Macrophage activation markers predict mortality in patients with liver cirrhosis without or with acute-on-chronic liver failure (ACLF)

Macrophage Activation Markers, CD163 and CD206, in Acute-on-Chronic Liver Failure

Macrophages facilitate essential homeostatic functions e.g., endocytosis, phagocytosis, and signaling during inflammation, and express a variety of scavenger receptors including CD163 and CD206, which are upregulated in response to inflammation. In healthy individuals, soluble forms of CD163 and CD206 are constitutively shed from macrophages, however, during inflammation pathogen- and damage-associated stimuli induce this shedding. Activation of resident liver macrophages viz. Kupffer cells is part of the inflammatory cascade occurring in acute and chronic liver diseases. We here review the existing literature on sCD163 and sCD206 function and shedding, and potential as biomarkers in acute and chronic liver diseases with a particular focus on Acute-on-Chronic Liver Failure (ACLF). In multiple studies sCD163 and sCD206 are elevated in relation to liver disease severity and established as reliable predictors of morbidity and mortality. However, differences in expression- and shedding-stimuli for CD163 and CD206 may explain dissimilarities in prognostic utility in patients with acute decompensation of cirrhosis and ACLF.

Peritoneal Level of CD206 Associates With Mortality and an Inflammatory Macrophage Phenotype in Patients With Decompensated Cirrhosis and Spontaneous Bacterial Peritonitis

BACKGROUND & AIMS

Peritoneal macrophages (PMs) regulate inflammation and control bacterial infections in patients with decompensated cirrhosis. We aimed to characterize PMs and associate their activation with outcomes of patients with spontaneous bacterial peritonitis (SBP).

METHODS

We isolated PMs from ascites samples of 66 patients with decompensated cirrhosis (19 with SBP) and analyzed them by flow cytometry, quantitative real-time polymerase chain reaction, functional analysis, and RNA microarrays. We used ascites samples of a separate cohort of 111 patients with decompensated cirrhosis (67 with SBP) and quantified the soluble form of the mannose receptor (CD206) and tumor necrosis factor by enzyme-linked immunosorbent assay (test cohort). We performed logistic regression analysis to identify factors associated with 90-day mortality. We validated our findings using data from 71 patients with cirrhosis and SBP. Data from 14 patients undergoing peritoneal dialysis for end-stage renal disease but without cirrhosis were included as controls.

RESULTS

We used surface levels of CD206 to identify subsets of large PMs (LPM) and small PMs (SPM), which differed in granularity and maturation markers, in ascites samples from patients with cirrhosis. LPMs vs SPMs from patients with cirrhosis had different transcriptomes; we identified more than 4000 genes that were differentially regulated in LPMs vs SPMs, including those that regulate the cycle, metabolism, self-renewal, and immune cell signaling. LPMs had an inflammatory phenotype, were less susceptible to tolerance induction, and released more tumor necrosis factor than SPMs. LPMs from patients with cirrhosis produced more inflammatory cytokines than LPMs from controls. Activation of PMs by Toll-like receptor agonists and live bacteria altered levels of CD206 on the surface of LPMs and release of soluble CD206. Analysis of serial ascites fluid from patients with SBP revealed loss of LPMs in the early phase of SBP, but levels increased after treatment. In the test and validation cohorts, patients with SBP and higher concentrations of soluble CD206 in ascites fluid (>0.53 mg/L) were less likely to survive for 90 days than those with lower levels.

CONCLUSIONS

Surface level of CD206 can be used to identify mature, resident, inflammatory PMs in patients with cirrhosis. Soluble CD206 is released from activated LPMs and increased concentrations in patients with cirrhosis and SBP indicate reduced odds of surviving for 90 days.

Disease severity and proton pump inhibitor use impact strongest on faecal microbiome composition in liver cirrhosis

BACKGROUND & AIMS

Compositional changes of the faecal microbiome in cirrhosis are well described and have been associated with complications and prognosis. However, it is less well known, which disease or treatment-related factors affect microbiome composition most distinctively.

METHODS

16S rDNA sequencing data of 88 cirrhotic outpatients were investigated. Factors influencing microbiome composition were analysed by univariate and multivariate redundancy analysis. The association of the identified factors with changes in diversity and taxonomic composition was studied in depth using analysis of composition of microbiome, LDA-effect size and least absolute shrinkage and selection operator regularized regression.

RESULTS

Disease severity and aetiology, proton pump inhibitor (PPI) use, nutritional status, age and C-reactive protein are significant explanatory variables for faecal microbiome composition in liver cirrhosis. Despite some taxonomic overlaps especially between disease severity and PPI use, we could show that the effects of disease severity, aetiology, PPI use and age are independent factors influencing microbiome composition also in subgroup analyses.

CONCLUSION

Our cross sectional system biology study identifies disease severity, aetiology, PPI use and age as independent factors that influence microbiome composition in liver cirrhosis. In chronic diseases with high morbidity, such as liver cirrhosis, precise patient metadata documentation is of utmost importance in microbiome analysis. Further studies with a higher sample size are necessary to validate this finding.

TRIAL REGISTRATION NUMBER

NCT01607528.

TNF-α/IFN-γ profile of HBV-specific CD4 T cells is associated with liver damage and viral clearance in chronic HBV infection

BACKGROUND & AIMS

The role of hepatitis B virus (HBV)-specific CD4 T cells in patients with chronic HBV infection is not clear. Thus, we aimed to elucidate this in patients with chronic infection, and those with hepatitis B flares.

METHODS

Through intracellular IFN-γ and TNF-α staining, HBV-specific CD4 T cells were analyzed in 68 patients with chronic HBV infection and alanine aminotransferase (ALT) <2x the upper limit of normal (ULN), and 28 patients with a hepatitis B flare. HBV-specific HLA-DRB1*0803/HLA-DRB1*1202-restricted CD4 T cell epitopes were identified.

RESULTS

TNF-α producing cells were the dominant population in patients' HBV-specific CD4 T cells. In patients with ALT <2xULN, both the frequency and the dominance of HBV-specific IFN-γ producing CD4 T cells increased sequentially in patients with elevated levels of viral clearance: HBV e antigen (HBeAg) positive, HBeAg negative, and HBV surface antigen (HBsAg) negative. In patients with a hepatitis B flare, the frequency of HBV core-specific TNF-α producing CD4 T cells was positively correlated with patients' ALT and total bilirubin levels, and the frequency of those cells changed in parallel with the severity of liver damage. Patients with HBeAg/HBsAg loss after flare showed higher frequency and dominance of HBV-specific IFN-γ producing CD4 T cells, compared to patients without HBeAg/HBsAg loss. Both the frequency and the dominance of HBV S-specific IFN-γ producing CD4 T cells were positively correlated with the decrease of HBsAg during flare. A differentiation process from TNF-α producing cells to IFN-γ producing cells in HBV-specific CD4 T cells was observed during flare. Eight and 9 HBV-derived peptides/pairs were identified as HLA-DRB1*0803 restricted epitopes and HLA-DRB1*1202 restricted epitopes, respectively.

