Cirrhosis-associated immune dysfunction: distinctive features and clinical relevance

No Increased Risk for Primary Osteoarthritis in Liver Cirrhosis - A Danish Nationwide Cohort Study

Objective

Chronic synovial inflammation causes primary osteoarthritis, but it is unknown whether chronic systemic inflammation does, too. Patients with cirrhosis have chronic systemic inflammation and therefore we examined the association between cirrhosis and primary osteoarthritis of the hip and knee.

Methods

In Danish healthcare databases we identified all residents over 60 years diagnosed with cirrhosis in 1994–2011, and for each of them we sampled five age- and gender-matched reference persons from the general population. We excluded everyone with risk factors for secondary osteoarthritis and computed incidence rates of primary osteoarthritis of the hip or knee. We used stratified Cox regression to estimate the hazard ratios of primary osteoarthritis for cirrhosis patients vs. reference persons in strata defined by gender, age, cirrhosis etiology, and ascites vs. no ascites. We also computed separate HRs for primary osteoarthritis of the hips or knees.

Results

We identified 10,049 cirrhosis patients. Their median age was 67 years, and 65% were men. Among the cirrhosis patients the crude incidence rate of primary osteoarthritis was 8.40 (95% CI: 7.30–9.63) per 1000 person-years. The rate was similar in the reference persons: 8.76 (95% CI: 8.43–9.12) per 1000 person-years. Accordingly, the hazard ratio for primary osteoarthritis for cirrhosis patients vs. reference persons was 0.99 (95% CI: 0.85–1.16), and we found the same null association in all patient strata and in both joints.

Conclusion

Cirrhosis, and thus chronic systemic inflammation, is not a risk factor for primary osteoarthritis.

TLR4/CD14 Variants-Related Serologic and Immunologic Dys-Regulations Predict Severe Sepsis in Febrile De-Compensated Cirrhotic Patients

Genetic variants and dysfunctional monocyte had been reported to be associated with infection susceptibility in advanced cirrhotic patients. This study aims to explore genetic predictive markers and relevant immune dysfunction that contributed to severe sepsis in febrile acute de-compensated cirrhotic patents. Polymorphism analysis of candidate genes was undergone in 108 febrile acute de-compensated cirrhotic patients and 121 healthy volunteers. Various plasma inflammatory/regulatory cytokines, proportion of classical (CD 16-, phagocytic) and non-classical (CD16+, inflammatory) monocytes, lipopolysaccharide (LPS)-stimulated toll-like receptor 4 (TLR4) and intracellular/extracellular cytokines on cultured non-classical monocytes, mCD14/HLA-DR expression and phagocytosis of classical monocytes were measured. For TLR4+896A/G variant allele carriers with severe sepsis, high plasma endotoxin/IL-10 inhibits HLA-DR expression and impaired phagocytosis were noted in their classical monocyte. In the same group, increased non-classical monocyte subset, enhanced LPS-stimulated TLR4 expression and TNFα/nitrite production, and systemic inflammation [high plasma soluble CD14 (sCD14) and total nitric oxide (NOx) levels] were noted. For CD14-159C/T variant allele carriers with severe sepsis, persist endotoxemia inhibited mCD14/HLA-DR expression and impaired phagocytosis of their classical monocyte. In the same group, increased non-classical monocyte subset up-regulated TLR4-NFκB-iNOS and p38MAPK pathway, stimulated TNFα/nitrite production and elicited systemic inflammation. In febrile acute de-compensated cirrhotic patients, TLR4+896A/G and CD14-159C/T polymorphisms-related non-classical and classical monocytes dysfunction resulted in increased severe sepsis risk. Malnutrition, high plasma endotoxin and sCD14 levels, single TLR4+896A/G or CD14-159C/T variant allele carriers and double variant allele carriers are significant predictive factors for the development of severe sepsis among them.

Macrophage activation marker, soluble CD163, is an independent predictor of short-term mortality in patients with cirrhosis and bacterial infection

BACKGROUND & AIMS

Innate immune system dysfunction is common in advanced cirrhosis, with a central role of the monocyte/macrophage system. Monocytes and macrophages express the scavenger receptor CD163, which is regulated by inflammatory mediators. Cleavage of the receptor leads to the formation of soluble (s)CD163 that represents an anti-inflammatory response. We aimed to study the clinical importance of sCD163 in cirrhosis.

