Circulating cell death biomarker: good candidates of prognostic indicator for patients with hepatitis B virus related acute-on-chronic liver failure

Recompensation of Liver Cirrhosis by TIPS Reduces Epithelial Cell Death Markers, Translating Into Improved Clinical Outcome

BACKGROUND AND AIMS

Portal hypertension is the main pathophysiological driver of decompensation in patients with liver cirrhosis. Epithelial cell death markers, m30 and m65, correlate with hepatic injury and predict outcomes across various stages of liver disease. We aim (i) to evaluate whether portal hypertension itself contributes to liver outcome-relevant epithelial injury, and (ii) to analyse the capacity of m30/m65 to predict outcome in patients receiving a transjugular intrahepatic portosystemic shunt (TIPS) for refractory ascites.

METHODS

Sixty-six patients undergoing TIPS placement for refractory ascites and 20 patients with compensated cirrhosis as controls were prospectively enrolled in this monocentric cohort study. Epithelial cell death markers were analysed pre-TIPS, as well as 1-3 and 6-9 months post-TIPS. The capacity of baseline levels of m30/m65 in predicting six-month transplant-free survival rates was analysed by multivariable Cox proportional hazards regression.

RESULTS

Levels of m30 and m65 were higher in patients with decompensated cirrhosis (pre-TIPS) compared with compensated cirrhosis (controls). Following correction of portal hypertension by TIPS and recompensation, both markers decreased over time, reaching levels comparable to patients with compensated cirrhosis. On multivariable analysis, pre-TIPS baseline levels of m30 and m65 were not predictive for six-month survival.

CONCLUSION

Correction of portal hypertension via TIPS reduces levels of epithelial cell death markers, indicating that portal hypertension is a driver of outcome-relevant, hepatic cell death in patients with decompensated cirrhosis. Baseline m30/m65 values do not affect six-month survival rates, which suggests that TIPS placement overcomes the unfavourable spontaneous prognosis otherwise indicated by elevated baseline m30/65 levels.

Serum Cytokeratin-18 levels as a prognostic biomarker in advanced liver disease: a comprehensive meta-analysis

Cytokeratin-18 (CK-18) is a marker of hepatic cell death. Serum CK-18 could serve as a prognostic marker for patients with advanced liver disease (ALD). This meta-analysis aims to explore the association between total CK-18 (M65) and caspase-cleaved CK-18 (M30) levels with the prognosis of ALD patients. Relevant longitudinal observational studies were identified through comprehensive searches of the Medline, Web of Science, and Embase databases. A random-effects model was utilized to synthesize the findings, accommodating heterogeneity among studies. The analysis included 14 datasets from 11 studies. Elevated serum CK-18 levels at admission were linked to a higher risk of death or liver transplantation during follow-up. This association was consistent for both M65 (risk ratio [RR] 1.99, 95% confidence interval [CI] 1.65 to 2.40, p < 0.001; I2 = 43%) and M30 (RR 1.94, 95% CI 1.57 to 2.40, p < 0.001; I2 = 46%). Subgroup analysis revealed that the relationship between serum M65 levels and adverse outcomes was attenuated in studies using multivariate analysis compared to those using univariate analysis (RR 1.78 vs. 2.80, p for subgroup difference = 0.03). Further subgroup analyses indicated that the prognostic significance of CK-18 for ALD patients was not significantly influenced by study design, methods of determining CK-18 cutoff values, or follow-up durations. Elevated serum CK-18 levels at admission indicate a poor prognosis in patients with ALD. This finding holds for both M65 and M30.

Prognostic Scores in Acute Liver Failure Due to Viral Hepatitis

Viral infections are among the major causes of acute liver failure (ALF) worldwide. While the role of agents such as hepatitis A, B, C, D and E viruses in precipitating ALF are well known, improvements in serological assays have led to the detection of viral agents such as Epstein Barr virus, cytomegalovirus etc. as atypical causes of ALF. Despite the plethora of literature available on viral hepatitis and ALF, there is very limited large-scale epidemiologic data on the prevalence, risk factors of progression and outcomes in ALF of viral causes. This is important as viral infections remain the leading cause of ALF in the East and in developing countries, while the impact of viral ALF in the West has largely been ameliorated by effective vaccination and sanitization programs. This review focuses specifically on the available prognostic scores that aid in the management of ALF of viral etiologies while also briefly reviewing the current literature on newer viral agents known to cause ALF, risk factors of progression, outcomes and how management algorithms can be developed by incorporation of prognostic scoring systems for referral and transplant listing.