CONCLUSIONS

HBV-specific TNF-α producing CD4 T cells are associated with liver damage, while HBV-specific IFN-γ producing CD4 T cells are associated with viral clearance in patients with chronic HBV infection.

LAY SUMMARY

TNF-α producing cells are the dominant population of hepatitis B virus (HBV)-specific CD4 T cells in patients with chronic HBV infection. This population of cells might contribute to the aggravation of liver damage in patients with a hepatitis B flare. HBV-specific IFN-γ producing CD4 T cells are associated with HBV viral clearance. Differentiation from HBV-specific TNF-α producing CD4 T cells into HBV-specific IFN-γ producing CD4 T cells might favor HBV viral clearance.

Soluble mannose receptor as a predictor of prognosis of hepatitis B virus-related acute-on-chronic liver failure

BACKGROUND

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a syndrome with a high short-term mortality rate, and it is crucial to identify those patients at a high mortality risk clinically.

AIM

To investigate the clinical value of soluble mannose receptor (sMR) in predicting the 90-day mortality of HBV-ACLF patients.

METHODS

A total of 43 patients were diagnosed with HBV-ACLF between October 2017 and October 2018 at the Second Hospital of Anhui Medical University, and all of them were enrolled in this retrospective study. Their serum sMR levels were determined using an enzyme-linked immunosorbent assay. Demographic and clinical data, including gender, age, albumin level, total bilirubin (TBIL) level, international normalized ratio, HBV-DNA level, HBV serological markers, procalcitonin level, interleukin-6 level, and model for end-stage liver disease (MELD) score were accessed at the time of diagnosis of HBV-ACLF. A multivariate logistic regression analysis was used to analyze the independent risk factors for mortality.

RESULTS

Serum sMR level was significantly increased in HBV-ACLF patients compared with chronic hepatitis B patients and healthy controls (P < 0.01). When compared with surviving patients, it was higher in those patients who succumbed to HBV-ACLF (P < 0.05). Serum sMR level was positively correlated with MELD score (r_s = 0.533, P = 0.001), HBV-DNA level (r_s = 0.497, P = 0.022), and TBIL level (r_s = 0.894, P < 0.001). Serum sMR level (odds ratio = 1.007, 95% confidence interval: 1.004–1.012, P = 0.001) was an independent risk factor for the 90-day mortality in the HBV-ACLF cases. The patients with HBV-ACLF were stratified into two groups in accordance with their serum sMR levels at the baseline (low risk: < 99.84 pg/mL and high risk: ≥ 99.84 pg/mL). The 90-day mortality rates were 27.3% in the low-risk group and 87.5% in the high-risk group. Furthermore, sMR level apparently improved the performance of MELD score for predicting the prognosis of patients with HBV-ACLF.

CONCLUSION

Serum sMR level may be a predictor of the prognosis of HBV-ACLF patients.

Biomarkers of Macrophage Activation and Immune Danger Signals Predict Clinical Outcomes in Alcoholic Hepatitis

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

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.

Increased Serum Soluble Urokinase Plasminogen Activator Receptor Predicts Short-Term Outcome in Patients with Hepatitis B-Related Acute-on-Chronic Liver Failure

Aims

Soluble urokinase plasminogen activator receptor (suPAR) reflects the immune activation in circumstances of inflammation and infection. It has been considered as a risk biomarker associated with poor outcome in various low-grade inflammation and infectious diseases. The study is aimed at investigating whether suPAR has a predictive value with short-term survival in patients with hepatitis B-related acute-on-chronic liver failure (HB-ACLF).

Methods

Serum suPAR expression was compared among patients with different states of chronic hepatitis B virus infection. Sixty HB-ACLF patients were recruited as the training cohort and followed up for 90 days. Serum suPAR level and the clinical relevance with short-term outcome were investigated. The temporal dynamics of suPAR were evaluated in 50 HB-ACLF patients with available serum sequentially at baseline, week 2 and week 4. Another 167 HB-ACLF patients were enrolled to validate the predictive value of suPAR with respect to the prognosis.

Results

Serum suPAR level was significantly increased in HB-ACLF patients compared to non-ACLF patients. In the training set of HB-ACLF, we observed higher suPAR level, INR, MELD score, and more complications in nonsurvivors than survivors. Longitudinal analysis revealed an increased trend of suPAR level in nonsurvivors during week 0 to week 4 and the modest decline in survivors. It showed that the synchronous suPAR level was higher in nonsurvivors at all indicated time points. Elevated suPAR level at baseline was identified as a strong predictor of a 90-day mortality of HB-ACLF patients. It was confirmed suPAR > 16.26 ng/ml had a positive predictive value of 72.22% and a negative predictive value of 77.88% for poor outcome in the validation cohort.

Conclusions

Serum suPAR level increases significantly in HB-ACLF patients and associated with a 90-day mortality. It suggests that suPAR might be a potential biomarker to predict the prognosis of HB-ACLF patients.

Macrophage markers soluble CD163 and soluble mannose receptor are associated with liver injury in patients with paracetamol overdose

The macrophage activation markers, soluble CD163 (sCD163) and soluble mannose receptor (sMR), are associated with liver disease severity and prognosis. We aimed to investigate macrophage activation reflected by sMR and sCD163 in patients with mild and severe paracetamol (PCM) intoxication and effects of antidote treatment in patients and healthy controls. We measured sMR and sCD163 levels by in-house enzyme-linked immunosorbent assays in two independent prospective cohorts of PCM overdosed patients: 49 patients with early mild PCM overdose from Aarhus University Hospital and 30 patients with severe acute liver injury included at the Royal Infirmary of Edinburgh. Furthermore, we investigated sMR and sCD163 in 14 healthy controls during N-acetylcysteine treatment. Within the mild PCM cohort, patients with elevated alanine transaminase on admission had significantly higher levels of sCD163 compared with patients with normal alanine transaminase (2.92[2.00-5.75] versus 1.29[1.02-1.69] mg/L, p = .009), whereas sMR showed no significant difference. In patients with acute liver injury, both markers were markedly higher compared to the mild PCM cohort (sCD163: 10.73[5.79-14.62] versus 1.34[1.06-1.96], p < .001; sMR: 0.80[0.63-1.14] versus 0.18[0.14-0.25], p < .001). Antidote treatment significantly reduced sCD163 levels in both PCM overdosed patients and healthy controls. In conclusion, macrophage activation assessed by the levels of sMR and sCD163 is associated with the degree of liver injury in patients with PCM intoxication and is ameliorated by antidote treatment, suggesting macrophage involvement in PCM-induced liver injury.

Dysfunctional Immune Response in Acute-on-Chronic Liver Failure: It Takes Two to Tango

Acute-on-chronic liver failure (ACLF) is characterized by the acute decompensation of cirrhosis associated with organ failure and high short-term mortality. The key event in the pathogenesis is a dysfunctional immune response arising from exacerbation of the two main immunological alterations already present in cirrhosis: systemic inflammation and immune cell paralysis. High-grade systemic inflammation due to predominant activation and dysregulation of the innate immune response leads to the massive release of cytokines. Recognition of acutely increased pathogen and damage-associated molecular patterns by specific receptors underlies its pathogenesis and contributes to tissue damage and organ failure. In addition, an inappropriate compensatory anti-inflammatory response over the course of ACLF, along with the exhaustion and dysfunction of both the innate and adaptive immune systems, leads to functional immune cell paralysis. This entails a high risk of infection and contributes to a poor prognosis. Therapeutic approaches seeking to counteract the immune alterations present in ACLF are currently under investigation.