METHODS

Sera of 378 patients were assayed for sCD163 by ELISA [193 outpatients and 185 patients with acute decompensation (AD)]. A 5-year follow-up observational study was conducted to assess the possible association between sCD163 level and poor disease outcomes.

RESULTS

sCD163 level was associated with disease severity, but not with the presence of varices or prior variceal bleeding. In outpatients, sCD163 level did not predict the development of disease-specific complications or the long-term mortality. In patients with AD episode, sCD163 level was significantly higher compared to outpatients but only in the presence of bacterial infection (INF) (AD-INF:4586, AD-NON-INF:3792 and outpatients: 3538 ng/ml, P < 0.015 and P = 0.001, respectively). sCD163 level gradually increased according to severity of infection. During bacterial infections, high sCD163 level (>7000 ng/ml) was associated with increased mortality rate (42% vs. 17%, P < 0.001) and was identified as an independent predictor of 28-day mortality (hazard ratio:2.96, 95% confidence intervals:1.27-6.95) in multivariate Cox-regression model comprising aetiology, co-morbidity, model for end-stage liver disease score and leucocyte count as covariates.

CONCLUSIONS

High sCD163 level is useful to identify patients with high-risk of death during an AD episode complicated by bacterial infection. This finding serves as an additional hint towards the significance of anti-inflammatory response during bacterial infection.

Infections in severe alcoholic hepatitis

Severe alcoholic hepatitis (sAH), defined by a modified discriminant function ≥32, is the most severe form of alcohol-induced liver disease and is associated with a 1-month mortality rate of around 30%. Corticosteroid treatment remains the only therapeutic option that improves short-term survival. Infectious complications, occurring in approximately 50% of patients, are the main causes of death, even in patients who benefit from corticosteroids. Liver failure, recent alcohol consumption and immunosuppressive drugs contribute to this infectious risk. Although infection is a well-described feature of cirrhosis, little is known about the characteristics of infections in sAH. Infection is mainly of bacterial origin and frequently affects the respiratory tract. Pathogens classically observed in cirrhosis, such as gram-negative bacilli, are frequently involved, but opportunistic pathogens, such as fungi (Aspergillus fumigatus, Pneumocystis jirovecii) or viruses (Cytomegalovirus, Herpes simplex) may appear, mainly related to corticosteroid treatment. A high level of suspicion with systematic screening and prompt, adequate treatment are warranted to improve outcomes in these patients. Prophylactic strategies in this high-risk population should be assessed in well-designed trials.

A Comparison of Human Neutrophils Acquired from Four Experimental Models of Inflammation

Defects in neutrophil function have been implicated in a wide spectrum of clinical conditions. Several models are employed to study activated human neutrophils akin to those found at a site of inflammation. These include whole blood (WB) ex vivo stimulation with lipopolysaccharide (LPS) and in vivo techniques: cantharidin blister, skin windows and intra-dermal injection of UV-killed E.coli (UVKEc). Neutrophils obtained from these have never been compared. We compared the activation status of neutrophils from each technique in order to inform the optimal model for use in human studies. Healthy male volunteers were randomised to undergo one of the four techniques (n = 5/group). LPS: WB stimulated with 1ng/ml of LPS for 4 hours. Cantharidin: 12.5μl of 0.1% cantharidin elicited a single blister, aspirated at 24 hours. Skin windows: four 6mm mechanical-suction blisters created, de-roofed and an exudate-collection chamber placed over the windows for 4 hours before aspiration. UVKEc: 1.5 x 10⁷ UVKEc injected intra-dermally. A single 10mm mechanical-suction blister formed and aspirated at 4 hours. Unstimulated WB used as the control. Flow cytometry was used to determine activation status using CD16, CD11b, CD54, CD62L and CD88. Functional status was assessed with a phagocytosis assay. The pattern of neutrophil activation was similar in all models. Neutrophil CD11b was elevated in all models, most markedly in UVKEc (p<0.0001), and CD54 was also elevated but only significant in the LPS model (p = 0.001). CD62L was significantly reduced in all 4 models (p<0.0001) and CD88 was also suppressed in all. There were no changes in CD16 in any model, neither was there any significant difference in the phagocytic capacity of the neutrophils. In summary, there are no significant differences in activation marker expression or phagocytic capacity in the neutrophils obtained from each technique. Therefore we believe whole blood stimulation is the best model in experimentally challenging inpatient populations.

