Altered immune function of monocytes in different stages of patients with acute on chronic liver failure

Prudent Use of Blood Cultures for Hospitalized Patients With Cirrhosis

Background No reliable risk stratification method is available to guide the extent of infectious work-up among hospitalized patients with cirrhosis. Therefore, we aimed to create a risk stratification method for obtaining blood cultures from hospitalized patients with cirrhosis. Methods This was a retrospective cohort study using the Healthcare Cost and Utilization Project - National Readmission Database 2019. Adult patients who were not immunocompromised comprised the final cohort. The primary outcome was the incidence of bacteremia among hospitalized patients with cirrhosis. Secondary outcomes included length of hospital stay, inpatient mortality, and 30-day readmission rate among cirrhosis patients with and without bacteremia. After propensity score matching, the χ2 test was used to assess the primary outcome and inpatient mortality. The Wilcoxon signed-rank test was used to compare the length of hospital stay. Readmission rates were compared via survival analysis. Concomitant bacterial infection, cirrhosis causes, and complications were assessed as potential risk factors for bacteremia using binomial regression. Results The risk ratio (RR) of bacteremia was 1.66 (95% confidence interval (CI): 1.55-1.78) among patients with cirrhosis compared to those without cirrhosis. A concomitant bacterial infection was found to have a strong association with bacteremia in patients with cirrhosis (RR: 3.3, 95% CI: 3.03-3.59). Among cirrhosis patients without concomitant bacterial infection, the incidence of bacteremia was 0.76% (<1%). Among the causes of cirrhosis, primary sclerosing cholangitis was found to have a strong association with bacteremia (RR: 3.88, 95% CI: 2.3-6.04, P < 0.001). Patients with cirrhosis who had bacteremia were hospitalized three days longer than those without bacteremia. There was no difference in inpatient mortality or 30-day readmission rates between cirrhotic patients with and without bacteremia. Conclusion This study suggests that, in the absence of another concomitant bacterial infection and primary sclerosing cholangitis, we can avoid unnecessary blood cultures among immunocompetent patients with cirrhosis. However, given some inherent limitations associated with the database (such as the unavailability of vitals or laboratory values), additional studies are needed to validate its findings.

Hemorrhagic and Ecthymatous Varicella in Immunosuppressed Adults: Report of Two Cases

Varicella infection in immunosuppressed adults can be severe with atypical presentation of skin lesions. Hemorrhagic and ecthymatous varicella is a rare entity and can be misdiagnosed due to its atypical presentation. In its severe form, individuals with underlying cell-mediated immunodeficiency disorders have a high risk of developing multiple organ involvement associated with varicella-zoster virus infection. Here, we report two cases of primary varicella with hemorrhagic and ecthymatous skin lesions in adults receiving systemic immunosuppressive drugs for autoimmune disorders. There are only a few case reports on hemorrhagic and ecthymatous varicella. Hence, this case report highlights the atypical presentation of varicella in immunosuppressed adults, which necessitates an early diagnosis and prompt treatment as a lifesaving step.

Risk factors for the mortality of hepatitis B virus-associated acute-on-chronic liver failure: a systematic review and meta-analysis

BACKGROUND

Hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) has been confirmed as a prevalent form of end-stage liver disease in people subjected to chronic HBV infection. However, there has been rare in-depth research on the risk factors for the mortality of HBV-ACLF. This study aimed at determining the risk factors for the mortality of HBV-ACLF.

METHODS

The relevant research was selected from four electronic databases that have been published as of August 2023. The existing research was reviewed in accordance with the inclusion and exclusion criteria. The level of quality of previous research was evaluated using the Newcastle-Ottawa scale. Moreover, a pooled estimate of the odds ratios (ORs) with their associated 95% confidence intervals (CIs) was provided through a meta-analysis. The data were combined, and the risk variables that at least two studies had considered were analyzed. The publication bias was examined through Egger's test and Begg's test.

RESULTS

Twenty two studies that conformed to the inclusion criteria were selected from 560 trials. Eight risk variables in terms of HBV-ACLF mortality were determined, which covered INR (OR = 1.923, 95% CI = 1.664-2.221, P < 0.001), Monocytes (OR = 1.201, 95% CI = 1.113-1.296, P < 0.001), Cirrhosis (OR = 1.432, 95% CI = 1.210-1.696, P < 0.001), HE (OR = 2.553, 95% CI = 1.968-3.312, P < 0.001), HE grade (OR = 2.059, 95% CI = 1.561-2.717, P < 0.001), SBP (OR = 1.383, 95% CI = 1.080-1.769, P = 0.010), Hyponatremia (OR = 1.941, 95% CI = 1.614-2.334, P < 0.001), as well as HRS (OR = 2.610, 95% CI = 1.669-4.080, P < 0.001).

CONCLUSION

The most significant risk factors for HBV-ACLF mortality comprise HRS, HE, and HE grade, followed by INR and hyponatremia. The Monocytes, cirrhosis, and SBP have been confirmed as the additional key risk factors for HBV-ACLF mortality.

CHINAT-CD4 Score Predicts Transplant-Free Survival in Patients with Acute-on-Chronic Liver Failure

Aim

The early prognosis evaluation of acute-on-chronic liver failure (ACLF) is important to decrease its mortality. We aimed to develop a new score to accurately predict the outcome of patients with ACLF.

Methods

A derivation set of 408 patients with hepatitis B virus-related ACLF (HBV-ACLF) based on the Asian Pacific Association for the Study of the Liver criteria is used to develop a prognostic score that was validated in 209 patients with HBV-ACLF and 195 patients with non-HBV-ACLF.

Results

Seven factors were significantly related to the 28-day mortality and constituted a new score (CHINAT-CD4 = 0.320 × ln (creatinine) + 0.668 × hepatic encephalopathy score + 0.745 × ln (international normalized ratio) + 0.476 × ln (neutrophil) + 0.251 × ln (aspartate aminotransferase) + 0.411 × ln (total bilirubin) - 0.605 × ln (CD4+ T cells count)). The C-indices of the new score for the 28-/90-day mortality (0.810/0.806) outperformed those of the other seven scores (p≤0.05). The results were confirmed in a validation set (0.798/793 for HBV-ACLF; 0.790/0.788 for non-HBV-ACLF). The novel score based on CD4⁺ T cell count showed high predictive performance for the 28-/90-day mortality of ACLF.

Conclusion

The novel score based on CD4⁺ T cell count can accurately predict the 28-/90-day mortality for patients with ACLF.

The Mechanisms of Systemic Inflammatory and Immunosuppressive Acute-on-Chronic Liver Failure and Application Prospect of Single-Cell Sequencing

Acute-on-chronic liver failure (ACLF) is a complex clinical syndrome, and patients often have high short-term mortality. It occurs with intense systemic inflammation, often accompanied by a proinflammatory event (such as infection or alcoholic hepatitis), and is closely related to single or multiple organ failure. Liver inflammation begins when innate immune cells (such as Kupffer cells (KCs)) are activated by binding of pathogen-associated molecular patterns (PAMPs) from pathogenic microorganisms or damage-associated molecular patterns (DAMPs) of host origin to their pattern recognition receptors (PRRs). Activated KCs can secrete inflammatory factors as well as chemokines and recruit bone marrow-derived cells such as neutrophils and monocytes to the liver to enhance the inflammatory process. Bacterial translocation may contribute to ACLF when there are no obvious precipitating events. Immunometabolism plays an important role in the process (including mitochondrial dysfunction, amino acid metabolism, and lipid metabolism). The late stage of ACLF is mainly characterized by immunosuppression. In this process, the dysfunction of monocyte and macrophage is reflected in the downregulation of HLA-DR and upregulation of MER tyrosine kinase (MERTK), which weakens the antigen presentation function and reduces the secretion of inflammatory cytokines. We also describe the specific function of bacterial translocation and the gut-liver axis in the process of ACLF. Finally, we also describe the transcriptomics in HBV-ACLF and the recent progress of single-cell RNA sequencing as well as its potential application in the study of ACLF in the future, in order to gain a deeper understanding of ACLF in terms of single-cell gene expression.

The role of platelet mediated thromboinflammation in acute liver injury

Acute liver injuries have wide and varied etiologies and they occur both in patients with and without pre-existent chronic liver disease. Whilst the pathophysiological mechanisms remain distinct, both acute and acute-on-chronic liver injury is typified by deranged serum transaminase levels and if severe or persistent can result in liver failure manifest by a combination of jaundice, coagulopathy and encephalopathy. It is well established that platelets exhibit diverse functions as immune cells and are active participants in inflammation through processes including immunothrombosis or thromboinflammation. Growing evidence suggests platelets play a dualistic role in liver inflammation, shaping the immune response through direct interactions and release of soluble mediators modulating function of liver sinusoidal endothelial cells, stromal cells as well as migrating and tissue-resident leucocytes. Elucidating the pathways involved in initiation, propagation and resolution of the immune response are of interest to identify therapeutic targets. In this review the provocative role of platelets is outlined, highlighting beneficial and detrimental effects in a spatial, temporal and disease-specific manner.