Liver Macrophages: Old Dogmas and New Insights

Inflammation is a hallmark of virtually all liver diseases, such as liver cancer, fibrosis, nonalcoholic steatohepatitis, alcoholic liver disease, and cholangiopathies. Liver macrophages have been thoroughly studied in human disease and mouse models, unravelling that the hepatic mononuclear phagocyte system is more versatile and complex than previously believed. Liver macrophages mainly consist of liver‐resident phagocytes, or Kupffer cells (KCs), and bone marrow‐derived recruited monocytes. Although both cell populations in the liver demonstrate principal functions of macrophages, such as phagocytosis, danger signal recognition, cytokine release, antigen processing, and the ability to orchestrate immune responses, KCs and recruited monocytes retain characteristic ontogeny markers and remain remarkably distinct on several functional aspects. While KCs dominate the hepatic macrophage pool in homeostasis (“sentinel function”), monocyte‐derived macrophages prevail in acute or chronic injury (“emergency response team”), making them an interesting target for novel therapeutic approaches in liver disease. In addition, recent data acquired by unbiased large‐scale techniques, such as single‐cell RNA sequencing, unraveled a previously unrecognized complexity of human and murine macrophage polarization abilities, far beyond the old dogma of inflammatory (M1) and anti‐inflammatory (M2) macrophages. Despite tremendous progress, numerous challenges remain in deciphering the full spectrum of macrophage activation and its implication in either promoting liver disease progression or repairing injured liver tissue. Being aware of such heterogeneity in cell origin and function is of crucial importance when studying liver diseases, developing novel therapeutic interventions, defining macrophage‐based prognostic biomarkers, or designing clinical trials. Growing knowledge in gene expression modulation and emerging technologies in drug delivery may soon allow shaping macrophage populations toward orchestrating beneficial rather than detrimental inflammatory responses.

Orchestration of Tryptophan-Kynurenine Pathway, Acute Decompensation, and Acute-on-Chronic Liver Failure in Cirrhosis

Systemic inflammation (SI) is involved in the pathogenesis of acute decompensation (AD) and acute-on-chronic liver failure (ACLF) in cirrhosis. In other diseases, SI activates tryptophan (Trp) degradation through the kynurenine pathway (KP), giving rise to metabolites that contribute to multiorgan/system damage and immunosuppression. In the current study, we aimed to characterize the KP in patients with cirrhosis, in whom this pathway is poorly known. The serum levels of Trp, key KP metabolites (kynurenine and kynurenic and quinolinic acids), and cytokines (SI markers) were measured at enrollment in 40 healthy subjects, 39 patients with compensated cirrhosis, 342 with AD (no ACLF) and 180 with ACLF, and repeated in 258 patients during the 28-day follow-up. Urine KP metabolites were measured in 50 patients with ACLF. Serum KP activity was normal in compensated cirrhosis, increased in AD and further increased in ACLF, in parallel with SI; it was remarkably higher in ACLF with kidney failure than in ACLF without kidney failure in the absence of differences in urine KP activity and fractional excretion of KP metabolites. The short-term course of AD and ACLF (worsening, improvement, stable) correlated closely with follow-up changes in serum KP activity. Among patients with AD at enrollment, those with the highest baseline KP activity developed ACLF during follow-up. Among patients who had ACLF at enrollment, those with immune suppression and the highest KP activity, both at baseline, developed nosocomial infections during follow-up. Finally, higher baseline KP activity independently predicted mortality in patients with AD and ACLF. Conclusion: Features of KP activation appear in patients with AD, culminate in patients with ACLF, and may be involved in the pathogenesis of ACLF, clinical course, and mortality.

Addressing Profiles of Systemic Inflammation Across the Different Clinical Phenotypes of Acutely Decompensated Cirrhosis

Background: Patients with acutely decompensated cirrhosis (AD) may or may not develop acute-on-chronic liver failure (ACLF). ACLF is characterized by high-grade systemic inflammation, organ failures (OF) and high short-term mortality. Although patients with AD cirrhosis exhibit distinct clinical phenotypes at baseline, they have low short-term mortality, unless ACLF develops during follow-up. Because little is known about the association of profile of systemic inflammation with clinical phenotypes of patients with AD cirrhosis, we aimed to investigate a battery of markers of systemic inflammation in these patients. Methods: Upon hospital admission baseline plasma levels of 15 markers (cytokines, chemokines, and oxidized albumin) were measured in 40 healthy controls, 39 compensated cirrhosis, 342 AD cirrhosis, and 161 ACLF. According to EASL-CLIF criteria, AD cirrhosis was divided into three distinct clinical phenotypes (AD-1: Creatinine<1.5, no HE, no OF; AD-2: creatinine 1.5-2, and or HE grade I/II, no OF; AD-3: Creatinine<1.5, no HE, non-renal OF). Results: Most markers were slightly abnormal in compensated cirrhosis, but markedly increased in AD. Patients with ACLF exhibited the largest number of abnormal markers, indicating "full-blown" systemic inflammation (all markers). AD-patients exhibited distinct systemic inflammation profiles across three different clinical phenotypes. In each phenotype, activation of systemic inflammation was only partial (30% of the markers). Mortality related to each clinical AD-phenotype was significantly lower than mortality associated with ACLF (p < 0.0001 by gray test). Among AD-patients baseline systemic inflammation (especially IL-8, IL-6, IL-1ra, HNA2 independently associated) was more intense in those who had poor 28-day outcomes (ACLF, death) than those who did not experience these outcomes. Conclusions: Although AD-patients exhibit distinct profiles of systemic inflammation depending on their clinical phenotypes, all these patients have only partial activation of systemic inflammation. However, those with the most extended baseline systemic inflammation had the highest the risk of ACLF development and death.

The role of macrophages in nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) and its inflammatory and often progressive subtype nonalcoholic steatohepatitis (NASH) are becoming the leading cause of liver-related morbidity and mortality worldwide, and a primary indication for liver transplantation. The pathophysiology of NASH is multifactorial and not yet completely understood; however, innate immunity is a major contributing factor in which liver-resident macrophages (Kupffer cells) and recruited macrophages play a central part in disease progression. In this Review, we assess the evidence for macrophage involvement in the development of steatosis, inflammation and fibrosis in NASH. In this process, not only the polarization of liver macrophages towards a pro-inflammatory phenotype is important, but adipose tissue macrophages, especially in the visceral compartment, also contribute to disease severity and insulin resistance. Macrophage activation is mediated by factors such as endotoxins and translocated bacteria owing to increased intestinal permeability, factors released from damaged or lipoapoptotic hepatocytes, as well as alterations in gut microbiota and defined nutritional components, including certain free fatty acids, cholesterol and their metabolites. Reflecting the important role of macrophages in NASH, we also review studies investigating drugs that target macrophage recruitment to the liver, macrophage polarization and their inflammatory effects as potential treatment options for patients with NASH.

