Evidence of neutrophil functional defect despite inflammation in stable cirrhosis

Alcoholic cirrhosis-associated immune dysfunction: What does it imply for us?

Alcoholic cirrhosis is a leading cause of chronic advanced liver disease. With the gradual eradication of viral hepatitis and the rising levels of alcohol consumption, the incidence of alcoholic cirrhosis is expected to increase steadily. Alcohol is primarily metabolized in the gastrointestinal tract, producing toxic metabolites that enter the portal vein circulation and are subsequently transported to the liver. Excessive alcohol intake activates the microsomal ethanol oxidation system and disrupts the intestinal microbiota-driven microenvironment dictated by intestinal microbiota, and increase intestinal permeability, all of which trigger severe systemic inflammatory responses and impaired immune function. This phenomenon, known as cirrhosis-associated immune dysfunction (CAID), is closely linked to the severity of cirrhosis and can significantly influence disease progression, potentially leading to multi-organ failure. This narrative review sheds light on the relationship between alcoholic cirrhosis and CAID, focusing on tailored interventions to modify immune response and modulate gut microbiota composition in hopes of mitigating the development and deterioration of alcoholic cirrhosis.

Invasive fungal infections in patients with liver disease: immunological and clinical considerations for the intensive care unit

Patients with liver disease in the intensive care unit (ICU) face a unique susceptibility to infection due to the complex immune dysfunction resulting from hepatic failure. Bacterial infections are commonly present in these patients upon arrival to the hospital, often being the primary reason for ICU admission. In contrast, invasive fungal infections (IFIs) afflict a smaller percentage of patients and are usually discovered in the course of the ICU stay. IFI diagnosis in the ICU, particularly in patients with liver disease, is often delayed or overlooked, contributing to the extremely high ICU mortality associated with IFI in these patients despite the availability of effective (and largely safe) antifungal therapy. Thus, to improve outcomes, it is crucial for intensive care clinicians to be vigilant for IFIs in patients with liver disease. This review aims to contribute to the intensive care literature in this regard. We begin with an overview of normal antifungal immunity followed by a summary of how it may become compromised in the setting of hepatic dysfunction. Next, a general discussion of IFIs in liver disease is presented and then the three most relevant fungal pathogens, namely Candida, Aspergillus, and Cryptococcus, are individually examined. This review concludes by highlighting key knowledge and practice gaps that require attention by the scientific and clinical communities in the coming years.

Perioperative infections as a prognostic risk factor in hepatocellular carcinoma and cholangiocellular carcinoma: a comparative analysis

BACKGROUND

Hepatocellular Carcinoma (HCC) and cholangiocellular adenocarcinoma (CCA) are the most common primary liver tumors representing a major global health burden. In early disease stages, tumor resection may provide long-term survival in selected patients. However, morbidity and mortality rates are still relatively high after extended liver surgery with perioperative bacterial infections representing major complications. In this study, we evaluate the impact of perioperative infection on the postoperative overall survival (OS) of patients undergoing resection of HCC or CCA.

MATERIAL AND METHODS

Two hundred two patients that received liver surgery for HCC (139) or CCA (63) at our tertiary referral center were included between 2008 and 2020. Infection prior or after surgery was assessed using patient documentation and correlated to patients´ survival rates and other clinical characteristics.

RESULTS

Patients with perioperative infection displayed a significantly impaired OS compared to patients without a documented infection (419 (95% CI: 262-576) days vs. 959 (95% CI: 637-1281) days; log rank X2(1) = 10.28; p < 0.001). Subgroup analysis revealed that this effect was only observed among HCC patients, while the outcome of CCA patients was independent of pre- or postoperative infections. Moreover, non-anatomical resection of liver tumors was beneficial in patients with HCC (1541 (95%CI: 1110-1972) vs. 749 (95%CI: 0-1528) days; log rank X2(1) = 5.387; p = 0.02) but not CCA.

CONCLUSION

Perioperative infection is an important prognostic factor after surgery for HCC but not CCA.

Immunology and treatments of fatty liver disease

Alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) are two major chronic liver diseases worldwide. The triggers for fatty liver can be derived from external sources such as adipose tissue, the gut, personal diet, and genetics, or internal sources, including immune cell responses, lipotoxicity, hepatocyte death, mitochondrial dysfunction, and extracellular vesicles. However, their pathogenesis varies to some extent. This review summarizes various immune mechanisms and therapeutic targets associated with these two types of fatty liver disease. It describes the gut-liver axis and adipose tissue-liver crosstalk, as well as the roles of different immune cells (both innate and adaptive immune cells) in fatty liver disease. Additionally, mitochondrial dysfunction, extracellular vesicles, microRNAs (miRNAs), and gastrointestinal hormones are also related to the pathogenesis of fatty liver. Understanding the pathogenesis of fatty liver and corresponding therapeutic strategies provides a new perspective for developing novel treatments for fatty liver disease.

Liver damage and immune responses

Chronic liver disease (CLD) has massive systemic repercussions including major impacts on the body's immune system. Abnormalities in phenotype, function and numbers of various immune cell subsets have been established by a large number of clinical and pre-clinical studies. The loss of essential immune functions renders CLD-patients exceptionally susceptible to bacterial and viral infections and also impairs the efficacy of vaccination. Consequently, infections represent a major clinical issue causing significant morbidity and mortality in these patients. Mechanistically, the immune dysfunction associated with CLD results from the increased translocation of bacteria and bacterial cues from the intestine. These trigger a signaling axis around the cytokines IFN I and IL-10 in hepatic myeloid cells, which aside from impairing the function of the myeloid cells themselves, also has notable negative impacts on the functionality of other immune cells. T cells in CLD-patients and -models are especially affected by this signaling axis and display a variety of quantitative and qualitative defects. Due to the high clinical relevance, understanding the mechanisms underlaying CED-associated immune dysfunction is of critical importance to discover and develop new therapeutic targets.

Bacterial Meningitis Associated With Spontaneous Bacterial Peritonitis Caused by Escherichia coli in a Patient With Alcoholic Liver Cirrhosis

Spontaneous Escherichia coli meningitis in adults is uncommon and many cases coexist with urinary tract infections. We herein report a 66-year-old man with E. coli meningitis complicated by spontaneous bacterial peritonitis. A patient with liver cirrhosis admitted with disturbed consciousness was diagnosed with spontaneous bacterial peritonitis due to E. coli and administered ceftriaxone. His level of consciousness improved, but it worsened on day 4. A cerebrospinal fluid examination revealed E. coli meningitis. On day 10, the patient died due to hepatorenal syndrome. Thus, spontaneous E. coli meningitis can coexist with spontaneous bacterial peritonitis, which may lead to a delayed diagnosis.

Liver Cirrhosis: The Immunocompromised State

Systemic inflammation and immunodeficiency are important components of cirrhosis-associated immune dysfunction (CAID), the severity of which is dynamic, progressive, and associated with the greater deterioration of liver function. Two inflammation phenotypes have been described: low-grade and high-grade systemic inflammation. Both of these phenotypes are related to liver cirrhosis function; thus, high-grade inflammation is correlated with the severity of hepatic insufficiency, bacterial translocation, and organic insufficiency, with which the risk of infections increases and the prognosis worsens. Bacterial translocation (BT) plays a relevant role in persistent systemic inflammation in patients with cirrhosis, and the prophylactic employment of antibiotics is useful for reducing events of infection and mortality.

