe and host choline co-metabolites in healthy controls and AH patients, finding elevated levels of the microbial metabolite trimethylamine (TMA) in AH. In subsequent studies, we treated mice with non-lethal bacterial choline TMA lyase (CutC/D) inhibitors to blunt gut microbe-dependent production of TMA in the context of chronic ethanol administration. Indices of liver injury were quantified by complementary RNA sequencing, biochemical, and histological approaches. In addition, we examined the impact of ethanol consumption and TMA lyase inhibition on gut microbiome structure via 16S rRNA sequencing. We show the gut microbial choline metabolite TMA is elevated in AH patients and correlates with reduced hepatic expression of the TMA oxygenase flavin-containing monooxygenase 3 (FMO3). Provocatively, we find that small molecule inhibition of gut microbial CutC/D activity protects mice from ethanol-induced liver injury. CutC/D inhibitor-driven improvement in ethanol-induced liver injury is associated with distinct reorganization of the gut microbiome and host liver transcriptome. The microbial metabolite TMA is elevated in patients with AH, and inhibition of TMA production from gut microbes can protect mice from ethanol-induced liver injury., Competing Interests: RH, TM, AK, VV, NS, EH, RB, AB, KF, WM, CN, DO, LO, RS, MM, AB, KP, AK, VP, MM, JA, BW, CM, MM, AM, SR, BB, GS, SD, JG, DR, DA, LN, JB No competing interests declared, ZW Kaiser Permanente (CME lecture sessions) Advisory Board for Incyte (on treatment of cholangiocarcinoma), SH Z.W. report being named as co-inventor on pending and issued patents held by the Cleveland Clinic relating to cardiovascular diagnostics and therapeutics. Z.W. reports being eligible to receive royalty payments for inventions or discoveries related to cardiovascular diagnostics or therapeutics from Zehna Therapeutics, Cleveland Heart Lab, a wholly owned subsidiary of Quest Diagnostics, and Procter & Gamble, (© 2022, Helsley et al.)

Background and Aims: We conducted a comprehensive serum transcriptomic analysis to explore the roles of microRNAs (miRNAs) in alcohol-associated hepatitis (AH) pathogenesis and their prognostic significance., Approach and Results: Serum miRNA profiling was performed in 15 controls, 20 heavy drinkers without liver disease, and 65 patients with AH and compared to publicly available hepatic miRNA profiling in AH patients. Among the top 26 miRNAs, expression of miR-30b-5p, miR-20a-5p, miR-146a-5p, and miR-26b-5p were significantly reduced in both serum and liver of AH patients. Pathway analysis of the potential targets of these miRNAs uncovered the genes related to DNA synthesis and cell-cycle progression pathways, including ribonucleotide reductase regulatory subunit M2 (RRM2), cyclin D1 (CCND1), cyclin D2 (CCND2), MYC proto-oncogene (MYC), and phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1). We found a significant increase in the protein expression of RRM2, CCND1, and CCND2, but not MYC and PMAIP1, in AH patients who underwent liver transplantation; miR-26b-5p and miR-30b-5p inhibited the 3'-UTR (untranslated region) luciferase activity of RRM2 and CCND2, and miR-20a-5p reduced the 3'-UTR luciferase activity of CCND1 and CCND2. During a median follow-up of 346 days, 21% of AH patients died; these patients had higher body mass index (BMI), Model for End-Stage Liver Disease (MELD), and serum miR-30b-5p, miR-20a-5p, miR-146a-5p, and miR-26b-5p than those who survived. Cox regression analysis showed that BMI, MELD score, miR-20a-5p, miR-146a-5p, and miR-26b-5p predicted mortality., Conclusions: Patients with AH attempt to deal with hepatocyte injury by down-regulating specific miRNAs and up-regulating genes responsible for DNA synthesis and cell-cycle progression. Higher expression of these miRNAs, suggestive of a diminished capacity in liver regeneration, predicts short-term mortality in AH patients., (© 2021 by the American Association for the Study of Liver Diseases.)

Background and Aims: Given the lack of effective therapies and high mortality in acute alcohol-associated hepatitis (AH), it is important to develop rationally designed biomarkers for effective disease management. Complement, a critical component of the innate immune system, contributes to uncontrolled inflammatory responses leading to liver injury, but is also involved in hepatic regeneration. Here, we investigated whether a panel of complement proteins and activation products would provide useful biomarkers for severity of AH and aid in predicting 90-day mortality., Approach and Results: Plasma samples collected at time of diagnosis from 254 patients with moderate and severe AH recruited from four medical centers and 31 healthy persons were used to quantify complement proteins by enzyme-linked immunosorbent assay and Luminex arrays. Components of the classical and lectin pathways, including complement factors C2, C4b, and C4d, as well as complement factor I (CFI) and C5, were reduced in AH patients compared to healthy persons. In contrast, components of the alternative pathway, including complement factor Ba (CFBa) and factor D (CFD), were increased. Markers of complement activation were also differentially evident, with C5a increased and the soluble terminal complement complex (sC5b9) decreased in AH. Mannose-binding lectin, C4b, CFI, C5, and sC5b9 were negatively correlated with Model for End-Stage Liver Disease score, whereas CFBa and CFD were positively associated with disease severity. Lower CFI and sC5b9 were associated with increased 90-day mortality in AH., Conclusions: Taken together, these data indicate that AH is associated with a profound disruption of complement. Inclusion of complement, especially CFI and sC5b9, along with other laboratory indicators, could improve diagnostic and prognostic indications of disease severity and risk of mortality for AH patients., (© 2020 by the American Association for the Study of Liver Diseases.)