Bone marrow stem cells and their niche components are adversely affected in advanced cirrhosis of the liver

Bone marrow (BM) is a reservoir for immune and hematopoietic cells and critical for tissue repair and regeneration. All of these functions are severely altered in cirrhosis. We investigated the cellular and functional state of BM in cirrhosis patients. We studied the histological, cellular, and molecular changes in BM of cirrhosis patients (n = 168) and controls (n = 44). Hematopoietic stem cells (HSCs) and associated niche cells, mesenchymal stem cells, Schwann cells, neural fibers, and endothelial cells were evaluated by immunohistochemistry. Cytokines and growth factors were analyzed in peripheral blood and BM plasma. Cirrhotic BM showed an inverse correlation between cluster of differentiation 34+HSCs and Model of End-Stage Liver Disease (ρ = -0.582, P < 0.001) and Child's scores (P < 0.038). BMs of cirrhosis patients with higher Model of End-Stage Liver Disease (>15) showed significantly decreased HSCs, mesenchymal stem cells, Schwann cells, and neural fibers; increased interleukin-1β (P = 0.004), tumor necrosis factor-α (P = 0.040), and interferon-γ (P = 0.03); and decreased oncostatin M (P = 0.04), stem cell factor (P = 0.05), and stromal cell-derived factor 1 (P = 0.03) compared to those with lower Model of End-Stage Liver Disease scores (≤15). The cluster of differentiation 34+ cell population was a predictor for the development of sepsis (P < 0.001), and per unit loss increased the probability of sepsis by 16%. Cirrhosis patients with fewer HSCs had lower hemoglobin (P = 0.05) and platelet counts (P = 0.05) and showed early graft dysfunction.

CONCLUSIONS

Increasing severity of cirrhosis causes derangement of the hematopoietic niche and loss of HSCs, contributing to the hematological and immunological dysfunctions and reduced potential for regeneration; restoring BM functions could provide new therapeutic options in cirrhosis. (Hepatology 2016;64:1273-1288).

Role of assessing liver fibrosis in management of chronic hepatitis C virus infection

Fibrosis progression is common in hepatitis C. Both host and viral factors influence its natural history. Liver fibrosis is a key predictive factor for advanced disease including endpoints such as liver failure, cirrhosis and hepatocellular carcinoma (HCC). METAVIR fibrosis stages F3-F4 have been considered as the threshold for antiviral therapy. However, this aspect is controversial after the advent of new direct-acting antivirals (DAAs) because they show an excellent efficacy and safety profile. Moreover, in the DAA era, fibrosis stage seems not to be a predictive factor of a sustained virological response (SVR). Viral eradication decreases liver damage by improving the inflammation, as well as by regressing fibrosis irrespective of the treatment regimen. Non-invasive methods are useful in the assessment of liver fibrosis, replacing liver biopsy in clinical practice; but their usefulness for monitoring fibrosis after SVR needs to be demonstrated. Fibrosis regression has been demonstrated after the eradication of hepatitis C virus infection and is associated with a lower risk of hepatic cirrhosis and liver cancer. However, patients showing advanced fibrosis and cirrhosis must be followed-up after SVR, as risks of portal hypertension and HCC remain.

The role of zinc in liver cirrhosis

Zinc is an essential trace element playing fundamental roles in cellular metabolism. It acts mostly by binding a wide range of proteins, thus affecting a broad spectrum of biological processes, which include cell division, growth and differentiation. Zinc is critical to a large number of structural proteins, enzymatic processes, and transcription factors. Zinc deficiency can result in a spectrum of clinical manifestations, such as poor of appetite, loss of body hair, altered taste and smell, testicular atrophy, cerebral and immune dysfunction, and diminished drug elimination capacity. These are common symptoms in patients with chronic liver diseases, especially liver cirrhosis. The liver is the main organ responsible for the zinc metabolism which can be affected by liver diseases. On the other hand, zinc deficiency may alter hepatocyte functions and also immune responses in inflammatory liver diseases. Liver cirrhosis represents the most advanced stage of chronic liver diseases and is the common outcome of chronic liver injury. It is associated with energy malnutrition, with numerous metabolic disorders, such as hypoalbuminemia, with imbalance between branched-chain amino acids and aromatic amino acids, and with reduced zinc serum concentrations. All these processes can influence the clinical outcome of patients, such ascites, hepatic encephalopathy and hepatocellular carcinoma. In the present review, we summarize the emerging evidence on the pitoval role of zinc in the pathogenesis of liver cirrhosis.

