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

Distinct clusters of bacterial and fungal microbiota in end-stage liver cirrhosis correlate with antibiotic treatment, intestinal barrier impairment, and systemic inflammation

Decompensated liver cirrhosis (dLC) is associated with intestinal dysbiosis, however, underlying reasons and clinical consequences remain largely unexplored. We investigated bacterial and fungal microbiota, their relation with gut barrier integrity, inflammation, and cirrhosis-specific complications in dLC-patients. Competing-risk analyses were performed to investigate clinical outcomes within 90 days. Samples were prospectively collected from 95 dLC-patients between 2017 and 2022. Quantitative metagenomic analyses clustered patients into three groups (G1-G3) showing distinct microbial patterns. G1 (n = 39) displayed lowest diversity and highest Enterococcus abundance, G2 (n = 24) was dominated by Bifidobacteria, G3 (n = 29) was most diverse and clustered most closely with healthy controls (HC). Of note, bacterial concentrations were significantly lower in cirrhosis compared with HC, especially for G1 that also showed the lowest capacity to produce short chain fatty acids and secondary bile acids. Consequently, fungal overgrowth, dominated by Candida spp. (51.63%), was observed in G1. Moreover, G1-patients most frequently received antibiotics (n = 33; 86.8%), had highest plasma-levels of Zonulin (p = 0.044) and a proinflammatory cytokine profile along with numerically higher incidences of subsequent infections (p = 0.09). In conclusion, distinct bacterial clusters were observed at qualitative and quantitative levels and correlated with fungal abundances. Antibiotic treatment significantly contributed to dysbiosis, which translated into intestinal barrier impairment and systemic inflammation.

Sepsis in liver failure patients: Diagnostic challenges and recent advancements

Acute liver failure (ALF) and acute-on-chronic LF (ACLF) are prevalent hepatic emergencies characterized by an increased susceptibility to bacterial infections (BI), despite significant systemic inflammation. Literature indicates that 30%–80% of ALF patients and 55%–81% of ACLF patients develop BI, attributed to immunological dysregulation. Bacterial sepsis in these patients is associated with adverse clinical outcomes, including prolonged hospitalization and increased mortality. Early detection of bacterial sepsis is critical; however, distinguishing between sterile systemic inflammation and sepsis poses a significant challenge due to the overlapping clinical presentations of LF and sepsis. Conventional sepsis biomarkers, such as procalcitonin and C-reactive protein, have shown limited utility in LF patients due to inconsistent results. In contrast, novel biomarkers like presepsin and sTREM-1 have demonstrated promising discriminatory performance in this population, pending further validation. Moreover, emerging research highlights the potential of machine learning-based approaches to enhance sepsis detection and characterization. Although preliminary findings are encouraging, further studies are necessary to validate these results across diverse patient cohorts, including those with LF. This article provides a comprehensive review of the magnitude, impact, and diagnostic challenges associated with BI in LF patients, focusing on novel advancements in early sepsis detection and characterization.

Circulating Biomarkers of Macrophage Activation in Different Stages of Chronic Pancreatitis: A Pilot Study

OBJECTIVES

Activation of type M2 macrophages has been implicated in the pathogenesis of chronic pancreatitis (CP). In a clinical pilot study, we investigated blood-based markers of macrophage activation at different stages of CP.

MATERIALS AND METHODS

We performed a cross-sectional analysis of prospectively collected plasma samples from healthy controls and patients with suspected or definitive CP according to the M-ANNHEIM criteria. Plasma concentrations of soluble CD163 (sCD163), soluble CD206 (sCD206), and monocyte chemoattractant protein-1 (MCP-1) were analyzed using enzyme-linked immunosorbent assays. Group and pairwise comparisons of analytes were performed using regression models and area under the receiver operating curves (AUC-ROC).

RESULTS

In total, 73 subjects with CP (28 suspected CP and 45 definitive CP) and 40 controls were included. Compared to controls, the median plasma concentrations of sCD163 ( P  = 0.019) and sCD206 ( P  = 0.033) were elevated in patients with definitive CP. sCD206 was also elevated in patients with definitive CP ( P  = 0.042) compared to suspected CP. ROC analysis revealed the optimal sCD163 cutpoint to distinguish definitive CP from controls was 1.84 mg/mL (AUC-ROC 0.65; 95% confidence interval [CI], 0.54-0.77). The optimal sCD206 cutpoint to distinguish definitive CP from controls was 0.24 mg/mL (AUC-ROC 0.66; 95% CI, 0.54-0.78). MCP-1 concentrations showed no differences across subgroups.

CONCLUSION

Our study demonstrates that subjects with definitive CP, sampled during a clinically quiescent phase, exhibited increased levels of sCD163 and sCD206. This indicates the presence of activated M2 macrophages in patients with CP at advanced, but not early, clinical stages.

The Covert Side of Ascites in Cirrhosis: Cellular and Molecular Aspects

Ascites, a common complication of portal hypertension in cirrhosis, is characterized by the accumulation of fluid within the peritoneal cavity. While traditional theories focus on hemodynamic alterations and renin-angiotensin-aldosterone system (RAAS) activation, recent research highlights the intricate interplay of molecular and cellular mechanisms. Inflammation, mediated by cytokines (interleukin-1, interleukin-4, interleukin-6, tumor necrosis factor-α), chemokines (chemokine ligand 21, C-X-C motif chemokine ligand 12), and reactive oxygen species (ROS), plays a pivotal role. Besides pro-inflammatory cytokines, hepatic stellate cells (HSCs), sinusoidal endothelial cells (SECs), and smooth muscle cells (SMCs) contribute to the process through their activation and altered functions. Once activated, these cell types can worsen ascites accumulationthrough extracellular matrix (ECM) deposition and paracrine signals. Besides this, macrophages, both resident and infiltrating, through their plasticity, participate in this complex crosstalk by promoting inflammation and dysregulating lymphatic system reabsorption. Indeed, the lymphatic system and lymphangiogenesis, essential for fluid reabsorption, is dysregulated in cirrhosis, exacerbating ascites. The gut microbiota and intestinal barrier alterations which occur in cirrhosis and portal hypertension also play a role by inducing inflammation, creating a vicious circle which worsens portal hypertension and fluid accumulation. This review aims to gather these aspects of ascites pathophysiology which are usually less considered and to date have not been addressed using specific therapy. Nonetheless, it emphasizes the need for further research to understand the complex interactions among these mechanisms, ultimately leading to targeted interventions in specific molecular pathways, aiming towards the development of new therapeutic strategies.

Potential therapies for acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a syndrome that develops in approximately 30% of patients hospitalised with cirrhosis and is characterised by an acute decompensation of liver function associated with extra-hepatic organ failures and a high short-term mortality. At present, no specific therapies are available for ACLF, and current management is limited to treatment of the precipitating event and organ support. Given the high prevalence and high mortality of this severe liver disease, there is an urgent need for targeted treatments. There is increasing evidence of the important role played by systemic inflammation and immune dysfunction in the pathophysiology of ACLF and a better understanding of these immune processes is resulting in new therapeutic targets. The aim of this review is to present an overview of ongoing studies of potentially promising therapies and how they could be utilised in the management of ACLF.

Organ dysfunction and failure in liver disease

Acute-on-chronic liver failure (ACLF) is a complex syndrome defined by the existence of different organ failures (OFs) in patients with chronic liver disease, mainly cirrhosis. Several definitions have been proposed to define the syndrome, varying in the grade of the subjacent liver disease, the type of precipitants and the organs considered in the definition. Liver, coagulation, brain, kidney, circulatory and pulmonary are the six types of OFs proposed in the different classifications, with different prevalence worldwide. Irrespective of the definition used, patients who develop ACLF present a hyperactive immune system, profound haemodynamic disturbances and several metabolic alterations that finally lead to organ dysfunction. These disturbances are triggered by different factors such as bacterial infections, alcoholic hepatitis, gastrointestinal bleeding or hepatitis B virus flare, among others. Because patients with ACLF present high short-term mortality, a prompt recognition is needed to start treatment of the trigger event and specific organ support. Liver transplantation is also feasible in carefully selected patients and should be evaluated.

Gene score to quantify systemic inflammation in patients with acutely decompensated cirrhosis

BACKGROUND AND AIMS

Quantifying systemic inflammation (SI) in acutely decompensated cirrhosis (ADC) is of major importance because SI is a driver of the most severe forms of ADC, including acute-on-chronic liver failure (ACLF). Blood biomarkers of SI already evaluated in ADC failed to appropriately assess SI in ADC. We aimed to investigate whether gene expression related to circulating immune cells could quantify SI in ADC.

METHODS

Standard biomarkers (white cell count, C reactive protein, cytokines) and genome-wide RNA expression (RNA-sequencing) were obtained in blood from 700 patients with ADC at the time of their hospital admission. A composite score based on standard biomarkers of SI (Chronic Liver Failure-Standard Biomarkers Composite (CLIF-SBC) score) and a gene score (CLIF-Systemic Inflammation Gene (SIG) score) composed of the 28 top differentially expressed immune cell-related genes in the comparison between high-severity and low-severity clinical phenotypes were computed. Among the 700 patients, the CLIF-SIG score was repeated once during follow-up in 375 patients, and 3 times or more in 46 patients.