Hepatocellular death contributes to progression of alcohol-associated (ALD-associated) and non-alcohol-associated (NAFL/NASH) liver diseases. However, receptor-interaction protein kinase 3 (RIP3), an intermediate in necroptotic cell death, contributes to injury in murine models of ALD but not NAFL/NASH. We show here that a differential role for mixed-lineage kinase domain-like protein (MLKL), the downstream effector of RIP3, in murine models of ALD versus NAFL/NASH and that RIP1-RIP3-MLKL can be used as biomarkers to distinguish alcohol-associated hepatitis (AH) from NASH. Phospho-MLKL was higher in livers of patients with NASH compared with AH or healthy controls (HCs). MLKL expression, phosphorylation, oligomerization, and translocation to plasma membrane were induced in WT mice fed diets high in fat, fructose, and cholesterol but not in response to Gao-binge (acute on chronic) ethanol exposure. Mlkl-/- mice were not protected from ethanol-induced hepatocellular injury, which was associated with increased expression of chemokines and neutrophil recruitment. Circulating concentrations of RIP1 and RIP3, but not MLKL, distinguished patients with AH from HCs or patients with NASH. Taken together, these data indicate that MLKL is differentially activated in ALD/AH compared with NAFL/NASH in both murine models and patients. Furthermore, plasma RIP1 and RIP3 may be promising biomarkers for distinguishing AH and NASH.

Background/aims: Despite high mortality of alcohol-associated hepatitis, there has been limited advancement in treatment strategies. Defeat Alcoholic Steatohepatitis (DASH) is a multicenter, randomized, double-blind controlled trial whose primary objective was to evaluate the safety and efficacy of a novel combination of 3 drugs targeting different perturbations in AH., Methods: Severe AH was diagnosed by liver biopsy or clinical and biochemical criteria and model for end stage liver disease (MELD) score ≥ 20 stratified by MELD scores (20-25 and ≥ 26) and randomized to a combination of an interleukin receptor 1 antagonist, Anakinra(100 mg daily for 14 days) to suppress acute inflammation, pentoxifylline (400 mg three times a day for 28 days) to prevent hepatorenal syndrome, and zinc sulfate (220 mg orally once daily for 6 months) or the standard of care therapy including methylprednisolone 32 mg orally once daily for 28 days. The primary efficacy outcome was the unadjusted log-rank test of the Kaplan-Meier survival estimates for the two treatment groups at 180 days., Results: Between July 2012 to March 2018, 500 subjects with severe AH were screened of which 104 subjects were enrolled with MELD score of 25.6 ± 3.2 (20.0-35.0) in the investigational arm and 25.8 ± 4.5 (20.0-40.0) in the standard of care arm. Causes of screen failures included not meeting eligibility criteria (n = 347), declining to participate (n = 39), and other reasons (n = 10)., Conclusions: Data from the DASH consortium studies will determine if a combination of drugs targeting multiple mechanisms of injury in the severe AH will improve clinical outcomes., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background & Aims: Acute alcoholic hepatitis (AAH) is a major cause of liver-related morbidity and mortality; there are no good blood biomarkers for diagnosis or determining magnitude of cell death. Keratin 18 (KRT18, also called K18), found in epithelial cells, is released from hepatocytes upon death. We investigated whether level of K18 is a better marker of hepatocyte death than standard biomarkers and might be used to identify patients with AAH at risk for death within 90 days., Methods: We analyzed data from 173 participants in a large trial performed at 4 medical centers. Participants with AAH were classified as severe (n = 57, model for end-stage liver disease [MELD] scores above 20) or moderate (n = 27, MELD scores from 12 to 19); 38 participants had alcohol use disorder with mild (n = 28) or no liver injury (n = 10); 34 participants had nonalcoholic steatohepatitis; and 17 participants were healthy (controls). We quantified serum levels of K18 using ELISAs and APOPTOSENSE kits., Results: Serum level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and the ratio of AST:ALT did not correlate with MELD scores. Patients with alcohol use disorder had higher serum levels of ALT than patients with severe AAH. Levels of K18M65 and K18M30 had statistically significant increases as liver disease worsened, as did the degree of necrosis (ratio of K18 M65:M30). The ratio of K18M65:ALT was increased in serum from patients with AAH compared with controls. Serum levels of K18 identified patients who died within 90 days with greater accuracy than commonly used static biomarkers., Conclusions: There is a stronger association between serum level of keratin 18 and amount of hepatocyte death and liver disease severity than for other biomarkers (AST, ALT, and the AST:ALT ratio). The ratio of K18M65:M30 might be used as marker of mechanism of hepatocyte death, and the ratio of K18M65:ALT might be used to distinguish patients with AAH from patients with nonalcoholic steatohepatitis. Serum levels of K18 might be used to identify patients with severe AAH at risk for death. ClinicalTrials.gov identifier # NCT01922895 and NCT01809132., (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background and Aims: Interleukin-22 has beneficial effects on inflammation and impaired hepatic regeneration that characterize alcohol-associated hepatitis (AH). F-652 is a recombinant fusion protein of human interleukin-22 and immunoglobulin G2 fragment crystallizable. This study aims to assess the safety and efficacy signals of F-652 in patients with moderate and severe AH., Approach and Results: A phase-2 dose-escalating study was carried out. F-652 (10 μg/kg, 30 μg/kg, or 45 μg/kg) administered on days 1 and 7 was tested in 3 patients each with moderate (Model for End-Stage Liver Disease [MELD] scores: 11-20) and severe AH (MELD scores: 21-28). Safety was defined by absence of serious adverse events and efficacy was assessed by Lille score, changes in MELD score, and serum bilirubin and aminotransferases at days 28 and 42. Three independent propensity-matched comparator patient cohorts were used. Plasma extracellular vesicles and multiplex serum cytokines were measured to assess inflammation and hepatic regeneration. Eighteen patients (9 moderate and 9 severe AH) were enrolled, 66% were male, and the mean age was 48 years. The half-life of F-652 following the first dose was 61-85 hours. There were no serious adverse events leading to discontinuation. The MELD score and serum aminotransferases decreased significantly at days 28 and 42 from baseline (P < 0.05). Day-7 Lille score was 0.45 or less in 83% patients as compared with 6%, 12%, and 56% among the comparator cohorts. Extracellular vesicle counts decreased significantly at day 28 (P < 0.013). Cytokine inflammatory markers were down-regulated, and regeneration markers were up-regulated at days 28 and 42., Conclusions: F-652 is safe in doses up to 45 μg/kg and associated with a high rate of improvement as determined by Lille and MELD scores, reductions in markers of inflammation and increases in markers of hepatic regeneration. This study supports the need for randomized placebo-controlled trials to test the efficacy of F-652 in AH., (© 2019 by the American Association for the Study of Liver Diseases.)