HMGB1-Induced Hepatocyte Pyroptosis Expanding Inflammatory Responses Contributes to the Pathogenesis of Acute-on-Chronic Liver Failure (ACLF)

Background

Acute-on-chronic liver failure (ACLF) is a critical disease with a high fatality rate. Immune dysfunction and inflammatory responses are key risk factors in ACLF. Pyroptosis is a form of programmed cell death characterized by the release of inflammatory cytokines, which causes the strong inflammatory responses. High mobility group box-1 (HMGB1) could induce pyroptosis and is closely related to ACLF. However, the role of HMGB1-induced hepatocyte pyroptosis in ACLF has never been proposed; whether HMGB1-induced hepatocyte pyroptosis participates in the development of ACLF and the mechanisms involved are barely understood.

Purpose

This study aimed to clarify the roles of HMGB1-induced hepatocyte pyroptosis in ACLF and the molecular mechanisms involved.

Methods

Wistar rats were randomly divided into five groups, viz.: Normal, ACLF model, HMGB1 inhibitor, Caspase-1 inhibitor, and HMGB1 inhibitor+Caspase-1 inhibitor groups. The ACLF rat model was established using 40% carbon tetrachloride-induced liver fibrosis, followed by D-galactosamine and lipopolysaccharide joint acute attacks. The liver function, coagulation function and pathological damage of rats in each group were evaluated. The biological mechanisms of HMGB1-induced pyroptosis and the release of inflammatory cytokines were investigated using Western blot, quantitative real-time PCR (RT-qPCR), immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay.

Results

The liver function and coagulation function of ACLF rats were seriously impaired; liver tissue showed massive or submassive necrosis, accompanied by inflammatory cell infiltration; the percentage of pyroptotic hepatocytes significantly increased, and a large number of inflammatory cytokines were released. The expression levels of pyroptosis-related genes and proteins in liver tissues and serum significantly increased. But these phenomenons were improved by the inhibition of HMGB1, and the dual inhibition of HMGB1 and Caspase-1 showed a stronger effect.

Conclusion

The findings indicate, for the first time, that pyroptosis is a crucial pathophysiological event of ACLF involved in its pathogenesis, and HMGB1-induced hepatocyte pyroptosis expands inflammatory responses to aggravate ACLF, suggesting that it may be a potential therapeutic target for ACLF treatment.

Quercetin Reduces Oxidative Stress and Apoptosis by Inhibiting HMGB1 and Its Translocation, Thereby Alleviating Liver Injury in ACLF Rats

Background

Acute on chronic liver failure (ACLF) is a syndrome of acute liver failure that occurs on the basis of chronic liver disease, which is characterized by a rapid deterioration in a short period and high mortality. High mobility group box 1 (HMGB1) may be involved in the pathological process of ACLF; its specific role remains to be further elucidated. Our previous studies have shown that quercetin (Que) exerts anti-oxidant and anti-apoptotic effects by inhibiting HMGB1 in vitro. The present study aimed to investigate the effect of Que on liver injury in ACLF rats.

Methods

The contents of ALT, AST, TBiL, and PT time of rats in each group were observed. HE staining was used to detect liver pathology. The levels of oxidative stress indicators such as MDA, GSH, and 4-HNE in the rat liver were detected. TUNEL assay was used to detect apoptosis in rat hepatocytes. Immunofluorescence and western blot analysis were performed to explore the protective effect of Que on ACLF rats and the underlying mechanism.

Results

The results showed that Que could reduce the increase of serum biochemical indices, improve liver pathology, and reduce liver damage in ACLF rats. Further results confirmed that Que reduced the occurrence of oxidative stress and apoptosis of hepatocytes, and these reactions may aggravate the progress of ACLF. Meanwhile, the results of immunofluorescence and western blotting also confirmed that the expression of HMGB1 and extranuclear translocation in ACLF rat hepatocytes were significantly increased, which was alleviated by the treatment of Que. In addition, when cotreated with glycyrrhizin (Gly), an inhibitor of HMGB1, the inhibition of Que on HMGB1 and its translocation, apoptosis and oxidative stress, and the related proteins of HMGB1-mediated cellular pathway have been significantly enhanced.

Conclusion

Thus, Que alleviates liver injury in ACLF rats, and its mechanism may be related to oxidative stress and apoptosis caused by HMGB1 and its translocation.