Plasticity of monocytes and macrophages in cirrhosis of the liver

Cirrhosis of the liver is a systemic condition with raising prevalence worldwide. Patients with cirrhosis are highly susceptible to develop bacterial infections leading to acute decompensation and acute-on-chronic liver failure both associated with a high morbidity and mortality and sparse therapeutic options other than transplantation. Mononuclear phagocytes play a central role in innate immune responses and represent a first line of defence against pathogens. Their function includes phagocytosis, killing of bacteria, antigen presentation, cytokine production as well as recruitment and activation of immune effector cells. Liver injury and development of cirrhosis induces activation of liver resident Kupffer cells and recruitment of monocytes to the liver. Damage- and pathogen-associated molecular patterns promote systemic inflammation which involves multiple compartments besides the liver, such as the circulation, gut, peritoneal cavity and others. The function of circulating monocytes and tissue macrophages is severely impaired and worsens along with cirrhosis progression. The underlying mechanisms are complex and incompletely understood. Recent 'omics' technologies help to transform our understanding of cellular diversity and function in health and disease. In this review we point out the current state of knowledge on phenotypical and functional changes of monocytes and macrophages during cirrhosis evolution in different compartments and their role in disease progression. We also discuss the value of potential prognostic markers for cirrhosis-associated immuneparesis, and future immunotherapeutic strategies that may reduce the need for transplantation and death.

Safety and efficacy of Thymosin α1 in the treatment of hepatitis B virus-related acute-on-chronic liver failure: a randomized controlled trial

BACKGROUND/PURPOSE OF THE STUDY

Mortality from hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) is high. Severe infection is the most important complication that affects the outcomes of ACLF patients. Thymosin α1 (Tα1) can improve immune imbalance and this study aimed to investigate the safety and efficacy of Tα1 treatment for HBV-related ACLF.

METHODS

From 2017 to 2019, 120 patients with HBV-related ACLF were enrolled in this open-label, randomized, and controlled clinical trial (ClinicalTrial ID: NCT03082885). The control group (N = 58) was treated with standard medical therapy (SMT) only. The experimental group (N = 56) was subcutaneously injected with 1.6 mg of Tα1 once a day for the first week and then twice a week from week 2 to week 12.

RESULTS

The 90-day cumulated liver transplantation free survival rate of the Tα1 group was 75.0% (95% confidence interval 63.2-86.8%) versus 53.4% (95% confidence interval 39.7-67.1%) for the SMT group (p = 0.030). No significant difference was found in the survival using competitive risk analysis. The incidences of new infection and hepatic encephalopathy in the Tα1 group were much lower than those in the SMT group (32.1% vs 58.6%, p = 0.005; 8.9% vs 24.1%, p = 0.029, respectively). Mortality from severe infection in the SMT group was higher than in the Tα1 group (24.1% vs 8.9%, p = 0.029).

CONCLUSION

Tα1 is safe for patients with HBV-related ACLF and significantly improves the 90-day liver transplantation-free survival rate. There may be a subgroup which may benefit from Tα1 therapy by the mechanism of preventing infection.

Plasma Proteomic Analysis Identified Proteins Associated with Faulty Neutrophils Functionality in Decompensated Cirrhosis Patients with Sepsis

Decompensated cirrhosis (DC) is susceptible to infections and sepsis. Neutrophils and monocytes provide the first line of defense to encounter infection. We aimed to evaluate proteins related to neutrophils functionality in sepsis. 70 (DC), 40 with sepsis, 30 without (w/o) sepsis and 15 healthy controls (HC) plasma was analyzed for proteomic analysis, cytokine bead array, endotoxin, cell free DNA and whole blood cells were analyzed for nCD64-mHLADR index, neutrophils-monocytes, functionality and QRT-PCR. nCD64-mHLADR index was significantly increased (p < 0.0001) with decreased HLA-DR expression on total monocytes in sepsis (p = 0.045). Phagocytic activity of both neutrophils and monocytes were significantly decreased in sepsis (p = 0.002 and p = 0.0003). Sepsis plasma stimulated healthy neutrophils, showed significant increase in NETs (neutrophil extracellular traps) and cell free DNA (p = 0.049 and p = 0.04) compared to w/o sepsis and HC. Proteomic analysis revealed upregulated- DNAJC13, TMSB4X, GPI, GSTP1, PNP, ANPEP, COTL1, GCA, APOA1 and PGAM1 while downregulated- AHSG, DEFA1,SERPINA3, MPO, MMRN1and PROS1 proteins (FC > 1.5; p < 0.05) associated to neutrophil activation and autophagy in sepsis. Proteins such as DNAJC13, GPI, GSTP1, PNP, ANPEP, COTL1, PGAM1, PROS1, MPO, SERPINA3 and MMRN1 showed positive correlation with neutrophils activity and number, oxidative burst activity and clinical parameters such as MELD, MELD Na and Bilirubin. Proteomic analysis revealed that faulty functionality of neutrophils may be due to the autophagy proteins i.e., DNAJC13, AHSG, TMSB4X, PROS1 and SERPINA3, which can be used as therapeutic targets in decompensated cirrhosis patients with sepsis.

Glucocorticoid Treatment Strategies in Liver Failure

Liver failure is characterized by serious liver decompensation and high mortality. The activation of systemic immune responses and systemic inflammation are widely accepted as the core pathogenesis of liver failure. Glucocorticoids (GCs) are most regularly utilized to suppress excessive inflammatory reactions and immunological responses. GCs have been used in the clinical treatment of liver failure for nearly 60 years. While there has been no unanimity on the feasibility and application of GC treatment in liver failure until recently. The most recent trials have produced conflicting results when it comes to the dose and time for GC therapy of different etiology of liver failure. Our review outlines the issues and options in managing GC treatment in liver failure based on an investigation of the molecular mechanism that GC may give in the treatment.

Hepatocytic Apoptosis and Immune Dysfunction in Decompensation of Alcoholic Liver Cirrhosis with Different Grades of Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) of varying grades was assessed in 110 patients with alcoholic liver cirrhosis using the on-line CLIF-C ACLF Calculator ( www.efclif.com/scientific-activity/score-calculators/clif-c-aclf ); fragments of cytokeratin-18, TNFα, IL-1β, IL-4, IL-6, and IL-8 were also assayed. As ACLF progressed from grade 0 to grade 3, the levels of cytokeratin-18 fragments, IL-6, and IL-8 significantly increased, while IL-4 decreased. TNFα peaked in ACLF grade 1, but decreased in grades 2 and 3. IL-1β did not depend on the ACLF grade. Thus, hepatic damage and immune dysfunction are implicated in the progression of ACLF.

Cirrhosis-associated immune dysfunction

The term cirrhosis-associated immune dysfunction (CAID) comprises the distinctive spectrum of immune alterations associated with the course of end-stage liver disease. Systemic inflammation and immune deficiency are the key components of CAID. Their severity is highly dynamic and progressive, paralleling cirrhosis stage. CAID involves two different immune phenotypes: the low-grade systemic inflammatory phenotype and the high-grade systemic inflammatory phenotype. The low-grade systemic inflammatory phenotype can be found in patients with compensated disease or clinical decompensation with no organ failure. In this phenotype, there is an exaggerated immune activation but the effector response is not markedly compromised. The high-grade systemic inflammatory phenotype is present in patients with acute-on-chronic liver failure, a clinical situation characterized by decompensation, organ failure and high short-term mortality. Along with high-grade inflammation, this CAID phenotype includes intense immune paralysis that critically increases the risk of infections and worsens prognosis. The intensity of CAID has important consequences on cirrhosis progression and correlates with the severity of liver insufficiency, bacterial translocation and organ failure. Therapies targeting the modulation of the dysfunctional immune response are currently being evaluated in preclinical and clinical studies.

Gene profiling of Toll-like receptor signalling pathways in neutrophils of patients with acute-on-chronic liver failure

Objectives

Toll-like receptors (TLRs) on neutrophils play a crucial role in detecting pathogens and organ/tissue injury in acute-on-chronic liver failure (ACLF). However, little is known about the exact mechanisms and potential signalling pathways. The aim of this study was to investigate alterations in TLR signalling pathways in neutrophils of ACLF patients.