Although mortality due to acute alcoholic hepatitis (AH) correlates with Model for End-Stage Liver Disease (MELD) scores, biomarkers are critically needed to manage this disease. Increases in inflammatory markers and macrophage activation are associated with acute AH and could be potential biomarkers of clinical events and/or mortality. We enrolled 89 clinically diagnosed AH patients in four US academic medical centers. Plasma from AH patients had a significant increase in gut microbial translocation indicators (endotoxin, bacterial 16S ribosomal DNA) and host response indicators (soluble cluster of differentiation 14 [sCD14] and lipopolysaccharide binding protein [LBP]) compared to controls. Patient MELD score and Glasgow Alcoholic Hepatitis score (GAHS) correlated with endotoxin levels. AH patients also had a significant increase in high mobility group protein 1 (HMGB1), a sterile danger signal molecule, and osteopontin (OPN), a multifunctional phosphoprotein involved in neutrophil activation, compared to controls. Increased levels of OPN positively correlated with increasing MELD score, GAHS, and LBP levels. Consistent with these results, AH patients had significantly increased circulating levels of macrophage activation (sCD163 and sCD206) markers compared to healthy controls, and sCD163 and sCD206 significantly and positively correlated with OPN, HMGB1, and LBP levels as well as with MELD score and GAHS. These findings indicate a connection between microbial translocation, immune cell activation, and AH severity. Plasma sCD14, OPN, sCD163, and sCD206 levels were significantly higher in nonsurvivors than survivors. In multivariate regression models, we identified sCD14, sCD163, and OPN as independent predictors of 90-day mortality, infection, and organ failure development, respectively. Conclusion: Our study suggests that sCD14, LBP, OPN, sCD163, and sCD206 are biomarkers to indicate severity and predict clinical outcomes in AH., (© 2019 by the American Association for the Study of Liver Diseases.)

Objectives: Alcoholic hepatitis (AH) develops in approximately 30% of chronic heavy drinkers. The immune system of patients with AH is hyperactivated, yet ineffective against infectious diseases. Mucosal-associated invariant T (MAIT) cells are innate-like lymphocytes that are highly enriched in liver, mucosa, and peripheral blood and contribute to antimicrobial immunity. We aimed to determine whether MAIT cells were dysregulated in heavy drinkers with and without AH and the effects of alcohol abstinence on MAIT cell recovery., Methods: MR1 tetramers loaded with a potent MAIT cell ligand 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil were used in multiparameter flow cytometry to analyze peripheral blood MAIT cells in 59 healthy controls (HC), 56 patients with AH, and 45 heavy drinkers without overt liver disease (HDC) at baseline and 6- and 12-month follow-ups. Multiplex immunoassays were used to quantify plasma levels of cytokines related to MAIT cell activation. Kinetic Turbidimetric Limulus Amebocyte Lysate Assay and ELISA were performed to measure circulating levels of 2 surrogate markers for bacterial translocation (lipopolysaccharide and CD14), respectively., Results: At baseline, patients with AH had a significantly lower frequency of MAIT cells than HDC and HC. HDC also had less MAIT cells than HC (median 0.16% in AH, 0.56% in HDC, and 1.25% in HC). Further, the residual MAIT cells in patients with AH expressed higher levels of activation markers (CD69, CD38, and human leukocyte antigen [HLA]-DR), the effector molecule granzyme B, and the immune exhaustion molecule PD-1. Plasma levels of lipopolysaccharide and CD14 and several cytokines related to MAIT cell activation were elevated in patients with AH (interferon [IFN]-α, interleukin [IL]-7, IL-15, IL-17, IL-18, IL-23, IFN-γ, and tumor necrosis factor α). Decreased MAIT cell frequency and upregulated CD38, CD69, and HLA-DR correlated negatively and positively, respectively, with aspartate aminotransferase level. MAIT cell frequency negatively correlated with IL-18. HLA-DR and CD38 levels correlated with several cytokines. At follow-ups, abstinent patients with AH had increased MAIT cell frequency and decreased MAIT cell activation. However, MAIT cell frequency was not fully normalized in patients with AH (median 0.31%)., Discussion: We showed that HDC had a reduction of blood MAIT cells despite showing little evidence of immune activation, whereas patients with AH had a severe depletion of blood MAIT cells and the residual cells were highly activated. Alcohol abstinence partially reversed those abnormalities.