Acute-on-Chronic Liver Failure: Pathophysiological Mechanisms and Management

Acute-on-chronic liver failure (ACLF) is a multifaceted condition with poor treatment options and high short-term mortality. ACLF can develop in patients with or without liver cirrhosis, where patients with decompensated cirrhosis display a higher risk of short-term mortality. Pathophysiological mechanisms include systemic inflammation due to bacterial and fungal infections and acute hepatic insult with drug, alcohol, and viral hepatitis. Cryptogenic factors also contribute to the development of ACLF. The clinical outcome of patients with ACLF gets further complicated by the occurrence of variceal hemorrhage, hepatorenal syndrome, hepatic encephalopathy, and systemic immune dysfunction. Regardless of the better understanding of pathophysiological mechanisms, no specific and definitive treatment is available except for liver transplantation. The recent approach of regenerative medicine using mesenchymal stem cells (MSCs) could be advantageous for the treatment of ACLF as these cells can downregulate inflammatory response by inducing antiinflammatory events and prevent hepatic damage and fibrosis by inhibiting hepatic stellate cell activation and collagen synthesis. Moreover, MSCs are involved in tissue repair by the process of liver regeneration. Considering the broad therapeutic potential of MSCs, it can serve as an alternative treatment to liver transplant in the near future, if promising results are achieved.

The "Traditional Chinese medicine regulating liver regeneration" treatment plan for reducing mortality of patients with hepatitis B-related liver failure based on real-world clinical data

On the basis of real-world clinical data, the study aimed to explore the effect and mechanisms of the treatment plan of “traditional Chinese medicine (TCM) regulating liver regeneration.” A total of 457 patients with HBV-related liver failure were retrospectively collected. The patients were divided into three groups: the modern medicine control group (MMC group), patients treated with routine medical treatment; the control group combining traditional Chinese and Western medicine (CTW), patients treated with routine medical treatment plus the common TCM formula; and the treatment group of “TCM regulating liver regeneration” (RLR), patients treated with both routine medical treatment and the special TCM formula of RLR. After 8 weeks of treatment, the mortality of patients in the RLR group (12.31%) was significantly lower than those in the MMC (50%) and CTW (29.11%) groups. Total bilirubin level significantly decreased and albumin increased in the RLR group when compared with the MMC and CTW groups (P < 0.05). In addition, there were significant differences in the expression of several cytokines related to liver regeneration in the RLR group compared with the MMC group. RLR treatment can decrease jaundice, improve liver function, and significantly reduce the mortality in patients with HBV-related liver failure. The mechanism may be related to the role of RLR treatment in influencing cytokines related to liver regeneration.

Acute-on-Chronic Liver Failure in Pregnant Patients with Chronic Hepatitis B: A Retrospective Observational Case Series Study

BACKGROUND AND AIMS

Acute-on-chronic liver failure (ACLF) is common in patients with end-stage liver disease and chronic hepatitis B (CHB) or hepatitis B virus- (HBV-) related cirrhosis. To date, no uniform definition and management strategy are available for ACLF. Although a considerable number of studies on ACLF has been published, there are few reports on ACLF in pregnant women with CHB. This study retrospectively reviewed five patients who were diagnosed with ACLF during pregnancy in the past 10 years. We aimed at investigating their clinical characteristics, treatment, biochemical test results, and maternal and fetal outcomes.

RESULTS

Asthenia, anorexia, and jaundice were the main initial clinical manifestations in these patients during the second or third trimester of pregnancy. All patients received antiviral therapy. None of the pregnant women died after treatment. Patient #4 was treated with an artificial liver support system, and patients #2 and #5 underwent transfusion therapy. The acute insult in all patients was HBV DNA reactivation. Except for patient #3, who chose an actively induced vaginal delivery because of intrauterine fetal demise, the remaining four patients underwent a preterm delivery via a cesarean section. The four neonates were alive, although all were small for gestational age.

CONCLUSION

Asthenia, anorexia, and jaundice during mid-late pregnancy should be immediately investigated. Before and during the pregnancy, hepatologists or obstetricians should actively screen pregnant women with CHB for HBV DNA status and alanine aminotransferase levels. Reactivation of HBV replication in pregnant women with CHB may lead to ACLF, especially in multiparous women. Once ACLF is diagnosed, antiviral therapy should be considered as soon as possible to protect maternal and fetal health.

