Gut microbiota-modulating agents in alcoholic liver disease: Links between host metabolism and gut microbiota

Alcoholic liver disease (ALD) involves a wide spectrum of diseases, including asymptomatic hepatic steatosis, alcoholic hepatitis, hepatic fibrosis, and cirrhosis, which leads to morbidity and mortality and is responsible for 0.9% of global deaths. Alcohol consumption induces bacterial translocation and alteration of the gut microbiota composition. These changes in gut microbiota aggravate hepatic inflammation and fibrosis. Alteration of the gut microbiota leads to a weakened gut barrier and changes host immunity and metabolic function, especially related to bile acid metabolism. Modulation and treatment for the gut microbiota in ALD has been studied using probiotics, prebiotics, synbiotics, and fecal microbial transplantation with meaningful results. In this review, we focused on the interaction between alcohol and gut dysbiosis in ALD. Additionally, treatment approaches for gut dysbiosis, such as abstinence, diet, pro-, pre-, and synbiotics, antibiotics, and fecal microbial transplantation, are covered here under ALD. However, further research through human clinical trials is warranted to evaluate the appropriate gut microbiota-modulating agents for each condition related to ALD.

Primary Biliary Cholangitis and Primary Sclerosing Cholangitis: Current Knowledge of Pathogenesis and Therapeutics

Cholangiopathies encompass various biliary diseases affecting the biliary epithelium, resulting in cholestasis, inflammation, fibrosis, and ultimately liver cirrhosis. Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are the most important progressive cholangiopathies in adults. Much research has broadened the scope of disease biology to genetic risk, epigenetic changes, dysregulated mucosal immunity, altered biliary epithelial cell function, and dysbiosis, all of which interact and arise in the context of ill-defined environmental triggers. An in-depth understanding of the molecular pathogenesis of these cholestatic diseases will help clinicians better prevent and treat diseases. In this review, we focus on the main underlying mechanisms of disease initiation and progression, and novel targeted therapeutics beyond currently approved treatments.

Recent Trends of Microbiota-Based Microbial Metabolites Metabolism in Liver Disease

The gut microbiome and microbial metabolomic influences on liver diseases and their diagnosis, prognosis, and treatment are still controversial. Research studies have provocatively claimed that the gut microbiome, metabolomics understanding, and microbial metabolite screening are key approaches to understanding liver cancer and liver diseases. An advance of logical innovations in metabolomics profiling, the metabolome inclusion, challenges, and the reproducibility of the investigations at every stage are devoted to this domain to link the common molecules across multiple liver diseases, such as fatty liver, hepatitis, and cirrhosis. These molecules are not immediately recognizable because of the huge underlying and synthetic variety present inside the liver cellular metabolome. This review focuses on microenvironmental metabolic stimuli in the gut-liver axis. Microbial small-molecule profiling (i.e., semiquantitative monitoring, metabolic discrimination, target profiling, and untargeted profiling) in biological fluids has been incompletely addressed. Here, we have reviewed the differential expression of the metabolome of short-chain fatty acids (SCFAs), tryptophan, one-carbon metabolism and bile acid, and the gut microbiota effects are summarized and discussed. We further present proof-of-evidence for gut microbiota-based metabolomics that manipulates the host's gut or liver microbes, mechanosensitive metabolite reactions and potential metabolic pathways. We conclude with a forward-looking perspective on future attention to the “dark matter” of the gut microbiota and microbial metabolomics.

Platelet-to-White Blood Cell Ratio Is Associated with Adverse Outcomes in Cirrhotic Patients with Acute Deterioration

Background: The platelet-to-white blood cell ratio (PWR) is a hematologic marker of the systemic inflammatory response. Recently, the PWR was revealed to have a role as an independent prognostic factor for mortality in patients with hepatitis B virus (HBV)-related acute-on-chronic failure (ACLF) and HBV-related liver cirrhosis (LC) with acute decompensation (AD). However, the prognostic role of the PWR still needs to be investigated in LC patients with AD. In this study, we analyzed whether the PWR could stratify the risk of adverse outcomes (death or liver transplantation (LT)) in these patients. Methods: A prospective cohort of 1670 patients with AD of liver cirrhosis ((age: 55.2 ± 7.8, male = 1226 (73.4%)) was enrolled and evaluated for 28-day and overall adverse outcomes. Results: During a median follow-up of 8.0 months (range, 1.9−15.5 months), 424 (25.4%) patients had adverse outcomes (death = 377, LT = 47). The most common etiology of LC was alcohol use (69.7%). The adverse outcome rate was higher for patients with a PWR ≤ 12.1 than for those with a PWR > 12.1. A lower PWR level was a prognostic factor for 28-day adverse outcomes (PWR: hazard ratio 1.707, p = 0.034) when adjusted for the etiology of cirrhosis, infection, ACLF, and the MELD score. In the subgroup analysis, the PWR level stratified the risk of 28-day adverse outcomes regardless of the presence of ACLF or the main form of AD but not for those with bacterial infection. Conclusions: A lower PWR level was associated with 28-day adverse outcomes, indicating that the PWR level can be a useful and simple tool for stratifying the risk of 28-day adverse outcomes in LC patients with AD.