Background: Lifetime prevalence of posttraumatic stress disorder (PTSD) in the general population is reported to be 6.8%. Individuals with alcohol dependence and substance abuse have high prevalence of PTSD. However, the prevalence of PTSD in heavy drinkers with alcoholic hepatitis (AH) is not known.The study's aim was to determine the prevalence of PTSD in heavy drinkers with and without AH., Methods: We screened for PTSD using the Primary Care-PTSD questionnaire among heavy drinkers with (n = 115) and without (n = 64) AH participating in a multicenter observational study in which participants were followed up to 12 months following their enrollment., Results: The prevalence of PTSD in heavy drinkers with AH was 34% and was not different from heavy drinking controls without liver disease (34%). In the entire group screened for PTSD, the presence of PTSD was associated with higher alcohol consumption as reported by average drinks per last 30 days and average grams of alcohol consumed per day (p = 0.047 for both tests), but not associated with relapse of heavy drinking or mortality. Similarly, patients with AH and PTSD did not have higher relapse rate or higher mortality compared to patients with AH but no PTSD., Conclusions: Compared to previously reported prevalence in general population, heavy drinking individuals with or without AH have significantly higher prevalence of PTSD. However, PTSD was not associated with higher relapse rate or higher mortality in this population., (© 2018 by the Research Society on Alcoholism.)

Intestinal dysbiosis is implicated in alcoholic hepatitis (AH). However, changes in the circulating microbiome, its association with the presence and severity of AH, and its functional relevance in AH is unknown. Qualitative and quantitative assessment of changes in the circulating microbiome were performed by sequencing bacterial DNA in subjects with moderate AH (MAH) (n = 18) or severe AH (SAH) (n = 19). These data were compared with heavy drinking controls (HDCs) without obvious liver disease (n = 19) and non-alcohol-consuming controls (NACs, n = 20). The data were related to endotoxin levels and markers of monocyte activation. Linear discriminant analysis effect size (LEfSe) analysis, inferred metagenomics, and predictive functional analysis using PICRUSt were performed. There was a significant increase in 16S copies/ng DNA both in MAH (P < 0.01) and SAH (P < 0.001) subjects. Compared with NACs, the relative abundance of phylum Bacteroidetes was significantly decreased in HDCs, MAH, and SAH (P < 0.001). In contrast, all alcohol-consuming groups had enrichment with Fusobacteria; this was greatest for HDCs and decreased progressively in MAH and SAH. Subjects with SAH had significantly higher endotoxemia (P = 0.01). Compared with alcohol-consuming groups, predictive functional metagenomics indicated an enrichment of bacteria with genes related to methanogenesis and denitrification. Furthermore, both HDCs and SAH showed activation of a type III secretion system that has been linked to gram-negative bacterial virulence. Metagenomics in SAH versus NACs predicted increased isoprenoid synthesis via mevalonate and anthranilate degradation, known modulators of gram-positive bacterial growth and biofilm production, respectively., Conclusion: Heavy alcohol consumption appears to be the primary driver of changes in the circulating microbiome associated with a shift in its inferred metabolic functions. (Hepatology 2018;67:1284-1302)., (© 2017 by the American Association for the Study of Liver Diseases.)

The TREAT Consortium has carried out clinical studies on alcoholic hepatitis (AH) for over 4 years. We encountered problems with participant recruitment, retention, and eligibility for specific protocols. To improve our ability to carry out such trials, we reviewed recruitment screening logs, end of study logs, and surveyed study coordinators to learn the reasons for missing patients, why patients declined enrollment, and the number of patients eligible for treatment trials. Associations of the recruited subjects' demographics with their adherence to follow-up appointments were examined. Three hundred eight-seven patients (AH and heavy drinking controls) were enrolled in the observational study, and 55 AH patients were recruited into treatment trials. About half of patients identified with AH could not be recruited; no specific reason could be determined for about two-thirds of these. Among the patients who gave a reason for not participating, the most common reasons were feeling too sick to participate, desire to concentrate on abstinence, and lack of interest in research. Approximately a quarter of the AH patients met eligibility criteria for treatment trials for moderate or severe AH and we were able to recruit half to two-thirds of those eligible. Approximately 35% of participants in the observational study returned for both 6- and 12-month follow-up visits. We did not identify biopsychosocial or demographic correlates of retention in the study. This analysis revealed that attempts at recruitment into trials for AH miss some subjects because of structural issues surrounding their hospital admission, and encounter a high rate of patient refusal to participate. Nonetheless, more than half of the patients who met the eligibility criteria for moderate or severe AH were entered into clinical trials. Retention rates for the observational study are relatively low. These findings need to be accounted for in clinical trial design and power analysis., (Copyright © 2017 by the Research Society on Alcoholism.)