Circulating Receptor-Interacting Protein Kinase 3 Are Increased in HBV Patients With Acute-on-Chronic Liver Failure and Are Associated With Clinical Outcome

Background and Aims

Necroptosis is a newly identified type of cell death with programmed pathways. The current study was performed to investigate necroptosis by measuring its key regulators; receptor interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like (MLKL) in patients with Hepatitis B virus (HBV) related acute-on-chronic liver failure (ACLF).

Methods

HBV-related ACLF (HBV-ACLF) patients (n = 90), non-ACLF patients without cirrhosis (N = 70), patients with cirrhosis (N = 40), and healthy controls (HCs; n = 70) were enrolled in the study. All patients were subject to serum RIPK3 measurement. Hepatic RIPK3 and MLKL were also determined in the livers of 18 patients and five donors, using immunohistochemistry.

Results

Serum RIPK3 was significantly elevated in HBV-ACLF patients compared to that of non-ACLF patients and the HCs. Serum RIPK3 in ACLF patients at recruitment was significantly higher in non-survivors than those in survivors at the 90-day follow-up. The predictive accuracy of serum RIPK3 at the 90-day outcome was relatively good with an area under the receiver operating curve (AUROC) of 0.72 (p < 0.001), similar to that of the model of end-staged liver disease (MELD) score (0.76, p < 0.001). The combined use of RIPK3 and MELD score further increased the AUROC to 0.80. The hepatic RIPK3 and MLKL measured by immunohistochemistry, significantly increased in the patients with HBV-ACLF than in the patients without ACLF and the HCs.

Conclusion

Circulating RIPK3 was significantly increased in patients with HBV-ACLF and was associated with a clinical outcome. The improved combined objective scores could offer additional prognostic value in ACLF patients, for physicians with more accurate expectations.

Long Non-coding RNA NEAT1 Alleviates Acute-on-Chronic Liver Failure Through Blocking TRAF6 Mediated Inflammatory Response

Background

Long non-coding RNAs (lncRNAs) have recently been tightly linked to plenty of human diseases. However, knowledge of acute-on-chronic liver failure (ACLF) related lncRNAs remains insufficient. In this work, we studied the role of the lncRNA nuclear enriched abundant transcript 1 (NEAT1) in the pathogenesis of ACLF.

Methods

ACLF model was established by challenging D-galactosamine (D-GalN)/ lipopolysaccharide (LPS) i.p. in rats with cirrhosis. The serum levels of IL-1, IL-6, and HMGB1 were determined using ELISA. Quantitative real time-PCR and western blot were performed to evaluate RNA and protein levels of inflammatory response. RNA immunoprecipitation assay was performed to confirm protein that interacts with NEAT1.

Findings

Over-expression of NEAT1 could interact with TRAF6 and decrease its ubiquitination level, and significantly reduced the expression levels of IL-6, IL-22. Importantly, in ACLF rat model, NEAT1 over-expression reduced several cytokines expression and alleviated the pathological status in contrast to the control group. Additionally, NEAT1 was increased and positively correlated with IL-22 and IL-6 levels in PBMCs from the ACLF patients.

Interpretation

NEAT1 can suppress inflammatory response through blockade of TRAF6 ubiquitination in ACLF rat model, suggesting that lncRNA NEAT1 might play protective roles in the pathogenesis of ACLF and provide promising novel target for pharmacological intervention.

Chinese Medicine Jiedu Huayu Granules Reduce Liver Injury in Rats by Regulating T-Cell Immunity

Liver injury, one of the causes of liver failure, is mainly due to T-cell-mediated immunity. Traditional Chinese medicine Jiedu Huayu granules are often used to suppress liver damage and improve liver function. The specific regulatory mechanism of Jiedu Huayu granules has not been fully studied, and its function in the immune system remains unclear. Therefore, in this study, the mechanism of Jiedu Huayu granules in the prevention of hepatic injury was studied in a rat model of hepatic injury induced by D-galactoside and lipopolysaccharide. The cytotoxic T lymphocytes (CTLs) in the peripheral blood were examined. Perforin, granule B, and PD1 expression in CTL increased after the induction of hepatic injury and could be reduced by Jiedu Huayu granules. Hepatic apoptotic factors OX62, FAS, and TNFR1 associated with CTL function were also reduced by Jiedu Huayu granules. These results suggested that Jiedu Huayu granules could inhibit the inflammatory response to relieve liver damage by mediating the T-cell immunity. Therefore, the discovery of the mechanism of action of Jiedu Huayu granules in the immune system could allow their use more effectively in clinical practice.