Neutrophil Extracellular Trap Scores Predict 90-Day Mortality in Hepatitis B-Related Acute-on-Chronic Liver Failure

Hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) is associated with pronounced systemic inflammation, and neutrophil extracellular traps (NETs) are key components of this response. The primary objective of this study was to establish an NET-related scoring system for patients with HBV-ACLF. A prospective training cohort of 81 patients from the Beijing Ditan Hospital was included. The concentrations of NET markers (cell-free DNA, myeloperoxidase DNA [MPO-DNA], and citrullinated histone H3) in peripheral blood were quantified. Random survival forest, LASSO regression, and multivariate Cox regression analyses were used to identify prognostic factors associated with 90-day mortality in ACLF patients and develop a nomogram for visualization, which was followed by evaluation in a validation cohort (n = 40). NET-related marker levels were significantly higher in the non-survival group than in the survival group (p < 0.05). The NET score was constructed by combining MPO-DNA, neutrophil-to-lymphocyte ratio, and age data. The score's diagnostic effectiveness, assessed by the area under the curve, yielded values of 0.83 and 0.77 in the training and validation sets, respectively, markedly surpassing those of other established models (p < 0.05). In both groups, the 90-day mortality rates were 88.8% and 75.0%, respectively, for patients categorized as high risk and 18.0% and 12.5%, respectively, for those classified as low risk.

The Impact of Liver Failure on the Immune System

Liver failure profoundly affects the immune system, leading to dysregulation of innate and adaptive immune response. This review explores the intricate relationship between liver function and immune homeostasis. The role of the liver as a central hub in immune response initiation is elucidated, emphasizing its involvement in hepatic inflammation induction and subsequent systemic inflammation. Cytokines, chemokines, growth factors, and lipid mediators orchestrate these immune processes, serving as both prognostic biomarkers and potential therapeutic targets in liver failure-associated immune dysregulation, which might result from acute-on-chronic liver failure (ACLF) and cirrhosis. Furthermore, the review delves into the mechanisms underlying immunosuppression in liver failure, encompassing alterations in innate immune cell functions such as neutrophils, macrophages, and natural killer cells (NK cells), as well as perturbations in adaptive immune responses mediated by B and T cells. Conclusion: Understanding the immunological consequences of liver failure is crucial for developing targeted therapeutic interventions and improving patient outcomes in liver disease management.

Wilson's Disease-Crossroads of Genetics, Inflammation and Immunity/Autoimmunity: Clinical and Molecular Issues

Wilson's disease (WD) is a rare, autosomal recessive disorder of copper metabolism caused by pathogenic mutations in the ATP7B gene. Cellular copper overload is associated with impaired iron metabolism. Oxidative stress, cuproptosis, and ferroptosis are involved in cell death in WD. The clinical picture of WD is variable. Hepatic/neuropsychiatric/other symptoms may manifest in childhood/adulthood and even old age. It has been shown that phenotypic variability may be determined by the type of ATP7B genetic variants as well as the influence of various genetic/epigenetic, environmental, and lifestyle modifiers. In 1976, immunological abnormalities were first described in patients with WD. These included an increase in IgG and IgM levels and a decrease in the percentage of T lymphocytes, as well as a weakening of their bactericidal effect. Over the following years, it was shown that there is a bidirectional relationship between copper and inflammation. Changes in serum cytokine concentrations and the relationship between cytokine gene variants and the clinical course of the disease have been described in WD patients, as well as in animal models of this disease. Data have also been published on the occurrence of antinuclear antibodies (ANAs), antineutrophil cytoplasmic antibodies (ANCAs), anti-muscle-specific tyrosine kinase antibodies, and anti-acetylcholine receptor antibodies, as well as various autoimmune diseases, including systemic lupus erythematosus (SLE), myasthenic syndrome, ulcerative colitis, multiple sclerosis (MS), polyarthritis, and psoriasis after treatment with d-penicillamine (DPA). The occurrence of autoantibodies was also described, the presence of which was not related to the type of treatment or the form of the disease (hepatic vs. neuropsychiatric). The mechanisms responsible for the occurrence of autoantibodies in patients with WD are not known. It has also not been clarified whether they have clinical significance. In some patients, WD was differentiated or coexisted with an autoimmune disease, including autoimmune hepatitis or multiple sclerosis. Various molecular mechanisms may be responsible for immunological abnormalities and/or the inflammatory processes in WD. Their better understanding may be important for explaining the reasons for the diversity of symptoms and the varied course and response to therapy, as well as for the development of new treatment regimens for WD.

Immune Response and Risk of Decompensation following SARS-CoV-2 Infection in Outpatients with Advanced Chronic Liver Disease

Advanced chronic liver disease (ACLD) is associated with a wide spectrum of immune dysfunction. The clinical impact of SARS-CoV-2 on the development of decompensation and immune response in unvaccinated outpatients has not as yet been clearly defined. This study aimed to evaluate the clinical and immunological impact of SARS-CoV-2 on outpatients with ACLD. This is an observational case-control study, in which ACLD outpatients were included prospectively and consecutively and classified into two groups: SARS-CoV-2 infected and non-infected. Patients' baseline characteristics and infection data were collected and analyzed. Immunoglobulin G (IgG) levels against Spike 1 were evaluated. The primary endpoint was risk of liver decompensation during follow-up, assessed after propensity score matching and adjusted by Cox regression. Between October 2020 and July 2021, ACLD outpatients (n = 580) were identified, and 174 patients with clinical follow-up were included. SARS-CoV-2 infection incidence was 7.6% (n = 44). Risk of liver decompensation was significantly higher after infection (HR = 2.43 [1.01-5.86], p = 0.048) vs. non-infection. The time of IgG evaluation was similar in all patients (n = 74); IgG concentrations were significantly higher in compensated vs. decompensated patients (1.02 ± 0.35 pg/mL vs. 0.34 ± 0.16 pg/mL, p < 0.0001) and correlated with hemoglobin levels. The dysregulation of the innate immune response in patients with decompensated liver disease increased the risk of further decompensation following SARS-CoV-2, mainly due to a worsening of ascites.

Evaluation of mucosal-associated invariant T-cells as a potential biomarker to predict infection risk in liver cirrhosis

BACKGROUND AND AIMS

Infection is a serious complication in patients with cirrhosis. Mucosal-associated invariant T (MAIT) cells are involved in the immune defense against infections and known to be impaired in several chronic conditions, including cirrhosis. Here, we evaluated if MAIT cell levels in peripheral blood are associated with risk of bacterial infections in patients with cirrhosis.

METHODS

Patients with cirrhosis seen at the Karolinska University Hospital, Stockholm, Sweden, between 2016 and 2019 were included. Levels of MAIT cells in peripheral blood were determined using flow cytometry. Baseline and follow-up data after at least two years of follow-up were collected by chart review for the primary outcome (bacterial infection) and secondary outcomes (decompensation and death). Competing risk and Cox regression were performed.

RESULTS

We included 106 patients with cirrhosis. The median MAIT cells fraction in the circulation was 0.8% in cirrhosis compared to 6.1% in healthy controls. In contrast to our hypothesis, we found an association in the adjusted analysis between relatively preserved MAIT cell levels, and a slightly higher risk to develop bacterial infections (adjusted subdistribution hazard ratio (aSHR) 1.15 (95%CI = 1.01-1.31). However, MAIT cell levels were not associated with the risk of hepatic decompensation (aSHR 1.19 (95%CI = 0.91-1.56)) nor with death (adjusted hazard ratio 1.10 (95%CI = 0.97-1.22)).

CONCLUSIONS

Relatively preserved MAIT cell levels in blood of patients with cirrhosis were associated with a somewhat higher risk of bacterial infections. The clinical relevance of this might not be strong. MAIT cells might however be an interesting biomarker to explore in future studies.

ALTA: a simple nutritional prognostic score for patients with hepatitis B virus-related acute-on-chronic liver failure

Background

Malnutrition, despite being a common complication, is often neglected in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). The objective of this study was to develop a simplified nutritional prognostic score to accurately predict mortality in HBV-ACLF patients.

Methods

In this multicenter retrospective study, clinical data from 530 HBV-ACLF patients were used to create a new prognostic score, which was then validated in two external cohorts (n = 229 and 248).