In vitro model of production of antibodies; a new approach to reveal the presence of key bacteria in polymicrobial environments

Background

There is a rapid emergence of multiple resistant gram-negative bacteria due to overuse of antibiotics in the treatment of infections. Biofilms consist of polymicrobial communities that survive the host’s defense system. The key bacteria in biofilms are slow growing and support an attachment and rapid growth of other microorganisms. Current antimicrobial strategies often fail due to poor diagnosis of key pathogens in biofilms.

The study aims to develop anti-bacterial human antibodies in vitro from patients who had recently undergone a systemic infection by pathogenic bacteria and to use these antibodies as a tool for detecting bacteria in biofilms.

Methods

Lymphocytes were separated from whole blood of patients (n = 10) and stimulated with heat-killed bacteria to produce antibodies in vitro. The specificity of antibodies in recognizing the bacteria against which they were directed was evaluated by surface plasmon resonance system (SPR) and electron microscopy. The ulcer secretions from patients with chronic and acute leg ulcers and healthy controls were analyzed by the SPR system and the results were compared with culture studies.

Results

The produced antibodies recognized bacteria with high sensitivity (SPR). The antibodies against Enterococcus fecalis bound specifically to the microorganism in a bacterial co-culture that was visualized by electron microscopy.

Conclusion

In the present work, a method for producing specific antibodies against bacteria is introduced to recognize bacterial components in body fluids of patients suffering from pathogenic biofilms. This diagnostic technique may be most useful in clinical microbiology and in the choice of antibiotics in the treatment of serious infections.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-016-0821-5) contains supplementary material, which is available to authorized users.

Characterization of Inflammatory Response in Acute-on-Chronic Liver Failure and Relationship with Prognosis

ACLF is characterized by a systemic inflammatory response, but the cytokines involved in this process have not been well studied. The aim of this study was to characterize the systemic inflammatory response in patients with cirrhosis and ACLF and its relationship with prognosis. Fifty-five patients with cirrhosis, 26 with ACLF, were studied prospectively. Systemic inflammatory response was analyzed by measuring a large array of plasma cytokines by using a multiplex kit. A principal component analysis show noticeable differences between ACLF and decompensated cirrhosis without ACLF. Patients with ACLF had significant abnormal levels of 12 cytokines compared to those without ACLF, including: VCAM-1, VEGF-A, Fractalkine, MIP-1α, Eotaxin, IP-10, RANTES, GM-CSF, IL-1β, IL-2, ICAM-1, and MCP-1. Cytokines showing the most marked relationship with ACLF were VCAM-1 and VEGF-A (AUCROC 0.77; p = 0.001). There was a significant relationship between some of inflammatory mediators and 3-month mortality, particularly VCAM-1, ICAM-1, and GM-CSF (AUCROC>0.7; p < 0.05). Functional Enrichment Analysis showed that inflammatory markers differentially expressed in ACLF patients were enriched in leukocyte migration, particularly monocytes and macrophages, and chemotaxis pathways. In conclusion, ACLF is characterized by a marked inflammatory reaction with activation of mediators of adhesion and migration of leukocytes. The intensity of the inflammatory reaction correlates with prognosis.

The prognostic significance of bacterial DNA in patients with decompensated cirrhosis and suspected infection

BACKGROUND & AIMS

Circulating and peritoneal fragments of microbial DNA (bactDNA) are evidence for bacterial translocation in decompensated cirrhosis and may serve as a rational approach for antibiotic therapy when infection is suspected.

METHODS

Prospective multicenter study to investigate whether identification of bactDNA from blood or ascitic fluid (AF) by multiplex polymerase chain reaction (PCR) is associated with increased 90-day mortality in 218 patients with cirrhosis and signs of infection.

RESULTS

BactDNA in either compartment was detected in 134 (61%) patients, comprising 54 with bactDNA in blood and AF, 48 with AF bactDNA only, and 32 with blood bactDNA only. BactDNA was associated with spontaneous bacterial peritonitis and blood stream infections (SBP/BSI), acute-on-chronic liver failure (ACLF), encephalopathy and markers of inflammation. The prevalence of bactDNA in patients with proven SBP/BSI (36/49; 73%) was similar to that in patients with sterile ACLF (37/52; 71%). Actuarial 90-day survival was 56 ± 5% in the absence of bactDNA in both compartments and did not differ if bactDNA was detected in blood only (63 ± 9%), AF only (63 ± 7%), or in blood and AF (52 ± 7%). Predictors of 90-day mortality were SBP (HR = 3.10; 95% CI: 1.90-5.06), BSI (HR = 4.94; 95% CI: 2.71-9.02), and ACLF (HR = 2.20; 95% CI: 1.44-3.35). The detection of resistance genes in blood or AF in the absence of SBP/BSI (n = 11) was associated with poor 1-year survival (HR = 2.35; 95% CI: 1.03-5.35).