Alcoholic hepatitis (AH) develops in only a small proportion of heavy drinkers. To better understand the mechanisms underlying this disparity, we conducted a study to define the relationship between AH development and dysregulated immune responses that might be ameliorated by alcohol abstinence. Sixty-eight AH patients, 65 heavy drinking controls without liver disease (HDC), and 20 healthy controls were enrolled and followed up to 12 months. At baseline, HDC and healthy controls had no significant differences in their plasma levels of 38 inflammatory cytokines/chemokines measured using multiplex immunoassays. However, compared to HDC, AH patients had higher baseline levels of 11 cytokines/chemokines (tumor necrosis factor alpha, interleukin 6 [IL-6], IL-8, interferon gamma-induced protein 10, IL-4, IL-9, IL-10, fibroblast growth factor 2, IL-7, IL-15, and transforming growth factor alpha) but lower levels of the anti-inflammatory macrophage-derived chemokine. AH patients also had more activated yet dysfunctional immune cells as monocytes, T cells, and B cells expressed higher levels of cluster of differentiation 38 (CD38) and CD69 but low levels of human leukocyte antigen DR, CD80, and CD86 at baseline. In addition, CD4 T cells produced less interferon-gamma in response to T-cell stimulation. Up-regulated IL-6, IL-8, CD38, and CD69 and down-regulated macrophage-derived chemokine, human leukocyte antigen DR, CD86, and CD80 correlated positively and negatively, respectively, with disease severity. Longitudinal analysis indicated that levels of IL-6, IL-8, CD38, and CD69 were reduced, whereas levels of macrophage-derived chemokine, human leukocyte antigen DR, CD80, and CD86 were increased in abstinent AH patients. All of the cellular immune abnormalities were reversed by day 360 in abstinent AH patients; however, plasma levels of tumor necrosis factor alpha, IL-8, IL-10, fibroblast growth factor 2, and IL-7 remained higher., Conclusion: AH patients were in a highly immune-dysregulated state, whereas HDC showed little evidence of immune activation; alcohol abstinence reversed most, but not all, of the immunological abnormalities. (Hepatology 2017;66:575-590)., (© 2017 by the American Association for the Study of Liver Diseases.)

Objective: To examine the natural history of acute alcoholic hepatitis (AH) and identify predictors of mortality for AH using data from a prospective multicenter observational study., Participants and Methods: We analyzed data from 164 patients with AH and 131 heavy-drinking controls with no liver disease. Participants underwent clinical/laboratory assessment at baseline and 6 and 12 months after enrollment. Multivariable analyses were conducted to identify variables associated with mortality and examine the association between coffee drinking and risk of AH., Results: Thirty-six patients with AH died during follow-up, with estimated 30-day, 90-day, 180-day, and 1-year survival of 0.91 (95% CI, 0.87-0.96), 0.85 (95% CI, 0.80-0.91), 0.80 (95% CI, 0.74-0.87), and 0.75 (95% CI, 0.68-0.83), respectively. In the multivariable analysis, higher serum bilirubin level (hazard ratio [HR]=1.059; 95% CI, 1.022-1.089), lower hemoglobin level (HR=1.263; 95% CI, 1.012-1.575), and lower platelet count (HR=1.006; 95% CI, 1.001-1.012) were independently associated with mortality in AH. Compared with controls, fewer patients with AH regularly consumed coffee (20% vs 44%; P <.001), and this association between regular coffee drinking and lower risk of AH persisted after controlling for relevant covariates (odds ratio=0.26; 95% CI, 0.15-0.46). Time-dependent receiver operating characteristic curve analysis revealed that Model for End-Stage Liver Disease; Maddrey Discriminant Function; age, serum bilirubin, international normalized ratio, and serum creatinine; and Child-Pugh scores all provided similar discrimination performance at 30 days (area under the curve=0.73-0.77)., Conclusion: Alcoholic hepatitis remains highly fatal, with 1-year mortality of 25%. Regular coffee consumption was associated with lower risk of AH in heavy drinkers.