Results

Four independent factors were significantly associated with 28-day mortality in HBV-ACLF patients, forming a novel prognostic score (ALTA score = 0.187 × age-0.849 × lymphocyte count-2.033 × total cholesterol-0.148 × albumin-0.971). Notably, the AUROC of ALTA score for 28/90-day mortality (0.950/0.967) were significantly higher than those of three other ACLF prognostic scores (COSSH-ACLF II, 0.864/0.734; MELD, 0.525/0.488; MELD-Na, 0.546/0.517; all P < 0.001), and three known nutritional scores (CONUT, 0.739/0.861; OPNI, 0.279/0.157; NRS-2002, 0.322/0.286; all P < 0.001). The prediction error rates of ALTA score for 28-day mortality were significantly lower than COSSH-ACLF II (7.3%), MELD (14.4%), MELD-Na (12.7%), CONUT (9.0%), OPNI (30.6%), and NRS2002 (34.1%) scores. Further classifying ALTA score into two strata, the hazard ratios of mortality at 28/90 days were notably increased in the high-risk groups compared to the low-risk group (15.959 and 5.740). These results were then validated in two external cohorts.

Conclusion

ALTA, as a simplified nutritional prognostic score for HBV-ACLF, demonstrates superiority over the COSSH-ACLF II and other scores in predicting short-term mortality among HBV-ACLF patients. Therefore, it may be used to guide clinical management, particularly in primary care settings.

Comparison of fungal vs bacterial infections in the medical intensive liver unit: Cause or corollary for high mortality?

BACKGROUND

Due to development of an immune-dysregulated phenotype, advanced liver disease in all forms predisposes patients to sepsis acquisition, including by opportunistic pathogens such as fungi. Little data exists on fungal infection within a medical intensive liver unit (MILU), particularly in relation to acute on chronic liver failure.

AIM

To investigate the impact of fungal infections among critically ill patients with advanced liver disease, and compare outcomes to those of patients with bacterial infections.

METHODS

From our prospective registry of MILU patients from 2018-2022, we included 27 patients with culture-positive fungal infections and 183 with bacterial infections. We compared outcomes between patients admitted to the MILU with fungal infections to bacterial counterparts. Data was extracted through chart review.

RESULTS

All fungal infections were due to Candida species, and were most frequently blood isolates. Mortality among patients with fungal infections was significantly worse relative to the bacterial cohort (93% vs 52%, P < 0.001). The majority of the fungal cohort developed grade 2 or 3 acute on chronic liver failure (ACLF) (90% vs 64%, P = 0.02). Patients in the fungal cohort had increased use of vasopressors (96% vs 70%, P = 0.04), mechanical ventilation (96% vs 65%, P < 0.001), and dialysis due to acute kidney injury (78% vs 52%, P = 0.014). On MILU admission, the fungal cohort had significantly higher Acute Physiology and Chronic Health Evaluation (108 vs 91, P = 0.003), Acute Physiology Score (86 vs 65, P = 0.003), and Model for End-Stage Liver Disease-Sodium scores (86 vs 65, P = 0.041). There was no significant difference in the rate of central line use preceding culture (52% vs 40%, P = 0.2). Patients with fungal infection had higher rate of transplant hold placement, and lower rates of transplant; however, differences did not achieve statistical significance.

CONCLUSION

Mortality was worse among patients with fungal infections, likely attributable to severe ACLF development. Prospective studies examining empiric antifungals in severe ACLF and associations between fungal infections and transplant outcomes are critical.

Circulating myeloid populations have prognostic utility in alcohol-related liver disease

Introduction

Alcohol-related liver disease (ARLD) accounts for over one third of all deaths from liver conditions, and mortality from alcohol-related liver disease has increased nearly five-fold over the last 30 years. Severe alcohol-related hepatitis almost always occurs in patients with a background of chronic liver disease with extensive fibrosis or cirrhosis, can precipitate 'acute on chronic' liver failure and has a high short-term mortality. Patients with alcohol-related liver disease have impaired immune responses, and increased susceptibility to infections, thus prompt diagnosis of infection and careful patient management is required. The identification of early and non-invasive diagnostic and prognostic biomarkers in ARLD remains an unresolved challenge. Easily calculated predictors of infection and mortality are required for use in patients who often exhibit variable symptoms and disease severity and may not always present in a specialized gastroenterology unit.

Methods

We have used a simple haematological analyser to rapidly measure circulating myeloid cell parameters across the ARLD spectrum.

Results and Discussion

We demonstrate for the first time that immature granulocyte (IG) counts correlate with markers of disease severity, and our data suggests that elevated counts are associated with increased short-term mortality and risk of infection. Other myeloid populations such as eosinophils and basophils also show promise. Thus IG count has the potential to serve alongside established markers such as neutrophil: lymphocyte ratio as a simply calculated predictor of mortality and risk of infectious complications in patients with alcohol-related hepatitis. This would allow identification of patients who may require more intensive management.

The implication of neutrophil extracellular traps in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is an expanding worldwide health concern, and the underlying mechanisms contributing to its progression still need further exploration. Neutrophil extracellular traps (NETs) are intricate formations comprised of nuclear constituents and diverse antimicrobial granules that are released into the extracellular milieu by activated neutrophils upon various triggers, which play a pivotal part in the onset and advancement of NAFLD. NETs actively participate in the genesis of NAFLD by fostering oxidative stress and inflammation, ultimately resulting in hepatic fat accumulation and the escalation of liver injury. Recent insights into the interaction with other hepatic immune populations and mediators, such as macrophages and T regulatory cells, have revealed several important mechanisms that can trigger further liver injury. In conclusion, the formation of NETs emerged as an important factor in the development of NAFLD, offering a promising target for innovative therapeutic approaches against this debilitating condition. This comprehensive review seeks to compile existing studies exploring the involvement of NETs in the genesis of NAFLD and their influence on the immune response throughout the progression of NAFLD.

Circulating neutrophil anti-pathogen dysfunction in cirrhosis

Neutrophils are the largest population of leucocytes and are among the first cells of the innate immune system to fight against intruding pathogens. In patients with cirrhosis, neutrophils exhibit altered functionality, including changes in phagocytic ability, bacterial killing, chemotaxis, degranulation, reactive oxygen species production and NET (neutrophil extracellular trap) formation. This results in their inability to mount an adequate antibacterial response and protect the individual from infection. Prognosis and survival in patients with cirrhosis are greatly influenced by the development of infectious complications. Multidrug-resistant bacterial infections in patients with cirrhosis are currently a growing problem worldwide; therefore, alternative methods for the prevention and treatment of bacterial infections in cirrhosis are urgently needed. The prevention and treatment of neutrophil dysfunction could be a potential way to protect patients from bacterial infections. However, the reasons for changes in neutrophil function in cirrhosis are still not completely understood, which limits the development of efficient therapeutic strategies. Both cellular and serum factors have been proposed to contribute to the functional impairment of neutrophils. Herein, we review the current knowledge on features and proposed causes of neutrophil dysfunction in cirrhosis, with a focus on current knowledge gaps and limitations, as well as opportunities for future investigations in this field.

The role of neutrophils in alcohol-related hepatitis

Alcohol-related liver disease is a major cause of liver disease-associated mortality, with inpatient care being a major contributor to its clinical and economic burden. Alcohol-related hepatitis (AH) is an acute inflammatory form of alcohol-related liver disease. Severe AH is associated with high short-term mortality, with infection being a common cause of death. The presence of AH is associated with increased numbers of circulating and hepatic neutrophils. We review the literature on the role of neutrophils in AH. In particular, we explain how neutrophils are recruited to the inflamed liver and how their antimicrobial functions (chemotaxis, phagocytosis, oxidative burst, NETosis) may be altered in AH. We highlight evidence for the existence of 'high-density' and 'low-density' neutrophil subsets. We also describe the potentially beneficial roles of neutrophils in the resolution of injury in AH through their effects on macrophage polarisation and hepatic regeneration. Finally, we discuss how manipulation of neutrophil recruitment/function may be used as a therapeutic strategy in AH. For example, correction of gut dysbiosis in AH could help to prevent excess neutrophil activation, or treatments could aim to enhance miR-223 function in AH. The development of markers that can reliably distinguish neutrophil subsets and of animal models that accurately reproduce human disease will be crucial for facilitating translational research in this important field.