CONCLUSIONS

BactDNA in sterile body fluids did not indicate increased mortality in cirrhotic patients with suspected infection. Using multiplex PCR for risk stratification cannot be recommended in these patients.

Urine Monocyte Chemoattractant Protein-1 Is an Independent Predictive Factor of Hospital Readmission and Survival in Cirrhosis

MCP-1 (monocyte chemoattractant protein-1) is a proinflammatory cytokine involved in chemotaxis of monocytes. In several diseases, such as acute coronary syndromes and heart failure, elevated MCP-1 levels have been associated with poor outcomes. Little is known about MCP-1 in cirrhosis.

AIM

To investigate the relationship between MCP-1 and outcome in decompensated cirrhosis.

METHODS

Prospective study of 218 patients discharged from hospital after an admission for complications of cirrhosis. Urine and plasma levels of MCP-1 and other urine proinflammatroy biomarkers: osteopontin(OPN), trefoil-factor3 and liver-fatty-acid-binding protein were measured at admission. Urine non-inflammatory mediators cystatin-C, β2microglobulin and albumin were measured as control biomarkers. The relationship between these biomarkers and the 3-month hospital readmission, complications of cirrhosis, and mortality were assessed.

RESULTS

69 patients(32%) had at least one readmission during the 3-month period of follow-up and 30 patients died(14%). Urine MCP-1 and OPN levels, were associated with 3-month probability of readmission (0.85 (0.27-2.1) and 2003 (705-4586) ug/g creat vs 0.47 (0.2-1.1) and 1188 (512-2958) ug/g creat, in patients with and without readmission, respectively; p<0.05; median (IQR)). Furthermore, urine levels of MCP-1 were significantly associated with mortality (1.01 (1-3.6) vs 0.5 (0.2-1.1) μg/g creat, in dead and alive patients at 3 months; p<0.05). Patients with higher levels of urine MCP-1 (above percentile 75th) had higher probability of development of hepatic encephalopathy, bacterial infections or AKI. Urine MCP-1 was an independent predictive factor of hospital readmission and combined end-point of readmission or dead at 3 months. Plasma levels of MCP-1 did not correlated with outcomes.

CONCLUSION

Urine, but not plasma, MCP-1 levels are associated with hospital readmission, development of complications of cirrhosis, and mortality. These results suggest that in cirrhosis there is an inflammatory response that is associated with poor outcomes.

Investigation of NS3 Protease Resistance-Associated Variants and Phenotypes for the Prediction of Treatment Response to HCV Triple Therapy

Triple therapy of chronic hepatitis C virus (HCV) infection with boceprevir (BOC) or telaprevir (TVR) leads to virologic failure in many patients which is often associated with the selection of resistance-associated variants (RAVs). These resistance profiles are of importance for the selection of potential rescue treatment options. In this study, we sequenced baseline NS3 RAVs population-based and investigated the sensitivity of NS3 phenotypes in an HCV replicon assay together with clinical factors for a prediction of treatment response in a cohort of 165 German and Swiss patients treated with a BOC or TVR-based triple therapy. Overall, the prevalence of baseline RAVs was low, although the frequency of RAVs was higher in patients with virologic failure compared to those who achieved a sustained virologic response (SVR) (7% versus 1%, P = 0.06). The occurrence of RAVs was associated with a resistant NS3 quasispecies phenotype (P<0.001), but the sensitivity of phenotypes was not associated with treatment outcome (P = 0.2). The majority of single viral and host predictors of SVR was only weakly associated with treatment response. In multivariate analyses, low AST levels, female sex and an IFNL4 CC genotype were independently associated with SVR. However, a combined analysis of negative predictors revealed a significantly lower overall number of negative predictors in patients with SVR in comparison to individuals with virologic failure (P<0.0001) and the presence of 2 or less negative predictors was indicative for SVR. These results demonstrate that most single baseline viral and host parameters have a weak influence on the response to triple therapy, whereas the overall number of negative predictors has a high predictive value for SVR.