Methods

Twenty-seven patients with compensated cirrhosis (n = 9), decompensated cirrhosis (n = 9) and ACLF (n = 9) were enrolled in the study. Neutrophils were isolated, and alterations in TLR signalling pathways were evaluated using an RT² Profiler™ PCR Array. The fold change for each gene (2(^−∆∆CT)) was compared among the groups. Genes with a fold change ratio of ≥ 2 or ≤ 0.5 along with a p value of < 0.05 were considered to be differentially expressed.

Results

A total of 17 genes were upregulated in neutrophils from patients with compensated cirrhosis and were mainly distributed in adaptors, TLR-interacting proteins and downstream pathways. Six genes were detected in patients with decompensated cirrhosis. A trend of downregulation of genes in the TLR signalling pathway was observed in neutrophils of patients with cirrhosis and ACLF. TLR3, IFNG, IL1B, TBK1, CCL2 and LTA were downregulated in neutrophils. Moreover, CD14 and IL10 were upregulated in neutrophils of ACLF patients.

Conclusions

TLR signalling pathway genes were differentially regulated in neutrophils between cirrhosis and ACLF. In ACLF patients, defective expression of TLR3 and IFN, along with enhanced CD14 and IL10 expression, was characterized by transcriptional alterations of neutrophils.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03135-3.

Clinical significance of small molecule metabolites in the blood of patients with different types of liver injury

To understand the characteristic of changes of serum metabolites between healthy people and patients with hepatitis B virus (HBV) infection at different stages of disease, and to provide reference metabolomics information for clinical diagnosis of liver disease patients. 255 patients with different stages of HBV infection were selected. 3 mL blood was collected from each patient in the morning to detect differences in serum lysophosphatidylcholine, acetyl-l-carnitine, oleic acid amide, and glycocholic acid concentrations by UFLC-IT-TOF/MS. The diagnostic values of four metabolic substances were evaluated by receiver operating characteristic (ROC) curve. The results showed that the optimal cut-off value of oleic acid amide concentration of the liver cirrhosis and HCC groups was 23.6 mg/L, with a diagnostic sensitivity of 88.9% and specificity of 70.6%. The diagnostic efficacies of the three substances were similar in the hepatitis and HCC groups, with an optimal cut-off value of 2.04 mg/L, and a diagnostic sensitivity and specificity of 100% and 47.2%, respectively. The optimal cut-off value of lecithin of the HBV-carrier and HCC groups was 132.85 mg/L, with a diagnostic sensitivity and specificity of 88.9% and 66.7%, respectively. The optimal cut-off value of oleic acid amide of the healthy and HCC groups was 129.03 mg/L, with a diagnostic sensitivity and specificity of 88.4% and 83.3%, respectively. Lysophosphatidylcholine, acetyl-l-carnitine, and oleic acid amide were potential metabolic markers of HCC. Among them, lysophosphatidylcholine was low in the blood of HCC patients, and its diagnostic efficacy was better than that of acetyl-l-carnitine and oleic acid amide, providing reference metabolomics information in clinical diagnosis and future research.

Impact of the Gut Microbiome on the Progression of Hepatitis B Virus Related Acute-on-Chronic Liver Failure

The relationship between the progression of hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) and the gut microbiota is poorly understood, and an HBV-ACLF-related microbiome has yet to be identified. In this study alterations in the fecal microbiome of 91 patients with HBV-ACLF (109 stool samples), including a cohort of nine patients at different stages of HBV-ACLF, were determined by high-throughput 16S rDNA sequencing. The operational taxonomic units and Shannon indexes indicated that the diversity and abundance of the gut microbiome significantly decreased with the progression of HBV-ACLF (p <0.05). The relative abundance of the Bacteroidetes phylum in the microbiome was significantly reduced, whereas the abundance of potentially pathogenic bacteria, such as Veilonella, Streptococcus, Enterococcus, and Klebsiella, was highly enriched in the HBV-ACLF group compared with the healthy control group. The abundance of Bacteroidetes was negatively correlated with the level of serum alpha fetoprotein, and the abundance of Veilonella was positively correlated with serum total bilirubin (TBIL). Furthermore, the abundance of Coprococcus was significantly negatively correlated with the level of serum TBIL and the international normalized ratio and positively correlated with prothrombin time activity. Our findings suggest that the gut microbiota plays an important role in the development of HBV-ACLF.

Patterns of dendritic cell and monocyte subsets are associated with disease severity and mortality in liver cirrhosis patients

Liver cirrhosis is often complicated by an immunological imbalance known as cirrhosis-associated immune dysfunction. This study aimed to investigate disturbances in circulating monocytes and dendritic cells in patients with acute decompensation (AD) of cirrhosis. The sample included 39 adult cirrhotic patients hospitalized for AD, 29 patients with stable cirrhosis (SC), and 30 healthy controls (CTR). Flow cytometry was used to analyze monocyte and dendritic cell subsets in whole blood and quantify cytokines in plasma samples. Cirrhotic groups showed higher frequencies of intermediate monocytes (iMo) than CTR. AD patients had lower percentages of nonclassical monocytes than CTR and SC. Cirrhotic patients had a profound reduction in absolute and relative dendritic cell numbers compared with CTR and showed higher plasmacytoid/classical dendritic cell ratios. Increased plasma levels of IL-6, IL-10, and IL-17A, elevated percentages of CD62L⁺ monocytes, and reduced HLA-DR expression on classical monocytes (cMo) were also observed in cirrhotic patients. Patients with more advanced liver disease showed increased cMo and reduced tissue macrophages (TiMas) frequencies. It was found that cMo percentages greater than 90.0% within the monocyte compartment and iMo and TiMas percentages lower than 5.7% and 8.6%, respectively, were associated with increased 90-day mortality. Monocytes and dendritic cells are deeply altered in cirrhotic patients, and subset profiles differ between stable and advanced liver disease. High cMo and low TiMas frequencies may be useful biomarkers of disease severity and mortality in liver cirrhosis.

The efficacy and safety of methylprednisolone in hepatitis B virus-related acute-on-chronic liver failure: a prospective multi-center clinical trial

BACKGROUND

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a severe condition with high mortality due to lack of efficient therapy. Until now, the use of methylprednisolone (MP) in HBV-ACLF is still controversial. We aimed to evaluate the efficacy and safety of MP in HBV-ACLF.

METHODS

Totally 171 HBV-ACLF patients from three medical centers were randomly allocated into MP group (83 patients treated with MP intravenously guttae for 7 days plus standard treatment: 1.5 mg/kg/day [day 1-3], 1 mg/kg/day [day 4-5], and 0.5 mg/kg/day [day 6-7]) and control group (88 patients treated with standard treatment). The primary endpoints were 6-month mortality and prognostic factors for 6-month survival. The survival time, cause of death, adverse events, liver function, and HBV DNA replication were analyzed.

RESULTS

The 6-month mortality was significantly lower in MP group than control group [32.4% vs. 42.5%, P = 0.0037]. MP treatment was an independent prognostic factor for 6-month survival [HR (95% CI) 0.547(0.308-0.973); P = 0.040]. Factors associated with reduced 6-month mortality in MP group included HBV DNA and lymphocyte/monocyte ratio (LMR) (P < 0.05). Based on ROC curve, LMR+MELD had a better predictive value for prognosis of HBV-ACLF under MP treatment. No significant difference in HBV DNA replication was observed between groups (P > 0.05).

CONCLUSIONS

MP therapy is an effective and safe clinical strategy in HBV-ACLF, increasing the 6-month survival rate. Clinical trials registered at http://www.chictr.org.cn as ChiCTR-TRC-13003113 registered on 16 March 2013.

Leukocytes, Systemic Inflammation and Immunopathology in Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is a complex syndrome that develops in patients with cirrhosis and is characterized by acute decompensation, organ failure(s) and high short-term mortality. ACLF frequently occurs in close temporal relationship to a precipitating event, such as acute alcoholic, drug-induced or viral hepatitis or bacterial infection and, in cases without precipitating events, probably related to intestinal translocation of bacterial products. Dysbalanced immune function is central to its pathogenesis and outcome with an initial excessive systemic inflammatory response that drives organ failure and mortality. This hyperinflammatory state ultimately impairs the host defensive mechanisms of immune cells, rendering ACLF patients immunocompromised and more vulnerable to secondary infections, and therefore to higher organ dysfunction and mortality. In this review, we describe the prevailing characteristics of the hyperinflammatory state in patients with acutely decompensated cirrhosis developing ACLF, with special emphasis on cells of the innate immune system (i.e., monocytes and neutrophils), their triggers (pathogen- and damage-associated molecular patterns [PAMPs and DAMPs]), their effector molecules (cytokines, chemokines, growth factors and bioactive lipid mediators) and the consequences on tissue immunopathology. In addition, this review includes a chapter discussing new emerging therapies based on the modulation of leukocyte function by the administration of pleiotropic proteins such as albumin, Toll-like receptor 4 antagonists, interleukin-22 or stem cell therapy. Finally, the importance of finding an appropriate intervention that reduces inflammation without inducing immunosuppression is highlighted as one of the main therapeutic challenges in cirrhosis.