RESULTS

The CLIF-SIG score was more accurate in reflecting clinical severity induced by SI than the CLIF-SBC score (area under the curve 0.803 vs 0.658). A CLIF-SIG score of 0.386 (Youden Index) was the best cut-off level discriminating patients with poor outcomes from the others, in all clinical scenarios. Sequential measurement of the CLIF-SIG score showed that 78% of patients were admitted at the peak or descending part of the SI-wave. ACLF developed during hospitalisation in 80% of patients with a CLIF-SIG score >0.386 on admission.

CONCLUSIONS

In patients with ADC, the CLIF-SIG score is an accurate estimator of SI, clinical course severity and prognosis.

Managing Multiorgan Failure in Acute on Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is defined as a clinical syndrome that develops in patients with chronic liver disease characterized by the presence of organ failure and high short-term mortality, although there is still no worldwide consensus on diagnostic criteria. Management of ACLF is mainly based on treatment of "precipitating factors" (the most common are infections, alcohol-associated hepatitis, hepatitis B flare, and bleeding) and support of organ failure, which often requires admission to the intensive care unit. Liver transplantation should be considered in patients with ACLF grades 2 to 3 as a potentially life-saving treatment. When a transplant is not indicated, palliative care should be considered after 3 to 7 days of full organ support in patients with at least four organ failures or a CLIF-C ACLF score of >70. This review summarizes the current knowledge on the management of organ failure in patients with ACLF, focusing on recent advances.

Hepatofugal portal flow is highly predictive of acute-on-chronic liver failure: A new hemodynamic patho-physiological hypothesis

BACKGROUND AND AIMS

Acute-on-chronic liver failure (ACLF) is a severe complication of advanced liver disease. A significant number of ACLF patients have not clear precipitating factors. The aim of the study was to investigate the role of alterations in porto-hepatic hemodynamics, especially non-forward portal flow (NFPF), in ACLF and liver-related mortality.

METHODS

233 cirrhotic patients were included in the study with a median follow-up of 24 months. Color-Doppler ultrasound was used to assess portal vein patency, flow direction and significant porto-systemic collaterals (>8 mm). Patients with active cancer, both at baseline and during follow-up and severe non liver-related comorbidities were excluded. ACLF and liver-related mortality were recorded during follow-up.

RESULTS

Fifty-six patients (24%) developed ACLF; 24 (10,3%) had baseline NFPF. In survival analysis, NFPF, but not portal vein thrombosis, was independently associated with ACLF development (HR 2.85 95% C.I. [1.49-5.42], p = 0.001) and liver-related mortality (HR 2.24 95% C.I. [1.16-4.28], p = 0.015), even after adjustment for liver disease severity scores, age and etiology of liver disease.

CONCLUSION

NFPF is independently associated with ACLF development and liver-related mortality, regardless of etiology, severity disease scores and portal vein thrombosis. Although there is no specific measure to reverse NFPF, patients with NFPF should receive prompt intensive management and urgent prioritization for liver transplantation.

CLINICAL TRIAL NUMBER

2730 CESC.

Baicalein upregulates macrophage TREM2 expression via TrKB-CREB1 pathway to attenuate acute inflammatory injury in acute-on-chronic liver failure

OBJECTIVE

Acute-on-chronic liver failure (ACLF) is a syndrome characterized by a high short-term mortality rate, and effective interventions are still lacking. This study aims to investigate whether the small molecule baicalein can mitigate ACLF and elucidate the molecular mechanisms.

METHODS

The ACLF mouse model was induced through chronic liver injury using carbon tetrachloride, followed by acute inflammation induction with lipopolysaccharide (LPS). Baicalein was administered through intraperitoneal injection to explore its therapeutic effects. In vitro experiments utilized the iBMDM macrophage cell line to investigate the underlying mechanisms. Peripheral blood was collected from clinical ACLF patients for validation.

RESULTS

In the LPS-induced ACLF mouse model, baicalein demonstrated a significant reduction in acute inflammation and liver damage, as evidenced by histopathological evaluation, liver function analysis, and inflammatory marker measurements. Transcriptomic analysis, coupled with molecular biology experiments, uncovered that baicalein exerts its effects in ACLF by activating the TrKB-CREB1 signaling axis to upregulate the surface expression of the TREM2 receptor on macrophages. This promotes M2 macrophage polarization and activates efferocytosis, thereby inhibiting inflammation and alleviating liver damage. Furthermore, we observed a substantial negative correlation between postoperative peripheral blood plasma soluble TREM2 (sTREM2) levels and inflammation, as well as adverse outcomes in clinical ACLF patients.

CONCLUSION

Baicalein plays a protective role in ACLF by enhancing the surface expression of the TREM2 receptor on macrophages, leading to the suppression of inflammation, mitigation of liver damage, and a reduction in mortality. Additionally, plasma sTREM2 emerges as a critical indicator for predicting adverse outcomes in ACLF patients.

Macrophage Perspectives in Liver Diseases: Programmed Death, Related Biomarkers, and Targeted Therapy

Macrophages, as important immune cells of the organism, are involved in maintaining intrahepatic microenvironmental homeostasis and can undergo rapid phenotypic changes in the injured or recovering liver. In recent years, the crucial role of macrophage-programmed cell death in the development and regression of liver diseases has become a research hotspot. Moreover, macrophage-targeted therapeutic strategies are emerging in both preclinical and clinical studies. Given the macrophages' vital role in complex organismal environments, there is tremendous academic interest in developing novel therapeutic strategies that target these cells. This review provides an overview of the characteristics and interactions between macrophage polarization, programmed cell death, related biomarkers, and macrophage-targeted therapies. It aims to deepen the understanding of macrophage immunomodulation and molecular mechanisms and to provide a basis for the treatment of macrophage-associated liver diseases.

Immunopathogenesis of acute on chronic liver failure

Acute-on-chronic liver failure is a well-established description of a high-mortality syndrome of chronic liver disease (usually cirrhosis) with organ failure. While the exact definition is under refinement, the accepted understanding of this entity is in patients with chronic liver disease and various organs in failure and where systemic inflammation is a major component of the pathobiology. There are limited therapies for a disease with such a poor prognosis, and while improvements in the critical care management and for very few patients, liver transplantation, mean 50% can survive to hospital discharge, rapid application of new therapies is required. Here we explain the current understanding of the immunologic abnormalities seen in acute-on-chronic liver failure across the innate and adaptive immune systems, the role of the hepatic cell death and the gut-liver axis, and recommendations for future research and treatment paradigms.

Thrombospondin 1 enhances systemic inflammation and disease severity in acute-on-chronic liver failure

BACKGROUND

The key role of thrombospondin 1 (THBS1) in the pathogenesis of acute-on-chronic liver failure (ACLF) is unclear. Here, we present a transcriptome approach to evaluate THBS1 as a potential biomarker in ACLF disease pathogenesis.

METHODS

Biobanked peripheral blood mononuclear cells (PBMCs) from 330 subjects with hepatitis B virus (HBV)-related etiologies, including HBV-ACLF, liver cirrhosis (LC), and chronic hepatitis B (CHB), and normal controls (NC) randomly selected from the Chinese Group on the Study of Severe Hepatitis B (COSSH) prospective multicenter cohort underwent transcriptome analyses (ACLF = 20; LC = 10; CHB = 10; NC = 15); the findings were externally validated in participants from COSSH cohort, an ACLF rat model and hepatocyte-specific THBS1 knockout mice.

RESULTS

THBS1 was the top significantly differentially expressed gene in the PBMC transcriptome, with the most significant upregulation in ACLF, and quantitative polymerase chain reaction (ACLF = 110; LC = 60; CHB = 60; NC = 45) was used to verify that THBS1 expression corresponded to ACLF disease severity outcome, including inflammation and hepatocellular apoptosis. THBS1 showed good predictive ability for ACLF short-term mortality, with an area under the receiver operating characteristic curve (AUROC) of 0.8438 and 0.7778 at 28 and 90 days, respectively. Enzyme-linked immunosorbent assay validation of the plasma THBS1 using an expanded COSSH cohort subjects (ACLF = 198; LC = 50; CHB = 50; NC = 50) showed significant correlation between THBS1 with ALT and γ-GT (P = 0.01), and offered a similarly good prognostication predictive ability (AUROC = 0.7445 and 0.7175) at 28 and 90 days, respectively. ACLF patients with high-risk short-term mortality were identified based on plasma THBS1 optimal cut-off value (< 28 µg/ml). External validation in ACLF rat serum and livers confirmed the functional association between THBS1, the immune response and hepatocellular apoptosis. Hepatocyte-specific THBS1 knockout improved mouse survival, significantly repressed major inflammatory cytokines, enhanced the expression of several anti-inflammatory mediators and impeded hepatocellular apoptosis.

CONCLUSIONS

THBS1 might be an ACLF disease development-related biomarker, promoting inflammatory responses and hepatocellular apoptosis, that could provide clinicians with a new molecular target for improving diagnostic and therapeutic strategies.