Clinical Data based XGBoost Algorithm for infection risk prediction of patients with decompensated cirrhosis: a 10-year (2012-2021) Multicenter Retrospective Case-control study

OBJECTIVES

To appraise effective predictors for infection in patients with decompensated cirrhosis (DC) by using XGBoost algorithm in a retrospective case-control study.

METHODS

Clinical data were retrospectively collected from 6,648 patients with DC admitted to five tertiary hospitals. Indicators with significant differences were determined by univariate analysis and least absolute contraction and selection operator (LASSO) regression. Further multi-tree extreme gradient boosting (XGBoost) machine learning-based model was used to rank importance of features selected from LASSO and subsequently constructed infection risk prediction model with simple-tree XGBoost model. Finally, the simple-tree XGBoost model is compared with the traditional logical regression (LR) model. Performances of models were evaluated by area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity.

RESULTS

Six features, including total bilirubin, blood sodium, albumin, prothrombin activity, white blood cell count, and neutrophils to lymphocytes ratio were selected as predictors for infection in patients with DC. Simple-tree XGBoost model conducted by these features can predict infection risk accurately with an AUROC of 0.971, sensitivity of 0.915, and specificity of 0.900 in training set. The performance of simple-tree XGBoost model is better than that of traditional LR model in training set, internal verification set, and external feature set (P < 0.001).

CONCLUSIONS

The simple-tree XGBoost predictive model developed based on a minimal amount of clinical data available to DC patients with restricted medical resources could help primary healthcare practitioners promptly identify potential infection.

Acute on Chronic Liver Failure in Patients with Alcohol-Associated Hepatitis: A Review

Acute on chronic liver failure (ACLF) is a unique disease process associated with significant short-term mortality wherein patients with either chronic liver disease or cirrhosis suffer rapid decompensation in hepatic function accompanied by extrahepatic organ failures. Alcohol-associated hepatitis (AH) is a common precipitant of ACLF and has been shown to uniquely affect the pathophysiology of systemic and hepatic immune responses in patients with ACLF. Treatment of AH-associated ACLF includes supportive measures as well as treatment directed at AH; however, AH-directed therapies unfortunately remain limited and are of suboptimal efficacy.

The efficacy of branched-chain amino acid granules to restore phagocytic activity in cirrhosis patients, a randomized controlled trial

BACKGROUND

Infection is a detrimental complication among cirrhotic patients, leading to major morbidity and mortality. Reduction in phagocytic activation, as part of immunoparesis, is a distinctive key component of cirrhosis-associated immune dysfunction (CAID) and predicts the development of infection. However, there are limited data on immunotherapeutic approaches to restore phagocytosis.

AIMS

We aimed to determine the effect of branched-chain amino acid (BCAA) granules on phagocytic activity in patients with CAID.

METHODS

In this double-blind randomized controlled trial, Participants were randomly assigned (1:1 ratio stratified by Child-Pugh status) to receive either BCAA granules or placebo. In the 3rd and 6th months, phagocytic activity was assessed by flow cytometry. The primary endpoint was the restoration of innate immunity at the 6th month, defined as ≥75% phagocytic activity; the secondary endpoints were the accretion of phagocytic activity and hospitalization due to infection.

RESULTS

A total of 37 patients were included. There were no differences among the patients in the baseline characteristics and phagocytic activity. At the 6th month, a higher proportion of patients with phagocytic restoration was observed in the BCAA granule group compared to the placebo group (68 vs. 5.6%, p < 0.001). The mean phagocytic activity was 75.4 and 63.4% in the BCAA granule and placebo groups, respectively (p < 0.001). Progressive accretion of phagocytic activity was observed during the 3rd and 6th months. There was no difference in hospitalization due to infection (3 vs. 2 events, p = 0.487).

CONCLUSION

Our results suggest that BCAA granules significantly restore phagocytic activity across various stages of cirrhosis. A longer follow-up period is required to demonstrate infection prevention.Clinical Trial Registration: www.clinicaltrials.in.th, TCTR20190830005.

Dysregulated biomarkers of innate and adaptive immunity predict infections and disease progression in cirrhosis

Background & Aims

Cirrhosis-associated immune dysfunction (CAID) affects both innate and adaptive immunity. This study investigated the complement system, immunoglobulins, and acute-phase proteins and their prognostic relevance in patients with advanced chronic liver disease (ACLD).

Methods

Patients with ACLD (hepatic venous pressure gradient [HVPG] ≥6 mmHg) but without acute decompensation/infections were characterised by HVPG and by clinical EASL stages: compensated (cACLD; S0-2) vs. decompensated ACLD (dACLD) with previous variceal bleeding (S3), non-bleeding decompensation (S4), or further decompensation (S5). Complement factors (C3c, C4, CH50), immunoglobulins (IgA, IgM, IgG, IgG1-4), acute-phase proteins and systemic inflammation biomarkers (white blood cells, C-reactive protein, IL-6, procalcitonin) were measured.

Results

A total of 245 patients (median model for end-stage liver disease score: 11 [9-15], median HVPG: 17 [12-21] mmHg) were included with 150 (61%) presenting dACLD. Complement levels and activity significantly decreased in dACLD substages S4 and S5 (p <0.001). Total IgA/IgM/IgG and IgG1-4 subtype levels increased in patients with dACLD (all p <0.05). Complement and immunoglobulin levels correlated negatively and positively, respectively, with systemic inflammation (all p <0.05). High IgG-1 (adjusted hazard ratio per 100 mg/dl: 1.12, 1.04-1.19, p = 0.002) and IL-6 (adjusted hazard ratio: 1.03, 1.00-1.05, p = 0.023) levels predicted the development of infections during follow-up. High IgA (stratified by median; log-rank p <0.001), high IgG1 (log-rank p = 0.043) and low C3c (log-rank p = 0.003) indicated a higher risk of first/further decompensation or liver-related death (composite endpoint). Next to HVPG and IL-6, low C3c (adjusted hazard ratio per mg/dl: 0.99, 0.97-0.99, p = 0.040) remained independently associated with the composite endpoint on multivariate Cox regression analysis.

Conclusions

Complement levels and immunoglobulins may serve as surrogates of cirrhosis-associated immune dysfunction and associate with cirrhosis severity and systemic inflammation. Low complement C3c predicted decompensation and liver-related death, whereas high IgG-1 indicated an increased risk for infections.

Impact and Implications

Patients with cirrhosis are at increased risk for infections, which worsen their prognosis. We found a significant dysregulation of several essential components of the immune system that was linked to disease severity and indicated a risk for infections and other complications. Simple blood tests identify patients at particularly high risk, who may be candidates for preventive measures.

Clinical Trials Registration

This study is registered at ClinicalTrials.gov (NCT03267615).

Pathological neutrophil migration predicts adverse outcomes in hospitalized patients with liver cirrhosis

BACKGROUND AND AIMS

Given the early response of neutrophil granulocytes to infections, detection of pathological neutrophil migration might help in predicting adverse events in patients with liver cirrhosis.

METHODS

Migration of blood neutrophils in hospitalized patients with cirrhosis was characterized by a novel standardized migration assay. Pathological neutrophil migration patterns were associated with a composite endpoint of ACLF, sepsis or death within 7 or 30 days.

RESULTS

Overall, 125 patients were included, of whom 11 (8.8%) had compensated cirrhosis, 84 (67.2%) had acute decompensation (AD) and 30 (24%) had acute-on-chronic liver failure (ACLF). The migration response of neutrophils from patients with AD or ACLF to stimulation with the chemotactic formylpeptide f-Met-Leu-Phe (fMLP) was significantly impaired, while the response to chemokine (C-X-C motif)-ligand 8 (CXCL8) was affected less pronouncedly. In contrast, no relevant differences in response to CXCL1 were observed. Of note, neutrophils of a number of patients with AD and ACLF were largely immotile at resting and stimulated conditions. Patients with non-migrating neutrophils at unstimulated conditions were at high risk to develop the composite endpoint of ACLF, sepsis or death. Moreover, expression of chemokine receptors CXCR1 and CXCR2 was significantly decreased in patients with ACLF. Interestingly, the expression of chemokine receptors did not correlate with neutrophil migration patterns, but-based on the increased expression of the cell surface markers CD66b and CD177-neutrophils of patients with AD and ACLF were strongly pre-activated.