Background & Aims: Only a minority of heavy drinking individuals develop alcoholic hepatitis (AH), for unclear reasons. We analyzed data from the Translational Research and Evolving Alcoholic Hepatitis Treatment cohort, consisting of subjects who drink heavily with normal results from liver tests (controls) and patients with AH. We examined risk factors for the development of AH including body mass index (BMI), drinking pattern and quantity, and sex., Methods: We compared data from 145 patients with AH and 124 controls based on BMI when they joined the cohort; groups were matched for sex and race. Drinking patterns were assessed using the timeline followback method, the Alcohol Use Disorders Identification Test, and the National Institute of Alcohol Abuse and Alcoholism 6-question survey. We performed univariable and multivariable analyses to assess the effects of these factors and their interaction in increasing the risk for AH. We also explored the association between PNPLA3 variants and AH., Results: Cases with AH were older (47 vs 44 y; P = .03). For nearly all measures of quantity of alcohol consumed or frequency of binge drinking, controls drank more heavily than cases with AH. We did not find an association between BMI, sex, drinking patterns, and the presence of AH. Age and BMI were independent predictors for the severity of AH. When we analyzed cases and controls of European ancestry, the PNPLA3 single-nucleotide polymorphism rs738409 was associated with risk for AH (odds ratio, 1.89; P = .007)., Conclusions: Compared with heavy drinkers without liver disease, subjects with AH consumed lower levels of alcohol and had less binge drinking, suggesting an increased sensitivity to the toxic effects of alcohol. The risk for AH may be associated with the PNPLA3 rs738409 polymorphism., Competing Interests: None of the authors have a conflict of interest to declare., (Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background & Aims: Proliferation of liver progenitor cells (LPCs) is associated with inflammation and fibrosis in chronic liver diseases. However, how inflammation and fibrosis affect LPCs remains obscure., Methods: We examined the role of interferon (IFN)-γ, an important pro-inflammatory and anti-fibrotic cytokine, in LPC expansion in HBV-infected patients and in mice challenged with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)- or choline-deficient, ethionine-supplemented (CDE) diet as well as in primary LPCs and LPC cell line., Results: The CK19 staining scores correlated with inflammation and fibrosis grades in the livers from 110 HBV-infected patients. Nine-month IFN-γ treatment decreased LPC numbers, inflammation, and fibrosis in these HBV-infected patients. Similarly, a two-week IFN-γ treatment also decreased LPC activation in DDC-treated mice. Disruption of IFN-γ or its signaling components (e.g., IFNGR, STAT1, and IRF-1) increased LPC proliferation and liver fibrosis in DDC-fed mice. In contrast, deletion of IFN-γ did not increase, but rather slightly reduced LPC proliferation in CDE-fed mice. In vitro, IFN-γ attenuated proliferation of the LPC cell line BMOL and of primary LPCs from wild type mice, but not STAT1(-/-) or IRF-1(-/-) mice. Furthermore, co-culture assays suggest that IFN-γ can indirectly promote LPC proliferation via the activation of macrophages but attenuate it via the inhibition of hepatic stellate cells., Conclusions: IFN-γ inhibits LPC expansion via the direct inhibition of LPC proliferation and indirect attenuation of liver fibrosis in the DDC model, but it may also enhance LPC expansion via the promotion of inflammation in the CDE model; thereby playing dual roles in regulating LPC proliferation in vivo., (Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

The liver lymphocyte population is enriched with natural killer (NK) cells, which play a key role in host defense against viral infection and tumor transformation. Recent evidence from animal models suggests that NK cells also play an important role in inhibiting liver fibrosis by selectively killing early or senescence activated hepatic stellate cells (HSCs) and by producing the anti-fibrotic cytokine IFN-γ. Furthermore, clinical studies have revealed that human NK cells can kill primary human HSCs and that the ability of NK cells from HCV patients to kill HSCs is enhanced and correlates inversely with the stages of liver fibrosis. IFN-α treatment enhances, while other factors (e.g., alcohol, TGF-β) attenuate, the cytotoxicity of NK cells against HSCs, thereby differentially regulating liver fibrogenesis. In addition, the mouse liver lymphocyte population is also enriched for natural killer T (NKT) cells, whereas human liver lymphocytes have a much lower percentage of NKT cells. Many studies suggest that NKT cells promote liver fibrogenesis by producing pro-fibrotic cytokines such as IL-4, IL-13, hedgehog ligands, and osteopontin; however, NKT cells may also attenuate liver fibrosis under certain conditions by killing HSCs and by producing IFN-γ. Finally, the potential for NK and NKT cells to be used as therapeutic targets for anti-fibrotic therapy is discussed. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease., (Published by Elsevier B.V.)

Pancreatitis occurs when digestive enzymes are activated in the pancreas. Severe pancreatitis has a 10-30% mortality rate. No specific treatments for pancreatitis exist now. Here, we discovered that interleukin-22 (IL-22) may have therapeutic potential in treating acute and chronic pancreatitis. Wild-type and IL-22 knockout mice were equally susceptible to cerulein-induced acute and chronic pancreatitis, whereas liver-specific IL-22 transgenic mice were completely resistant to cerulein-induced elevation of serum digestive enzymes, pancreatic necrosis and apoptosis, and inflammatory cell infiltration. Treatment of wild-type mice with recombinant IL-22 or adenovirus IL-22 markedly attenuated the severity of cerulein-induced acute and chronic pancreatitis. Mechanistically, we show that the protective effect of IL-22 on pancreatitis was mediated via the induction of Bcl-2 and Bcl-X(L), which bind to Beclin-1 and subsequently inhibit autophagosome formation to ameliorate pancreatitis. In conclusion, IL-22 ameliorates cerulein-induced pancreatitis by inhibiting the autophagic pathway. IL-22 could be a promising therapeutic drug to treat pancreatitis.