Elevated CD169 expressing monocyte/macrophage promotes systemic inflammation and disease progression in cirrhosis

Systemic inflammation is related to disease progression and prognosis in patients with advanced cirrhosis. However, the mechanisms underlying the initiation of inflammation are still not fully understood. The role of CD169+ monocyte/macrophage in cirrhotic systemic inflammation was undetected. Flow cytometry analysis was used to detect the percentage and phenotypes of CD169+ monocytes as well as their proinflammatory function in patient-derived cirrhotic tissue and blood. Transcriptome differences between CD169+ and CD169- monocytes were also compared. Additionally, a mouse model with specific depletion of CD169+ monocytes/macrophages was utilized to define their role in liver injury and fibrosis. We observed increased CD169 expression in monocytes from cirrhotic patients, which was correlated with inflammatory cytokine production and disease progression. CD169+ monocytes simultaneously highly expressed M1- and M2-like markers and presented immune-activated profiles. We also proved that CD169+ monocytes robustly prevented neutrophil apoptosis. Depletion of CD169+ monocytes/macrophages significantly inhibited inflammation and liver necrosis in acute liver injury, but the spontaneous fibrin resolution after repeated liver injury was impaired. Our results indicate that CD169 defines a subset of inflammation-associated monocyte that correlates with disease development in patients with cirrhosis. This provides a possible therapeutic target for alleviating inflammation and improving survival in cirrhosis.

Novel prognostic biomarkers in decompensated cirrhosis: a systematic review and meta-analysis

BACKGROUND

Patients with decompensated cirrhosis experience high mortality rates. Current prognostic scores, including the model for end-stage liver disease (MELD), may underperform in settings other than in those they were initially developed. Novel biomarkers have been proposed to improve prognostication accuracy and even to predict development of complications.

METHODS

We performed a systematic review and meta-analysis on novel urine and blood biomarkers and their ability to predict 90-day mortality in patients with decompensated cirrhosis. Secondary outcomes included 28-day and 1-year mortality, and development of acute-on-chronic liver failure, acute kidney injury and other complications. To overcome differences in units, temporal changes in assays and reporting heterogeneity, we used the ratio of means (RoM) as measure of association for assessing strength in predicting outcomes. An RoM>1 implies that the mean biomarker level is higher in those that develop the outcome than in those that do not.

RESULTS

Of 6629 unique references, 103 were included, reporting on 29 different biomarkers, with a total of 31 362 biomarker patients. Most studies were prospective cohorts of hospitalised patients (median Child-Pugh-Turcotte score of 9 and MELD score of 18). The pooled 90-day mortality rate was 0.27 (95% CI 0.24 to 0.29). The RoM for predicting 90-day mortality was highest for interleukin 6 (IL-6) (2.56, 95% CI 2.39 to 2.74), followed by urinary neutrophil gelatinase-associated lipocalin (uNGAL) (2.42, 95% CI 2.20 to 2.66) and copeptin (2.33, 95% CI 2.17 to 2.50). These RoMs were all higher than for MELD (1.44, 95% CI 1.42 to 1.46).

CONCLUSION

Novel biomarkers, including IL-6, uNGAL and copeptin, can probably improve prognostication of patients with decompensated cirrhosis compared with MELD alone.

Intravenous BCAA Infusion Does Not Lead to a Sustained Recovery From Overt HE in ACLF - An Open Label Randomized Clinical Trial

Background

Hepatic encephalopathy (HE) in acute-on-chronic liver failure (ACLF) is associated with significant morbidity and mortality. We conducted a prospective, randomized controlled clinical trial to study the efficacy of intravenous branched chain amino acids (IV-BCAA) with lactulose versus lactulose alone for improvement in HE at 24 h, day 3, and day 7. The primary outcome was an improvement in encephalopathy by ≥ 1 grade at 72 h.

Patients and methods

European association for study of liver (EASL) defined ACLF patients with overt HE were assessed and randomized into the experimental arm (IV-BCAA - 500 mL/day for 3 days + Lactulose; n = 39) and the comparator arm (Lactulose alone; n = 37). Six patients developed COVID-19 after randomization and were excluded (4-experimental arm and 2-comparator arm).

Results

Of 222 screened patients, 70 (35 in each arm) were included in the analysis. Baseline characteristics, including HE grade (2.9 ± 0.7 vs 2.8 ± 0.7; P = 0.86) and (chronic liver failure) CLIF-C ACLF score (54.2 ± 5.6 vs 54.8 ± 5.7; P = 0.65), were similar. Overall survival was 40% at 28 days (48.5% vs 31.4%; P = 0.14). Improvement in hepatic encephalopathy scoring algorithm (HESA) by ≥ 1 grade at 24 h occurred in 14 patients (40%) in the BCAA arm and 6 patients (17.1%) in the control group (P = 0.03) which translated to a shorter intensive care unit (ICU) stay. The median change in HESA at 24 h was greater in the BCAA arm than the control arm (P = 0.006), which was not sustained at days 3 or 7. Ammonia levels did not correlate with the grade of HE (Spearman's correlation coefficient (ρ) = - 0.0843; P = 0.29).

Conclusion

Intravenous BCAA does not lead to a sustained improvement in HE grade in ACLF.

Trial registration no

NCT04238416 (clinicaltrials.gov).

Macrophage metabolism in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) and its inflammatory and often progressive subtype nonalcoholic steatohepatitis (NASH), have emerged as significant contributors to hepatic morbidity worldwide. The pathophysiology of NAFLD/NASH is multifaceted, variable, and remains incompletely understood. The pivotal role of liver-resident and recruited macrophages in the pathogenesis of NAFLD and NASH is widely acknowledged as a crucial factor in innate immunity. The remarkable plasticity of macrophages enables them to assume diverse activation and polarization states, dictated by their immunometabolism microenvironment and functional requirements. Recent studies in the field of immunometabolism have elucidated that alterations in the metabolic profile of macrophages can profoundly influence their activation state and functionality, thereby influencing various pathological processes. This review primarily focuses on elucidating the polarization and activation states of macrophages, highlighting the correlation between their metabolic characteristics and the transition from pro-inflammatory to anti-inflammatory phenotypes. Additionally, we explore the potential of targeting macrophage metabolism as a promising therapeutic approach for the management of NAFLD/NASH.

Fungal translocation measured by serum 1,3-ß-D-glucan correlates with severity and outcome of liver cirrhosis-A pilot study

BACKGROUND & AIMS

On a global scale, liver cirrhosis is attributable to ~1 million deaths per year. This systemic disease comes along with diverse sequelae, including microbiota alterations, increased gut permeability and translocation of microbial components into the systemic circulation. Alongside the extensively studied influence of bacterial translocation and its host-pathogen interactions, far less is known about the role and impact of fungal components once having crossed the intestinal barrier.

METHODS

Including 70 patients with different aetiologies of liver cirrhosis, we investigated the relationship between fungal translocation, measured by 1,3-β-D-glucan (BDG), and biomarkers of gut integrity, inflammation and severity/outcome of liver disease.

RESULTS

Patients with cirrhosis Child-Pugh class (CPC)-B were more likely to have positive serum BDG (aOR 5.4, 95% CI 1.2-25.2) compared to patients with cirrhosis CPC-A. BDG showed a moderate positive correlation with several markers of inflammation (sCD206, sCD163, Interleukin 8, interferon-gamma-induced protein). Mortality differed significantly between patients with positive versus negative BDG (log-rank test, p = 0.015). The multivariable Cox regression model yielded an aHR of 6.8 (95% CI 1.8-26.3).

DISCUSSION

We observed trends for increased fungal translocation depending on the severity of liver cirrhosis, an association of BDG with an inflammatory environment and the adverse effects of BDG on disease outcome. In order to gain more in-depth knowledge about (fungal-)dysbiosis and its detrimental consequences in the setting of liver cirrhosis, these trends need to be studied in more detail including prospective sequential testing in larger cohorts together with mycobiome analyses. This will further elucidate complex host-pathogen interactions and potentially introduce points of application for therapeutic interventions.

The association between soluble CD163, disease severity, and ursodiol treatment in patients with primary biliary cholangitis

INTRODUCTION

The macrophage activation marker soluble (s)CD163 is associated with disease severity and prognosis in patients with primary biliary cholangitis (PBC). Ursodeoxycholic acid (UDCA) treatment attenuates fibrosis progression in PBC patients, but its effect on macrophage activation is unclear. We examined the effect of UDCA on macrophage activation, as determined by sCD163 levels.

METHODS

We included 2 cohorts of PBC patients; 1 cohort with prevalent PBC patients, and 1 cohort of incident PBC patients before start of UDCA treatment and with follow-up after 4 weeks and 6 months. We measured sCD163 and liver stiffness in both cohorts. Further, we measured sCD163 and TNF-α shedding in vitro in monocyte-derived macrophages after UDCA and lipopolysaccharide incubation.

RESULTS

We included 100 patients with prevalent PBC [93% women, median age 63 y (interquartile range: 51-70)] and 47 patients with incident PBC [77% women, median age 60 y (49-67)]. Prevalent PBC patients had a lower median sCD163 of 3.54 mg/L (2.77-4.72) than incident PBC patients with a median sCD163 of 4.33 mg/L (2.83-5.99) at inclusion. Patients with an incomplete response to UDCA and patients with cirrhosis had higher sCD163 than responders to UDCA and noncirrhosis patients. After 4 weeks and 6 months of UDCA treatment median sCD163 decreased by 4.6% and 9.0%, respectively. In in vitro experiments, UDCA attenuated shedding of TNF-α, but not sCD163, from monocyte-derived macrophages.

CONCLUSION

In PBC patients, sCD163 levels correlated with liver disease severity and treatment response to UDCA. Further, after 6 months of UDCA treatment, we observed a decrease in sCD163, which may be related to the treatment.

Biomarkers of hepatocellular synthesis in patients with decompensated cirrhosis

BACKGROUND AND AIM

Since hepatocytes produce majority of serum proteins, patients with cirrhosis display substantial alterations in the serum proteome. The aim of the current study was to characterize these changes and to study the prognostic utility of hepatocellular proteins available in routine clinical testing.