Acute-on-chronic liver failure: definition, prognosis and management

Acute-on-chronic liver failure (ACLF) is a recently described entity in chronic liver disease defined by acute hepatic decompensation, organ failure and a high risk of short-term mortality (usually less than 4 weeks). This condition is distinct from acute liver failure and stable progression of cirrhosis in numerous ways, including triggering precipitant factors, systemic inflammation, rapid progression and a potential for recovery. While a clear definition of ACLF has been forwarded from a large European Consortium study, some heterogeneity remains in how patients present and the types of organ failure, depending on whether they are described in Asian or European studies. Active alcoholism, acute alcoholic hepatitis and infections are the most frequent precipitants for ACLF. Underpinning the pathophysiology of ACLF is a state of persistent inflammation and immune dysfunction, collectively driving a systematic inflammatory response syndrome and an increased propensity to sepsis. Prevention and early treatment of organ failure are key in influencing survival. Given increasing organ shortage and more marginal grafts, liver transplantation is a limited resource and emphasises the need for new therapies to improve ACLF outcomes. Recent data indicate that liver transplantation has encouraging outcomes even in patients with advanced ACLF if patients are carefully selected during the permissive window of clinical presentation. ACLF remains a significant challenge in the field of hepatology, with considerable research and resource being channelled to improve upon the definition, prognostication, treatment and unravelling of mechanistic drivers. This Review discusses updates in ACLF definition, prognosis and management.

The impact of HBV flare on the outcome of HBV-related decompensated cirrhosis patients with bacterial infection

BACKGROUND

Hepatitis B virus (HBV) flare can occur in HBV patients either naïve or have interruption to treatment. Bacterial infection (BI) is a common complication of cirrhosis with potential severe outcomes. We aimed to assess the impact of HBV flare on the outcome of patients with HBV-related decompensated cirrhosis and BI.

METHODS

This was a retrospective study from 2 tertiary academic hospitals in Shanghai, China of HBV patients admitted with or developed BI during admission. The characteristics of BI, prevalence of HBV flare, its impact on organ failure, acute-on-chronic liver failure (ACLF) and 90-day survival were evaluated.

RESULTS

A total of 360 hospitalized patients (median age: 50 years, male: 79%, BI: at admission: 58.6%; during admission: 41.4%) were included. All patients including those with HBV flare (21%) received antiviral therapy after admission. Patients with HBV flare and BI had significantly higher percentage of liver (93.3% vs 48.8%), coagulation (64.0% vs 39.6%), cerebral (40.0% vs 21.8%) (all P < 0.01), and kidney failure (38.7% vs 26.3%, P < 0.05) compared to BI alone, associated with a higher risk of developing ACLF with a subdistribution hazard ratio (sHR) of 2.23 (95% confidence interval [CI]: 1.68-2.96). Multivariate analysis showed that ACLF development was the strongest risk factor for 90-day mortality (sHR, 95%CI: 7.36, 4.12-13.16).

CONCLUSIONS

In HBV-related decompensated cirrhosis patients admitted with BI, HBV flare increased the risk of additional organ failures and ACLF, raising the risk of 90-day mortality by seven-fold. Optimization of HBV treatment in these patients should minimize the risk of HBV flare with improved outcomes.

Dynamic Prognostication in Critically Ill Cirrhotic Patients With Multiorgan Failure in ICUs in Europe and North America: A Multicenter Analysis

OBJECTIVES

To evaluate the Chronic Liver Failure-Consortium Acute on Chronic Liver Failure score in acute on chronic liver failure patients admitted to ICUs from different global regions and compare discrimination ability with previously published scores.

DESIGN

Retrospective pooled analysis.

SETTING

Academic ICUs in Canada (Edmonton, Vancouver) and Europe (Paris, Barcelona, Chronic liver failure/Acute-on-Chronic Liver Failure in Cirrhosis [CANONIC] study).

PATIENTS

Sample of analysis of 867 cirrhotic patients with acute on chronic liver failure admitted to ICU. Cumulative incidence functions of death were estimated by acute on chronic liver failure grade at admission and at day 3. Survival discrimination abilities of Chronic Liver Failure-Consortium Acute on Chronic Liver Failure, Model for End-Stage Liver Disease, Acute Physiology and Chronic Health Evaluation II, and Child-Turcotte-Pugh scores were compared.