Acute-on-Chronic Liver Failure From Chronic-Hepatitis-B, Who Is the Behind Scenes

Acute-on-chronic liver failure (ACLF) is an acute syndrome accompanied with decompensation of cirrhosis, organ failure with high 28-day mortality rate. Systemic inflammation is the main feature of ACLF, and poor outcome is closely related with exacerbated systemic inflammatory responses. It is well known that severe systemic inflammation is an important event in chronic hepatitis B (CHB)-ACLF, which eventually leads to liver injury. However, the initial CHB-ACLF events are unclear; moreover, the effect of these events on host immunity as well as that of immune imbalance on CHB-ACLF progression are unknown. Here, we investigate the initial events of ACLF progression, discuss possible mechanisms underlying ACLF progression, and provide a new model for ACLF prediction and treatment. We review the characteristics of ACLF, and consider its plausible immune predictors and alternative treatment strategies.

Abnormal Innate Immunity in Acute-on-Chronic Liver Failure: Immunotargets for Therapeutics

Acute-on-chronic liver failure (ACLF) is a severe life-threatening condition with high risk of multiorgan failure, sepsis, and mortality. ACLF activates a multifaceted interplay of both innate and adaptive immune response in the host which governs the overall outcome. Innate immune cells recognize the conserved elements of microbial and viral origin, both to extort instant defense by transforming into diverse modules of effector responses and to generate long-lasting immunity but can also trigger a massive intrahepatic immune inflammatory response. Acute insult results in the activation of innate immune cells which provokes cytokine and chemokine cascade and subsequently initiates aggressive systemic inflammatory response syndrome, hepatic damage, and high mortality in ACLF. Dysregulated innate immune response not only plays a critical role in disease progression but also potentially correlates with clinical disease severity indices including Child-Turcotte-Pugh, a model for end-stage liver disease, and sequential organ failure assessment score. A better understanding of the pathophysiological basis of the disease and precise immune mechanisms associated with liver injury offers a novel approach for the development of new and efficient therapies to treat this severely ill entity. Immunotherapies could be helpful in targeting immune-mediated organ damage which may constrain progression toward liver failure and eventually reduce the requirement for liver transplantation. Here, in this review we discuss the defects of different innate immune cells in ACLF which updates the current knowledge of innate immune response and provide potential targets for new therapeutic interventions.

Innate immune cells in cirrhosis

Cirrhosis is a multisystemic disease wherein inflammatory responses originating from advanced liver disease and its sequelae affect distant compartments. Patients with cirrhosis are susceptible to bacterial infections, which may precipitate acute decompensation and acute-on-chronic liver failure, both of which are associated with high short-term mortality. Innate immune cells are an essential first line of defence against pathogens. Activation of liver macrophages (Kupffer cells) and resident mastocytes generate proinflammatory and vaso-permeating mediators that induce accumulation of neutrophils, lymphocytes, eosinophils and monocytes in the liver, and promote tissue damage. During cirrhosis progression, damage- and pathogen-associated molecular patterns activate immune cells and promote development of systemic inflammatory responses which may involve different tissues and compartments. The antibacterial function of circulating neutrophils and monocytes is gradually and severely impaired as cirrhosis worsens, contributing to disease progression. The mechanisms underlying impaired antimicrobial responses are complex and incompletely understood. This review focuses on the continuous and distinct perturbations arising in innate immune cells during cirrhosis, including their impact on disease progression, as well as reviewing potential therapeutic targets.

The Management of Glucocorticoid Therapy in Liver Failure

Liver failure is characterized by rapid progression and high mortality. Excessive systemic inflammation is considered as the trigger of liver failure. Glucocorticoids (GCs) can rapidly suppress excessive inflammatory reactions and immune response. GCs have been applied in the treatment of liver failure since the 1970s. However, until now, the use of GCs in the treatment of liver failure has been somewhat unclear and controversial. New research regarding the molecular mechanisms of GCs may explain the controversial actions of GCs in liver failure. More results should be confirmed in a larger randomized clinical trial; this can aid the discovery of better definitions in terms of treatment schedules according to different clinical settings. Meanwhile, the timing and dosing of GCs in the treatment of liver failure should also be explored.

The immunological roles in acute-on-chronic liver failure: An update

BACKGROUND

Acute-on-chronic liver failure (ACLF) refers to the acute deterioration of liver function that occurs in patients with chronic liver disease. ACLF is characterized by acute decompensation, organ failure and high short-term mortality. Numerous studies have been conducted and remarkable progress has been made regarding the pathophysiology and pathogenesis of this disease in the last decade. The present review was to summarize the advances in this field.

DATA SOURCES

A comprehensive search in PubMed and EMBASE was conducted using the medical subject words "acute-on-chronic liver failure", "ACLF", "pathogenesis", "predictors", and "immunotherapy" combined with free text terms such as "systemic inflammation" and "immune paralysis". Relevant papers published before October 31, 2018, were included.

RESULTS

ACLF has two marked pathophysiological features, namely, excessive systemic inflammation and susceptibility to infection. The systemic inflammation is mainly manifested by a significant increase in the levels of plasma pro-inflammatory factors, leukocyte count and C-reactive protein. The underlying mechanisms are unclear and may be associated with decreased immune inhibitory cells, abnormal expression of cell surface molecules and intracellular regulatory pathways in immune cells and increased damage-associated molecular patterns in circulation. However, the main cause of susceptibility to infection is immune paralysis. Immunological paralysis is characterized by an attenuated activity of immune cells. The mechanisms are related to elevations of immune inhibitory cells and the concentration of plasma anti-inflammatory molecules. Some immune biological indicators, such as soluble CD163, are used to explore the pathogenesis and prognosis of the disease, and some immunotherapies, such as glucocorticoids and granulocyte colony-stimulating factor, are effective on ACLF.

CONCLUSIONS

Overwhelming systemic inflammation and susceptibility to infection are two key features of ACLF. A better understanding of the state of a patient's immune system will help to guide immunotherapy for ACLF.

Myeloid-derived suppressor cells expansion is closely associated with disease severity and progression in HBV-related acute-on-chronic liver failure

Dysregulation of the host immune responses induced by host hepatitis B virus (HBV) interactions has been observed in acute-on-chronic liver failure (ACLF). Myeloid-derived suppressor cells (MDSCs), well known for their immunomodulatory properties, can suppress T-cell function by regulating the expression of CD3 ζ chain in cancer and autoimmune/infectious diseases while rarely have been studied in ACLF. In this study, MDSCs, CD4⁺ /CD8⁺ T cells, and CD3 ζ chain were analyzed by flow cytometry in peripheral blood mononuclear cells obtained from HBV-related ACLF patients, chronic hepatitis B (CHB) patients and healthy controls. ACLF patients were followed up for dynamic detection of MDSCs and observation of outcomes after treatment. Interestingly, peripheral CD14⁺ CD33⁺ CD11b⁺ HLA-DR^-/low MDSCs from ACLF patients were significantly increased compared to those from CHB patients and healthy controls. CD4⁺ /CD8⁺ T cell frequency and CD3 ζ chain expression in T cells were decreased in ACLF patients compared to those of healthy controls and were negatively correlated with matched MDSC frequency. Meanwhile, the frequency of MDSCs was closely correlated with biochemical parameters that are relevant for liver injury rather than virological parameters. Moreover, a lower level of MDSCs was correlated with a better short-term prognosis (within 4 weeks but not at 8 weeks), and MDSCs remained high in ACLF patients whose conditions worsened within a 4-week follow-up period after treatment. These results suggest that MDSCs are closely involved in cell-mediated immunity in HBV-related ACLF and that peripheral MDSC expansion is closely associated with disease severity and progression in HBV-related ACLF, which may serve as a predictor of short-term prognosis.

Altered PGE2-EP2 is associated with an excessive immune response in HBV-related acute-on-chronic liver failure

Background and aims

Prostaglandin E receptor 2 (EP2) is an immune modulatory molecule that regulates the balance of immunity. Here we investigated the role of EP2 in immune dysregulation in patients with acute-on-chronic liver failure (ACLF).