CONCLUSION

Pathological neutrophil migration in patients with cirrhosis indicates a high risk of developing adverse outcomes.

Copper deficiency is an independent risk factor for mortality in patients with advanced liver disease

BACKGROUND AND AIM

Copper is an essential trace metal serving as a cofactor in innate immunity, metabolism, and iron transport. We hypothesize that copper deficiency may influence survival in patients with cirrhosis through these pathways.

METHODS

We performed a retrospective cohort study involving 183 consecutive patients with cirrhosis or portal hypertension. Copper from blood and liver tissues was measured using inductively coupled plasma mass spectrometry. Polar metabolites were measured using nuclear magnetic resonance spectroscopy. Copper deficiency was defined by serum or plasma copper below 80 µg/dL for women or 70 µg/dL for men.

RESULTS

The prevalence of copper deficiency was 17% (N=31). Copper deficiency was associated with younger age, race, zinc and selenium deficiency, and higher infection rates (42% vs. 20%, p=0.01). Serum copper correlated positively with albumin, ceruloplasmin, hepatic copper, and negatively with IL-1β. Levels of polar metabolites involved in amino acids catabolism, mitochondrial transport of fatty acids, and gut microbial metabolism differed significantly according to copper deficiency status. During a median follow-up of 396 days, mortality was 22.6% in patients with copper deficiency compared with 10.5% in patients without. Liver transplantation rates were similar (32% vs. 30%). Cause-specific competing risk analysis showed that copper deficiency was associated with a significantly higher risk of death before transplantation after adjusting for age, sex, MELD-Na, and Karnofsky score (HR: 3.40, 95% CI, 1.18-9.82, p=0.023).

CONCLUSIONS

In advanced cirrhosis, copper deficiency is relatively common and is associated with an increased infection risk, a distinctive metabolic profile, and an increased risk of death before transplantation.

Pre-transplant Biomarkers of Immune Dysfunction Improve Risk Assessment of Post-transplant Mortality Compared to Conventional Clinical Risk Scores

Introduction

There is a critical need to accurately stratify liver transplant (LT) candidates' risk of post-LT mortality prior to LT to optimize patient selection and avoid futility. Here, we compare previously described pre-LT clinical risk scores with the recently developed Liver Immune Frailty Index (LIFI) for prediction of post-LT mortality. LIFI measures immune dysregulation based on pre-LT plasma HCV IgG, MMP3 and Fractalkine. LIFI accurately predicts post-LT mortality, with LIFI-low corresponding to 1.4% 1-year post-LT mortality compared with 58.3% for LIFI-high (C-statistic=0.85).

Methods

LIFI was compared to MELD, MELD-Na, MELD 3.0, D-MELD, MELD-GRAIL, MELD-GRAIL-Na, UCLA-FRS, BAR, SOFT, P-SOFT, and LDRI scores on 289 LT recipients based on waitlist data at the time of LT. Survival, hazard of early post-LT death, and discrimination power (C-statistic) were assessed.

Results

LIFI showed superior discrimination (highest C-statistic) for post-LT mortality when compared to all other risk scores, irrespective of biologic MELD. On univariate analysis, the LIFI showed a significant correlation with mortality 6-months, as well as 1-, 3-, and 5-years. No other pre-LT scoring system significantly correlated with post-LT mortality. On bivariate adjusted analysis, African American race (p<0.05) and pre-LT cardiovascular disease (p=0.053) were associated with early- and long-term post-LT mortality. Patients who died within 1-yr following LT had a significantly higher incidence of infections, including 30-day and 90-day incidence of any infection, pneumonia, abdominal infections, and UTI (p<0.05).

Conclusions

LIFI, which measures pre-LT biomarkers of immune dysfunction, more accurately predicts risk of post-LT futility compared with current clinical predictive models. Pre-LT assessment of immune dysregulation may be critical in predicting mortality after LT and may optimize selection of candidates with lowest risk of futile outcomes.

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.

Blood concentrations of mediators released from activated neutrophils are related to the severity of alcohol-induced liver damage

BACKGROUND

Immune dysregulation and neutrophil infiltration are hallmarks of alcohol-related liver disease (ALD). Our objective was to evaluate the blood profile of neutrophil-derived mediators [neutrophil elastase (NE), myeloperoxidase (MPO), alpha1-antitrypsin (A1AT)], and their potential relevance in ALD.

METHODS

62 patients with ALD /47 males, and 15 females, aged 49,2 ± 9,9/ were prospectively recruited and distributed according to their 1/ gender, 2/ severity of liver dysfunction (by Child-Turcotte-Pugh, MELD scores, and mDF) 3/ presence of complications of ALD complications, and followed for 90 days. 24 age- and sex-matched healthy volunteers served as the control group. Neutrophil-derived biomarkers were quantified using enzyme-linked immunosorbent assays (ELISAs).

RESULTS

Blood concentrations of MPO and NE were significantly higher in ALD patients in comparison with controls. A1AT levels were not different. There were no gender-related differences in the studied biomarker levels. Both NE and MPO correlated with routine markers of inflammation, while NE with MELD and mDF scores. Patients with a severe ALD course i.e. MELD>20 or mDF>32, presented with significantly higher NE blood concentrations.

CONCLUSIONS

Our results point out the critical role of neutrophils in the pathogenesis of ALD. NE and MPO correlated with the intensity of inflammation, and NE was related to the severity of liver dysfunction.

Assessment of neutrophil subsets and immune checkpoint inhibitor expressions on T lymphocytes in liver transplantation: A preliminary study beyond the neutrophil-lymphocyte ratio

Background: Advanced stages of cirrhosis are characterized by the occurrence of progressive immune alterations known as CAID (Cirrhosis Associated Immune Dysfunction). In advanced cirrhosis, liver transplantation (LT) remains the only curative treatment. Sepsis, shares many similarities with decompensated cirrhosis in terms of immuno-inflammatory response. In both conditions, the neutrophil-lymphocyte ratio (NLR) is associated with poor outcomes. Based on alterations in sepsis, we hypothesized that we could observe in cirrhotic and LT patients more detailed neutrophil and lymphocyte phenotypes. To this end, along with leukocyte count, we assessed immature neutrophils, LOX-1⁺ MDSC and PD-1 and TIM-3 lymphocyte expressions in cirrhotic patients before transplantation in association with liver disease severity and during the first month after transplantation. Methods: We conducted a prospective monocentric study including cirrhotic patients registered on LT waiting-list. Blood samples were collected at enrolment before LT and for 1 month post-LT. In addition to NLR, we assessed by whole blood flow cytometry the absolute count of immature neutrophils and LOX-1⁺ MDSC as well as the expressions of immune checkpoint receptors PD-1 and TIM-3 on T lymphocytes. Results: We included 15 healthy volunteers (HV) and 28 patients. LT was performed for 13 patients. Pre-LT patients presented with a higher NLR compared to HV and NLR was associated with cirrhosis severity. Increased immature neutrophils and LOX-1⁺ MDSC counts were observed in the most severe patients. These alterations were mainly associated with acute decompensation of cirrhosis. PD-1 and TIM-3 expressions on T lymphocytes were not different between patients and HV. Post-LT immune alterations were dominated by a transitory but tremendous increase of NLR and immature neutrophils during the first days post-LT. Then, immune checkpoint receptors and LOX-1⁺ MDSC tended to be overexpressed by the second week after surgery. Conclusion: The present study showed that NLR, immature neutrophils and LOX-1⁺ MDSC counts along with T lymphocyte count and checkpoint inhibitor expression were altered in cirrhotic patients before and after LT. These data illustrate the potential interest of immune monitoring of cirrhotic patients in the context of LT in order to better define risk of sepsis. For this purpose, larger cohorts of patients are now necessary in order to move forward a more personalised care of LT patients.