The Role of Gut Dysbiosis in Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is an important syndrome of liver failure that has a high risk of short-term mortality in patients with chronic liver disease. The development of ACLF is associated with proinflammatory precipitating events, such as infection, alcoholic hepatitis, and intense systemic inflammation. Recently, the role of the gut microbiome has increasingly emerged in human health and disease. Additionally, the gut microbiome might have a major role in the development of liver disease. In this review, we examine evidence to support the role of gut dysbiosis in cirrhosis and ACLF. Additionally, we explore the mechanism by which the gut microbiome contributes to the development of ACLF, with a focus on alcohol-induced liver disease.

Significance of gut microbiota in alcoholic and non-alcoholic fatty liver diseases

Liver-gut communication is vital in fatty liver diseases, and gut microbes are the key regulators in maintaining liver homeostasis. Chronic alcohol abuse and persistent overnutrition create dysbiosis in gut ecology, which can contribute to fatty liver disease. In this review, we discuss the gut microbial compositional changes that occur in alcoholic and nonalcoholic fatty liver diseases and how this gut microbial dysbiosis and its metabolic products are involved in fatty liver disease pathophysiology. We also summarize the new approaches related to gut microbes that might help in the diagnosis and treatment of fatty liver disease.

Gut Microbiota-Related Cellular and Molecular Mechanisms in the Progression of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common and increasing liver diseases worldwide. NAFLD is a term that involves a variety of conditions such as fatty liver, steatohepatitis, or fibrosis. Gut microbiota and its products have been extensively studied because of a close relation between NAFLD and microbiota in pathogenesis. In the progression of NAFLD, various microbiota-related molecular and cellular mechanisms, including dysbiosis, leaky bowel, endotoxin, bile acids enterohepatic circulation, metabolites, or alcohol-producing microbiota, are involved. Currently, diagnosis and treatment techniques using these mechanisms are being developed. In this review, we will introduce the microbiota-related mechanisms in the progression of NAFLD and future directions will be discussed.

Dynamic assessments of hepatic encephalopathy and ammonia levels predict mortality in acute-on-chronic liver failure

BACKGROUND

We evaluated the dynamics of hepatic encephalopathy (HE) and ammonia estimation in acute-on-chronic liver failure (ACLF) patients due to a paucity of evidence.

METHODS

ACLF patients recruited from the APASL-ACLF Research Consortium (AARC) were followed up till 30 days, death or transplantation, whichever earlier. Clinical details, including dynamic grades of HE and laboratory data, including ammonia levels, were serially noted.

RESULTS

Of the 3009 ACLF patients, 1315 (43.7%) had HE at presentation; grades I-II in 981 (74.6%) and grades III-IV in 334 (25.4%) patients. The independent predictors of HE at baseline were higher age, systemic inflammatory response, elevated ammonia levels, serum protein, sepsis and MELD score (p < 0.05; each). The progressive course of HE was noted in 10.0% of patients without HE and 8.2% of patients with HE at baseline, respectively. Independent predictors of progressive course of HE were AARC score (≥ 9) and ammonia levels (≥ 85 μmol/L) (p < 0.05; each) at baseline. A final grade of HE was achieved within 7 days in 70% of patients and those with final grades III-IV had the worst survival (8.9%). Ammonia levels were a significant predictor of HE occurrence, higher HE grades and 30-day mortality (p < 0.05; each). The dynamic increase in the ammonia levels over 7 days could predict nonsurvivors and progression of HE (p < 0.05; each). Ammonia, HE grade, SIRS, bilirubin, INR, creatinine, lactate and age were the independent predictors of 30-day mortality in ACLF patients.

CONCLUSIONS

HE in ACLF is common and is associated with systemic inflammation, poor liver functions and high disease severity. Ammonia levels are associated with the presence, severity, progression of HE and mortality in ACLF patients.