METHODS

Sera from 29 healthy controls and 43 patients with cirrhosis were subjected to untargeted proteomic analysis. Unsupervised hierarchical clustering was performed with Perseus software and R. Ingenuity pathway analysis (IPA) suggested upstream regulators that were validated in liver tissues. The behavior and prognostic usefulness of selected biomarkers was investigated in 61 controls and 285 subjects with decompensated cirrhosis.

RESULTS

Proteomics uncovered 65 and 16 hepatocellular serum proteins that are significantly downregulated or upregulated in patients with cirrhosis vs. controls. Hierarchical clustering revealed two main clusters and six sub-clusters. IPA identified HNF4α and IL-6 as the two major upstream regulators that were confirmed by hepatic gene expression analyses. Among pseudocholinesterase, transferrin, transthyretin, albumin, and apolipoprotein AI (Apo-AI), Apo-AI was the best predictor of 90-days transplant-free survival (AUROC 0.678; p = 0.0001) and remained an independent predictor in multivariable Cox independently of the presence of acute-on-chronic liver failure.

CONCLUSION

Our study reveals cirrhosis-associated changes in hepatocellular serum proteins and underlying transcription factors. Serum apolipoprotein AI may constitute a useful prognostic adjunct in patients with decompensated cirrhosis.

Plasma human neutrophil peptides as biomarkers of disease severity and mortality in patients with decompensated cirrhosis

BACKGROUND & AIMS

Human neutrophil peptides (HNP)-1, -2 and -3 are the most abundant proteins in neutrophil azurophilic granules and are rapidly released via neutrophil degranulation upon activation. The aims of our study were to assess the role of HNP1-3 as biomarkers of disease severity in patients with decompensated cirrhosis and their value in predicting short-term mortality.

METHODS

In this study, 451 patients with acutely decompensated cirrhosis (AD) were enrolled at the two medical centres. Overall, 281 patients were enrolled as the training cohort from October 2015 to April 2019, and 170 patients were enrolled as the validation cohort from June 2020 to February 2021. Plasma HNP1-3 levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Plasma HNP1-3 increased stepwise with disease severity (compensated cirrhosis: 0.3 (0.2-0.4); AD without acute-on-chronic liver failure (ACLF): 1.9 (1.3-4.8); ACLF-1: 2.3 (1.8-6.1); ACLF-2: 5.6 (2.9-12.3); ACLF-3: 10.3 (5.7-17.2) ng/ml). From the multivariate Cox regression analysis, HNP1-3 emerged as independent predictors of mortality at 30 and 90 days. Similar results were observed in the subgroup analysis. On ROC analysis, plasma HNP1-3 showed better predictive accuracy for 30- and 90-day mortality (area under the receiver operating characteristic (AUROC) of 0.850 and 0.885, respectively) than the neutrophil-to-lymphocyte ratio (NLR) and similar accuracy as end-stage liver disease (MELD: 0.881 and 0.874) and chronic liver failure-sequential organ failure (CLIF-SOFA: 0.887 and 0.878).

CONCLUSIONS

Plasma HNP1-3 levels were closely associated with disease severity and might be used to identify patients with AD at high risk of short-term mortality.

Soluble CD163 and CD163 Expression on Monocytes Associated with Chronic Hepatitis B Inflammation and HBsAg Loss

BACKGROUND AND AIMS

Monocyte/macrophage-associated CD163 is an indicator of the severity of liver inflammation and cirrhosis, but the difference of soluble CD163 (sCD163) levels in chronic hepatitis B (CHB) patients and hepatitis B surface antigen (HBsAg)-loss patients is unclear. Herein, we aimed to compare the sCD163 levels in CHB patients and HBsAg-loss patients with or without antiviral treatment.

METHODS

sCD163 and CD163 expression on monocytes were compared among four groups, healthy subjects, treatment-naïve CHB patients, spontaneous HBsAg-loss patients, and treatment-related HBsAg-loss patients. The correlation between sCD163 levels and clinical parameters in CHB patients was analyzed. A group of 80 patients with hepatitis B virus (HBV) infection and liver biopsy were recruited.

RESULTS

sCD163 levels were higher in the CHB group than in the other three groups. sCD163 levels were higher in treatment-related HBsAg-loss patients than in spontaneous HBsAg-loss patients. sCD163 levels were negatively correlated with hepatitis B e-antigen (HBeAg) and HBsAg levels in HBeAg-positive patients. Liver biopsy results further demonstrated that sCD163 levels were elevated in CHB patients with substantial inflammation (A≥2) or fibrosis (F≥2). The sCD163 model was more sensitive in predicting inflammation than other noninvasive models. Its levels were higher in patients with normal alanine aminotransferase levels and significant inflammation (A≥2) than in patients with no or mild inflammation.

CONCLUSIONS

sCD163 and CD163 expression on monocytes were associated with CHB inflammation and HBsAg loss, and may be used as markers to predict HBV-specific immune activation.

Characterization of intrahepatic B cells in acute-on-chronic liver failure

Background and objectives

Acute on chronic liver failure (ACLF) is characterized by the immunologic dissonance during the prolonged pathogenic development. Both abnormal innate immune response and adaptive T-cell response have been reported in patients with ACLF; however, less is known regarding B cells in ACLF pathogenesis. Previous reports were only based on immunophenotyping of peripheral blood samples. Here, we aim to dissect liver-infiltrating B-cell subpopulation in ACLF.

Methods

Paired liver perfusate and peripheral blood were freshly collected from healthy living donors and recipients during liver transplantation. Liver tissues were obtained from patients with ACLF, cirrhosis, and healthy controls. Flow cytometry was used to characterize the phenotypic and functional alterations in intrahepatic and circulating B-cell populations from ACLF, cirrhosis, and healthy controls. The expression of CD19⁺ and CD138⁺ on liver tissues was examined by immunohistochemistry staining.

Results

In this study, we first deciphered the intrahepatic B cells subsets of patients with ACLF. We found that the ACLF liver harbored reduced fraction of naïve B cells and elevated percentage of CD27⁺CD21^- activated memory B cells (AM), CD27^-CD21^- atypical memory B cells (atMBC), CD27⁺IgD^-IgM⁺(IgM⁺ memory B cells), and CD27⁺CD38⁺⁺ plasma cells than cirrhosis and healthy controls. Moreover, these B subpopulations demonstrated enhanced activation and altered effector functions. Specifically, the ACLF liver was abundant in atMBC expressing higher CD11c and lower CD80 molecule, which was significantly correlated to alanine aminotransferase and aspartate aminotransferase. In addition, we found that intrahepatic CD27⁺CD38⁺⁺plasma cells were preferentially accumulated in ACLF, which expressed more CD273 (PD-L2) and secreted higher granzyme B and IL-10. Finally, the enriched hepatic plasma B cells were in positive association with disease severity indices including alkaline phosphatase and gamma-glutamyl transferase.

Conclusions

In this pilot study, we showed an intrahepatic B-cell landscape shaped by the ACLF liver environment, which was distinct from paired circulating B-cell subsets. The phenotypic and functional perturbation in atMBC and plasma cells highlighted the unique properties of infiltrating B cells during ACLF progression, thereby denoting the potential of B-cell intervention in ACLF therapy.

CD206+CD68+ mono-macrophages and serum soluble CD206 level are increased in antineutrophil cytoplasmic antibodies associated glomerulonephritis

Background

Antineutrophil Cytoplasmic Antibodies (ANCA) associated glomerulonephritis (AGN) is a group of autoimmune diseases and mono-macrophages are involved in its glomerular injuries. In this study, we aim to investigate the role of CD206⁺ mono-macrophages in AGN.

Methods

27 AGN patients (14 active AGN, 13 remissive AGN) together with healthy controls (n = 9), disease controls (n = 6) and kidney function adjusted controls (n = 9) from Department of Nephrology, Ruijin hospital were recruited. Flow cytometry was used to study proportion of CD206⁺ cells in peripheral blood. Immunohistochemistry for CD206 staining was performed and CD206 expression was scored in different kidney regions. Serum soluble CD206 (sCD206) was measured by enzyme-linked immunosorbent assay (ELISA). We also generated murine myeloperoxidase (MPO) (muMPO) ANCA by immunizing Mpo^−/− mice. Mouse bone marrow-derived macrophages (BMDMs) from wild C57BL/6 mice and peripheral blood mononuclear cell (PBMC) derived macrophages from healthy donors were treated with MPO ANCA with or without its inhibitor AZD5904 to investigate the effects of MPO-ANCA on CD206 expression.

Results

The proportion of peripheral CD206⁺CD68⁺ cells in active AGN patients were significantly higher than that in remissive patients (p < 0.001), healthy controls (p < 0.001) and kidney function adjusted controls (p < 0.001). Serum sCD206 level in active AGN patients was higher than that in healthy controls (p < 0.05) and remissive patients (p < 0.01). Immunohistochemistry showed CD206 was highly expressed in different kidney regions including fibrinoid necrosis or crescent formation, glomeruli, periglomerular and tubulointerstitial compartment in active AGN patients in comparison with disease controls. Further studies showed MPO ANCA could induce CD206 expression in BMDMs and PBMC derived macrophages and such effects could be reversed by its inhibitor AZD5904.

Conclusion

ANCA could induce CD206 expression on mono-macrophages and CD206⁺ mono-macrophages are activated in AGN. CD206 might be involved in the pathogenesis of AAV and may be a potential target for the disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-022-00529-w.