Prognostic utility of novel biomarkers in acute-on-chronic liver failure (ACLF) associated with hepatitis B: A multicenter prospective study

AIM

Flare-ups of chronic hepatitis B can sometimes be severe and even progress to acute-on-chronic liver failure (ACLF), with high short-term mortality. A timely estimation of the risk of death should be initiated early. The aim of the present study was to determine whether novel biomarkers add prognostic information beyond current clinical scoring systems.

METHODS

Patients with hepatitis B-associated ACLF were prospectively enrolled from five hospitals in China between August 2017 and March 2018. Their plasma was screened for soluble CD163 (sCD163), neutrophil gelatinase-associated lipocalin (NGAL), and copeptin. The association between these biomarkers and mortality was analyzed. The performance of the Model for End-stage Liver Disease, Asian-Pacific Association for the Study of the Liver-ACLF Research Consortium score, and the Chronic Liver Failure Consortium ACLF score, with or without biomarkers, were compared.

RESULTS

One hundred fifty one patients were enrolled. Advanced ACLF patients had significantly higher levels than early ACLF individuals of plasma biomarkers sCD163 (P = 0.001), NGAL (P = 0.006), and copeptin (P = 0.049). Thirty-four deaths occurred during the 28-day follow-up period (22.5%). Both sCD163 and NGAL showed a strong independent association with 28-day mortality, whereas copeptin did not. Scoring systems incorporating sCD163 and NGAL had better discrimination and calibration, as measured by area under the receiver operating characteristic curves, the Akaike information criteria, integrated discrimination improvement, and net reclassification improvement.

CONCLUSIONS

Soluble CD163 and NGAL are independently associated with short-term mortality in hepatitis B-associated ACLF. Use of a combination of sCD163 and NGAL improves prognostication.

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.

Macrophage Markers Are Poorly Associated With Liver Histology in Children With Nonalcoholic Fatty Liver Disease

OBJECTIVES

We have previously demonstrated associations between the macrophage activation marker soluble (s)CD163 and histology of nonalcoholic fatty liver disease (NAFLD) in adults, and elevated sCD163 levels in children with obesity with NAFLD. Macrophage activation has, however, not been investigated in children with biopsy-proven NAFLD, which was the objective of the present study.

METHODS

We used in-house enzyme-linked immunosorbent assays to measure sCD163 and the novel macrophage marker soluble mannose receptor (sMR) in a cross-sectional (n = 155) pediatric NAFLD cohort, and a cohort of NAFLD children (n = 36) undergoing a randomized trial by the probiotic VSL#3. We included 56 healthy nonobese children for comparison.

RESULTS

Levels of sCD163 and sMR were higher in both of the NAFLD cohorts compared with controls (P < 0.001). In the cross-sectional cohort, sCD163 only showed trends toward association with ballooning (rho = 0.14, P = 0.08) and portal inflammation (rho = 0.17, P = 0.08). sMR showed similar associations with liver histology. In the VSL#3 cohort, sCD163 correlated inversely with steatosis (rho = -0.35, P = 0.04), and lobular (rho = -0.57, P < 0.001) and portal inflammation (rho = -0.38, P = 0.02); sMR was not associated with any histological scores. Neither sCD163 nor sMR changed significantly during intervention, and without association with NAFLD resolution.

CONCLUSIONS

The macrophage activation markers sCD163 and sMR showed poor associations with liver histology in 2 different cohorts of children with biopsy-proven NAFLD, and none of the markers decreased during successful intervention. These results are in contrast with studies of adult NAFLD and may suggest a possibility of different roles for macrophages in the pathogenesis of adult and pediatric NAFLD.

Th17 cells over 5.9% at admission indicate poor prognosis in patients with HBV-related acute-on-chronic liver failure

Our previous study demonstrated that Th17 cells increased significantly in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). However, their prognostic role in HBV-ACLF patients remains unknown.Sixty-eight consecutive HBV-ACLF patients were enrolled in this cohort study. Th17 cells were examined using flow cytometry. Disease severity scores were assessed. ROC curves were used to evaluate the value in predicting prognosis. Survival was analyzed using Kaplan-Meier curves. Predictors of mortality were determined by regression analysis.Th17 cells were significantly higher in HBV-ACLF patients compared to patients with chronic hepatitis B and normal controls (both P < .001). Also, Th17 cells were higher in nonsurviving HBV-ACLF patients than in surviving patients (P = .014). Th17 cells were positively correlated with CLIF-Consortium ACLF (CLIF-C ACLF) score (r = 0.240, P = .048). ROC curves showed that the frequency of Th17 cells had accuracy in predicting 90-day prognosis equivalent to MELD, MELD-Na and CLIF-C ACLF scores in HBV-ACLF (P = .34, P = .26, and P = .15, respectively). More importantly, the area under the ROC curve (AUROC) increased when Th17 cells were combined with MELD, MELD-Na or CLIF-C ACLF score than using Th17 cells alone (P = .021, P = .006, and P = .023, respectively). Kaplan-Meier analysis revealed that higher Th17 cells (≥5.9%) were closely associated with poor overall survival in HBV-ACLF (P = .0086). Additionally, multivariate regression analysis showed that the frequency of Th17 cells over 5.9% was an independent predictor of mortality (OR = 0.154, P = .025).Circulating Th17 cells positively correlated with disease severity in HBV-ACLF. The frequency of Th17 cells over 5.9% could serve as a prognostic biomarker for HBV-ACLF patients.

High hepatic macrophage activation and low liver function in stable Wilson patients - a Danish cross-sectional study

Background

Hepatic macrophage (Kupffer cell) hyperplasia is often described in Wilson’s disease (WD). In many liver diseases, Kupffer cell activation is related to disease severity, liver function, and fibrosis but the importance in WD is unknown. Kupffer cell activation can be assessed by the P-concentration of soluble (s)CD163, metabolic liver function by the galactose elimination capacity (GEC), and fibrosis by Fibroscan. We investigated the associations between sCD163, selected inflammatory cytokines, GEC, and liver fibrosis in Danish WD patients.

Methods

In a cross-sectional design, we studied 29 stable and well-treated patients (male/female15/14) with a median age of 35 years (IQR 24–50). P-sCD163 and cytokines were measured by ELISA. The GEC was measured by intra-venous galactose loading.

Results

The median P-sCD163 value at 2.96 mg/L (1.97–3.93) was high in the normal range (0.7–3.9) and seven patients (24%) had a value above the upper normal value. sCD163 correlated with TNF-α, IL-6 and IL-8 (rho> 0.50, p < 0.005). A higher sCD163 value was closely associated with a lower GEC (rho = − 0.51, p = 0.02). sCD163 was not related to the liver fibrosis indices.

Conclusions

Stable WD patients showed various degrees of Kupffer cell activation which was accompanied by loss of metabolic liver function. Neither activation nor liver function was related to liver fibrosis. The findings suggest that in WD inflammatory Kupffer cell activation may be involved in the loss of liver function over time. sCD163 may serve as a non-invasive biomarker of loss of liver function in WD, which the degree of fibrosis evidently may not.