Comparative accuracy of prognostic models for short-term mortality in acute-on-chronic liver failure patients: CAP-ACLF

BACKGROUND

Multiple predictive models of mortality exist for acute-on-chronic liver failure (ACLF) patients that often create confusion during decision-making. We studied the natural history and evaluated the performance of prognostic models in ACLF patients.

METHODS

Prospectively collected data of ACLF patients from APASL-ACLF Research Consortium (AARC) was analyzed for 30-day outcomes. The models evaluated at days 0, 4, and 7 of presentation for 30-day mortality were: AARC (model and score), CLIF-C (ACLF score, and OF score), NACSELD-ACLF (model and binary), SOFA, APACHE-II, MELD, MELD-Lactate, and CTP. Evaluation parameters were discrimination (c-indices), calibration [accuracy, sensitivity, specificity, and positive/negative predictive values (PPV/NPV)], Akaike/Bayesian Information Criteria (AIC/BIC), Nagelkerke-R², relative prediction errors, and odds ratios.

RESULTS

Thirty-day survival of the cohort (n = 2864) was 64.9% and was lowest for final-AARC-grade-III (32.8%) ACLF. Performance parameters of all models were best at day 7 than at day 4 or day 0 (p < 0.05 for C-indices of all models except NACSELD-ACLF). On comparison, day-7 AARC model had the numerically highest c-index 0.872, best accuracy 84.0%, PPV 87.8%, R² 0.609 and lower prediction errors by 10-50%. Day-7 NACSELD-ACLF-binary was the simple model (minimum AIC/BIC 12/17) with the highest odds (8.859) and sensitivity (100%) but with a lower PPV (70%) for mortality. Patients with day-7 AARC score > 12 had the lowest 30-day survival (5.7%).

CONCLUSIONS

APASL-ACLF is often a progressive disease, and models assessed up to day 7 of presentation reliably predict 30-day mortality. Day-7 AARC model is a statistically robust tool for classifying risk of death and accurately predicting 30-day outcomes with relatively lower prediction errors. Day-7 AARC score > 12 may be used as a futility criterion in APASL-ACLF patients.

An Overview of the Molecular Mechanisms Contributing to Musculoskeletal Disorders in Chronic Liver Disease: Osteoporosis, Sarcopenia, and Osteoporotic Sarcopenia

The prevalence of osteoporosis and sarcopenia is significantly higher in patients with liver disease than in those without liver disease and osteoporosis and sarcopenia negatively influence morbidity and mortality in liver disease, yet these musculoskeletal disorders are frequently overlooked in clinical practice for patients with chronic liver disease. The objective of this review is to provide a comprehensive understanding of the molecular mechanisms of musculoskeletal disorders accompanying the pathogenesis of liver disease. The increased bone resorption through the receptor activator of nuclear factor kappa (RANK)-RANK ligand (RANKL)-osteoprotegerin (OPG) system and upregulation of inflammatory cytokines and decreased bone formation through increased bilirubin and sclerostin and lower insulin-like growth factor-1 are important mechanisms for osteoporosis in patients with liver disease. Sarcopenia is associated with insulin resistance and obesity in non-alcoholic fatty liver disease, whereas hyperammonemia, low amount of branched chain amino acids, and hypogonadism contributes to sarcopenia in liver cirrhosis. The bidirectional crosstalk between muscle and bone through myostatin, irisin, β-aminoisobutyric acid (BAIBA), osteocalcin, as well as the activation of the RANK and the Wnt/β-catenin pathways are associated with osteosarcopenia. The increased understandings for these musculoskeletal disorders would be contributes to the development of effective therapies targeting the pathophysiological mechanism involved.

Alteration of Gut Microbiota in Carbapenem-Resistant Enterobacteriaceae Carriers during Fecal Microbiota Transplantation According to Decolonization Periods

Fecal microbiota transplantation (FMT) has been suggested as an alternative therapeutic option to decolonize carbapenem-resistant Enterobacteriaceae (CRE). However, the analysis of gut microbiota alteration in CRE carriers during FMT is still limited. Here, gut microbiota changes in CRE carriers were evaluated during FMT according to decolonization periods. The decolonization of 10 CRE carriers was evaluated after FMT, using serial consecutive rectal swab cultures. Alterations of gut microbiota before and after FMT (56 serial samples) were analyzed using high-throughput sequencing. The decolonization rates of CRE carriers were 40%, 50%, and 90% within 1, 3 and 5 months after initial FMT, respectively. Gut microbiota significantly changed after FMT (p = 0.003). Microbiota alteration was different between the early decolonization carriers (EDC) and late decolonization carriers (LDC). Microbiota convergence in carriers to donors was detected in EDC within 4 weeks, and keystone genera within the Bacteroidetes were found in the gut microbiota of EDC before FMT. The relative abundance of Klebsiella was lower in EDC than in LDC, before and after FMT. Our results indicate that FMT is a potential option for CRE decolonization. The gut microbiota of CRE carriers could be used to predict decolonization timing after FMT, and determine repeated FMT necessity.