Circulating soluble CD36 as a novel biomarker for progression and prognosis of HBV-related liver diseases

BACKGROUND

Our previous study suggested CD36 may be a positive regulator of hepatitis B virus (HBV) replication in vitro. Therefore, the present study aimed to investigate whether circulating soluble CD36 (sCD36) could serve as a diagnostic and prognostic biomarker for HBV-related liver diseases based on the clinic collected data.

METHODS

A total of 282 subjects were divided into healthy controls (HC, n = 47), chronic hepatitis B (CHB, n = 68), HBV-related liver cirrhosis (HBV-LC, n = 167). Soluble CD36 in plasma was measured by ELISA, and monocyte or platelet CD36 expression was determined by flow cytometry.

RESULTS

There was a step-wise increase of sCD36 with the progression of chronic HBV infection, and it was the highest in the HBV- LC group with liver failure (1.50, IQR:1.04-2.00) as compared with HC (0.38, IQR:0.27-0.38), CHB (0.75, IQR:0.40-1.13), and HBV-LC without liver failure (1.02, IQR,0.61-1.35) group. Circulating sCD36 was not correlated with serum HBV DNA levels, but correlated with liver function parameters. Additionally, ROC analysis confirmed sCD36 could be used to predict liver failure for HBV-LC patients, which yielded an AUC of 0.775 with 71.0% sensitivity and 72.2% specificity. Multivariate logistic regression analysis revealed sCD36 is an independent risk factor in predicting liver failure. Moreover, plasma sCD36 in HBV-LC patients was significantly correlated with prognostic indices, including MELD, MELD-Na and CHILD-PUGH scores. On the other hand, CD36 expression on monocytes or platelets was positively correlated with plasma sCD36 levels, whereas they were not strongly associated with the disease severity.

CONCLUSION

Circulating sCD36 could be used as a novel noninvasive biomarker for predicting liver failure and prognosis in chronic HBV infected patients.

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.

Spotlight on liver macrophages for halting liver disease progression and injury

INTRODUCTION

Over the past two decades, understanding of hepatic macrophage biology has provided astounding details of their role in the progression and regression of liver diseases. The hepatic macrophages constitute resident macrophages, Kupffer cells, and circulating bone marrow monocyte-derived macrophages, which play a diverse role in liver injury and repair. Imbalance in the macrophage population leads to pathological consequences and is responsible for the initiation and progression of acute and chronic liver injuries. Further, distinct populations of hepatic macrophages and their high heterogeneity make their complex role enigmatic. The unique features of distinct phenotypes of macrophages have provided novel biomarkers for defining the stages of liver diseases. The distinct mechanisms of hepatic macrophages polarization and recruitment have been at the fore front of research. In addition, the secretome of hepatic macrophages and their immune regulation has provided clinically relevant therapeutic targets.

AREAS COVERED

Herein we have highlighted the current understanding in the area of hepatic macrophages, and their role in the progression of liver injury.

EXPERT OPINION

It is essential to ascertain the physiological and pathological role of evolutionarily conserved distinct macrophage phenotypes in different liver diseases before viable approaches may see a clinical translation.

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.

Soluble mannose receptor CD206 and von Willebrand factor are early biomarkers to identify patients at risk for severe or necrotizing acute pancreatitis

Background

In acute pancreatitis (AP), microcirculatory dysfunction and leukocyte activation contribute to organ damage, inflammation, and mortality. Given the role of macrophage activation, monocyte recruitment, and microthrombus formation in the early pathogenesis of AP, we examined the macrophage activation marker soluble mannose receptor (sCD206) and the endothelial function marker von Willebrand factor (vWF) in patients admitted for AP.

Methods

In an exploratory analysis, serum sCD206 and plasma vWF were prospectively analyzed on day 1 and day 3 in 81 patients with AP admitted to the hospital. In addition, blood samples from 59 patients with early AP admitted to the intensive care unit and symptom onset < 24 h were retrospectively analyzed. Patients were dichotomized as per study protocol into two groups: (i) “non-severe edematous AP” including patients with mild AP without organ failure and patients with transient organ failure that resolves within 48 h and (ii) “severe/necrotizing AP” including patients with severe AP and persistent organ failure > 48 h and/or patients with local complications.

Results

In the prospective cohort, 17% developed severe/necrotizing pancreatitis compared with 56% in the ICU cohort. Serum concentrations of sCD206 on admission were higher in patients with severe/necrotizing AP than in patients with non-severe edematous AP (prospective: 1.57 vs. 0.66 mg/l, P = 0.005; ICU: 1.76 vs. 1.25 mg/l, P = 0.006), whereas other inflammatory markers (leukocytes, C-reactive protein, procalcitonin) and disease severity (SOFA, SAPS II, APACHE II) did not show significant differences. Patients with severe/necrotizing AP had a greater increase in sCD206 than patients with non-severe edematous AP at day 3 in the prospective cohort. In contrast to routine coagulation parameters, vWF antigen levels were elevated on admission (prospective cohort: 375 vs. 257%, P = 0.02; ICU cohort: 240 vs. 184%, P = 0.03). When used as continuous variables, sCD206 and VWF antigen remained predictors of severe/necrotizing AP after adjustment for etiology and age in both cohorts.

Conclusions

sCD206 identifies patients at risk of severe AP at earlier timepoints than routine markers of inflammation and coagulation. Prospective studies are needed to investigate whether incorporating early or repeated measurements into the existing scoring system will better identify patients at increased risk for complications of AP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-022-00619-2.

Increased Serum Levels of sCD206 Are Associated with Adverse Prognosis in Patients with HBV-Related Decompensated Cirrhosis

Background

HBV-associated decompensated cirrhosis (HBV-DeCi) is attracting considerable attention due to disease acceleration and substantial mortality. Macrophages regulate the fibrotic process in DeCi. Soluble CD206 (sCD206) is primarily expressed by macrophages. We aimed to investigate whether sCD206 predicts mortality in patients with HBV-DeCi.

Materials and Methods

A total of 382 patients were enrolled between February 2020 and February 2021 and divided into nonsurviving and surviving groups according to 28-day, 3-month, and 6-month outcomes. Cox regression analysis was performed to confirm the independent prognostic factors of HBV-DeCi, and Kaplan–Meier analysis was performed to draw survival curves of sCD206. The predictive value of sCD206 was assessed at three time points according to the AUROC.

Results

The serum sCD206 level was significantly higher in deceased patients than surviving patients. Multivariate analysis showed that the level of sCD206 was related to an increased risk of 28-day, 3-month, and 6-month mortality (HR = 3.914, P < 0.001; HR = 3.895, P < 0.001; and HR = 4.063, P < 0.001, respectively). Patients with higher sCD206 levels had a worse prognosis than those with lower sCD206 levels. The best separation between the decedents and survivors was obtained by using the sCD206 level (AUROC: 0.830, 0.802, and 0.784, respectively) at 28 days, 3 months, and 6 months.

Conclusion

The macrophage-related marker serum sCD206 was associated with mortality in HBV-DeCi patients. High levels of serum sCD206 indicated a poor prognosis in these patients. Serum sCD206 has great predictive value for short-term and midterm mortality compared with the Child-Turcotte-Pugh (CTP) and model for end-stage liver disease (MELD) scores.

Clinical Implication of Plasma CD163 in Patients With Acute-on-Chronic Liver Failure

BACKGROUND

It was postulated that CD163 plasma level should be incorporated into existing predictive systems to improve prognostic performance in patients with acute-on-chronic liver failure (ACLF).

PATIENTS AND METHODS

Plasma CD163 was assessed in 24 consecutive patients with ACLF (17 male, 7 female; mean age 54.9 years; 50% with alcohol-related liver disease) and compered with the existing scoring tools to predict the availability of transplantation or survival without liver transplant (LT).

RESULTS

There were no differences in plasma CD163 levels between graft recipients and deceased patients on the waiting list or transplant survivors vs nonsurvivors. CD163 did not correlate with CLIF-ACLF, CLIF Consortium organ failure score (CLIF-OF), and ACLF grades (all P < .05). However, sequential organ failure assessment (SOFA), CLIF Consortium acute-on-chronic liver failure score (CLIF-C) ACLF, and CLIF-C OF scores correlated significantly with mortality (P < .01) in contrast to Child-Pugh scale and Model for End-Stage Liver Disease score (all P > .05). Transplanted survivors and deceased individuals differed robustly with respect to the SOFA and CLIF-SOFA scores and the CLIF-C OF, CLIF-C Grade, and CLIF-C ACLF scales (all P < .05). CLIF-C performed well in ACLF prognostication with an area under receiver operating characteristic curve (AUROC) 0.893 (95% CI, 0.766-1), surpassing in that respect CD163 with AUROC of 0.664 (95% CI, 0417-0.911).

CONCLUSIONS

Our preliminary results showed that the plasma CD163 level in patients with ACLF played only a minor role in predicting LT futility/benefit, with no impact on the narrow transplant window. Moreover, to optimize LT outcomes, newly developed CLIF-C scales showed superior predictive value.