Alcohol consumption is a predominant etiological factor in the pathogenesis of chronic liver diseases worldwide, causing fatty liver, alcoholic hepatitis, fibrosis/cirrhosis, and hepatocellular carcinoma. In the past few decades, significant progress has been made in our understanding of the molecular mechanisms underlying alcoholic liver injury. Activation of innate immunity components such as Kupffer cells, LPS/TLR4, and complements in response to alcohol exposure plays a key role in the development and progression of alcoholic liver disease (ALD). LPS activation of Kupffer cells also produces IL-6 and IL-10 that may play a protective role in ameliorating ALD. IL-6 activates signal transducer and activator of transcription 3 (STAT3) in hepatocytes and sinusoidal endothelial cells, while IL-10 activates STAT3 in Kupffer cells/macrophages, subsequently protecting against ALD. In addition, alcohol consumption also inhibits some components of innate immunity such as natural killer (NK) cells, a type of cells that play key roles in anti-viral, anti-tumor, and anti-fibrotic defenses in the liver. Ethanol inhibition of NK cells likely contributes significantly to the pathogenesis of ALD. Understanding the roles of innate immunity and cytokines in alcoholic liver injury may provide insight into novel therapeutic targets in the treatment of alcoholic liver disease., (Copyright © 2011 by the Research Society on Alcoholism.)

IL-10R2 is a shared cell surface receptor required for the activation of five class 2 cytokines (IL-10, IL-22, IL-26, IL-28, and IL-29) that play critical roles in host defense. To define the molecular mechanisms that regulate its promiscuous binding, we have determined the crystal structure of the IL-10R2 ectodomain at 2.14 A resolution. IL-10R2 residues required for binding were identified by alanine scanning and used to derive computational models of IL-10/IL-10R1/IL-10R2 and IL-22/IL-22R1/IL-10R2 ternary complexes. The models reveal a conserved binding epitope that is surrounded by two clefts that accommodate the structural and chemical diversity of the cytokines. These results provide a structural framework for interpreting IL-10R2 single nucleotide polymorphisms associated with human disease., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Conditional targeted cell ablation is a powerful approach for investigating the pathogenesis of human diseases and in vivo cellular functions. Intermedilysin (ILY) is a cytolytic pore-forming toxin secreted by Streptococcus intermedius that lyses human cells exclusively, owing to its receptor specificity for human CD59. We generated two transgenic mouse strains that express human CD59 either on erythrocytes (strain ThCD59(RBC)) or on endothelia (strain ThCD59(END)). Intravenous injection of ILY in ThCD59(RBC) mice induced acute intravascular hemolysis, leading to reduced nitric oxide bioavailability, increased platelet activation and rapid death. In ThCD59(END) mice, ILY induced rapid endothelial damage, leading to acute death and disseminated intravascular coagulation. Additionally, we show that human serum contains ILY-specific neutralizing antibodies not found in any other animal species. Together, these results suggest that this new rapid conditional targeted ILY-mediated cell ablation technique can be used in combination with any available transgenic expression system to study the physiologic role of specific cell populations.

Hepatic stellate cells (HSCs) store 75% of the body's supply of vitamin A (retinol) and play a key role in liver fibrogenesis. During liver injury, HSCs become activated and susceptible to natural killer (NK) cell killing due to increased expression of the NK cell activating ligand retinoic acid early inducible gene 1 (RAE-1). To study the mechanism by which RAE-1 is upregulated in HSCs during activation, an in vitro model of cultured mouse HSCs was employed. RAE-1 was detected at low levels in quiescent HSCs but upregulated in 4- and 7-day cultured HSCs (early activated HSCs), whereas 21-day cultured HSCs (fully activated HSCs) lost RAE-1 expression. High levels of RAE-1 in 4- and 7-day cultured HSCs correlated with their susceptibility to NK cell killing, which was diminished by treatment with RAE-1 neutralizing antibody. Furthermore, retinoic acid (RA) and retinal dehydrogenase (Raldh) levels were upregulated in early activated HSCs compared with quiescent or fully activated HSCs. Blocking RA synthesis by the Raldh inhibitor or blocking RA signaling by the retinoic acid receptor antagonist abolished upregulation of RAE-1 whereas treatment with RA induced RAE-1 expression in HSCs. In conclusion, during activation, HSCs lose retinol, which is either secreted out or oxidized into RA; the latter stimulates RAE-1 expression and sensitizes early activated HSCs to NK cell killing. In contrast, fully activated HSCs become resistant to NK cell killing because of lack of RAE1 expression, leading to chronic liver fibrosis and disease.