Gut Microbiota at the Intersection of Alcohol, Brain, and the Liver

Over the last decade, increased research into the cognizance of the gut-liver-brain axis in medicine has yielded powerful evidence suggesting a strong association between alcoholic liver diseases (ALD) and the brain, including hepatic encephalopathy or other similar brain disorders. In the gut-brain axis, chronic, alcohol-drinking-induced, low-grade systemic inflammation is suggested to be the main pathophysiology of cognitive dysfunctions in patients with ALD. However, the role of gut microbiota and its metabolites have remained unclear. Eubiosis of the gut microbiome is crucial as dysbiosis between autochthonous bacteria and pathobionts leads to intestinal insult, liver injury, and neuroinflammation. Restoring dysbiosis using modulating factors such as alcohol abstinence, promoting commensal bacterial abundance, maintaining short-chain fatty acids in the gut, or vagus nerve stimulation could be beneficial in alleviating disease progression. In this review, we summarize the pathogenic mechanisms linked with the gut-liver-brain axis in the development and progression of brain disorders associated with ALD in both experimental models and humans. Further, we discuss the therapeutic potential and future research directions as they relate to the gut-liver-brain axis.

Nutritional Status and Diet Style Affect Cognitive Function in Alcoholic Liver Disease

Malnutrition and cognitive dysfunction are typical features of alcoholic liver disease (ALD) and are correlated with the development of complications. The aim of this study is to explore the effect of nutritional state and diet on cognitive function in ALD. A total of 43 patients with compensated alcoholic cirrhosis were enrolled, and a neuropsychological test was assessed according to body mass index (BMI, <22 and ≥22). In the ALD animal study, mice were divided into five groups (n = 9/group; normal liquid, 5% EtOH + regular liquid, 5% EtOH + high-carbohydrate liquid, 5% EtOH + high-fat liquid, and 5% EtOH + high-protein liquid diet) and fed the same calories for eight weeks. To assess cognitive function, we performed T-maze studies weekly before/after alcohol binging. In cognitive function (BMI < 22/≥22), language score of Korea mini-mental state (7.4 ± 1.4/7.9 ± 0.4), Boston naming (11.7 ± 2.7/13.0 ± 1.8), forward digit span (6.7 ± 1.8/7.5 ± 1.6), Korean color word stroop (24.2 ± 26.5/43.6 ± 32.4), and interference score (33.9 ± 31.9/52.3 ± 33.9) revealed significant differences. In the T-maze test, alcohol significantly delayed the time to reach food, and binge drinking provided a temporary recovery in cognition. The alcohol-induced delay was significantly reduced in the high-carbohydrate and high-fat diet groups. Synaptic function exhibited no changes in all groups. Cognitive dysfunction is affected by nutritional status and diet in ALD.

Serum Myostatin Predicts the Risk of Hepatocellular Carcinoma in Patients with Alcoholic Cirrhosis: A Multicenter Study

Background and Aim: Previous studies reported that serum myostatin is associated with sarcopenia. We aimed to elucidate the association between serum myostatin levels and hepatocellular carcinoma (HCC) development in patients with alcoholic liver cirrhosis (ALC). Methods: This retrospective, multicenter study assessed 1077 Asian ALC patients enrolled from 2007 to 2017. The primary endpoint was the development of HCC within 5 years. Cox proportional hazards model analyses were used to assess the association of serum myostatin levels and HCC development. The time-dependent areas under the receiver operating characteristic curve (AUROC) of serum myostatin for 5-year HCC development were calculated. Serum myostatin levels were measured using an enzyme-linked immunosorbent assay with samples collected on the index date. Results: During a median follow-up of 2.5 years, 5-year cumulative HCC incidence rates were 6.7% in the total population. The median level of serum myostatin was 3.3 ng/mL (interquartile, 2.1-5.2 ng/mL). The AUROC of serum myostatin for 5-year HCC development was 0.78 (95% confidence interval [CI], 0.76-0.81). In Cox proportional hazards model analyses, age, gender, platelet counts, and serum myostatin levels were independent risk factors for HCC development (adjusted hazard ratios [HRs] of age, male gender, platelet counts, and serum myostatin: 1.03, 2.79, 0.996, 1.18, respectively; all p < 0.05). Patients with high myostatin levels had a significantly higher risk of 5-year HCC development than those with low myostatin levels (HR 7.53, p < 0.001). Conclusion: Higher serum myostatin levels were significantly associated with a higher risk of developing HCC in ALC patients, which could identify high-risk patients who need stringent surveillance.