This study is registered at clinical trials with name: “sCD163 and sMR in Wilsons Disease - Associations With Disease Severity and Fibrosis”, NCT02702765. Date of registration: 26.02.16. Date of enrolment of the first participant to the trial: 17.03.16. ULR: https://clinicaltrials.gov/ct2/show/NCT02702765.

No effect of rifaximin on soluble CD163, mannose receptor or type III and IV neoepitope collagen markers in decompensated cirrhosis: Results from a randomized, placebo controlled trial

BACKGROUND AND AIMS

Macrophages play a significant role in chronic liver disease as reflected by elevated soluble (s)CD163 and mannose receptor (sMR) levels and associated with liver disease severity and prognosis. Extracellular matrix remodelling associated with fibrogenesis may be affected by systemic inflammation induced by bacterial translocation. Therefore, we aimed to investigate the effect of rifaximin-α, an antibiotic with effect on gut bacteria, on sCD163, sMR, and collagen metabolites.

METHODS

Fifty-four clinically stable patients with decompensated cirrhosis were randomized to 4 weeks treatment with rifaximin-α (n = 36) or placebo (n = 18). Macrophage markers sCD163, sMR and markers of collagen fibrogenesis (C3M and C4M) and formation (PRO-C3 and P4NPS7) were analysed in plasma before and after treatment.

RESULTS

sCD163 and sMR levels were associated with liver disease severity (MELD score, sCD163 rho = 0.47, p<0.001 and sMR rho = 0.37, p = 0.005). There was no effect of Rifaximin-α on sCD163 levels (median (range) sCD163 5.64(2.02 to 10.8) at baseline versus 4.42(1.98 to 8.92) at follow-up in the rifaximin-α group and 4.85 (2.29 to 12.1) at baseline versus 4.32 (1.98 to 12.4) at follow-up in the placebo-group), p = 0.34); nor sMR levels, p = 0.34. Also in patients with elevated lipopolysaccharide binding protein (> 5.9 μg/ml, 38 patients) there was no effect of rifaximin-α on sCD163 (p = 0.49) or sMR levels (p = 0.32).

CONCLUSION

We confirmed that macrophage activation markers sCD163 and sMR are directly associated to liver disease severity (MELD score). However, rifaximin-α has no effect on sCD163, sMR or collagen markers in decompensated cirrhosis and does therefore not seem to interfere with macrophage activation or fibrogenesis.

Immunodysfunction in Acute-on-Chronic Liver Failure

BACKGROUND

Increasing evidence reveals a close and reciprocal link between acute-on-chronic liver failure (ACLF) and immunodysfunction.

METHODS

A literature search in PubMed and abstract databases of relevant congresses was performed.

RESULTS

Important characteristics of liver cirrhosis like tissue hypoxia, cell death, or bacterial translocation maintain a state of chronic inflammation. Precipitating events of ACLF such as infections or alcoholic hepatitis are capable of strongly augmenting cirrhosis-associated systemic inflammation to grades sufficient to induce ACLF-defining organ failures. Chronic systemic inflammation, however, is causally linked to profound immunosuppression. As a consequence, patients with liver cirrhosis and in particular with ACLF are at high risk for severe infections. Promising strategies to ameliorate immunodysfunction, like albumin substitution, administration of recombinant interleukin-22 or granulocyte colony-stimulating factor, antibiotic prophylaxis, or anticoagulation, are under development and offer the chance to specifically prevent and treat ACLF.

CONCLUSION

A better understanding of the immunopathology of ACLF will likely translate into the implementation of specific therapeutic modalities to prevent and overcome ACLF.

Rapid and persistent decline in soluble CD163 with successful direct-acting antiviral therapy and associations with chronic hepatitis C histology

BACKGROUND AND AIM

Soluble CD 163 (sCD163) is released from activated liver macrophages in chronic viral hepatitis C (HCV) and serum levels reflect liver disease severity. The impact of direct-acting antiviral (DAA)-therapy on sCD163-levels and the ability of sCD163 to predict the presence of liver fibrosis remain unclear. In a combined observational and prospective study, we aimed to investigate changes in sCD163 with DAA-treatment, to investigate associations between sCD163 and histopathological activity and fibrosis and to validate the sCD163-based fibrosis score in HCV-patients.

METHODS

We examined three groups of patients: an Australian (n = 28) treated with pegylated-interferon and a first-generation DAA, a Danish (n = 38) treated with sofosbuvir-based DAA-regimens and a Japanese (n = 562) assessed for activity and fibrosis (Metavir scoring system) in liver biopsies. Serum sCD163-levels were quantified by ELISA.

RESULTS

Thirteen (46%) of the Australian patients achieved sustained virological response (SVR) and only these patients had significant decreases in sCD163-levels (2.7 (95%CI:1.9-3.6) vs. 4.1(2.9-5.7) mg L ^- 1, p = .008). In the Danish group, 37 (97%) patients achieved SVR at 12-weeks post-treatment with 32% reduction in sCD163-levels (5.0 (4.3-5.8) vs. 7.4 (6.3-8.7), p < .001). The decline was rapid and persisted 12 months after treatment cessation (p < .007). sCD163 levels increased in parallel with inflammatory activity and fibrosis (p < .001). The sCD163-based fibrosis score outperformed established fibrosis scores for significant fibrosis (areas under the receiver operating characteristics curves (AUROCs): 0.79 (0.75-0.83) vs. aspartate aminotransferase to platelet ratio index (APRI) 0.73 (0.69-0.77), Fibrosis-4 (FIB-4) 0.74 (0.70-0.78), p < .001).

CONCLUSION

sCD163-levels decline rapidly with successful DAA therapy and are associated with histological inflammatory activity and fibrosis, confirming a key role for macrophages in HCV inflammation and fibrosis and supporting sCD163 as a biomarker of treatment response.

Iron-Overload triggers ADAM-17 mediated inflammation in Severe Alcoholic Hepatitis

Severe alcoholic hepatitis (SAH) is associated with iron accumulation in hepatocytes/macrophages. This possibly correlates with inflammation and stress but the exact mechanism still remains obscure. To understand the role of iron and the mechanisms of systemic iron-overload, a transcriptomic study of liver and Peripheral Blood -Mononuclear-Cells (PBMCs) was undertaken in SAH patients, with and without hepatic iron-overload. Our results show that iron-overload in hepatocytes/macrophages is due to an increased expression of iron-loading receptors and CD163 signaling cascade. Increase in labile iron pool induces expression of iron-loading, oxidative-stress and inflammatory genes along with expression of CD163 and ADAM17. Increased liver iron correlated with circulatory iron, TNF-α, macrophage activation (sCD163) and peroxide-stress in CD163⁺macrophages in patients who were iron-overloaded and died. Circulatory TNF-α and sCD163 levels were associated with poor outcome. Temporal iron/Fenton stress induced in healthy monocyte-derived-macrophage (MDM)/Tohoku-Hospital-Pediatrics-1(THP1) cells showed higher expression of iron-regulatory, inflammatory and oxidative-stress genes. These genes could be suppressed by iron-chelation. These results suggest that iron mediates inflammation through ADAM17 induction, resulting in macrophage activation and increased shedding of TNF-α and sCD163. These events could be inhibited with iron chelation or with ADAM17-blockade, postulating a therapeutic strategy for SAH patients with iron overload.