Methods

Plasma Progstaglandin E2 (PGE2) levels and EP2 expression on immune cells were determined in blood samples collected from patients with chronic hepatitis B related ACLF(HB-ACLF), patients with chronic hepatitis B (CHB), acute decompensated cirrhosis without ACLF (AD) and healthy controls (HC). Cytokine production, bacterial phagocytosis and reactive oxygen species (ROS) production were detected to explore the role of EP2 in regulating immune cell functions.

Results

The plasma PGE2 levels were increased and EP2 expression on CD8⁺ T cells was decreased in HB-ACLF compared with those in controls. The levels of PGE2 and EP2 were associated with systemic inflammation and disease severity. Small molecular chemicals against EP2 increased both cytokine secretion in PBMCs and ROS production in neutrophils and monocytes, but decreased monocytic phagocytosis. By contrast, an EP2-selective agonist reduced the production of a series of cytokines in PBMCs, but increased G-CSF.

Conclusion

Altered PGE2-EP2 augmented the excessive inflammation of innate and adaptive immune cells in response to LPS or E. coli in HB-ACLF. EP2 might be a new potential target for HB-ACLF treatment.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1844-0) contains supplementary material, which is available to authorized users.

Causes and Consequences of Innate Immune Dysfunction in Cirrhosis

Liver cirrhosis is an increasing health burden and public health concern. Regardless of etiology, patients with cirrhosis are at risk of a range of life-threatening complications, including the development of infections, which are associated with high morbidity and mortality and frequent hospital admissions. The term Cirrhosis-Associated Immune Dysfunction (CAID) refers to a dynamic spectrum of immunological perturbations that develop in patients with cirrhosis, which are intimately linked to the underlying liver disease, and negatively correlated with prognosis. At the two extremes of the CAID spectrum are systemic inflammation, which can exacerbate clinical manifestations of cirrhosis such as hemodynamic derangement and kidney injury; and immunodeficiency, which contributes to the high rate of infection in patients with decompensated cirrhosis. Innate immune cells, in particular monocytes/macrophages and neutrophils, are pivotal effector and target cells in CAID. This review focuses on the pathophysiological mechanisms leading to impaired innate immune function in cirrhosis. Knowledge of the phenotypic manifestation and pathophysiological mechanisms of cirrhosis associated immunosuppression may lead to immune targeted therapies to reduce susceptibility to infection in patients with cirrhosis, and better biomarkers for risk stratification, and assessment of efficacy of novel immunotherapies.

Immunodeficiency caused by cirrhosis

The syndrome of decreased immunity caused by cirrhosis is a combination of different immunological mechanisms and reactions which result from an advanced stage of the liver disease. The synthesis of proteins of the acute phase becomes impaired, there develop different deficiencies of the complement system, and there ensues a decrease of receptors that are meant to recognize antigens. The negative changes become apparent in the field of cell responses, e.g. there are changes in the amounts of generated monocytes and macrophages, and their phagocytic capabilities and chemotaxic reactions are impacted as well. The humoral response results in distorted synthesis of particular antigen categories. The risk of detrimental immunoresponses with the end result of endotoxemia is not rarely coupled with both local and global infections. The combination of the aforesaid immunodeficiencies worsens the healing chances of cirrhosis sufferers and more often than not it increases the mortality of the affected patients.

Monocyte human leukocyte antigen - Antigen D related, neutrophil oxidative burst and cytokine analysis in patients of decompensated cirrhosis with and without acute-on chronic liver failure

Background and aim

Due to a dysregulated immune response, patients with acute-on-chronic liver failure (ACLF) have increased risk of infection and multi organ failure in comparison to compensated cirrhosis. The comparative data on the presence of ‘immune paresis’ in patients with ACLF and decompensated cirrhosis without ACLF is not available. Aim of the present study was to compare the immunological parameters in patients with decompensated cirrhosis with and without ACLF.

Methodology

In a prospective study, 76 patients with decompensated cirrhosis with (n = 38) and without (n = 38) ACLF and 10 healthy controls (HC) were evaluated for monocytic human leukocyte antigen–antigen D Related (HLA-DR) expression, mean density of HLA-DR expressed on the surface of these cells, neutrophil oxidative burst (NOB) capacity and serum levels of cytokines (IL-1, IL-6, IL-8, IL10, IL-12, and TNF-α).

Results

Patients of decompensated cirrhosis with and without ACLF demonstrated significantly lower mean percentage of monocytes expressing HLA-DR and quantitative increase in the NOB after stimulation with PMA when compared to HC. However there was no difference in mean percentage of monocytes with HLA-DR expression (43.61±26.56% vs. 43.10±20.98%) (p = 0.91), mean density of HLA-DR expression on the surface (30.34±29.32 vs. 41.71±52.13) (p = 0.42) and quantitative increase in NOB after stimulation with PMA (16.55±11.91 vs. 17.24±16.18) (p = 0.47) amongst patients with decompensated cirrhosis with and without ACLF. Patients with ACLF had significantly higher pro-inflammatory and anti-inflammatory cytokines in comparison to patients with decompensated cirrhosis without ACLF.

Conclusion

Patients with decompensated cirrhosis demonstrate a component of immune-paresis, however there is similar impairment in HLA–DR expression and NOB capacity in patients with and without ACLF. Both inflammatory and anti-inflammatory cytokines are increased in patients with ACLF in comparison to patients with decompensated cirrhosis without ACLF.

Disruption of the gut-liver axis in the pathogenesis of acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is characterized by organ failure mediated by acute decompensation of cirrhosis. Recent studies have highlighted the importance of the gut-liver axis (GLS) and its association with ACLF pathogenesis. In this review, we discuss the mechanisms related to the alteration of the GLA and their involvement in ACLF pathogenesis and suggest some possible therapeutic options that could modulate the GLA dysfunction. This knowledge may provide information useful for the design of therapeutic strategies for gut dysbiosis and its complications in ACLF.

TLR2 Expression in Peripheral CD4+ T Cells Promotes Th17 Response and Is Associated with Disease Aggravation of Hepatitis B Virus-Related Acute-On-Chronic Liver Failure

Th17 responses have been shown to play crucial roles in the pathogenesis of hepatitis B virus (HBV)-associated acute-on-chronic liver failure (ACLF). The mechanism underlying the enhanced Th17 responses in these patients remains largely unclear. Here we investigated toll-like receptors (TLRs) expression in peripheral T cells and their roles in Th17 cell differentiation and disease aggravation in ACLF patients. 18 healthy subjects (HS), 20 chronic HBV-infected (CHB) patients, and 26 ACLF patients were enrolled and examined for TLRs expression in peripheral blood mononuclear cells (PBMCs). The correlations of T cell TLR2 expression with the antigen non-specific Th17 responses and disease aggravation, as well as the Th17 response to TLR2 ligand stimulation were evaluated in ACLF patients. Compared to HS and CHB patients, ACLF patients showed a distinct TLRs expression pattern in PBMCs. Significantly increased TLR2 expression in T cells was observed in ACLF patients. The TLR2 expression in CD4+ T cells was correlated with the Th17 responses and the clinical markers for disease aggravation in ACLF patients. Moreover, TLR2 ligands stimulation promoted Th17 cell differentiation and response in PBMCs of ACLF patients. These findings implicate that TLR2 signaling plays critical roles in Th17 cell differentiation and disease aggravation of HBV-related ACLF.

Acute-on-chronic liver failure: recent update

Acute on chronic liver failure (ACLF) was first described in 1995 as a clinical syndrome distinct to classic acute decompensation. Characterized by complications of decompensation, ACLF occurs on a background of chronic liver dysfunction and is associated with high rates of organ failure and significant short-term mortality estimated between 45% and 90%. Despite the clinical relevance of the condition, it still remains largely undefined with continued disagreement regarding its precise etiological factors, clinical course, prognostic criteria and management pathways. It is concerning that, despite our relative lack of understanding of the condition, the burden of ACLF among cirrhotic patients remains significant with an estimated prevalence of 30.9%. This paper highlights our current understanding of ACLF, including its etiology, diagnostic and prognostic criteria and pathophysiology. It is evident that further refinement of the ACLF classification system is required in order to detect high-risk patients and improve short-term mortality rates. The field of metabolomics certainly warrants investigation to enhance diagnostic and prognostic parameters, while the use of granulocyte-colony stimulating factor is a promising future therapeutic intervention for patients with ACLF.

Hypermethylation of the galectin-3 promoter is associated with poor prognosis of acute-on-chronic hepatitis B liver failure

BACKGROUND AND AIMS

The possible role of galectin-3 in acute-on-chronic hepatitis B liver failure (ACHBLF) remains unknown. This study aimed to determine the methylation status of the galectin-3 promoter in patients with ACHBLF and analyze its prognostic value.