Application of Hepatic Venous Pressure Gradient to Predict Prognosis in Cirrhotic Patients with a Low Model for End-Stage Liver Disease Score

Background/aim: We aimed to derive a model representing the dynamic status of cirrhosis and to discriminate patients with poor prognosis even if the Model for End-Stage Liver Disease (MELD) score is low. Methods: This study retrospectively enrolled 700 cirrhotic patients with a MELD score of less than 20 who underwent hepatic venous pressure gradient (HVPG) measurement. A model named H6C score (= HVPG + 6 × CTP score) to predict overall survival was derived and internal and external validations were conducted with the derivation and validation cohorts. Results: The H6C score using the HVPG was developed based on a multivariate Cox regression analysis. The H6C score showed a great predictive power for overall survival with a time-dependent AUC of 0.733, which was superior to that of a MELD of 0.602. In patients with viral etiology, the performance of the H6C score was much improved with a time-dependent AUC of 0.850 and was consistently superior to that of the MELD (0.748). Patients with an H6C score below 45 demonstrated an excellent overall survival with a 5-year survival rate of 91.5%. Whereas, patients with an H6C score above 64 showed a dismal prognosis with a 5-year survival rate of 51.1%. The performance of the H6C score was further verified to be excellent in the validation cohort. Conclusion: This new model using the HVPG provides an excellent predictive power in cirrhotic patients, especially with viral etiology. In patients with H6C above 64, it would be wise to consider early liver transplantation to positively impact long-term survival, even when the MELD score is low.

Global and regional impacts of alcohol use on public health: Emphasis on alcohol policies

Alcohol is a well-known risk factor for premature morbidity and mortality. The per capita alcohol consumption of the world's population rose from 5.5 L in 2005 to 6.4 L in 2010 and was still at the level of 6.4 L in 2016. Alcohol-attributable deaths and disability-adjusted life years (DALYs) declined from 2000 to 2016 by 17.9% and 14.5%, respectively. However, these gains observed in the alcohol-attributable burden have proportionally not kept pace with the total health gains during the same period. In 2016, 3.0 million deaths worldwide and 132 million DALYs were attributable to alcohol, responsible for 5.3% of all deaths and 5.0% of all DALYs. These burdens are the highest in the regions of Eastern Europe and sub-Saharan Africa. The alcohol-attributable burden is particularly heavy among young adults, accounting for 7.2% of all premature mortalities. Among the disease categories to which alcohol is related, injuries, digestive diseases, and cardiovascular diseases are the leading causes of the alcohol-attributable burden. To reduce the harmful use of alcohol in a country, the 'whole of government' and 'whole of society' approaches are required with the implementation of evidence-based alcohol control policies, the pursuit of public health priorities, and the adoption of appropriate policies over a long period of time. In this review, we summarize previous efforts to investigate the alcohol-attributable disease burden and the best ways to protect against harmful use of alcohol and promote health.

The Influence of Histologic Inflammation on the Improvement of Liver Stiffness Values Over 1 and 3 Years

BACKGROUND

Transient elastography is now an indispensable tool for estimating liver fibrosis. Although many clinical factors other than fibrosis itself are known to affect liver stiffness (LS) values, it is still not yet clear what factors are related to improving LS values. The aim of this study was to find out how baseline histologic inflammation influences LS values and how much this inflammation affects improvement in LS values over time, regardless of actual fibrosis content.

METHODS

This retrospective study included 678 consecutive patients who underwent liver biopsy and sequential LS assessment from 2006 to 2015 at six tertiary hospitals in Korea. Linear regression analysis was used to evaluate how improvement of LS value can be associated with other factors besides fibrosis content.