Emerging therapeutic biomarkers of autoimmune hepatitis and their impact on current and future management

Autoimmune hepatitis lacks a quantifiable biomarker that is close to its pathogenic mechanisms and that accurately reflects inflammatory activity, correlates with treatment response, and ensures inactive disease before treatment withdrawal. Areas covered: Micro-ribonucleic acids, programmed death-1 protein and its ligands, macrophage migration inhibitory factor, soluble CD163, B cell activating factor, and metabolite patterns in blood were considered the leading candidates as therapeutic biomarkers after search of PubMed from August 1981 to August 2017 using the search words 'biomarkers of autoimmune hepatitis'. Expert commentary: Each of the candidate biomarkers is close to the putative pathogenic mechanisms of autoimmune hepatitis, and each has attributes that support its potential role as a surrogate marker of inflammatory activity that can be monitored during treatment. Future studies must demonstrate the superiority of each biomarker to conventional indices of inflammatory activity and validate their correlation with treatment response and outcome. A reliable therapeutic biomarker would facilitate the individualization of current management algorithms, ensure that pathogenic mechanisms were disrupted or eliminated prior to treatment withdrawal, and reduce the frequency of relapse or unnecessary protracted therapy. The biomarker might also prove to be a target of next-generation therapies.

Fibroblast growth factor 21 is an early predictor of acute-on-chronic liver failure in critically ill patients with cirrhosis

Acute-on-chronic liver failure (ACLF) develops in acute decompensation (AD) of cirrhosis and shows high mortality. In critically ill patients, early diagnosis of ACLF could be important for therapeutic decisions (eg, renal replacement, artificial liver support, liver transplantation). This study evaluated fibroblast growth factor 21 (FGF21) as a marker of mitochondrial dysfunction in the context of ACLF. The study included 154 individuals (112 critically patients and 42 healthy controls) divided into a training and a validation cohort. In the training cohort of 42 healthy controls and 34 critically ill patients (of whom 24 were patients with cirrhosis), levels of FGF21, interleukin (IL) 6, and IL8 were measured. In the validation cohort of 78 patients with cirrhosis, 17 patients were admitted with or developed ACLF during follow-up and underwent daily clinical and nutritional assessment. Levels of FGF21 were higher in critically ill patients, especially in patients with cirrhosis admitted to the intensive care unit (ICU). Moreover, FGF21 as well as IL6 and IL8 levels were higher in patients with ACLF, but they did not increase with the severity of ACLF. Interestingly, in the validation cohort, FGF21 was also elevated in the patients who developed ACLF in the next 7 days. In these patients, FGF21 levels were an independent predictor of ACLF presence and development in multivariate analysis together with Child-Pugh score. FGF21 levels had no impact on the survival of critically ill patients with cirrhosis. In conclusion, this study demonstrates that FGF21 levels are of specific diagnostic value regarding the presence and development of ACLF in patients admitted to ICU for AD of liver cirrhosis. Further studies are warranted to address pathophysiological and possible therapeutic implications. Liver Transplantation 24 595-605 2018 AASLD.

Cell death markers in patients with cirrhosis and acute decompensation

The aims of this study were to determine the role of cell death in patients with cirrhosis and acute decompensation (AD) and acute on chronic liver failure (ACLF) using plasma-based biomarkers. The patients studied were part of the CANONIC (CLIF Acute-on-Chronic Liver Failure in Cirrhosis) study (N = 337; AD, 258; ACLF, 79); additional cohorts included healthy volunteers, stable patients with cirrhosis, and a group of 16 AD patients for histological studies. Caspase-cleaved keratin 18 (cK18) and keratin 18 (K18), which reflect apoptotic and total cell death, respectively, and cK18:K18 ratio (apoptotic index) were measured in plasma by enzyme-linked immunosorbent assay. The concentrations of cK18 and K18 increased and the cK18:K18 ratio decreased with increasing severity of AD and ACLF (P < 0.001, respectively). Alcohol etiology, no previous decompensation, and alcohol abuse were associated with increased cell death markers whereas underlying infection was not. Close correlation was observed between the cell death markers and, markers of systemic inflammation, hepatic failure, alanine aminotransferase, and bilirubin, but not with markers of extrahepatic organ injury. Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining confirmed evidence of greater hepatic cell death in patients with ACLF as opposed to AD. Inclusion of cK18 and K18 improved the performance of the CLIF-C AD score in prediction of progression from AD to ACLF (P < 0.05).

CONCLUSION

Cell death, likely hepatic, is an important feature of AD and ACLF and its magnitude correlates with clinical severity. Nonapoptotic forms of cell death predominate with increasing severity of AD and ACLF. The data suggests that ACLF is a heterogeneous entity and shows that the importance of cell death in its pathophysiology is dependent on predisposing factors, precipitating illness, response to injury, and type of organ failure. (Hepatology 2018;67:989-1002).

Soluble CD163 and soluble mannose receptor predict survival and decompensation in patients with liver cirrhosis, and correlate with gut permeability and bacterial translocation

BACKGROUND

Activated hepatic macrophages play a key role in inflammation and fibrosis progression in chronic liver disease.

AIM

To assess the prognostic value of soluble (s)CD163 and mannose receptor (sMR) in cirrhotic patients and explore associations with markers of intestinal permeability (lactulose-mannitol ratio, diamine oxidase), bacterial translocation (endotoxin, lipopolysaccharide-binding protein) and markers of systemic immune activation (interleukin-6, interleukin-8, sCD14).

METHODS

We prospectively investigated 101 cirrhotic patients (Child-Pugh class A: n = 72, Child-Pugh classes B and C: n = 29) and 31 healthy controls. Patients were observed for a median follow-up of 37 months.

RESULTS

Median plasma levels of sCD163 and soluble mannose receptor were significantly elevated in cirrhotic patients (P < .001) and increased with disease severity (sCD163 in healthy controls = 1.3, Child-Pugh class A = 4.2, Child-Pugh classes B and C = 8.4 mg/L; sMR in healthy controls = 15.8, Child-Pugh class A = 36.5, Child-Pugh classes B and C = 66.3 μg/dL). A total of 21 patients died during the observation period. Patients with sCD163 levels above 5.9 mg/L showed significantly reduced survival (survival rate after 36 months: 71% versus 98%, P < .001). Patients with soluble mannose receptor levels above 45.5 μg/dL developed significantly more complications of cirrhosis within 12 months (73% versus 9%, P < .001). Furthermore, both variables correlated with the lactulose-mannitol ratio, diamine oxidase, lipopolysaccharide and interleukin-8.

CONCLUSION

Our data demonstrate the prognostic value of sCD163 in predicting long-term survival in patients with liver cirrhosis and identify soluble mannose receptor as a prognostic marker for occurrence of cirrhosis-associated complications. The correlation between gut barrier dysfunction and activation of macrophages points towards a link between them.