INTERVENTIONS

ICU admission for organ support.

MEASUREMENTS AND MAIN RESULTS

At admission 169 subjects (19%) had acute on chronic liver failure 1, 302 (35%) acute on chronic liver failure 2, and 396 (46%) had acute on chronic liver failure 3 with 90-mortality rates of 33%, 40%, and 74%, respectively (p < 0.001). At admission, Chronic Liver Failure-Consortium Acute on Chronic Liver Failure demonstrated superior discrimination at 90 days compared with Acute Physiology and Chronic Health Evaluation II (n = 532; concordance index 0.67 vs 0.62; p = 0.0027) and Child-Turcotte-Pugh (n = 666; 0.68 vs 0.64; p = 0.0035), but not Model for End-Stage Liver Disease (n = 845; 0.68 vs 0.67; p = 0.3). A Chronic Liver Failure-Consortium Acute on Chronic Liver Failure score greater than 70 at admission or on day 3 was associated with 90-day mortality rates of approximately 90%. Ninety-day mortality in grade 3 acute on chronic liver failure patients at admission who demonstrated improvement by day 3 was 40% (vs 79% in patients who did not).

CONCLUSIONS

The Chronic Liver Failure-Consortium Acute on Chronic Liver Failure demonstrated better discrimination at day 28 and day 90 compared with Acute Physiology and Chronic Health Evaluation II and Child-Turcotte-Pugh. Patients who demonstrated clinical improvement post-ICU admission (e.g., acute on chronic liver failure 3 to 1 or 2) at day 3 had better outcomes than those who did not. In high-risk ICU patients (Chronic Liver Failure-Consortium Acute on Chronic Liver Failure > 70), decisions regarding transition to palliation should be explored between patient families and the ICU providers after a short trial of therapy.

Serum keratin-18 fragments as cell death biomarker in association with disease progression and prognosis in hepatitis B virus-related cirrhosis

Extensive hepatocyte death leads to hepatic inflammation and contributes to systemic inflammation in decompensated cirrhosis. We aimed to investigate the prognostic value of serum cell death markers in patients with hepatitis B virus (HBV)-related acute decompensation (AD) of cirrhosis with and without acute-on-chronic liver failure (ACLF). We studied two cohorts-cohort 1: 201 outpatients with stable chronic hepatitis B (49 cirrhosis); cohort 2: 232 inpatients with HBV-related cirrhosis admitted for AD. Cell death was determined with serum keratin-18 (K18) for total death and serum caspase-cleaved-K18 (cK18) for apoptosis. Survival analyses were performed using competing risk method. We found that serum K18 and cK18 were significantly (P < 0.001) higher in patients from cohort 2 than those from cohort 1. Among cohort 2, ACLF patients had significantly (P < 0.001) increased K18 and cK18 comparing to those without ACLF. Increased K18 and cK18 were mainly attributed to HBV flare and were associated with liver and coagulation failure. HBV-AD patients without ACLF who admitted with upper tertile of K18 or cK18 were at higher risk of developing ACLF during follow-up. Baseline serum K18 or cK18 was significantly associated with transplant-free 90-day survival independent of leucocytes, HBV DNA, bacterial infection, encephalopathy and severity scores. The combination of cell death biomarkers significantly improved the prognostic value of the currently established prognostic scores. The reduction of cell death level after standard treatment was associated with increased short-term survival. In conclusion, measurements of serum K18 or cK18 in HBV decompensated cirrhosis are a promising tool for predicting ACLF and risk stratification of short-term outcome.

The Role of Monocytes and Macrophages in Acute and Acute-on-Chronic Liver Failure