Cirrhosis is a risk factor for total hip arthroplasty for avascular necrosis

Background and purpose - There are limited data on risk factors for avascular necrosis of the hip, but cirrhosis has been proposed as a risk factor. We examined the association between cirrhosis and incidence of total hip arthroplasty for avascular necrosis. Methods - We used nationwide healthcare data to identify all Danish residents diagnosed with cirrhosis in 1994-2011, and matched them 1:5 by age and sex to non-cirrhotic reference individuals from the general population. We excluded people with a previous total hip arthroplasty, a previous hip fracture, or a previous diagnosis of avascular necrosis. We used stratified Cox regression to estimate the hazard ratio (HR) for cirrhosis patients relative to reference individuals, adjusting for potential confounders. We used the cumulative incidence function to compute 5-year risks. Results - We included 25,421 cirrhosis patients and 114,052 reference individuals. Their median age was 57 years, and 65% were men. 45 cirrhosis patients and 44 reference individuals underwent total hip arthroplasty for avascular necrosis. Cirrhosis patients' HR for a total hip arthroplasty for avascular necrosis was 10 (95% CI: 6-17), yet their 5-year risk of avascular necrosis was only 0.2%. For the reference individuals, the 5-year risk was 0.02%. Interpretation - Cirrhosis is a strong risk factor for avascular necrosis of the hip, but it is rare even in cirrhosis patients.

Impaired intracellular signaling, myeloperoxidase release and bactericidal activity of neutrophils from patients with alcoholic cirrhosis

BACKGROUND & AIMS

Myeloperoxidase exocytosis and production of hydrogen peroxide via the neutrophil superoxide-generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidase contribute to efficient elimination of bacteria. Cirrhosis impairs immune functions and increases susceptibility to bacterial infection. We recently showed that neutrophils from patients with decompensated alcoholic cirrhosis exhibit a severe impairment of formylpeptide receptor (fPR)-mediated intracellular signaling and superoxide production. Here, we performed ex vivo studies with these patients' neutrophils to further investigate myeloperoxidase release, bactericidal capacity and signaling events following fPR stimulation by the formylpeptide formyl-met-leu-phe (fMLP).

METHODS

Myeloperoxidase release was studied by measuring extracellular myeloperoxidase activity. Activation of signaling effectors was studied by Western blot and their respective contribution to myeloperoxidase release studied using pharmacological antagonists.

RESULTS

fMLP-induced myeloperoxidase release was strongly impaired in patients' neutrophils whereas the intracellular myeloperoxidase stock was unaltered. The fMLP-induced phosphorylation of major signaling effectors, AKT, ERK1/2 and p38-MAP-Kinases, was also strongly deficient despite a similar expression of signaling effectors or fPR. However, based on effector inhibition in healthy neutrophils, AKT and p38-MAPK but not ERK1/2 upregulated fMLP-induced myeloperoxidase exocytosis. Interestingly, patients' neutrophils exhibited a defective bactericidal capacity that was reversed ex vivo by the TLR7/8 agonist CL097, through potentiation of the fMLP-induced AKT/p38-MAPK signaling axis and myeloperoxidase release.

CONCLUSIONS

We provide first evidence that neutrophils from patients with decompensated alcoholic cirrhosis exhibit a deficient AKT/p38-MAPK signaling, myeloperoxidase release and bactericidal activity, which can be reversed via TLR7/8 activation. These defects, together with the previously described severe deficient superoxide production, may increase cirrhotic patients' susceptibility to bacterial infections.

Obeticholic acid reduces bacterial translocation and inhibits intestinal inflammation in cirrhotic rats

BACKGROUND & AIMS

In advanced cirrhosis, gut bacterial translocation is the consequence of intestinal barrier disruption and leads to bacterial infection. Bile acid abnormalities in cirrhosis could play a role in the integrity of the intestinal barrier and the control of microbiota, mainly through the farnesoid X receptor. We investigated the long-term effects of the farnesoid X receptor agonist, obeticholic acid, on gut bacterial translocation, intestinal microbiota composition, barrier integrity and inflammation in rats with CCl4-induced cirrhosis with ascites.

METHODS

Cirrhotic rats received a 2-week course of obeticholic acid or vehicle starting once ascites developed. We then determined: bacterial translocation by mesenteric lymph node culture, ileum expression of antimicrobial peptides and tight junction proteins by qPCR, fecal albumin loss, enteric bacterial load and microbiota composition by qPCR and pyrosequencing of ileum mucosa-attached contents, and intestinal inflammation by cytometry of the inflammatory infiltrate.