The Tumor Microenvironment of Hepatocellular Carcinoma: Untying an Intricate Immunological Network

HCC, the most prevalent form of primary liver cancer, is prototypically an inflammation-driven cancer developing after years of inflammatory insults. Consequently, the hepatic microenvironment is a site of complex immunological activities. Moreover, the tolerogenic nature of the liver can act as a barrier to anti-tumor immunity, fostering cancer progression and resistance to immunotherapies based on immune checkpoint inhibitors (ICB). In addition to being a site of primary carcinogenesis, many cancer types have high tropism for the liver, and patients diagnosed with liver metastasis have a dismal prognosis. Therefore, understanding the immunological networks characterizing the tumor microenvironment (TME) of HCC will deepen our understanding of liver immunity, and it will underpin the dominant mechanisms controlling both spontaneous and therapy-induced anti-tumor immune responses. Herein, we discuss the contributions of the cellular and molecular components of the liver immune contexture during HCC onset and progression by underscoring how the balance between antagonistic immune responses can recast the properties of the TME and the response to ICB.

Kinetics Accelerated CRISPR-Cas12a Enabling Live-Cell Monitoring of Mn2+ Homeostasis

The CRISPR/Cas12a system has been repurposed as a versatile nuclei acid bio-imaging tool, but its utility in sensing non-nucleic acid analytes in living cells has been less exploited. Herein, we demonstrated the ability of Mn2+ to accelerate cleavage kinetics of Cas12a and deployed for live-cell Mn2+ sensing by leveraging the accelerated trans-cleavage for signal reporting. In this work, we found that Mn2+ could significantly boost both the cis-cleavage and trans-cleavage activities of Cas12a. On the basis of this phenomenon, we harnessed CRISPR-Cas12a as a direct sensing system for Mn2+, which achieved robust Mn2+ detection in the concentration range of 0.5-700 μM within 15 min in complex biological samples. Furthermore, we also demonstrated the versatility of this system to sense Mn2+ in the cytoplasm of living cells. With the usage of a conditional guide RNA, this Cas12a-based sensing method was applied to study the cytotoxicity of Mn2+ in living nerve cells, offering a valuable tool to reveal the cellular response of nerve cells to Mn2+ disorder and homeostasis.

Position statement on the use of albumin in liver cirrhosis

Cirrhosis is characterised by a prolonged asymptomatic period in which the inflammation persists, increasing as the disease progresses. Characteristic of this is the increase in pro-inflammatory cytokines and pro-oxidant molecules which are determining factors in the development of multiple organ dysfunction. In the early development of cirrhosis, splanchnic arterial vasodilation, activation of vasoconstrictor systems (renin-angiotensin-aldosterone) and the sympathetic nervous system (noradrenaline) bring about bacterial translocation and systemic dissemination via portal circulation of bacterial products, and molecular patterns associated with damage, which exacerbate the systemic inflammation present in the patient with cirrhosis. Albumin is a molecule that undergoes structural and functional changes as liver damage progresses, affecting its antioxidant, immunomodulatory, oncotic and endothelial stabilising properties. Our knowledge of the properties of albumin reveals a molecule with multiple treatment options in patients with cirrhosis, from the compensated then decompensated phases to multiple organ dysfunction. Its recognised uses in spontaneous bacterial peritonitis, post-paracentesis circulatory dysfunction, acute kidney injury and hepatorenal syndrome are fully validated, and a treatment option has opened up in decompensated cirrhosis and in acute-on-chronic liver disease.

Liver cirrhosis and immune dysfunction

Cirrhosis is end-stage liver disease resulting from various etiologies and is a common cause of death worldwide. The progression from compensated to decompensated cirrhosis to acute-on-chronic liver failure (ACLF) is due to multiple factors, including continuation of alcohol use or continued exposure to other toxins, an imbalance of the gut microbiota (dysbiosis), increased gut permeability and a disrupted immune response. This disrupted immune response is also named cirrhosis-associated immune dysfunction, which is characterized by worsening systemic inflammation with concomitant immune paralysis, as liver disease deteriorates. This review highlights central immunologic events during the exacerbation of cirrhosis and characterizes the different immune cell populations involved therein.

Exaggerated inflammatory response to bacterial products in decompensated cirrhotic patients is orchestrated by interferons IL-6 and IL-8

Cirrhosis-associated immune dysfunction (CAID) contributes to disease progression and organ failure development. We interrogated immune system function in nonseptic compensated and decompensated cirrhotic patients using the TruCulture whole blood stimulation system, a novel technique that allows a more accurate representation than traditional methods, such as peripheral blood mononuclear cell culture, of the immune response in vivo. Thirty cirrhotics (21 decompensated and 9 compensated) and seven healthy controls (HCs) were recruited. Whole blood was drawn directly into three TruCulture tubes [unstimulated to preloaded with heat-killed Escherichia coli 0111:B4 (HKEB) or lipopolysaccharide (LPS)] and incubated in dry heat blocks at 37°C for 24 h. Cytokine analysis of the supernatant was performed by multiplex assay. Cirrhotic patients exhibited a robust proinflammatory response to HKEB compared with HCs, with increased production of interferon-γ-induced protein 10 (IP-10) and IFN-λ1, and to LPS, with increased production of IFN-λ1. Decompensated patients demonstrated an augmented immune response compared with compensated patients, orchestrated by an increase in type I, II, and III interferons, and higher levels of IL-1β, IL-6, and IL-8 post-LPS stimulation. IL-1β, TNF-α, and IP-10 post-HKEB stimulation and IP-10 post-LPS stimulation negatively correlated with biochemical markers of liver disease severity and liver disease severity scores. Cirrhotic patients exposed to bacterial products exhibit an exaggerated inflammatory response orchestrated by IFNs, IL-6, and IL-8. Poststimulation levels of a number of proinflammatory cytokines negatively correlate with markers of liver disease severity raising the possibility that the switch to an immunodeficient phenotype in CAID may commence earlier in the course of advanced liver disease. NEW & NOTEWORTHY Decompensated cirrhotic patients, compared with compensated patients, exhibit a greater exaggerated inflammatory response to bacterial products orchestrated by interferons, IL-6, and IL-8. Postbacterial product stimulation levels of a number of pro-inflammatory cytokines negatively correlate with liver disease severity biomarkers and liver disease severity scores raising the possibility that the switch to an immunodeficient phenotype in cirrhosis-associated immune dysfunction may commence earlier in the course of advanced liver disease.

Immune cells in alcohol-related liver disease

Alcohol-related liver disease (ALD), which is caused by excessive alcohol consumption, is one of the most common types of liver disease and a primary cause of hepatic injury, with a disease spectrum that includes steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Various lines of evidence have indicated that immune cells play a significant role in the inflammatory processes of ALD. On the one hand, the liver contains various resident immune cells that have been proven to perform different functions in ALD. For example, in the progression of the disease, Kupffer cells (KCs) are activated by lipopolysaccharide-Toll-like receptor 4 signaling and release various proinflammatory cytokines. Moreover, alcohol intake has been shown to depress the function of natural killer cells. Additionally, two types of unconventional T cells (natural killer T cells and mucosal-associated invariant T cells) are involved in the development of ALD. On the other hand, alcohol and many different cytokines stimulate the recruitment and infiltration of circulating immune cells (neutrophils, T cells, macrophages, and mast cells) into the liver. The neutrophils can produce proinflammatory mediators and cause the dysfunction of anti-infection processes. Additionally, alcohol intake can change the phenotype of T cells, resulting in their increased production of interleukin-17. Aside from KCs, infiltrating macrophages have also been observed in patients with ALD, but the roles of all of these cells in the progression of the disease have shown both similarities and differences. Additionally, the activated mast cells are also associated with the development of ALD. Herein, we review the diverse roles of the various immune cells in the progression of ALD.