Current Advances of Innate and Adaptive Immunity in Acute-on-Chronic Hepatitis B Liver Failure

Abstract

Acute-on-chronic hepatitis B liver failure (ACHBLF) is a term used to define the acute deterioration of liver function that occurs in patients with chronic hepatitis B virus infection or hepatitis B virus-related liver cirrhosis. The specific pathogenesis of ACHBLF is still not completely understood. Current research has shown that an intense systemic inflammation is involved in the development of acute-on-chronic liver failure (ACLF). Meanwhile, a subsequent immune paresis over the course of ACLF favors the development of infection and sepsis. Deregulation in both the innate and adaptive immunity is the notable feature of ACLF. The dysregulated immune responses play a crucial role in disease progression and potentially drive organ failure and mortality in ACHBLF. In this review, we highlight the current knowledge of innate and adaptive immune cells in ACHBLF.

Scavenger Receptors: Novel Roles in the Pathogenesis of Liver Inflammation and Cancer

The scavenger receptor superfamily represents a highly diverse collection of evolutionarily-conserved receptors which are known to play key roles in host homeostasis, the most prominent of which is the clearance of unwanted endogenous macromolecules, such as oxidized low-density lipoproteins, from the systemic circulation. Members of this family have also been well characterized in their binding and internalization of a vast range of exogenous antigens and, consequently, are generally considered to be pattern recognition receptors, thus contributing to innate immunity. Several studies have implicated scavenger receptors in the pathophysiology of several inflammatory diseases, such as Alzheimer's and atherosclerosis. Hepatic resident cellular populations express a diverse complement of scavenger receptors in keeping with the liver's homeostatic functions, but there is gathering interest in the contribution of these receptors to hepatic inflammation and its complications. Here, we review the expression of scavenger receptors in the liver, their functionality in liver homeostasis, and their role in inflammatory liver disease and cancer.

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.

Urinary L-FABP is a promising prognostic biomarker of ACLF and mortality in patients with decompensated cirrhosis

BACKGROUND & AIMS

Decompensated cirrhosis (DC) is associated with high mortality, mainly owing to the development of acute-on-chronic liver failure (ACLF). Identifying the patients with DC who are at high risk of mortality and ACLF development is an unmet clinical need. Liver fatty acid-binding protein (L-FABP) is expressed in several organs and correlates with liver and systemic inflammation. Herein, we aimed to assess the prognostic value of L-FABP in patients with DC.

METHODS

A prospective series of 444 patients hospitalized for DC was divided into 2 cohorts: study cohort (305 patients) and validation cohort (139 patients). L-FABP was measured in urine and plasma samples collected at admission. Neutrophil gelatinase-associated lipocalin (NGAL) was also measured in urine samples for comparison.

RESULTS

Urine but not plasma L-FABP correlated with 3-month survival on univariate analysis. On multivariate analysis, urine L-FABP and model for end-stage liver disease (MELD)-Na were the only independent predictors of prognosis. Urine L-FABP levels were higher in patients with ACLF than in those without and also predicted the development of ACLF, together with MELD-Na, during follow-up. In patients with ACLF, urine L-FABP correlated with liver, coagulation, and circulatory failure. Urine L-FABP levels were also increased in patients with acute kidney injury, particularly in those with acute tubular necrosis. The ability of urinary L-FABP to predict survival and ACLF development was confirmed in the validation cohort. Urine NGAL predicted outcome on univariate but not multivariate analysis.

CONCLUSIONS

Urinary L-FABP levels are independently associated with the 3-month clinical course in patients with DC, in terms of mortality and ACLF development. Urinary L-FABP is a promising prognostic biomarker for patients with DC.

LAY SUMMARY

Increased levels of liver fatty acid-binding protein (L-FABP), a protein related to lipid metabolism, have been associated with liver-related diseases. The present study analyzed urinary L-FABP levels in 2 independent groups of patients with decompensated cirrhosis and showed that higher urinary L-FABP levels correlated with increased mortality and risk of acute-on-chronic liver failure development. Therefore, urinary L-FABP levels could be useful as a new tool to predict complications in patients with decompensated cirrhosis.

Recognizing Dysfunctional Innate and Adaptive Immune Responses Contributing to Liver Damage in Patients With Cirrhosis

The human host immune system wards off attacks by enemies such as viruses by mounting an inflammatory response which may sometimes injure self-tissues. Dysfunctional immune/inflammatory response by the host may affect the functioning of vital organs. The largest number of innate immune cells in the body resides in the liver. On encountering a new insult or injury to the liver, the innate immune system responds quickly to counter it. Acute liver insults may trigger acute liver failure or acute on chronic liver failure; these disorders are associated with a predominant innate immune response. Activation of the reticuloendothelial system (part of the innate immune response) predicts short-term and medium-term survival in patients with acute on chronic liver failure. Liver diseases associated with an aberrant adaptive immune response like autoimmune hepatitis respond well to treatment with steroids and other immunosuppressants, while those associated with innate immune dysfunction like acute on chronic liver failure do not respond well to steroids; recent reports suggest that the latter disorders may respond to therapeutic plasma exchange. How does the immune system in a patient with liver disease respond to SARS CoV2 infection? While commonly used tests in routine clinical practice provide clues to activation of different arms of immune response in patients with cirrhosis, specialized tests may help characterize this further. This review discusses the tests which reflect aberrant immune responses and treatment of patients with cirrhosis.

Reticuloendothelial activation correlates with disease severity and predicts mortality in severe alcoholic hepatitis

BACKGROUND

Overactivation of reticuloendothelial cells lining liver sinusoids - Kupffer cells (macrophages) and sinusoidal endothelial cells - may narrow the sinusoidal lumen, impair perfusion in liver microcirculation and contribute to disease severity in alcoholic hepatitis.

AIM

The aim of the article was to assess reticuloendothelial activation in patients with severe alcoholic hepatitis (SAH).

METHODS

In SAH patients, we prospectively studied baseline reticuloendothelial activation markers [serum ferritin, sCD163 and plasma von Willebrand factor (VWF) antigen] and Macrophage Activation Syndrome (MAS) criteria, correlated them with disease severity scores [model for end-stage liver disease (MELD) and Sequential Organ Failure Assessment (SOFA) scores] and analyzed their ability to predict survival over a 90-day follow-up period.

RESULTS

A total of 50 SAH patients [45 (37-49) years, median (interquartile range), 49 males, discriminant function, 76.2 (54.5-106.6); MELD score, 30 (26.2-36)] were studied. 41 SAH patients (82%) had ferritin >500 ng/mL, and all (100%) had markedly raised sCD163 and VWF levels. The median sCD163 level was 10-fold higher than healthy controls and the median VWF level was 5-fold above the upper limit of normal. In total, 37 SAH patients (74%) met MAS criteria. Reticuloendothelial activation markers correlated with MELD and SOFA scores (P < 0.05). VWF was an independent marker to predict mortality in SAH [adjusted hazard ratio, 1.002 (1.000-1.004)].

CONCLUSIONS

The reticuloendothelial system was markedly activated and correlated with disease severity scores in SAH patients.VWF predicted short-term mortality independent of MELD and sCD163. Further larger multicentric studies are needed to validate these findings.

Biomarkers of extracellular matrix formation are associated with acute-on-chronic liver failure

Background & Aims

Acute-on-chronic liver failure (ACLF) is characterised by organ failure(s), high short-term mortality, and, pathophysiologically, deranged inflammatory responses. The extracellular matrix (ECM) is critically involved in regulating the inflammatory response. This study aimed to determine alterations in biomarkers of ECM turnover in ACLF and their association with inflammation, organ failures, and mortality.

Methods

We studied 283 patients with cirrhosis admitted for acute decompensation (AD) with or without ACLF, 64 patients with stable cirrhosis, and 30 healthy controls. A validation cohort (25 ACLF, 9 healthy controls) was included. Plasma PRO-C3, PRO-C4, PRO-C5, PRO-C6, and PRO-C8 (i.e. collagen type III–VI and VIII formation) and C4M and C6M (i.e. collagen type IV and VI degradation) were measured. Immunohistochemistry of PRO-C6 was performed on liver biopsies (AD [n = 7], ACLF [n = 5]). A competing-risk regression analysis was performed to explore the prognostic value of biomarkers of ECM turnover with 28- and 90-day mortality.

Results

PRO-C3 and PRO-C6 were increased in ACLF compared to AD (p = 0.089 and p <0.001, respectively), whereas collagen degradation markers C4M and C6M were similar. Both PRO-C3 and PRO-C6 were strongly associated with liver function and inflammatory markers. Only PRO-C6 was associated with extrahepatic organ failures and 28- and 90-day mortality (hazard ratio [HR; on log-scale] 6.168, 95% CI 2.366–16.080, p <0.001, and 3.495, 95% CI 1.509–8.093, p = 0.003, respectively). These findings were consistent in the validation cohort. High PRO-C6 expression was observed in liver biopsies of patients with ACLF.

Conclusions

This study shows, for the first time, evidence of severe net interstitial collagen deposition in ACLF and makes the novel observation of the association between PRO-C6 and (extrahepatic) organ failures and mortality. Further studies are needed to define the pathogenic significance of these observations.

Lay summary

This study describes a disrupted turnover of collagen type III and VI in Acute-on-chronic liver failure (ACLF). Plasma biomarkers of these collagens (PRO-C3 and PRO-C6) are associated with the severity of liver dysfunction and inflammation. PRO-C6, also known as the hormone endotrophin, has also been found to be associated with multi-organ failure and prognosis in acute decompensation and ACLF.

•

Collagen type III and VI formation is increased in ACLF compared to AD.

•

PRO-C3 and PRO-C6 correlate with the severity of liver dysfunction and inflammation in AD and ACLF.

•

High PRO-C6 levels were found to be indicative for the presence of multi-organ failure and worse survival.