METHODS

The methylation status of the galectin-3 promoter in patients with ACHBLF, chronic hepatitis B (CHB) and healthy controls (HCs) was determined by methylation-specific polymerase chain reaction (MSP). The galectin-3 mRNA level in peripheral blood mononuclear cells (PBMCs) was detected using real-time polymerase chain reaction (RT-PCR).

RESULTS

The methylation frequency of the galectin-3 promoter was significantly higher while galectin-3 mRNA was lower in ACHBLF than in CHB and HCs. Galectin-3 promoter methylation was negatively correlated with the mRNA level in ACHBLF. In addition, ACHBLF patients carrying the methylated promoter showed shorter survival time, higher 3-month mortality, and higher model for end-stage liver disease (MELD) score when compared to ACHBLF patients carrying the unmethylated promoter. Moreover, promoter methylation was a better predictor of 3-week mortality than the MELD score in ACHBLF patients.

CONCLUSION

Our results suggest that hypermethylation of the galectin-3 promoter might be an early biomarker for predicting disease severity and prognosis in patients with ACHBLF.

Toll like receptor 4 and hepatocellular carcinoma; A systematic review

INTRODUCTION

Toll like receptor 4 (TLR4) is an extracellular pathogen recognition receptor (PRR) which recognizes a wide range of pathogens and damage associated molecular patterns (PAMPs and DAMPs). It can activate intracellular signaling and consequently transcription factors which participate in transcription from either immune related or malignancy genes. Thus, it has been hypothesized that TLR4 may be a cause of hepatocellular carcinoma (HCC). This article has reviewed the roles of TLR4 in the pathogenesis of HCC.

METHOD

"TLR4", "hepatocellular carcinoma", "liver tumor" and "liver cancer" were used as key words for searching in Scopus, Google Scholar and MEDLINE scientific databases.

RESULTS

Most of the investigations documented the roles of TLR4 in induction of HCC via several mechanisms including increased number of T regulatory lymphocytes and liver resident follicular helper like cells, increased production of pro-inflammatory and malignancy related molecules including cytokines, NANOG, Caspase-1, Ephrin-A1, NO and BCL6. TLR4 participates in the proliferation of the cells and also production of the molecules in both chronic infectious and non-infectious inflammatory diseases.

DISCUSSION

TLR4 is an innate immunity receptor which plays a pathogenic role during chronic inflammation and can induce HCC in human.

Risk of different precipitating events for progressing to acute-on-chronic liver failure in HBV-related cirrhotic patients

OBJECTIVE

Acute-on-chronic liver failure (ACLF) is a distinct syndrome that develops in patients with cirrhosis and acute decompensation (AD). This study focused on the precipitating events (PEs) of hepatitis B virus (HBV)-related cirrhotic patients diagnosed as ACLF based on the Chronic Liver Failure Consortium organ failure (CLIF-C OF) score.

METHODS

Hospitalized patients with HBV-related cirrhosis and AD were retrospectively included. The patients' characteristics, laboratory test results, PEs, CLIF-C OF score and short-term prognosis were evaluated.

RESULTS

Of the 890 patients enrolled 300 (33.7%) were diagnosed as ACLF and 590 (66.3%) without ACLF. ACLF patients had a higher incidence of PEs than those without ACLF. The ACLF patients were more prone to having PEs of bacterial infection (P < 0.001), HBV reactivation (P < 0.001), active alcoholism (P = 0.036) and superimposed hepatitis virus infection (P = 0.031), whereas portal vein thrombosis (P = 0.002) were less common in the non-ACLF group. ACLF patients with the top four single PEs had diverse types of organ failures. However, they shared a similar short-term prognosis. While in patients without PEs the ACLF group had higher systemic inflammation and deterirated outcomes compared with the non-ACLF group.

CONCLUSIONS

PEs of bacterial infection, HBV reactivation, active alcoholism and superimposed hepatitis virus infection, but not GI hemorrhage or portal vein thrombosis, were risk factors for ACLF. There may be two types of patients with ACLF based on the differences in the clinical manifestation of the disease.

Serum Toll-Like Receptor-2, Toll-Like Receptor-4 Levels in Patients with HBeAg-Negative Chronic Viral Hepatitis B

Toll-like receptors (TLRs) may play an important role in hepatitis-B pathogenesis. However, serum TLR-2 and TLR-4 levels and their association with serum liver enzymes, hepatitis B virus (HBV) DNA, quantitative HBsAg levels, and liver biopsy findings, are unknown. A total of naive 40 HBeAg (-) chronic hepatitis B (CHB) patients and 20 healthy control subjects were recruited in this study. Liver tests, HBV DNA, serum TLR-2 and TLR-4, and quantitative HBsAg levels were evaluated among all groups. The relationship among TLR-2, TLR-4, quantitative HBsAg levels and liver tests, and liver histological findings were investigated with correlation analysis. Serum TLR-2 and TLR-4 levels in HBeAg (-) CHB patients were higher than in the control group. There was a positive correlation between serum TLR-2, TLR-4, and HBV DNA and ALT levels. We have further demonstrated that serum TLR-2 levels are correlated with AST and quantitative HBsAg levels. However, TLRs levels were not linked to the liver biopsy findings. TLR can have an important role in hepatitis B pathogenesis. Liver injury in CHB may cause elevated TLR-2 and TLR-4 levels.

Immune Dysfunction in Cirrhosis

Cirrhosis due to any etiology disrupts the homeostatic role of liver in the body. Cirrhosis-associated immune dysfunction leads to alterations in both innate and acquired immunity, due to defects in the local immunity of liver as well as in systemic immunity. Cirrhosis-associated immune dysfunction is a dynamic phenomenon, comprised of both increased systemic inflammation and immunodeficiency, and is responsible for 30% mortality. It also plays an important role in acute as well as chronic decompensation. Immune paralysis can accompany it, which is characterized by increase in anti-inflammatory cytokines and suppression of proinflammatory cytokines. There is also presence of increased gut permeability, reduced gut motility and altered gut flora, all of which leads to increased bacterial translocation. This increased bacterial translocation and consequent endotoxemia leads to increased blood stream bacterial infections that cause systemic inflammatory response syndrome, sepsis, multiorgan failure and death. The gut microbiota of cirrhotic patients has more pathogenic microbes than that of non-cirrhotic individuals, and this disturbs the homeostasis and favors gut translocation. Prompt diagnosis and treatment of such infections are necessary for better survival. We have reviewed the various mechanisms of immune dysfunction and its consequences in cirrhosis. Recognizing the exact pathophysiology of immune dysfunction will help treating clinicians in avoiding its complications in their patients and can lead to newer therapeutic interventions and reducing the morbidity and mortality rates.

Acute-on-chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is a distinct entity that differs from acute liver failure and decompensated cirrhosis in timing, presence of treatable acute precipitant, and course of disease, with a potential for self-recovery. The core concept is acute deterioration of existing liver function in a patient of chronic liver disease with or without cirrhosis in response to an acute insult. The insult should be a hepatic one and presentation in the form of liver failure (jaundice, encephalopathy, coagulopathy, ascites) with or without extrahepatic organ failure in a defined time frame. ACLF is characterized by a state of deregulated inflammation. Initial cytokine burst presenting as SIRS, progression to CARS and associated immunoparalysis leads to sepsis and multi-organ failure. Early identification of the acute insult and mitigation of the same, use of nucleoside analogue in HBV-ACLF, steroid in severe alcoholic hepatitis, steroid in severe autoimmune hepatitis and/or bridging therapy lead to recovery, with a 90-day transplant-free survival rate of up to 50 %. First-week presentation is crucial concerning SIRS/sepsis, development, multiorgan failure and consideration of transplant. A protocol-based multi-disciplinary approach including critical care hepatology, early liver transplant before multi-organ involvement, or priority for organ allocation may improve the outcome. Presentation with extrahepatic organ involvement or inclusion of sepsis as an acute insult in definition restricts the therapy, i.e., liver transplant or bridging therapy, and needs serious consideration. Augmentation of regeneration, cell-based therapy, immunotherapy, and gut microbiota modulation are the emerging areas and need further research.

Metabolite variations between acute-on-chronic liver failure and chronic liver failure caused by hepatitis B virus based on ultra-performance liquid chromatography mass spectrometry

OBJECTIVE

The present study aims to compare serum metabolite alterations between acute-on-chronic liver failure (ACLF) and chronic liver failure (CLF), and find the specific biomarkers associated with the diseases.

METHODS

Serum samples were collected from patients with ACLF (n=76) and CLF (n=56) as well as healthy individuals (n=20) and assayed by ultra-performance liquid chromatography mass spectrometry (UPLC-MS). The acquired data was analyzed using principal components analysis (PCA) and partial least squares discriminate analysis (PLS-DA).