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.

Activation and Functional Priming of Blood Neutrophils in Non-Alcoholic Fatty Liver Disease Increases in Non-Alcoholic Steatohepatitis

Introduction

In non-alcoholic fatty liver disease (NAFLD), neutrophils in liver infiltrates are activated, which may contribute to disease progression towards non-alcoholic steatohepatitis (NASH). However, the functional status of the blood neutrophils remains unknown and their role in the disease mechanisms is thus uncertain. We therefore characterized activation and function of blood neutrophils in patients with NAFLD in relation to clinical disease markers and the NAFLD plasma milieu.

Methods

We studied 20 patients with NAFLD, among these 6 patients with NASH, and 14 healthy persons. Neutrophil activation, interleukin (IL)-8 production and oxidative burst were measured by flow cytometry on participants´ neutrophils and on healthy neutrophils exposed in vitro to plasma from the study participants.

Results

Blood neutrophils from the NASH patients showed a doubling in their expression of the activation marker CD62L. Also, all NAFLD patients had 50–100% increased expression of CD11b. Functionally, NASH neutrophils had 30% elevated IL-8 production and more than doubled spontaneous oxidative burst. In all NAFLD patients, higher spontaneous oxidative burst was associated with worse liver function. Incubation of healthy neutrophils with NAFLD plasma paradoxically slightly reduced CD62L and CD11b expression, and NASH plasma also reduced the frequency of IL-8-producing neutrophils.

Conclusion

In NAFLD, blood neutrophils are activated, and in NASH also functionally primed. This suggests a progressive neutrophil aggressiveness already present with liver fat infiltration. However, NAFLD plasma in vitro, if anything, had the opposite effect on the healthy neutrophils so the NAFLD-related neutrophil activation cannot be attributed to humoral factors and remains unexplained.

[Functional activity of blood neutrophilic granulocytes in patients with opisthorchiasis, depending on the severity of liver fibrosis]

AIM

To study the activity of neutrophilic granulocytes in patients with opisthorchiasis, depending on the severity of liver fibrosis.

MATERIALS AND METHODS

A total of 74 patients with chronic opisthorchiasis (39 men and 35 women, average age 42.3 years) and 32 practically healthy patients (17 men and 15 women, average age 41.5 years) aged 24 to 60 years were examined. Diagnosis of opisthorchiasis was carried out by two methods: coprooscopy and identification of eggs or bodies of adult parasites in duodenal content. Liver fibrosis was determined by the method of elastometry according to the METAVIR scale in all 74 patients with opisthorchiasis. The study of the functional activity of neutrophils in the blood was performed to all 74 patients with opisthorchiasis and 32 healthy individuals from the control group by chemiluminescent analysis with measurement of the reactive oxygen species (ROS) production intensity in a spontaneous and zymosan-induced reaction in lucigenin and luminol-dependent processes.

RESULTS

Liver fibrosis F2 by METAVIR was registered in 20.3% of the examined individuals, liver fibrosis F3F4 by METAVIR was detected in 17.6% of patients with opisthorchiasis. In patients with opisthorchiasis with liver fibrosis F3F4 by METAVIR, a significant decrease in the functional activity of neutrophilic granulocytes was registered in comparison with individuals with liver fibrosis F0F1 by METAVIR, as evidenced by a significant decrease in the maximum intensity of ROS production (Imax) and the area under the curve (S) chemiluminescence in lucigenin and luminol-dependent processes both in the spontaneous and zymosan-induced reaction.

CONCLUSION

These results provide new information to explain the mechanisms of liver fibrosis in patients opisthorchiasis and create opportunities for the development of diagnostics and preventive technologies.

Transition to decompensation and acute-on-chronic liver failure: Role of predisposing factors and precipitating events

The transition from compensated to decompensated cirrhosis results from a complex interplay of predisposing and precipitating factors and represents an inflection point in the probability of a patient surviving. With the progression of cirrhosis, patients accumulate multiple disorders (e.g. altered liver architecture, portal hypertension, local and systemic inflammation, bacterial translocation, gut dysbiosis, kidney vasoconstriction) that predispose them to decompensation. On the background of these factors, precipitating events (e.g. bacterial infection, alcoholic hepatitis, variceal haemorrhage, drug-induced liver injury, flare of liver disease) lead to acute decompensation (ascites, hepatic encephalopathy, variceal bleeding, jaundice) and/or organ failures, which characterise acute-on-chronic liver failure. In this review paper, we will discuss the current hypotheses and latest evidences regarding predisposing and precipitating factors associated with the transition to decompensated liver disease.

Two Faces of Neutrophils in Liver Disease Development and Progression

Neutrophils, the most abundant type of leukocyte in human blood, play a major role in host defense against invading pathogens and in sterile injury. Neutrophil infiltration is characteristic of inflammation because of its antimicrobial and cytotoxic activities. Neutrophils also actively participate in the resolution of inflammation and subsequent tissue repair by acting as a critical mediator between the inflammation and resolution phases of tissue damage. However, neutrophils that are consistently exposed to inflammatory conditions lose their self-resolving capabilities and maintain an inflammatory phenotype, further exacerbating tissue damage. The current review describes how neutrophils interact with tissue microenvironments and acquire disease-specific phenotypes under chronic inflammatory conditions. Here, we aim to provide a better understanding of neutrophil-mediated pathogenesis of various liver diseases.

The multifactorial mechanisms of bacterial infection in decompensated cirrhosis

Infections, due to a dysfunctional immune response, pose a great risk to patients with decompensated cirrhosis and herald the beginning of the terminal phase of this disease. Infections typically result from breaches in innate immune barriers and inadequate clearance by immune cells. This leads to bacterial and bacterial product translocation to the systemic circulation, which is already primed by ongoing hepatic inflammation in patients with cirrhosis, who are particularly prone to developing organ failure in the presence of an infection. Early identification of bacterial infection, along with the prompt use of appropriate antibiotics, have reduced the mortality associated with certain infections in patients with decompensated cirrhosis. Judicious use of antibiotic therapy remains imperative given the emergence of multidrug-resistant infections in the cirrhotic population. Important research over the last few years has identified molecular targets on immune cells that may enhance their function, and theoretically prevent infections. Clinical trials are ongoing to delineate the beneficial effects of targeted molecules from their off-target effects. Herein, we review the mechanisms that predispose patients with cirrhosis to bacterial infections, the clinical implications of infections and potential targets for the prevention or treatment of infections in this vulnerable population.

A Case of Bordetella bronchiseptica Bacteremia in a Patient With Decompensated Liver Cirrhosis

Bordetella bronchiseptica is a rare cause of respiratory tract infection in humans, most commonly found in immunocompromised individuals exposed to infected animals. It colonizes the respiratory tract and can lead to infection in dogs, cats, rabbits, and others. In immunocompromised patients, it has been reported to result in life-threatening infections but rarely affects immunocompetent individuals. Here, we are the first to report a case B. bronchiseptica bacteremia in a patient with decompensated liver cirrhosis without known animal exposure.