Acute and acute-on-chronic liver failure (ALF and ACLF), though distinct clinical entities, are considered syndromes of innate immune dysfunction. Patients with ALF and ACLF display evidence of a pro-inflammatory state with local liver inflammation, features of systemic inflammatory response syndrome (SIRS) and vascular endothelial dysfunction that drive progression to multi-organ failure. In an apparent paradox, these patients are concurrently immunosuppressed, exhibiting acquired immune defects that render them highly susceptible to infections. This paradigm of tissue injury succeeded by immunosuppression is seen in other inflammatory conditions such as sepsis, which share poor outcomes and infective complications that account for high morbidity and mortality. Monocyte and macrophage dysfunction are central to disease progression of ALF and ACLF. Activation of liver-resident macrophages (Kupffer cells) by pathogen and damage associated molecular patterns leads to the recruitment of innate effector cells to the injured liver. Early monocyte infiltration may contribute to local tissue destruction during the propagation phase and results in secretion of pro-inflammatory cytokines that drive SIRS. In the hepatic microenvironment, recruited monocytes mature into macrophages following local reprogramming so as to promote resolution responses in a drive to maintain tissue integrity. Intra-hepatic events may affect circulating monocytes through spill over of soluble mediators and exposure to apoptotic cell debris during passage through the liver. Hence, peripheral monocytes show numerous acquired defects in acute liver failure syndromes that impair their anti-microbial programmes and contribute to enhanced susceptibility to sepsis. This review will highlight the cellular and molecular mechanisms by which monocytes and macrophages contribute to the pathophysiology of ALF and ACLF, considering both hepatic inflammation and systemic immunosuppression. We identify areas for further research and potential targets for immune-based therapies to treat these devastating conditions.

Transcriptome Analysis of Porcine PBMCs Reveals the Immune Cascade Response and Gene Ontology Terms Related to Cell Death and Fibrosis in the Progression of Liver Failure

BACKGROUND

The key gene sets involved in the progression of acute liver failure (ALF), which has a high mortality rate, remain unclear. This study aims to gain a deeper understanding of the transcriptional response of peripheral blood mononuclear cells (PBMCs) following ALF.

METHODS

ALF was induced by D-galactosamine (D-gal) in a porcine model. PBMCs were separated at time zero (baseline group), 36 h (failure group), and 60 h (dying group) after D-gal injection. Transcriptional profiling was performed using RNA sequencing and analysed using DAVID bioinformatics resources.

RESULTS

Compared with the baseline group, 816 and 1,845 differentially expressed genes (DEGs) were identified in the failure and dying groups, respectively. A total of five and two gene ontology (GO) term clusters were enriched in 107 GO terms in the failure group and 154 GO terms in the dying group. These GO clusters were primarily immune-related, including genes regulating the inflammasome complex and toll-like receptor signalling pathways. Specifically, GO terms related to cell death, including apoptosis, pyroptosis, and autophagy, and those related to fibrosis, coagulation dysfunction, and hepatic encephalopathy were enriched. Seven Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, cytokine-cytokine receptor interaction, hematopoietic cell lineage, lysosome, rheumatoid arthritis, malaria, and phagosome and pertussis pathways were mapped for DEGs in the failure group. All of these seven KEGG pathways were involved in the 19 KEGG pathways mapped in the dying group.

CONCLUSION

We found that the dramatic PBMC transcriptome changes triggered by ALF progression was predominantly related to immune responses. The enriched GO terms related to cell death, fibrosis, and so on, as indicated by PBMC transcriptome analysis, seem to be useful in elucidating potential key gene sets in the progression of ALF. A better understanding of these gene sets might be of preventive or therapeutic interest.

Acute-on-chronic liver failure in chronic hepatitis B: an update

Acute-on-chronic liver failure is a common pattern of end-stage liver disease in clinical practice and occurs frequently in patients with chronic hepatitis B or HBV-related cirrhosis. New progress in recent years leads to a better understanding of this disease. Areas covered: This review updates the current comprehensive knowledge about HBV-ACLF from epidemiological studies, experimental studies, and clinical studies and provide new insights into the definition, diagnostic criteria, epidemiology, nature history, pathogenesis, treatment and prognostication of HBV-ACLF. Expert commentary: Patients with chronic hepatitis B or HBV-related cirrhosis are at risk of developing acute-on-chronic liver failure, with multi-organ failure and high short-term mortality. The precipitating events can be intra-hepatic or extra-hepatic and the underlying chronic liver injury can be cirrhotic or non-cirrhotic. Host and viral factors contribute to the susceptibility of developing HBV-ACLF. Systemic inflammation is the driver of HBV-ACLF, which can be attributed to non-sterile and sterile factors. Liver transplantation is the definitive treatment for HBV-ACLF. Cell therapy is a promising alternative to LT, but requires validation and still has concern of long-term safety. Other medical therapies, such as nucleoside analogue, artificial liver supporting and glucocorticoid may improve survival in a specific subgroup. New scoring systems improve the accuracy of prognostication in HBV-ACLF, which is critical for early identification of candidates for LT.