RESULTS

The PLS-DA model with satisfactory explanatory and predictive ability (R2=0.979, Q2=0.918) is capable of discriminate ACLF patients from CLF patients. Significant difference in the metabolomics among the three groups was observed, metabolites that decreased significantly in the serum of ACLF and CLF included phosphatidylcholines (PCs) and lysophosphatidylcholines (LPCs), whereas conjugated bile acids (GCDCA, GUDCA) increased significantly, these metabolites considered as common biomarkers of liver failure. Linoleyl carnitine showed significant increase in CLF compared with controls while no significant change was observed in ACLF, it could be special biomarkers of ACLF and CLF.

CONCLUSION

Metabolomics based on ultra-performance liquid chromatography mass spectrometry provide a new way to diagnose and reveal the pathogenesis of ACLF and CLF.

Acute-on-chronic liver failure: terminology, mechanisms and management

Acute-on-chronic liver failure (ACLF) is a distinct clinical entity and differs from acute liver failure and decompensated cirrhosis in timing, presence of acute precipitant, course of disease and potential for unaided recovery. The definition involves outlining the acute and chronic insults to include a homogenous patient group with liver failure and an expected outcome in a specific timeframe. The pathophysiology of ACLF relates to persistent inflammation, immune dysregulation with initial wide-spread immune activation, a state of systematic inflammatory response syndrome and subsequent sepsis due to immune paresis. The disease severity and outcome can be predicted by both hepatic and extrahepatic organ failure(s). Clinical recovery is expected with the use of nucleoside analogues for hepatitis B, and steroids for severe alcoholic hepatitis and, possibly, severe autoimmune hepatitis. Artificial liver support systems help remove toxins and metabolites and serve as a bridge therapy before liver transplantation. Hepatic regeneration during ongoing liver failure, although challenging, is possible through the use of growth factors. Liver transplantation remains the definitive treatment with a good outcome. Pre-emptive antiviral agents for hepatitis B before chemotherapy to prevent viral reactivation and caution in using potentially hepatotoxic drugs can prevent the development of ACLF.

Up-regulation of A20 gene expression in peripheral blood mononuclear cells is associated with acute-on-chronic hepatitis B liver failure

Aberrant immunity contributes to the pathogenesis of acute-on-chronic hepatitis B liver failure (ACHBLF), and A20 is a newly identified negative regulatory molecule of the immune response. However, no data have been reported for the role of A20 in ACHBLF. This study aimed to investigate A20 mRNA expression in ACHBLF and to determine the potential of A20 as a biomarker for the prognosis of ACHBLF. Quantitative real-time polymerase chain reaction (qPCR) was used to measure the mRNA expression of A20 in peripheral blood mononuclear cells (PBMCs) from 137 ACHBLF patients, 105 chronic hepatitis B (CHB) and 35 healthy controls (HCs). A secondary cohort with 37 ACHBLF patients was set up as validation data set. The plasma levels of interleukin (IL)-1β, IL-6 and IL-10 were determined using enzyme-linked immunosorbent assay (ELISA). Receiver-operating characteristic (ROC) curves were used to determine the predictive value of A20 for the prognosis of ACHBLF patients. A20 mRNA expression in ACHBLF was significantly higher compared with CHB and HCs. In ACHBLF patients, A20 mRNA was closely associated with total bilirubin, albumin, international normalized ratio, prothrombin time activity and model for end-stage liver disease. Furthermore, A20 mRNA was significantly correlated with IL-6 and IL-10. An optimal cut-off value of 12.32 for A20 mRNA had significant power in discriminating survival or death in ACHBLF patients. In conclusion, our results suggest that the up-regulation of the A20 gene might contribute to the severity of ACHBLF and A20 mRNA level might be a potential predictor for the prognosis of ACHBLF.

ATTIRE: Albumin To prevenT Infection in chronic liveR failurE: study protocol for a single-arm feasibility trial

INTRODUCTION

Circulating prostaglandin E2 levels are elevated in acutely decompensated cirrhosis and have been shown to contribute to immune suppression. Albumin binds and inactivates this hormone. Human albumin solution could thus be repurposed as an immune restorative drug in these patients.This feasibility study aims to determine whether it is possible and safe to restore serum albumin to >30 g/L and maintain it at this level in patients admitted with acute decompensated cirrhosis using repeated 20% human albumin infusions according to daily serum albumin levels.

METHODS AND ANALYSIS

Albumin To prevenT Infection in chronic liveR failurE (ATTIRE) stage 1 is a multicentre, open label dose feasibility trial. Patients with acutely decompensated cirrhosis admitted to hospital with a serum albumin of <30 g/L are eligible, subject to exclusion criteria. Daily intravenous human albumin solution will be infused, according to serum albumin levels, for up to 14 days or discharge in all patients. The primary end point is daily serum albumin levels for the duration of the treatment period and the secondary end point is plasma-induced macrophage dysfunction. The trial will recruit 80 patients. Outcomes will be used to assist with study design for an 866 patient randomised controlled trial at more than 30 sites across the UK.

ETHICS AND DISSEMINATION

Research ethics approval was given by the London-Brent research ethics committee (ref: 15/LO/0104). The clinical trials authorisation was issued by the medicines and healthcare products regulatory agency (ref: 20363/0350/001-0001).

RESULTS

Will be disseminated through peer reviewed journals and international conferences. Recruitment of the first participant occurred on 26/05/2015.

TRIAL REGISTRATION NUMBER

The trial is registered with the European Medicines Agency (EudraCT 2014-002300-24) and has been adopted by the NIHR (ISRCTN 14174793). This manuscript refers to V.4.0 of the protocol; Pre-results.

Upregulation of toll-like receptor 4 on T cells in PBMCs is associated with disease aggravation of HBV-related acute-on-chronic liver failure

Immune-mediated inflammatory injury is an important feature of the disease aggravation of hepatitis B virus-related acute-on-chronic liver failure (ACLF). Toll-like receptors (TLRs) have been shown previously to play a pivotal role in the activation of innate immunity. The purpose of this study was to characterize the TLR4 expression in peripheral blood mononuclear cells (PBMCs) of ACLF patients and its possible role in the disease aggravation. Twelve healthy subjects, 15 chronic HBV-infected (CHB) patients and 15 ACLF patients were enrolled in this study. The TLR4 expression in PBMCs and T cells of all subjects was examined by real-time PCR and flow cytometry. The correlation of TLR4 expression on T cells with the markers of disease aggravation was evaluated in ACLF patients. The ability of TLR4 ligands stimulation to induce inflammatory cytokine production in ACLF patients was analyzed by flow cytometry. The results showed that TLR4 mRNA level was upregulated in PBMCs of ACLF patients compared to that in the healthy subjects and the CHB patients. Specifically, the expression of TLR4 on CD4(+) and CD8(+) T cells of PBMCs was significantly increased in ACLF patients. The TLR4 levels on CD4(+) and CD8(+) T cells were positively correlated with serum total bilirubin (TBIL), direct bilirubin (DBIL), international normalized ratio (INR) levels and white blood cells (WBCs), and negatively correlated with serum albumin (ALB) levels in the HBV-infected patients, indicating TLR4 pathway may play a role in the disease aggravation of ACLF. In vitro TLR4 ligand stimulation on PBMCs of ACLF patients induced a strong TNF-α production by CD4(+) T cells, which was also positively correlated with the serum markers for liver injury severity. It was concluded that TLR4 expression is upregulated on T cells in PBMCs, which is associated with the aggravation of ACLF.

Early warning and clinical outcome prediction of acute-on-chronic hepatitis B liver failure

Hepatitis B virus (HBV) associated acute-on-chronic liver failure (ACLF) is an increasingly recognized fatal liver disease encompassing a severe acute exacerbation of liver function in patients with chronic hepatitis B (CHB). Despite the introduction of an artificial liver support system and antiviral therapy, the short-term prognosis of HBV-ACLF is still extremely poor unless emergency liver transplantation is performed. In such a situation, stopping or slowing the progression of CHB to ACLF at an early stage is the most effective way of reducing the morbidity and mortality of HBV-ACLF. It is well-known that the occurrence and progression of HBV-ACLF is associated with many factors, and the outcomes of HBV-ACLF patients can be significantly improved if timely and appropriate interventions are provided. In this review, we highlight recent developments in early warning and clinical outcome prediction in patients with HBV-ACLF and provide an outlook for future research in this field.