The soluble mannose receptor (sMR) is elevated in alcoholic liver disease and associated with disease severity, portal hypertension, and mortality in cirrhosis patients

Background and aims

Hepatic macrophages (Kupffer cells) are involved in the immunopathology of alcoholic liver disease (ALD). The mannose receptor (MR, CD206), expressed primarily by macrophages, mediates endocytosis, antigen presentation and T-cell activation. A soluble form, sMR, has recently been identified in humans.

We aimed to study plasma sMR levels and its correlation with disease severity and survival in ALD patients.

Methods

We included 50 patients with alcoholic hepatitis (AH), 68 alcoholic cirrhosis (AC) patients (Child-Pugh A (23), B (24), C (21)), and 21 healthy controls (HC). Liver status was described by the Glasgow Alcoholic Hepatitis Score (GAHS), Child-Pugh (CP) and MELD-scores, and in AC patients the hepatic venous pressure gradient (HVPG) was measured by liver vein catheterisation. We used Kaplan-Meier statistics for short-term survival (84-days) in AH patients and long-term (4 years) in AC patients. We measured plasma sMR by ELISA.

Results

Median sMR concentrations were significantly elevated in AH 1.32(IQR:0.69) and AC 0.46(0.5) compared to HC 0.2(0.06) mg/L; p<0.001 and increased in a stepwise manner with the CP-score (p<0.001). In AC sMR predicted portal hypertension (HVPG ≥10 mmHg) with an area under the Receiver Operator Characteristics curve of 0.86 and a high sMR cut-off (>0.43 mg/l) was associated with increased mortality (p = 0.005).

Conclusion

The soluble mannose receptor is elevated in alcoholic liver disease, especially in patients with AH. Its blood level predicts portal hypertension and long-term mortality in AC patients.

The Acute-on-Chronic Liver Failure Syndrome, or When the Innate Immune System Goes Astray

The acute-on-chronic liver failure (ACLF) syndrome is characterized by acute decompensation of cirrhosis, organ failure, and high 28-d mortality. ACLF displays key features of systemic inflammation and its poor outcome is closely associated with exacerbated systemic inflammatory responses. In this review, we describe the prevailing characteristics of systemic inflammation in patients with decompensated cirrhosis and ACLF, with special emphasis on the principal features of the cytokine storm the mechanisms underlying this intense systemic inflammatory response (i.e., presence of circulating pathogen- and damage-associated molecular patterns), and their implication in tissue and organ damage in this condition.

Adipocyte Fatty-Acid Binding Protein is Overexpressed in Cirrhosis and Correlates with Clinical Outcomes

Fatty-acid-binding proteins (FABPs) are small intracellular proteins that coordinate lipid-mediated processes by targeting metabolic and immune response pathways. The aim of the study was to investigate plasma FABPs levels and their relationship with clinical outcomes in cirrhosis. Plasma levels of L-FABP1(liver and kidney), I-FABP2(intestine), and A-FABP4(adipocyte and macrophages) were measured in 274 patients with decompensated cirrhosis. Hepatic gene expression of FABPs was assessed in liver biopsies from patients with decompensated cirrhosis and in liver cell types from mice with cirrhosis. Immunohistochemistry of A-FABP4 in human liver biopsy was also performed. Plasma levels of FABPs were increased in patients with decompensated cirrhosis compared to those of healthy subjects (L-FABP1: 25 (17–39) vs 10 (9–17) ng/mL p = 0.001, I-FABP2: 1.1 (0.5–2.1) vs 0.6 (0.4–1) ng/mL p = 0.04 and A-FABP4: 37 (20–68) vs 16 (11–33) ng/mL p = 0.002), respectively. Increased A-FABP4 levels were associated with complications of cirrhosis, acute-on-chronic liver failure and poor survival. Hepatic A-FABP4 gene expression was upregulated in decompensated cirrhosis. Macrophages were the main liver cell that over-expressed A-FABP4 in experimental cirrhosis and increased A-FABP4 was found in macrophages of human biopsies by immunohistochemistry. A-FABP4 levels are increased in decompensated cirrhosis and correlate with poor outcomes. Liver macrophages appear to be the main source of A-FABP4 in decompensated cirrhosis.

The soluble mannose receptor is released from the liver in cirrhotic patients, but is not associated with bacterial translocation

BACKGROUND & AIMS

Intestinal bacterial translocation is involved in activation of liver macrophages in cirrhotic patients. Macrophages play a key role in liver inflammation and are involved in the pathogenesis of cirrhosis and complications. Bacterial translocation may be determined by presence of bacterial DNA and macrophage activation, by the soluble mannose receptor. We hypothesize that the soluble mannose receptor is released from hepatic macrophages in cirrhosis and associated with bacterial DNA, portal pressure and complications.

METHODS

We investigated 28 cirrhotic patients set for transjugular intrahepatic portosystemic shunt insertion as a result of refractory ascites (n=17), acute (n=3), or recurrent variceal bleeding (n=8). We analysed plasma from the portal and hepatic veins for bacterial DNA and soluble mannose receptor with qPCR and ELISA.

RESULTS

The median soluble mannose receptor level was elevated in the hepatic vein compared with the portal vein (0.57(interquartile range 0.31) vs 0.55(0.40) mg/L, P=.005). The soluble mannose receptor levels were similar in bacterial DNA-positive and -negative patients. The soluble mannose receptor level in the portal and hepatic veins correlated with the portal pressure prior to transjugular intrahepatic portosystemic shunt insertion (r=.52, P<.008, both) and the levels correlated with Child-Pugh score (r=.63 and r=.56, P<.004, both). We observed higher soluble mannose receptor levels in patients with acute variceal bleeding compared to other indications (P<.05).

CONCLUSION

This study showed hepatic soluble mannose receptor excretion with a higher level in the hepatic than the portal vein, though with no associations to bacterial DNA. We observed associations between soluble mannose receptor levels and portal pressure and higher levels in patients with acute variceal bleeding indicating the soluble mannose receptor as a marker of complications of cirrhosis, but not bacterial translocation.

Low serum transferrin correlates with acute-on-chronic organ failure and indicates short-term mortality in decompensated cirrhosis

BACKGROUND & AIMS

Iron represents an essential, but potentially harmful micronutrient, whose regulation has been associated with poor outcome in liver disease. Its homeostasis is tightly linked to oxidative stress, bacterial infections and systemic inflammation. To study the prognostic short-term significance of iron parameters in a cohort study of patients with decompensation of cirrhosis at risk of acute-on-chronic liver failure (ACLF).

METHODS

Ferritin, transferrin, iron, transferrin saturation (TSAT) and hepcidin were determined in sera from 292 German patients hospitalized for decompensation of cirrhosis with ascites, of which 78 (27%) had ACLF. Short-term mortality was prospectively assessed 30 and 90 days after inclusion.

RESULTS

Transferrin concentrations were significantly lower, whereas ferritin and TSAT were higher in patients with ACLF compared to patients without ACLF (P≤.006). Transferrin, TSAT and ferritin differentially correlated with the severity of organ failure, active alcoholism and surrogates of systemic inflammation and macrophage activation. As compared with survivors, 30-day non-survivors displayed lower serum transferrin (P=.0003) and higher TSAT (P=.003), whereas 90-day non-survivors presented with higher ferritin (P=.03) and lower transferrin (P=.02). Lower transferrin (continuous or dichotomized at 87 mg/dL) and consecutively higher TSAT (continuous or dichotomized >41%) indicated increased mortality within 30 days and remained significant after adjustment for organ failure and inflammation in multivariate regression models and across subgroups of patients.