The microbiota in cirrhosis and its role in hepatic decompensation

Cirrhosis - the common end-stage of chronic liver disease - is associated with a cascade of events, of which intestinal bacterial overgrowth and dysbiosis are central. Bacterial toxins entering the portal or systemic circulation can directly cause hepatocyte death, while dysbiosis also affects gut barrier function and increases bacterial translocation, leading to infections, systemic inflammation and vasodilation, which contribute to acute decompensation and organ failure. Acute decompensation and its severe forms, pre-acute-on-chronic liver failure (ACLF) and ACLF, are characterised by sudden organ dysfunction (and failure) and high short-term mortality. Patients with pre-ACLF and ACLF present with high-grade systemic inflammation, usually precipitated by proven bacterial infection and/or severe alcoholic hepatitis. However, no precipitant is identified in 30% of these patients, in whom bacterial translocation from the gut microbiota is assumed to be responsible for systemic inflammation and decompensation. Different microbiota profiles may influence the rate of decompensation and thereby outcome in these patients. Thus, targeting the microbiota is a promising strategy for the prevention and treatment of acute decompensation, pre-ACLF and ACLF. Approaches include the use of antibiotics such as rifaximin, faecal microbial transplantation and enterosorbents (e.g. Yaq-001), which bind microbial factors without exerting a direct effect on bacterial growth kinetics. This review focuses on the role of microbiota in decompensation and strategies targeting microbiota to prevent acute decompensation.

Divergences in Macrophage Activation Markers Soluble CD163 and Mannose Receptor in Patients With Non-cirrhotic and Cirrhotic Portal Hypertension

Introduction

Macrophages are involved in development and progression of chronic liver disease and portal hypertension. The macrophage activation markers soluble (s)CD163 and soluble mannose receptor (sMR), are associated with portal hypertension in patient with liver cirrhosis but never investigated in patients with non-cirrhotic portal hypertension. We hypothesized higher levels in cirrhotic patients with portal hypertension than patients with non-cirrhotic portal hypertension. We investigated sCD163 and sMR levels in patients with portal hypertension due to idiopathic portal hypertension (IPH) and portal vein thrombosis (PVT) in patients with and without cirrhosis.

Methods

We studied plasma sCD163 and sMR levels in patients with IPH (n = 26), non-cirrhotic PVT (n = 20), patients with cirrhosis without PVT (n = 31) and with PVT (n = 17), and healthy controls (n = 15).

Results

Median sCD163 concentration was 1.51 (95% CI: 1.24-1.83) mg/L in healthy controls, 1.96 (95% CI: 1.49-2.56) in patients with non-cirrhotic PVT and 2.16 (95% CI: 1.75-2.66) in patients with IPH. There was no difference between non-cirrhotic PVT patients and healthy controls, whereas IPH patients had significantly higher levels than controls (P < 0.05). The median sCD163 was significantly higher in the cirrhotic groups compared to the other groups, with a median sCD163 of 6.31 (95% CI: 5.16-7.73) in cirrhotics without PVT and 5.19 (95% CI: 4.18-6.46) with PVT (P < 0.01, all). Similar differences were observed for sMR.

Conclusion

Soluble CD163 and sMR levels are elevated in patients with IPH and patients with cirrhosis, but normal in patients with non-cirrhotic PVT. This suggests that hepatic macrophage activation is more driven by the underlying liver disease with cirrhosis than portal hypertension.

Macrophages in Chronic Liver Failure: Diversity, Plasticity and Therapeutic Targeting

Chronic liver injury results in immune-driven progressive fibrosis, with risk of cirrhosis development and impact on morbidity and mortality. Persistent liver cell damage and death causes immune cell activation and inflammation. Patients with advanced cirrhosis additionally experience pathological bacterial translocation, exposure to microbial products and chronic engagement of the immune system. Bacterial infections have a high incidence in cirrhosis, with spontaneous bacterial peritonitis being the most common, while the subsequent systemic inflammation, organ failure and immune dysregulation increase the mortality risk. Tissue-resident and recruited macrophages play a central part in the development of inflammation and fibrosis progression. In the liver, adipose tissue, peritoneum and intestines, diverse macrophage populations exhibit great phenotypic and functional plasticity determined by their ontogeny, epigenetic programming and local microenvironment. These changes can, at different times, promote or ameliorate disease states and therefore represent potential targets for macrophage-directed therapies. In this review, we discuss the evidence for macrophage phenotypic and functional alterations in tissue compartments during the development and progression of chronic liver failure in different aetiologies and highlight the potential of macrophage modulation as a therapeutic strategy for liver disease.

Metabolomic profiles of breath odor compounds for prognostic prediction in patients with acute-on-chronic liver failure: A pilot study

AIM

The aim of this study was to use a metabonomics approach to identify potential biomarkers of exhaled breath condensate (EBC) for predicting the prognosis of acute-on-chronic liver failure (ACLF).

METHODS

Using liquid chromatography mass spectrometry, EBC metabolites of ACLF patients surviving without liver transplantation (n = 57) and those with worse outcomes (n = 45), and controls (n = 15) were profiled from a specialized liver disease center in Beijing. The metabolites were used to identify candidate biomarkers, and the predicted performance of potential biomarkers was tested.

RESULTS

Forty-one metabolites, involving glycerophospholipid metabolism, sphingolipid metabolism, arachidonic acid metabolism, and amino acid metabolism, as candidate biomarkers for discriminating the different outcomes of ACLF were selected. A prognostic model was constructed by a panel of four metabolites including phosphatidylinositol [20:4(5Z,8Z,11Z,14Z)/13:0], phosphatidyl ethanolamine (12:0/22:0), L-metanephrine and ethylbenzene, which could predict the worse prognosis in ACLF patients with sensitivity (84.4%) and specificity (89.5%) (area under the receiver operating characteristic curve [AUC] = 0.859, 95% confidence interval [CI] = 0.787-0.931). Compared with Model for End-Stage Liver Disease (MELD) score (AUC = 0.639, 95% CI = 0.526-0.753) and MELD-sodium (MELD-Na) score (AUC = 0.692, 95% CI = 0.582-0.803), EBC-associated metabolite signature model could better predict worse outcomes in patients with ACLF (p < 0.05). Using the MELD-Na score and EBC metabolite signatures, a decision tree model was built for predicting the prognosis of ACLF identified on logistic regression analyses (AUC = 0.906, 95% CI = 0.846-0.965).

CONCLUSION

EBC metabolic signatures show promise as potential biomarkers for predicting worse prognosis of ACLF.

Circulating Macrophage Activation Markers Predict Transplant-Free Survival in Patients With Primary Sclerosing Cholangitis

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a progressive liver disease characterized by bile duct inflammation and fibrosis. The role of macrophages in PSC development and progression is less studied. Macrophage activation markers soluble (s)CD163 and mannose receptor (sMR) are associated with disease severity and outcome in other liver diseases, but not previously investigated in PSC. We evaluated sCD163 and sMR regarding disease severity and prognosis in patients with PSC.

METHODS

We investigated 2 independent PSC cohorts from Oslo (n = 138) and Helsinki (n = 159) and analyzed blood sCD163 and sMR levels. The Mayo score, Enhanced Liver Fibrosis Test, and Amsterdam-Oxford model were assessed for comparison.

RESULTS

Median (interquartile range) sCD163 was 3.32 (2.27-5.60) and 1.96 (1.47-2.70) mg/L in the Oslo and Helsinki cohorts, respectively, reflecting differences in disease severity between cohorts. Median sMR was similar in both cohorts, 0.28 (0.22-0.44) and 0.28 mg/L (0.20-0.36), respectively. In both cohorts, sCD163 and sMR levels raised with increasing disease severity (liver enzymes, Mayo score, and enhanced liver fibrosis test). Patients with high baseline levels of sCD163 had shorter transplant-free survival than patients with low baseline levels. Furthermore, sCD163 was associated with transplant-free survival in univariate cox-regression analyses. Both sCD163 and sMR performed better in the Oslo cohort of more severely diseased patients than those in the Helsinki cohort of more mildly diseased patients.

DISCUSSION

Macrophage activation markers are elevated according to disease severity suggesting an important role of macrophages in PSC. Furthermore, sCD163 was identified as a prognostic marker and predictor of transplant-free survival in PSC (see Visual Abstract, Supplementary Digital Content 4, http://links.lww.com/CTG/A516).

Profiling circulating microRNAs in patients with cirrhosis and acute-on-chronic liver failure

Background & Aims

MicroRNAs (miRNAs) circulate in several body fluids and can be useful biomarkers. The aim of this study was to identify blood-circulating miRNAs associated with cirrhosis progression and acute-on-chronic liver failure (ACLF).

Methods

Using high-throughput screening of 754 miRNAs, serum samples from 45 patients with compensated cirrhosis, decompensated cirrhosis, or ACLF were compared with those from healthy individuals (n = 15). miRNA levels were correlated with clinical parameters, organ failure, and disease progression and outcome. Dysregulated miRNAs were evaluated in portal and hepatic vein samples (n = 33), liver tissues (n = 17), and peripheral blood mononuclear cells (PBMCs) (n = 16).