RESULTS

Obeticholic acid reduced bacterial translocation from 78.3% to 33.3% (p<0.01) and upregulated the expression of the farnesoid X receptor-associated gene small heterodimer partner. Treatment improved ileum expression of antimicrobial peptides, angiogenin-1 and alpha-5-defensin, tight junction proteins zonulin-1 and occludin, and reduced fecal albumin loss and liver fibrosis. Enteric bacterial load normalized, and the distinctive mucosal microbiota of cirrhosis was reduced. Gut immune cell infiltration was reduced and inflammatory cytokine and Toll-like receptor 4 expression normalized.

CONCLUSIONS

In ascitic cirrhotic rats, obeticholic acid reduces gut bacterial translocation via several complementary mechanisms at the intestinal level. This agent could be used as an alternative to antibiotics to prevent bacterial infection in cirrhosis.

Epidemiology of bacterial infections in patients with liver cirrhosis. Experience in a Spanish tertiary health center

INTRODUCTION

Bacterial infections represent a serious complication of liver cirrhosis. Traditionally, Gram negative bacteria have been described as the microorganisms responsible for the majority of the infections. However, in the past few years, changes in the microbiological spectrum have been described, and multiresistant bacteria are observed more frequently. 

OBJECTIVE

To assess the proportion of patients with infections caused by multiresistant bacteria admitted to our hospital, and to obtain information about their epidemiology, risk factors and clinical impact. 

MATERIALS AND METHODS

We performed a retrospective evaluation of 294 cirrhotic patients admitted to our unit due to infection between June, 2011, and June, 2013. 

RESULTS

We isolated 310 microorganisms from 294 patients; 109 (35.2%) were Gram positive, 167 (53.9%), Gram negative, and 34, fungi (11%). As for the microbiological agents, the most frequent was Escherichia coli (98 isolations). The infection was community-acquired in 22.9% of cases, healthcareassociated in 38.1% and nosocomial in 39%. Worse liver infections and septic shock were more frequent among patients with multiresistant isolates (p=0.05); and intrahospital mortality was also higher among them (p=0.017). Previous hospital admission, antibiotic treatment 60 days before, nosocomial or healthcare-associated acquisition and bacterial isolation in control cultures were identified as possible risk factors for the development of multiresistant infection. 

DISCUSSION

The results of our study confirm that important changes have ocurred in the microbiological spectrum of bacterial infections in patients with liver cirrhosis. Multiresistant bacteria are associated with high morbidity and mortality, as well as failure of traditional antibiotic treatment. Successfull control of the infection requires an early identification of patients at risk.

Cancer Risk in Patients With Empyema: A Nationwide Population-Based Study

This study aimed to evaluate cancer risk and possible risk factors in patients diagnosed with empyema. A total of 31,636 patients with newly diagnosed empyema between January 1, 1999 and December 31, 2010 were included in this study. Standardized incidence ratios (SIRs) were calculated to compare the cancer incidence in these empyema patients to that in the general population. Adjusted hazard ratios were also calculated to investigate whether characteristics increased cancer risk. During the 12-year study period, 2,654 cancers occurred in 31,636 patients with empyema, yielding an SIR of 2.67 (95% confidence interval [CI] 2.57-2.78). We excluded cancer that occurred within 1 year to avoid surveillance bias. The cancer risk remained significantly increased (SIR 1.50, 95% CI 1.41-1.58). Specifically, patients with empyema had higher SIR of cancers of the head and neck (1.50, 95% CI 1.41-1.58), esophagus (2.56, 95% CI 1.92-3.33), stomach (1.49, 95% CI 1.16-1.89), liver and biliary tract (2.18, 95% CI 1.93-2.45), and lung and mediastinum (1.62, 95% CI 1.39-1.86). Age ≥ 60, male sex, diabetes mellitus, and liver cirrhosis were independent risk factors for cancer development. Our study demonstrates an increased incidence of cancer development in patients with empyema, and patients' age ≥ 60, men, and those with diabetes mellitus and liver cirrhosis showed a higher incidence of developing cancer compared to the general population. The association between such kind of infection and secondary malignancy may be elucidated by further study.