Liver lymphocytes are enriched in natural killer (NK) cells, which are involved in innate immune defenses against viral infection and tumor transformation in the liver. Recent evidence indicates that NK cell activation by IFN-alpha, IFN-gamma or dsRNA attenuates liver fibrosis through the direct killing of activated hepatic stellate cells (HSCs). Interestingly, NK cells do not kill quiescent or fully activated HSCs, but only early-activated HSCs, as only these cells express elevated levels of the NK cell-activating ligand retinoic acid-induced early transcript (RAE)-1 and TNF-related apoptosis-inducing ligand receptors, in addition to downregulated levels of the NK-cell inhibitory ligand, MHC-I. Inhibition of liver fibrosis by NK cells can also be achieved through production of IFN-gamma, which induces HSC cell cycle arrest and apoptosis in a STAT1-dependent manner. Clinically, it has also been observed that NK cell activity is negatively correlated with liver fibrosis in patients with chronic hepatitis C infection. Therefore, since NK cells inhibit liver fibrosis, stimulating NK activity could potentially be a novel strategy to treat liver fibrosis. Clinical studies will be required to confirm whether stimulating NK cell activity is effective and safe in treating human liver fibrosis.

Liver fibrosis, a common scarring response to chronic liver injury, is a precursor to cirrhosis and liver cancer. Here, we identified signal transducer and activator of transcription 1 (STAT1) as an important negative regulator in liver fibrosis. Our findings show that disruption of the STAT1 gene accelerated liver fibrosis and hepatic stellate cell (HSC) proliferation in an in vivo model of carbon tetrachloride (CCl4)-induced liver fibrosis. In vitro treatment with IFN-gamma inhibited proliferation and activation of wild-type HSCs, but not STAT1-/- HSCs. Moreover, compared to wild-type cells, cellular proliferation stimulated by serum or platelet-derived growth factor (PDGF) was enhanced and accelerated in STAT1-/- HSCs, which was partially mediated via elevated PDGF receptor beta expression on such cells. Polyinosinic-polycytidylic acid (poly I:C) or IFN-gamma treatment inhibited liver fibrosis in wild-type mice but not in STAT1-/- mice. Induction of NK cell killing of activated HSCs by poly I:C was attenuated in STAT1-/- mice compared to wild-type mice, which was likely due to reduced NKG2D and TRAIL expression on STAT1-/- NK cells. Finally, activation of TGF-beta/Smad3 signaling pathway was accelerated, whereas induction of Smad7 was diminished in the liver of STAT1-/- mice after CCl4 administration compared to wild-type mice. In conclusion, activation of STAT1 attenuates liver fibrosis through inhibition of HSC proliferation, attenuation of TGF-beta signaling, and stimulation of NK cell killing of activated HSCs. STAT1 could be a new therapeutic target for treating liver fibrosis.

Increasing evidence suggests that liver regeneration is suppressed in patients with chronic HCV infection; however, the underlying mechanisms remain unclear. Previously, we demonstrated that injection of the synthetic double-stranded RNA (dsRNA) poly I:C to mimic viral infection suppresses liver regeneration in the partial hepatectomy (PHx) model, whereby IFN-gamma contributes to the inhibition. In this study, we examined the role of the IFN-gamma-activated downstream signal (STAT1) and genes (IRF-1, p21(cip1), and SOCS1) in liver regeneration and hepatocyte proliferation. Results show that disruption of the STAT1 gene abolished poly I:C suppression of liver regeneration and the inhibitory effect of poly I:C on liver regeneration was diminished in IRF-1(-/-) and p21(cip1-/-)mice. Treatment with IFN-gamma in vitro inhibited cell proliferation of wild-type mouse hepatocytes, but not STAT1(-/-) hepatocytes. The inhibitory effect of IFN-gamma on cell proliferation was also diminished in IRF-1(-/-) and p21(cip1-/-) hepatocytes, but enhanced in SOCS1(-/-) hepatocytes. Hepatocyte proliferation was unaffected by treatment with poly I:C alone, but when hepatocytes were co-cultured with liver lymphocytes, proliferation was inhibited by IFN-gamma/STAT1-dependent mechanisms. Moreover, in HCV-infected livers with cirrhosis, activation of STAT1 was detected and correlated positively with liver injury (elevated serum levels of AST) but negatively with hepatocyte proliferation (hepatocyte PCNA and Ki-67 positive immunostaining). In conclusion, STAT1 is involved in dsRNA suppression of liver regeneration; not only does STAT1 activation contribute to liver injury, it may also block liver repair through inhibition of hepatocyte proliferation in HCV-infected patients, playing an important role in the pathogenesis of disease.

Cholangiocellular carcinoma (CC), the second most common primary liver cancer, is associated with a poor prognosis. It has been shown that CCs harbor alterations of a number of tumor-suppressor genes and oncogenes, yet key regulators for tumorigenesis remain unknown. Here we have generated a mouse model that develops CC with high penetrance using liver-specific targeted disruption of tumor suppressors SMAD4 and PTEN. In the absence of SMAD4 and PTEN, hyperplastic foci emerge exclusively from bile ducts of mutant mice at 2 months of age and continue to grow, leading to tumor formation in all animals at 4-7 months of age. We show that CC formation follows a multistep progression of histopathological changes that are associated with significant alterations, including increased levels of phosphorylated AKT, FOXO1, GSK-3beta, mTOR, and ERK and increased nuclear levels of cyclin D1. We further demonstrate that SMAD4 and PTEN regulate each other through a novel feedback mechanism to maintain an expression balance and synergistically repress CC formation. Finally, our analysis of human CC detected PTEN inactivation in a majority of p-AKT-positive CCs, while about half also lost SMAD4 expression. These findings elucidate the relationship between SMAD4 and PTEN and extend our understanding of CC formation.