Results

miRNA screening analysis revealed that circulating miRNAs are dysregulated in cirrhosis progression, with 51 miRNAs being differentially expressed among all groups of patients. Unsupervised clustering and principal component analysis indicated that the main differences in miRNA expression occurred at decompensation, showing similar levels in patients with decompensated cirrhosis and those with ACLF. Of 43 selected miRNAs examined for differences among groups, 10 were differentially expressed according to disease progression. Moreover, 20 circulating miRNAs were correlated with model for end-stage liver disease and Child-Pugh scores. Notably, 11 dysregulated miRNAs were associated with kidney or liver failure, encephalopathy, bacterial infection, and poor outcomes. The most severely dysregulated miRNAs (i.e. miR-146a-5p, miR-26a-5p, and miR-191-5p) were further evaluated in portal and hepatic vein blood and liver tissue, but showed no differences. However, PBMCs from patients with cirrhosis showed significant downregulation of miR-26 and miR-146a, suggesting a extrahepatic origin of some circulating miRNAs.

Conclusions

This study is a repository of circulating miRNA data following cirrhosis progression and ACLF. Circulating miRNAs were profoundly dysregulated during the progression of chronic liver disease, were associated with failure of several organs and could have prognostic utility.

Lay summary

Circulating miRNAs are small molecules in the blood that can be used to identify or predict a clinical condition. Our study aimed to identify miRNAs for use as biomarkers in patients with cirrhosis or acute-on-chronic liver failure. Several miRNAs were found to be dysregulated during the progression of disease, and some were also related to organ failure and disease-related outcomes.

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Circulating miRNAs are dysregulated with cirrhosis progression and in patients with ACLF.

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Patient decompensation is associated with important changes in the levels of circulating miRNAs.

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A total of 11 circulating miRNAs were identified as associated with organ failure and 7 with poor outcome.

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The miRNAs most dysregulated during cirrhosis progression were miR-146a, miR-26a, and miR-191.

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miR-146a was dysregulated in PBMCs of patients with decompensated cirrhosis vs. compensated cirrhosis.

Macrophage Activation Markers, Soluble CD163 and Mannose Receptor, in Liver Fibrosis

Macrophages are essential components of the human host immune system, which upon activation facilitates a broad pallet of immunomodulatory events including release of pro- or anti-inflammatory cytokines and chemokines, restoration of immune homeostasis and/or wound healing. Moreover, some macrophage phenotypes are crucially involved in fibrogenesis through stimulation of myofibroblasts, while others promote fibrolysis. During the last decades, the role of resident liver macrophages viz. Kupffer cells and recruited monocytes/macrophages in acute and chronic liver diseases has gained interest and been extensively investigated. Specifically, the scavenger receptors CD163 and mannose receptor (CD206), expressed by macrophages, are of utmost interest since activation by various stimuli induce their shedding to the circulation. Thus, quantifying concentrations of these soluble biomarkers may be of promising clinical relevance in estimating the severity of inflammation and fibrosis and to predict outcomes such as survival. Here, we review the existing literature on soluble CD163 and soluble mannose receptor in liver diseases with a particular focus on their relationship to hepatic fibrosis in metabolic associated fatty liver disease, as well as in chronic hepatitis B and C.

Improved prediction of mortality by combinations of inflammatory markers and standard clinical scores in patients with acute-on-chronic liver failure and acute decompensation

BACKGROUND AND AIM

Acute-on-chronic liver failure (ACLF) is a sinister prognosis, and there is a need for accurate biomarkers and scoring systems to better characterize ACLF patients and predict prognosis. Systemic inflammation and renal failure are hallmarks in ACLF disease development and progression. We hypothesized that the combination of specific inflammatory markers in combination with clinical scores are better predictors of survival than the originally developed CLIF-C acute decompensation (AD) and CLIF-C ACLF scores.

METHODS

We reevaluated all previously measured inflammatory markers in 522 patients from the CANONIC study, 342 without and 180 with ACLF. We used the Harrell's C-index to determine the best marker alone or in combination with the original scores and calculated new scores for prediction of mortality in the original CANONIC cohort.

RESULTS

The best markers to predict 90-day mortality in patients without ACLF were the plasma macrophage activation markers soluble (s)CD163 and mannose receptor (sMR). Urinary neutrophil gelatinase associated lipocalin (UNGAL) and sCD163 were predictors for 28-day mortality in patients with ACLF. The newly developed CLIF-C AD + sMR score in patients without ACLF improved 90-day mortality prediction compared with the original CLIF-C AD score (C-index 0.82 [0.78-0.86] vs 0.74 [0.70-0.78, P = 0.004]). Further, the new CLIF-C ACLF + sCD163 + UNGAL improved the original CLIF-C ACLF score for 28-day mortality (0.85 [0.79-0.91] vs 0.75 [0.70-0.80], P = 0.039).

CONCLUSIONS

The capability of these inflammatory markers to improve the original prognostic scores in cirrhosis patients without and with ACLF points to a key role of macrophage activation and inflammation in the development and progression of AD and ACLF.

Macrophage Markers Do Not Add to the Prediction of Liver Fibrosis by Transient Elastography in Patients With Metabolic Associated Fatty Liver Disease

Background and Aims: Non-invasive fibrosis staging is essential in metabolic associated fatty liver disease (MAFLD). Transient elastography (TE) is a well-established method for liver fibrosis assessment. We have previously shown that the macrophage marker sCD163 is an independent predictor for fibrosis in MAFLD. In the present study we tested whether the combination of macrophage markers and TE improves fibrosis prediction. Methods: We measured macrophage markers soluble (s)CD163 and mannose receptor (sMR) in two independent cohorts from Italy (n = 141) and Sweden (n = 70) with biopsy-proven MAFLD and available TE. Results: In the Italian cohort, TE and sCD163 showed similar moderate associations with liver fibrosis (rho = 0.56, p < 0.001 and rho = 0.42, p < 0.001, respectively). TE had an area under the Receiver Operating Characteristics curve (AUROC, with 95% CI) for fibrosis; F ≥ 2 = 0.79 (0.72-0.86), F ≥ 3 = 0.81 (0.73-0.89), F4 = 0.95 (0.90-1.0). sCD163 also predicted fibrosis well [F ≥ 2 = 0.71 (0.63-0.80), F ≥ 3 = 0.82 (0.74-0.90), F4 = 0.89 (0.76-1.0)]. However, combining sCD163 and TE did not improve the AUROCs significantly [F ≥ 2 = 0.79 (0.72-0.86), F ≥ 3 = 0.85 (0.78-0.92), F4 = 0.97 (0.93-1.0)]. In the Swedish cohort, TE showed a closer association with fibrosis (rho = 0.73, p < 0.001) than sCD163 (rho = 0.43, p < 0.001) and sMR (rho = 0.46, p < 0.001). TE predicted fibrosis well [F ≥ 2 = 0.88 (0.80-0.97), F ≥ 3 = 0.90 (0.83-0.97), F4 = 0.87 (0.78-0.96)], whereas sCD163 did not (best AUROC 0.75). sMR showed a better prediction [F ≥ 2 = 0.68 (0.56-0.81), F ≥ 3 = 0.82 (0.71-0.92), F4 = 0.79 (0.66-0.93)], but the addition of sMR did not further improve the prediction of fibrosis by TE. Conclusion: In these cohorts of MAFLD patients, TE was superior to macrophage markers for fibrosis prediction and in contrast to our hypothesis the addition of these markers to TE did not improve its predictive capability.

Balance between macrophage migration inhibitory factor and sCD74 predicts outcome in patients with acute decompensation of cirrhosis

Background & Aims

Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine and an important regulator of innate immune responses. We hypothesised that serum concentrations of MIF are associated with disease severity and outcome in patients with decompensated cirrhosis and acute-on-chronic liver failure (ACLF).

Methods

Circulating concentrations of MIF and its soluble receptor CD74 (sCD74) were determined in sera from 292 patients with acute decompensation of cirrhosis defined as new onset or worsening of ascites requiring hospitalisation. Of those, 78 (27%) had ACLF. Short-term mortality was assessed 90 days after inclusion.

Results

Although serum concentrations of MIF and sCD74 did not correlate with liver function parameters or ACLF, higher MIF (optimum cut-off >2.3 ng/ml) and lower concentrations of sCD74 (optimum cut-off <66.5 ng/ml) both indicated poorer 90-day transplant-free survival in univariate analyses (unadjusted hazard ratio [HR] 2.01 [1.26-3.22]; p = 0.004 for MIF; HR 0.59 [0.38-0.92]; p = 0.02 for sCD74) and after adjustment in multivariable models. Higher MIF concentrations correlated with surrogates of systemic inflammation (white blood cells, p = 0.005; C-reactive protein, p = 0.05) and were independent of genetic MIF promoter polymorphisms. Assessment of MIF plasma concentrations in portal venous blood and matched blood samples from the right atrium in a second cohort of patients undergoing transjugular intrahepatic portosystemic shunt insertion revealed a transhepatic MIF gradient with higher concentrations in the right atrial blood.

Conclusions

Serum concentrations of MIF and its soluble receptor CD74 predict 90-day transplant-free survival in patients with acute decompensation of cirrhosis. This effect was independent of liver function and genetic predispositions, but rather reflected systemic inflammation. Therefore, MIF and sCD74 represent promising prognostic markers beyond classical scoring systems in patients at risk of ACLF.

Lay summary

Inflammatory processes contribute to the increased risk of death in patients with cirrhosis and ascites. We show that patients with high serum levels of the inflammatory cytokine macrophage migration inhibitory factor (MIF) alongside low levels of its binding receptor sCD74 in blood indicate an increased mortality risk in patients with ascites. The cirrhotic liver is a relevant source of elevated circulating MIF levels.

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.