Upregulated Expression of A20 on Monocytes is Associated With Increased Severity of Acute-on-Chronic Hepatitis B Liver Failure: A Case-Control Study

A20 expression is increased in various inflammatory diseases. However, the role of A20 in acute-on-chronic liver failure is unknown. This study was to evaluate A20 expression on monocytes and its associations with the severity of acute-on-chronic hepatitis B liver failure (ACHBLF). Thirty-seven patients with ACHBLF, 20 patients with chronic hepatitis B (CHB), and 15 healthy controls (HC) were enrolled in this case-control study. A20-positive monocytes were identified using flow cytometry. Serum levels of interleukin (IL)-10, IL-12p70, and TNF-α were determined using bead cytometry. A20 and IL-10 expressions were examined in THP-1 cells stimulated by lipopolysaccharide (LPS). The frequency of A20+ monocytes was significantly increased in patients with ACHBLF compared with HC (median [interquartile range, IQR]: 15.7 [22.8]% vs 2.5 [4.7]%, P < 0.001). Increased monocyte A20 expression was detected during the progression phase (including the mild/moderate and severe grades of ACHBLF) compared with patients in the recovery phase (both P < 0.05), and in the ACHBLF worsening group compared with patients in the improvement group (P < 0.001). LPS treatment upregulated A20 and IL-10 expressions in THP-1 cells. A20 expression on monocytes from patients with ACHBLF was positively correlated with total bilirubin (r = 0.60, P = 0.0001), direct bilirubin (r = 0.63, P < 0.0001), and MELD score (r = 0.43, P = 0.008), and inversely with prothrombin activity (r = -0.33, P = 0.046). IL-10 and TLR4 expression levels in monocytes, and serum levels of IL-10, IL-12p70, and TNF-α were increased in patients with ACHBLF compared with patients with CHB and HC. Increased A20 expression on monocytes was associated with the severity of ACHBLF.

Decreased Tim-3 expression is associated with functional abnormalities of monocytes in decompensated cirrhosis without overt bacterial infection

BACKGROUND & AIMS

Patients with advanced cirrhosis usually exhibit altered monocyte function. However, the molecular mechanisms underlying the functional changes of monocytes are poorly understood.

METHODS

We investigated the role of T-cell immunoglobulin domain and mucin domain-containing molecule-3 (Tim-3) in regulating monocyte function in 94 patients with decompensated liver cirrhosis (DC-LC) (decompensation was defined by ascites, hepatic encephalopathy or upper gastrointestinal bleeding), 58 with compensated liver cirrhosis (C-LC) and 52 healthy controls (HC) by characterizing the frequency of Tim-3(+) monocytes, their phagocytosis capacity, HLA-DR expression, cytokine secretion and MAP kinase activation induced by lipopolysaccharide (LPS).

RESULTS

Tim-3 expression on CD14(+) monocytes in DC-LC group were significantly lower than that in C-LC and HC and were associated with increased levels of plasma endotoxin, enhanced cytokine production, decreased phagocytic capacity, and reduced HLA-DR expression. Tim-3 expression on monocytes and monocyte function did not differ between C-LC and HC group. Tim-3(+)CD14(+) cells had more potent phagocytic capacity, higher levels of HLA-DR, CD86, CD80, CD163, and CD206 expression, but lower levels of CD1a and CD83, related to that of Tim-3(-)CD14(+) monocytes. In addition, Tim-3(+)CD14(+) cells produced less TNF-α but higher levels of IL-10 in response to LPS. Treatment with anti-Tim-3 antibody significantly reduced phagocytic capacity, but enhanced LPS-stimulated TNF-α, IL-6, and IL-10 secretion. Furthermore, blocking Tim-3 signaling increased p38 MAP kinase phosphorylation in monocytes upon LPS stimulation.

CONCLUSIONS

Downregulation of Tim-3 expression was associated with endotoxemia and functional alterations of monocytes in patients with decompensated cirrhosis.

Immunotherapy in the treatment and prevention of infection in acute-on-chronic liver failure

Chronic liver disease, depicted by gradual destruction and fibrosis of the liver, is a condition with high and probably increasing prevalence worldwide. Its deterioration, acute-on-chronic liver failure (ACLF), is characterized by an in-hospital mortality of up to 65%. Infectious complications are the main precipitants eliciting ACLF and concurrently the main cause of death from ACLF. Patients have a marked susceptibility to bacterial infections, which is thought to arise a consequence of an inadequate immune response to microbial challenge, termed immuneparesis. The pathophysiologic mechanisms remain poorly understood. Treatments aimed at restoring the patients' immune function may prevent onset of ACLF and death from secondary infections. A number of drugs approved for patients with liver disease bear immunomodulatory potential such as albumin, glucocorticoids, N-acetylcysteine. Specific targets have been defined that may lead to development of new immunotherapeutic agents. Here, we summarize the pathophysiology of immuneparesis in ACLF and drug candidates to restore immune function and improve survival in the future.

Elevated mean platelet volume is associated with poor short-term outcomes in hepatitis B virus-related acute-on-chronic liver failure patients

BACKGROUND AND AIM

It has been shown that mean platelet volume (MPV) can be used as a prognostic biomarker in some chronic diseases. The aim of the present study is to investigate the possible association between MPV and clinical outcome and prognosis in patients with HBV-related acute-on-chronic liver failure (HBV-ACLF) within 4 weeks.

METHODS

This study included 64 patients with HBV-ACLF, 19 chronic hepatitis B (CHB) patients, 27 patients with hepatitis B-related cirrhosis (CR, Child-Pugh A/B), 51 healthy subjects (healthy controls [HC]). The complete blood counts and biochemical examination of blood were obtained after 12h of fasting. In the ACLF group, the relationships between the prognosis and the MPV were analyzed.

RESULTS

At baseline, a statistically significant increase in MPV was shown in patients with ACLF (median 9.5, range 7.1-14.1) compared with HC (8.0, 7.2-11.9, P<0.001), CR (8.4, 5.9-11.1, P<0.001) and CHB (8.3, 7.3-12.0, P<0.001). The MPV value was positively correlated with model of end-stage liver disease (MELD) score and international normalized ratio (INR). The MPV level was significantly increased in nonsurvivors than survivors. High MPV level showed a significantly lower survival rate (P=0.001). Multivariate logistic regression analysis showed that only MPV level was independent factor predicting poor short-term outcomes.

CONCLUSION

MPV values at presentation were higher among nonsurvivors than survivors, and this parameter was well correlated with liver function parameters and may be used as a predictor for 4-week mortality rate in patients with HBV-ACLF.

Appropriate and timely antimicrobial therapy in cirrhotic patients with spontaneous bacterial peritonitis-associated septic shock: a retrospective cohort study

BACKGROUND

Spontaneous bacterial peritonitis (SBP)-associated septic shock carries significant mortality in cirrhosis.

AIM

To determine whether practice-related aspects of antimicrobial therapy contribute to high mortality.

METHODS

Retrospective cohort study of all (n = 126) cirrhotics with spontaneous bacterial peritonitis (neutrophil count >250 or positive ascitic culture)-associated septic shock (1996-2011) from an international, multicenter database. Appropriate antimicrobial therapy implied either in vitro activity against a subsequently isolated pathogen (culture positive) or empiric management consistent with broadly accepted norms (culture negative).

RESULTS

Overall hospital mortality was 81.8%. Comparing survivors (n = 23) with non-survivors (n = 103), survivors had lower Acute Physiology and Chronic Health Evaluation (APACHEII) (mean ± s.d.; 22 ± 7 vs. 32 ± 8) and model for end-stage liver disease (MELD) (24 ± 9 vs. 34 ± 11) scores and serum lactate on admission (4.9 ± 3.1 vs. 8.9  ± 5.3), P < 0.001 for all. Survivors were less likely to receive inappropriate initial antimicrobial therapy (0% vs. 25%, P = 0.013) and received appropriate antimicrobial therapy earlier [median 1.8 (1.1-5.2) vs. 9.5 (3.9-14.3) h, P < 0.001]. After adjusting for covariates, APACHEII [OR, odds ratio 1.45 (1.04-2.02) per 1 unit increment, P = 0.03], lactate [OR 2.34 (1.04-5.29) per unit increment, P = 0.04] and time delay to appropriate antimicrobials [OR 1.86 (1.10-3.14) per hour increment, P = 0.02] were significantly associated with increased mortality.

CONCLUSIONS

Cirrhotic patients with septic shock secondary to spontaneous bacterial peritonitis have high mortality (>80%). Each hour of delay in appropriate antimicrobial therapy was associated with a 1.86 times increased hospital mortality. Admission APACHEII and serum lactate also significantly impacted hospital mortality. Earlier initiation of appropriate antimicrobial therapy could substantially improve outcome.