RESULTS

Basal LS values increased with increasing inflammation in the same fibrosis stage. Degree of inflammation influenced the baseline LS value in a proportional manner (beta coefficient (BE), 6.476; 95% confidence interval (CI), 2.24-10.72; p = 0.003). Moreover, histologic inflammation affected the change in LS value significantly. Higher inflammation grade at baseline was a significant predictor for an improvement in LS value, regardless of the fibrosis stage (BE, -8.581; 95% CI, -15.715--1.447; p = 0.019). In a subgroup analysis of patients who received repeated liver biopsies, the results showed a similar tendency.

CONCLUSIONS

The LS value is affected by the degree of inflammation even at a low ALT level. Furthermore, baseline histologic inflammation has a significant impact on the improvement of LS values over time. Therefore, baseline inflammation should be taken into consideration when interpreting an improvement in LS value.

Trends in the prevalence of chronic liver disease in the Korean adult population, 1998-2017

Data on the trends in the prevalence of chronic liver disease (CLD) in Korea are scarce. This study aimed to evaluate whether the CLD prevalence changed between 1998-2001 and 2016-2017. Data were extracted from the Korea National Health and Nutrition Examination Survey (1998-2001 to 2016-2017; n=25,893). Non-alcoholic fatty liver disease (NAFLD) was defined as a hepatic steatosis index >36 in the absence of any other evidence of CLD. The definition of alcoholrelated liver disease (ALD) was excessive alcohol consumption (≥210 g/week for men and ≥140 g/week for women) and an ALD/NAFLD index >0. The prevalence of NAFLD increased from 18.6% (95% confidence interval [CI], 17.8-19.5%) in 1998-2001 to 21.5% (95% CI, 20.6-22.6%) in 2016-2017. During the same time period, increases were observed in the prevalence of obesity (27.0 vs. 35.1%), central obesity (29.4 vs. 36.0%), diabetes (7.5 vs. 10.6%), and excessive drinking (7.3 vs. 10.5%). ALD prevalence also increased from 3.8% (95% CI, 3.4-4.2%) to 7.0% (95% CI, 6.4-7.6%). In contrast, chronic hepatitis B decreased from 5.1% (95% CI, 4.6-5.5%) to 3.4% (95% CI, 3.0-3.8%). The prevalence of chronic hepatitis C was approximately 0.3% in 2016-2017. The prevalence of NAFLD and ALD increase among Korean adults. Our results suggest potential targets for interventions to reduce the future burden of CLD.

The Impact of Previous Acute Decompensation on the Long-Term Prognosis of Alcoholic Hepatitis in Cirrhotic Patients

Recurrent episodes of liver injury may either waste hepatic reserve or induce tolerance to further injury. We aimed to investigate whether the previous acute decompensation (AD) in liver cirrhosis (LC) affects the long-term transplant-free survival of patients with alcoholic hepatitis (AH). The survival data of 894 alcoholic LC cohort who had been admitted with acute deterioration in 21 academic hospitals in Korea were prospectively followed up. Enrolled patients were divided into three groups: Group 1, without AH; group 2, with nonsevere AH; and group 3, with severe AH. Although the baseline liver function was not different between the groups with or without previous AD, it was a significant predictor of poor long-term outcomes. The presence of previous AD negatively affected long-term overall survival (HR 1.62, 95% C.I. 1.20–2.18, p = 0.002) in groups 1 and 2 as a whole, independent of the Model for End-stage Liver Disease score. The three-month conditional survival was significantly worse in group 3 for up to 12 months in the presence of previous AD (p < 0.05). We concluded that not only the severity of AH, but also the prior AD is an important predictor of long-term outcomes in alcoholic LC patients with acute deterioration.

Bone Diseases in Patients with Chronic Liver Disease

Osteoporosis is a frequently observed complication in patients with chronic liver disease, particularly liver cirrhosis and cholestatic liver diseases. In addition, osteoporosis is critical in patients receiving a liver transplant. Nevertheless, few studies have evaluated bone diseases in patients with more frequently observed chronic liver disease, such as chronic viral hepatitis, nonalcoholic fatty liver disease and alcoholic liver disease. Osteoporosis is a disease caused by an imbalance in the activities of osteoblasts and osteoclasts. Over the last few decades, many advances have improved our knowledge of the pathogenesis of osteoporosis. Importantly, activated immune cells affect the progression of osteoporosis, and chronic inflammation may exert an additional effect on the existing pathophysiology of osteoporosis. The microbiota of the intestinal tract may also affect the progression of bone loss in patients with chronic liver disease. Recently, studies regarding the effects of chronic inflammation on dysbiosis in bone diseases have been conducted. However, mechanisms underlying osteoporosis in patients with chronic liver disease are complex and precise mechanisms remain unknown. The following special considerations in patients with chronic liver disease are reviewed: bone diseases in patients who underwent a liver transplant, the association between chronic hepatitis B virus infection treatment and bone diseases, the association between sarcopenia and bone diseases in patients with chronic liver disease, and the association between chronic liver disease and avascular necrosis of the hip. Few guidelines are currently available for the management of low bone mineral density or bone diseases in patients with chronic liver disease. Due to increased life expectancy and therapeutic advances in chronic liver disease, the importance of managing osteoporosis and other bone diseases in patients with chronic liver disease is expected to increase. Consequently, specific guidelines need to be established in the near future.