Loss of Coordinated Neutrophil Responses to the Human Fungal Pathogen, Candida albicans, in Patients With Cirrhosis

Neutrophils are the most abundant white blood cell in the body and are key participants in the defense against fungal infections. Fungal infections occur often in patients with cirrhosis and are associated with increased 30-day and 90-day mortality. Previous studies have shown that specific neutrophil functions are abnormal in patients with cirrhosis, although the extent of neutrophil dysfunction is not well understood. We tested the ability of neutrophils from 21 hospitalized patients with cirrhosis and 23 healthy control patients to kill Candida albicans, a common fungal pathogen in patients with cirrhosis. Using an assay, we also measured the ability of neutrophils to coordinate multicellular, synchronized control of C. albicans hyphae through a process known as swarming. We found that neutrophils from patients with cirrhosis have significantly decreased fungicidal capacity compared with healthy control neutrophils (53% vs. 74%, P < 0.0001) and diminished ability to control hyphal growth normalized as a ratio to healthy control (0.22 vs. 0.65, P < 0.0001). Moreover, serum from patients with cirrhosis decreases the ability of healthy control neutrophils to kill C. albicans (from 60% to 41%, P < 0.003). Circulating concentration of the inflammatory cytokines tumor necrosis factor α, interleukin-6, and interleukin-8 were found to be significantly elevated in patients with cirrhosis compared to healthy controls. Following pretreatment with granulocyte-colony stimulating factor and granulocyte-macrophage colony-stimulating factor, neutrophil function was restored to almost that of healthy controls. Conclusion: Our data establish profound neutrophil dysfunction against, and altered swarming to, C. albicans in patients with cirrhosis. This dysfunction can be partially reversed with cytokine augmentation ex vivo.

Circulating Neutrophil Dysfunction in HBV-Related Acute-on-Chronic Liver Failure

Background and Aims

Acute-on-chronic liver failure (ACLF) is characterized by systemic inflammation accompanied by defective anti-bacterial immunity. The role of neutrophils in immune derangement of ACLF has not been fully elucidated. This study is aimed to characterize the role of circulating neutrophils in HBV-related ACLF patients.

Methods

Quantitative, phenotypic, transcriptomic, and functional alterations of circulating neutrophils were compared in ACLF and non-ACLF subjects and analyzed for associations with short-term outcomes. Interventional experiments were performed to test the impact on ACLF-patient neutrophil function in vitro.

Results

Circulating absolute neutrophil count was significantly increased in patients with ACLF and was an independent risk factor for 28-day mortality. ACLF-patient neutrophils differentially expressed a panel of surface markers (include TLR-1, TLR-2, TLR-4, CEACAM-1 and FPR1), as well as a distinct transcriptomic signature. ACLF-neutrophils displayed significantly impaired phagocytosis but an increased capacity to form neutrophil extracellular traps (NETs), which was more pronounced in patients with poor outcome. Healthy neutrophils mimicked functional characteristics of ACLF counterpart after co-cultured with plasma from ACLF patients. The oxidative burst and cytokine production capacities remained unchanged. Plasma GM-CSF, IL-6, IL-8, IL-10, and IP-10 levels, as well as lipopolysaccharide (LPS) concentration, were markedly elevated in ACLF patients but not DAMP molecules HMGB-1 and HSP70. Finally, a glycolysis inhibitor, 2-deoxy-glucose, reduced NET formation of ACLF patients’ neutrophils.

Conclusions

Circulating ACLF-patient neutrophils exhibit alterations in number, phenotype, gene expression and function, which was associated with poor outcome and shaped by the ACLF circulatory environment. Inhibiting glycolysis can reverse neutrophil dysfunction in ACLF patients.

Innate immune cells in cirrhosis

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

A Double-Blind, Randomized Placebo-Controlled Trial of Probiotic Lactobacillus casei Shirota in Stable Cirrhotic Patients

Background: In cirrhosis, a pathological gut microbiome has been linked with immune dysfunction. A pilot study of probiotic Lactobacillus casei Shirota (LcS) in alcoholic cirrhosis demonstrated significant improvement in neutrophil function. This study aimed to evaluate the efficacy of LcS on neutrophil function and significant infection rates in patients with cirrhosis. Methods: 92 cirrhotic patients (Child-Pugh score ≤10) were randomized to receive LcS or placebo, three times daily for six months. Primary end-points were incidence of significant infection and neutrophil function. Secondary end-points were cytokine profile, endotoxin, bacterial DNA positivity, intestinal permeability and quality of life. Results: Rates of infection, decompensation or neutrophil function did not differ between placebo and probiotic groups. LcS significantly reduced plasma monocyte chemotactic protein-1 and, on subgroup analysis, plasma interleukin-1β (alcoholic cirrhosis), interleukin-17a and macrophage inflammatory protein-1β (non-alcoholic cirrhosis), compared with placebo. No significant differences in intestinal permeability, bacterial translocation or metabolomic profile were observed. Conclusion: LcS supplementation in patients with early cirrhosis is safe. Although no significant infections were observed in either group, LcS improved cytokine profile towards an anti-inflammatory phenotype, an effect which appears to be independent of bacterial translocation.

Albumin in decompensated cirrhosis: new concepts and perspectives

The pathophysiological background of decompensated cirrhosis is characterised by a systemic proinflammatory and pro-oxidant milieu that plays a major role in the development of multiorgan dysfunction. Such abnormality is mainly due to the systemic spread of bacteria and/or bacterial products from the gut and danger-associated molecular patterns from the diseased liver triggering the release of proinflammatory mediators by activating immune cells. The exacerbation of these processes underlies the development of acute-on-chronic liver failure. A further mechanism promoting multiorgan dysfunction and failure likely consists with a mitochondrial oxidative phosphorylation dysfunction responsible for systemic cellular energy crisis. The systemic proinflammatory and pro-oxidant state of patients with decompensated cirrhosis is also responsible for structural and functional changes in the albumin molecule, which spoil its pleiotropic non-oncotic properties such as antioxidant, scavenging, immune-modulating and endothelium protective functions. The knowledge of these abnormalities provides novel targets for mechanistic treatments. In this respect, the oncotic and non-oncotic properties of albumin make it a potential multitarget agent. This would expand the well-established indications to the use of albumin in decompensated cirrhosis, which mainly aim at improving effective volaemia or preventing its deterioration. Evidence has been recently provided that long-term albumin administration to patients with cirrhosis and ascites improves survival, prevents complications, eases the management of ascites and reduces hospitalisations. However, variant results indicate that further investigations are needed, aiming at confirming the beneficial effects of albumin, clarifying its optimal dosage and administration schedule and identify patients who would benefit most from long-term albumin administration.

Neutrophil dysfunction predicts 90-day survival in patients with acute on chronic liver failure: A longitudinal case-control study

Background and Aim

Innate immune disarray is a key component in the development and progression of acute on chronic liver failure (ACLF) and predisposition to infections. We evaluated the neutrophil dysfunction and its impact on outcomes in patients with ACLF.

Methods

Forty patients with acute decompensation of cirrhosis (10 each of grades 0, 1, 2, and 3 ACLF) and 10 healthy controls were prospectively evaluated for neutrophil immunophenotype (NP), neutrophil phagocytic capacity (NPC), and oxidative burst (OB) in both resting and stimulated conditions. The patients were followed up for 90 days or until death or transplant, whichever was earlier.

Results

NP was normal (in %) and NPC (in mean fluorescence intensity [MFI]) was better in controls compared to patients with ACLF (83.74 ± 12.38 vs 63.84 ± 22.98; P = 0.007 and 98.33 ± 130.60 vs 18.73 ± 17.88, P = 0.001, respectively). Resting OB was higher in patients with ACLF compared to controls (97 ± 4.9% vs 91 ± 9%; P = 0.034), but it failed to increase further after stimulation, suggesting an immune exhaustion. NP was normal (in %) and NPC (in MFI) was better in 90‐day survivors compared to nonsurvivors (78 ± 11.9 vs 62.2 ± 24.11, P = 0.02 and 33.3 ± 22.7 vs 16.36 ± 13.3; P = 0.004, respectively). Phenotypically normal neutrophils >71.7% had 78.6% sensitivity and 65.4% specificity with an area under receiver operating curve (AUROC) of 0.70 (95% confidence interval [CI]: 0.55–0.90); P = 0.017, and NPC >17.32. MFI had 71.4% sensitivity and 69.6% specificity with an AUROC of 0.73 (95% CI: 0.54–0.86), P = 0.035, in predicting 90‐day survival.

Conclusion

Neutrophils have impaired bactericidal function in patients with ACLF compared to healthy adults. Neutrophil phenotype and phagocytic capacity may be used to predict 90‐day survival in patients with ACLF.