CONCLUSION

Among the investigated indicators of iron metabolism, serum transferrin concentration was the best indicator of organ failure and an independent predictor of short-term mortality at 30 days.

Reviewing the diagnostic criteria for acute-on-chronic liver failure

For over 20 years, acute-on-chronic liver failure (ACLF) has taken multiple definitions and/or classifications. The definition outlines the acute and chronic insults to include a homogenous patient group with liver failure and an expected outcome in a specific time frame. Early and accurate diagnosis is essential as this inflammation of the liver may tilt the balance of liver destruction and regeneration adversely. Various factors such as superadded systemic sepsis, liver reserve, cause of primary chronic liver disease, state of immune system or the state of gut microbial flora might determine the ultimate prognosis. Areas covered: To date, there has been no universally accepted definition of ACLF. In this review, we discuss the strengths and weaknesses, controversies and basis for early identification and accurate diagnosis of ACLF. PubMed and Google scholar database searches were conducted, search terms included 'acute on chronic liver failure,' 'ACLF,' and 'diagnostic criteria.' Expert commentary: With recent advances in the management of advanced cirrhosis, research will gradually shift towards ACLF in the near future, focusing on the pathogenesis, new treatment options and improving survival. Once we improve understanding of this syndrome, newer definitions will evolve, thereby enabling earlier diagnosis and novel therapeutic avenues.

Single-centre experience of the macrophage activation marker soluble (s)CD163 - associations with disease activity and treatment response in patients with autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis (AIH) is characterised by liver inflammation with reversibility upon anti-inflammatory treatment. Soluble (s)CD163, a specific macrophage activation marker, is associated with inflammation in other liver diseases, but never investigated in AIH.

AIM

To investigate sCD163 in patients with acute AIH and in complete and incomplete responders to standard anti-inflammatory pharmacotherapy, and during follow-up in treatment naive patients.

METHODS

In a cross-sectional design, we studied 121 AIH patients (female/male 89/32, median age 49 years); of these, we prospectively studied 10 treatment naïve AIH patients during prednisolone treatment and tapering. Twenty patients had variant syndromes of AIH and primary biliary cholangitis or primary sclerosing cholangitis. sCD163 was compared with markers of disease activity, severity and treatment response.

RESULTS

In the patients with acute AIH (n = 21), sCD163 was sixfold increased compared with the normalised levels in patients (n = 32) with complete response to standard treatment [9.5 (3.3-28.8) vs. 1.6 (0.8-3.2) mg/L, P < 0.01)], while the patients (n = 27) with incomplete response had higher sCD163 [2.2 (1.3-7.9), P < 0.05] than the complete responders. sCD163 was positively associated with ALAT, IgG and bilirubin (rho: 0.45-0.59, P < 0.001, all), and negatively to external coagulation factors (rho:-0.34, P < 0.001). In the treatment naïve patients, sCD163 fell during high-dose prednisolone treatment and tapering. Immunohistochemical staining confirmed increased CD163 expression in liver biopsies from patients with acute AIH.

CONCLUSIONS

sCD163 was markedly elevated in AIH in the acute phase, normalised by successful treatment in complete responders, but remained higher in the incompletely responding cases. Our results demonstrate macrophage activation in AIH paralleling disease activity, severity and treatment response, suggesting a role for macrophage activation in AIH.

The macrophage activation marker sCD163 is associated with morphological disease stages in patients with non-alcoholic fatty liver disease

BACKGROUND & AIMS

Macrophage activation plays a key pathogenic role in experimental non-alcoholic fatty liver disease (NAFLD) and contributes to the progression of steatohepatitis (NASH) and fibrosis. We studied macrophage activation in human NAFLD by measuring soluble (s)CD163, a specific macrophage activation marker, hypothesizing that sCD163 would be associated with the patients' morphological disease grade. Furthermore, we investigated an association between sCD163 and the apoptosis marker cytokeratin-18 (CK-18) to explore a link between macrophage activation and apoptosis.

METHODS

sCD163 associations with biochemical and histological measures of NAFLD were investigated in two independent cohorts of 157 Australian and 174 Italian NAFLD patients, with liver biopsies graded for NAFLD severity, steatosis and fibrosis. sCD163 and CK-18 were measured by enzyme-linked immunosorbent assay.

RESULTS

In both cohorts sCD163 increased in parallel with the patients' morphological disease grading, being independently associated with the Kleiner fibrosis score (P < 0.001). A high sCD163 predicted advanced fibrosis {F ≥ 3; Australian cohort: area under receiver-operating characteristics curve 0.77 [95% confidence interval (CI): 0.76-0.87], Italian cohort: 0.80 (95% CI: 0.72-0.88)}. In both groups, sCD163 was independently associated with CK-18 (P < 0.001).

CONCLUSION

Soluble CD163 reflecting macrophage activation is associated with morphological features of NAFLD suggesting their involvement in the pathogenesis of NAFLD, NASH and particularly fibrosis. An independent association between sCD163 and cytokeratin-18 suggests that apoptosis may contribute to macrophage activation in NAFLD/NASH.

The macrophage activation marker sCD163 combined with markers of the Enhanced Liver Fibrosis (ELF) score predicts clinically significant portal hypertension in patients with cirrhosis

BACKGROUND

Noninvasive identification of significant portal hypertension in patients with cirrhosis is needed in hepatology practice.

AIM

To investigate whether the combination of sCD163 as a hepatic inflammation marker and the fibrosis markers of the Enhanced Liver Fibrosis score (ELF) can predict portal hypertension in patients with cirrhosis.

METHODS

We measured sCD163 and the ELF components (hyaluronic acid, tissue inhibitor of metalloproteinase-1 and procollagen-III aminopeptide) in two separate cohorts of cirrhosis patients that underwent hepatic vein catheterisation. To test the predictive accuracy we developed a CD163-fibrosis portal hypertension score in an estimation cohort (n = 80) and validated the score in an independent cohort (n = 80). A HVPG ≥10 mmHg was considered clinically significant.

RESULTS

Both sCD163 and the ELF components increased in a stepwise manner with the patients' Child-Pugh score (P < 0.001, all), and also with increasing HVPG (P < 0.001). receiver operator characteristics (ROC) analyses showed that each one of the individual components predicted a HVPG >10 mmHg with AUROC's of approximately 0.80. The combined score optimised by logistic regression analyses improved the AUROC to 0.91 in the estimation cohort and 0.90 in the validation cohort. Furthermore, a high value of the combined score was associated with a high short-term mortality.

CONCLUSIONS

The combination of the macrophage activation marker sCD163 and the fibrosis markers predicted significant portal hypertension in patients with cirrhosis. This score may prove useful for screening purposes and highlights the importance of both the inflammatory and the fibrotic components of cirrhotic portal hypertension.