Response-Related Factors of Bone Marrow-Derived Mesenchymal Stem Cells Transplantation in Patients with Alcoholic Cirrhosis

Liver cirrhosis leads to hepatic dysfunction and life-threatening conditions. Although the clinical efficacy of autologous bone marrow-derived mesenchymal stem cells (BM-MSC) transplantation in alcoholic cirrhosis (AC) was demonstrated, the relevant mechanism has not been elucidated. We aimed to identify the predictive factors and gene/pathways for responders after autologous BM-MSC transplantation. Fifty-five patients with biopsy-proven AC underwent autologous BM-MSC transplantation. The characteristics of responders who showed improvement in fibrosis score (≥1) after transplantation were compared with those of non-responders. BM-MSCs were analyzed with cDNA microarrays to identify gene/pathways that were differentially expressed in responders. Thirty-three patients (66%) were responders. A high initial Laennec score (p = 0.007, odds ratio 3.73) and performance of BM-MSC transplantation (p = 0.033, odds ratio 5.75) were predictive factors for responders. Three genes (olfactory receptor2L8, microRNA4520-2, and chloride intracellular channel protein3) were upregulated in responders, and CD36 and retinol-binding protein 4 are associated with the biologic processes that are dominant in non-responders. Eleven pathways (inositol phosphate, ATP-binding cassette transporters, protein-kinase signaling, extracellular matrix receptor interaction, endocytosis, phagosome, hematopoietic cell lineage, adipocytokine, peroxisome proliferator-activated receptor, fat digestion/absorption, and insulin resistance) were upregulated in non-responders (p < 0.05). BM-MSC transplantation may be warranted treatment for AC patients with high Laennec scores. Cell-based therapy utilizing response-related genes or pathways can be a treatment candidate.

Gut microbiota: novel therapeutic target for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common and increasing liver diseases worldwide with a prevalence of 20-33%. NAFLD may progress to fibrosis, compensated cirrhosis, advanced cirrhosis, or hepatocellular carcinoma. Despite the increasing prevalence of NAFLD, definitive medical treatment has not been established, with the exception of lifestyle modification with exercise. Because of the direct connection via portal vein between the intestines and the liver (gut-gut microbiota-liver axis), gut microbiota and associated dysbiosis have been known as regulators in the pathophysiology of NAFLD. Area covered: New therapeutic approaches for modulation of gut microbiota have been proposed and the effectiveness of new therapies including probiotics, prebiotics, synbiotics, bile acid regulation, absorbent, and fecal microbiota transplantation have been demonstrated in recent several studies. This review focuses on the available evidences for new therapies modulating gut microbiota in the management and the prevention of NAFLD. Expert commentary: Gut-gut microbiota-liver axis may play an important role in the etiology of many liver diseases, including NAFLD. It is logical to seek the manipulation of this axis, and further studies are required to understand the underlying precise mechanisms of microbiota-modulation on NAFLD.

Long-term Prognosis of Acute-on-Chronic Liver Failure Survivors

GOALS

We aimed to investigate significant factors influencing the long-term prognosis of patients who survived acute-on-chronic liver failure (ACLF).

BACKGROUND

The mortality of ACLF is predominantly affected by the organ failure severity. However, long-term outcomes of patients who survive ACLF are not known.

STUDY

A cohort of 1084 cirrhotic patients who survived for more than 3 months following acute deterioration of liver function was prospectively followed. ACLF was defined by the European Association for the Study of the Liver Chronic Liver Failure Consortium definition.

RESULTS

The mean follow-up duration was 19.4±9.9 months. In the subgroup of patients without previous acute decompensation (AD), ACLF occurrence did not affect long-term outcomes. However, in patients with previous AD, ACLF negatively affected long-term transplant-free survival even after overcoming ACLF (hazard ratio, 2.00, P=0.012). Previous AD was the significant predictive factor of long-term mortality and was independent of the Model for End-stage Liver Disease score in these ACLF-surviving patients. Organ failure severity did not affect transplant-free survival in patients who survived an ACLF episode.