Plasma Apolipoprotein A-V Predicts Long-term Survival in Chronic Hepatitis B Patients with Acute-on-Chronic Liver Failure

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a life-threatening condition, and the lipid metabolism disorder is common in the development of this disease. This prospective observational study aimed to define the characteristics of plasma apolipoprotein A-V (apoA-V) in long-term outcome prediction of HBV-ACLF, and a total of 330 HBV-ACLF patients were included and followed for more than 12 months. In this cohort, the 4-week, 12-week, 24-week and 48-week cumulative mortality of HBV-ACLF was 18.2%(60/330), 50.9%(168/330), 59.7%(197/330) and 63.3%(209/330), respectively. As compared to survivors, the non-survivors had significantly lower concentrations of plasma apoA-V on admission. Plasma apoA-V concentrations were positively correlated with prothrombin time activity (PTA), and negatively correlated with interleukin-10, tumor necrosis factor-α, and iMELD scores. Though plasma apoA-V, PTA, total bilirubin(TBil) and blood urea nitrogen(BUN) were all independent factors to predict one-year outcomes of HBV-ACLF, plasma apoA-V had the highest prediction accuracy. And its optimal cutoff value for one-year survival prediction was 480.00 ng/mL, which had a positive predictive value of 84.68% and a negative predictive value of 92.23%. In summary, plasma apoA-V decreases significantly in non-survivors of HBV-ACLF, and it may be regarded as a new predictive marker for the prognosis of patients with HBV-ACLF.

Serum hepatocyte apoptosis biomarker predicts the presence of significant histological lesion in chronic hepatitis B virus infection

BACKGROUND

Hepatocyte death, either apoptosis or necrosis, is closely associated with hepatic inflammation and fibrosis.

AIMS

To investigate the potential values of hepatocytes death biomarker, M30 (apoptosis) and M65 (total death) in predicting histological lesions in chronic hepatitis B virus (HBV) infection.

METHODS

Total 201 treatment-naïve patients were prospectively recruited. Liver biopsies were performed prior to antiviral treatments for treatments starting evaluation. Sera were collected on the day of liver biopsy for biomarker measurements. Sera from 200 age-matched healthy volunteers served as healthy controls (HCs).

RESULTS

Significant histological lesions (SHL, i.e. significant inflammation and/or significant fibrosis) were confirmed in 150 (74.63%) patients. There were significantly higher serum M30 and M65 in patients with SHL than those without SHL (p<0.001) or than HCs (p<0.001). Serum M30, but not M65, independently predicted SHL [odds ratio:3.4 (95% CI, 1.8-6.2) per increase of 50U/L, p<0.001] after adjusting other potential confounding factors. A novel model based on M30 provided good diagnostic performance in predicting SHL [AUC, 0.87 (0.81-0.92)]. Cut-off value of >0 to confirm or ≤-0.5 to exclude SHL has ∼12% misclassification rate.

CONCLUSION

Hepatocyte apoptosis biomarker, M30 is a promising non-invasive alternative to liver biopsy in chronic HBV infection upon treatment evaluation.

Cytokeratin 18-based cell death markers indicate severity of liver disease and prognosis of cirrhotic patients

BACKGROUND & AIMS

Hepatocyte death is an important factor in development and progression of cirrhosis. Cytokeratin 18-based serum markers reflecting apoptotic (M30) and overall epithelial cell death (M65 and M65EpiDeath) have been used as prognostic parameters for survival in patients with acute liver failure. However, there has been no trial investigating M30, M65 and M65EpiDeath as survival parameters in patients with cirrhosis and acute-on-chronic liver failure.

METHODS

Patients with cirrhosis were enrolled and followed until death, liver transplantation or last contact. M30, M65 and M65EpiDeath serum levels were quantified in patient's sera.

RESULTS

Three hundred and thirty-one patients were screened and 211 patients could be included in this study. The median duration of follow-up was 322 days with a range of 1-1382 days. All three cell death parameters correlated with the extent of the severity of the disease. However, M65EpiDeath was the only of the three parameters which was associated with the severe complications of cirrhosis including ascites, spontaneous bacterial peritonitis and hepatorenal syndrome. Additionally, M65EpiDeath was the only cell death parameter which was independently from liver function and its surrogate parameter such as Child-Pugh score and the model of end-stage liver disease associated with overall survival.

CONCLUSIONS

Epithelial cell death reflected by M65EpiDeath serum levels is an indicator for the severity of cirrhosis and a prognostic survival parameter in cirrhotic patients.