CONCLUSIONS

A prior history of AD is the most important factor affecting long-term outcomes following an ACLF episode regardless of Model for End-stage Liver Disease score. Prevention of a first AD episode may improve the long-term transplant-free survival of liver cirrhosis patients.

Efficacy of granulocyte colony stimulating factor in patients with severe alcoholic hepatitis with partial or null response to steroid (GRACIAH trial): study protocol for a randomized controlled trial

Background

Alcoholic hepatitis (AH) has the most severe presentation among alcohol-related liver diseases. Corticosteroids are the most widely recommended treatment for severe AH. However, more innovative, refined treatment measures are required because of its high mortality despite corticosteroid treatment. This study aims to determine whether granulocyte colony stimulating factor (G-CSF) treatment increases short-term survival in patients with severe AH refractory to corticosteroid treatment.

Methods/design

Patients with severe AH whose Maddrey’s discriminant function (MDF) score is ≥ 32 and who will be treated with prednisolone (40 mg/day) for 1 week will be screened. Among them, 190 subjects with a partial response (PR) (Lille score 0.16–0.56), and 78 subjects with a null response (NR) (Lille score ≥ 0.56) will be enrolled. Subjects with PR will be randomized to steroid plus placebo or steroid plus 12 G-CSF injections (5 μg/kg/day for 5 days followed by every 3 days) at a ratio of 1:1. Subjects with a NR will be randomized to the placebo or G-CSF group (1:1). Study subjects in the PR group will be treated with prednisolone for 28 days followed by dose tapering for an additional 2 weeks. The primary endpoint is the 2-month survival rate in the NR group and the 6-month survival rate in the PR group. Child–Turcotte–Pugh, model for end-stage liver disease score, and the change in the proportion of peripheral circulating CD34-positive cells will be analyzed as risk factors for mortality. Preliminary safety data for the initial 10 study subjects enrolled in the PR study will be assessed to determine whether the PR study would be continued, according to the G-CSF-mobilized, peripheral-blood stem cell donor assessment protocol of the National Marrow Donor Program.

Discussion

We hypothesized that G-CSF would prolong short-term survival of patients with severe AH refractory to corticosteroid treatment. This is a proof-of-concept trial designed to assess the efficacy of Lille-score-guided G-CSF treatment. This trial is also designed to identify a special subgroup in whom G-CSF rescue treatment would improve liver function and prolong survival.

Trial registration

ClinicalTrials.gov, NCT02442180. Prospectively registered on 13 May 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3092-7) contains supplementary material, which is available to authorized users.

Validation of prognostic scores to predict short-term mortality in patients with acute-on-chronic liver failure

BACKGROUND AND AIM

The aim of this study was to validate the chronic liver failure-sequential organ failure assessment score (CLIF-SOFAs), CLIF consortium organ failure score (CLIF-C OFs), CLIF-C acute-on-chronic liver failure score (CLIF-C ACLFs), and CLIF-C acute decompensation score in Korean chronic liver disease patients with acute deterioration.

METHODS

Acute-on-chronic liver failure was defined by either the Asian Pacific Association for the study of the Liver ACLF Research Consortium (AARC) or CLIF-C criteria. The diagnostic performances for short-term mortality were compared by the area under the receiver operating characteristic curve.

RESULTS

Among a total of 1470 patients, 252 patients were diagnosed with ACLF according to the CLIF-C (197 patients) or AARC definition (95 patients). As the ACLF grades increased, the survival rates became significantly lower. The areas under the receiver operating characteristic of the CLIF-SOFAs, CLIF-C OFs, and CLIF-C ACLFs were significantly higher than those of the Child-Pugh, model for end-stage liver disease, and model for end-stage liver disease-Na scores in ACLF patients according to the CLIF-C definition (all P < 0.05), but there were no significant differences in patients without ACLF or in patients with ACLF according to the AARC definition. The CLIF-SOFAs, CLIF-C OFs, and CLIF-C ACLFs had higher specificities with a fixed sensitivity than liver specific scores in ACLF patients according to the CLIF-C definition, but not in ACLF patients according to the AARC definition.

CONCLUSIONS

The CLIF-SOFAs, CLIF-C OFs, and CLIF-C ACLFs are useful scoring systems that provide accurate information on prognosis in patients with ACLF according to the CLIF-C definition, but not the AARC definition.