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

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

Bloodstream infections in patients with liver cirrhosis

Bloodstream infections are a serious complication in patients with liver cirrhosis. Dysregulated intestinal bacterial translocation is the predominant pathophysiological mechanism of infections in this setting. For this reason enteric Gram-negative bacteria are commonly encountered as the first etiological cause of infection. However, through the years, the improvement in the management of cirrhosis, the recourse to invasive procedures and the global spread of multidrug resistant pathogens have importantly changed the current epidemiology. Bloodstream infections in cirrhotic patients are characterized by high mortality rate and complications including metastatic infections, infective endocarditis, and endotipsitis (or transjugular intrahepatic portosystemic shunt-related infection). For this reason early identification of patients at risk for mortality and appropriated therapeutic management is mandatory. Liver cirrhosis can significantly change the pharmacokinetic behavior of antimicrobials. In fact hypoproteinaemia, ascitis and third space expansion and impairment of renal function can be translated in an unpredictable drug exposure.

Soluble Adhesion Molecules in Patients Coinfected with HIV and HCV: A Predictor of Outcome

BACKGROUND

Higher serum levels of adhesion molecules (sICAM-1 and sVCAM-1) are associated with advanced liver fibrosis in patients coinfected with human immunodeficiency virus and hepatitis C virus. We assessed the relationship between serum levels of adhesion molecules and liver-related events (LRE) or death, in coinfected patients.

METHODS

We studied clinical characteristics and outcomes of 182 coinfected patients with a baseline liver biopsy (58 with advanced fibrosis) and simultaneous plasma samples who were followed for median of 9 years. We used receiver-operating characteristic (ROC) curves to calculate optimized cutoff values (OCV) of sICAM-1 and sVCAM-1, defined as the values with the highest combination of sensitivity and specificity for LRE. We used multivariate regression analysis to test the association between OCVs of sICAM-1 and sVCAM-1 and outcomes. The variables for adjustment were age, HIV transmission category, liver fibrosis, baseline CD4+ T-cell counts, antiretroviral therapy, and sustained virologic response (SVR).

RESULTS

During the study period 51 patients had SVR, 19 had LRE, and 16 died. The OCVs for LRE were 5.68 Log pg/mL for sICAM-1 and 6.25 Log pg/mL for sVCAM-1, respectively. The adjusted subhazard ratio (aSHR) (95% confidence interval [CI]) of death or LRE, whichever occurred first, for sICAM-1 and sVCAM-1 > OCV were 3.98 ([1.14; 13.89], P = 0.030) and 2.81 ([1.10; 7.19], respectively (P = 0.030).

CONCLUSIONS

Serum levels of sICAM-1 and sVCAM-1 can serve as markers of outcome in HIV/HCV-coinfected patients. Therapies targeting necroinflammatory damage and fibrogenesis may have a role in the management chronic hepatitis C.

A variant in the nuclear dot protein 52kDa gene increases the risk for spontaneous bacterial peritonitis in patients with alcoholic liver cirrhosis

BACKGROUND

Spontaneous bacterial peritonitis is frequently a fatal infection in patients with liver cirrhosis. We investigated if nuclear dot protein 52kDa (NDP52), a negative regulator of toll-like receptor (TLR) signalling and autophagy adaptor protein, might be involved.

METHODS

Two cohorts comprising 152 (derivation cohort) and 198 patients (validation cohort) with decompensated liver cirrhosis and 168 healthy controls were genotyped for the rs2303015 polymorphism in the NDP52 gene and prospectively followed-up for spontaneous bacterial peritonitis.

RESULTS

Overall, 57 (38%) patients in the derivation cohort and 77 (39%) in the validation cohort had spontaneous bacterial peritonitis. Cirrhosis was due to alcohol abuse in 57% of the derivation and 66% of the validation cohort. In patients with alcoholic cirrhosis, patients with spontaneous bacterial peritonitis had an increased frequency of the NDP52 rs2303015 minor variant in the derivation (p=0.04) and in the validation cohort (p=0.01). Multivariate analysis confirmed this minor variant (odds ratio 4.7, p=0.002) and the TLR2 -16934 TT variant (odds ratio 2.5, p=0.008) as risk factors for spontaneous bacterial peritonitis. In addition, presence of the NDP52 minor variant affected survival negatively.

CONCLUSION

Presence of the NDP52 rs2303015 minor variant increases the risk for spontaneous bacterial peritonitis in patients with alcoholic cirrhosis.

Bifidobacterium pseudocatenulatum CECT7765 induces an M2 anti-inflammatory transition in macrophages from patients with cirrhosis

BACKGROUND & AIMS

Patients with cirrhosis show recurrent access of bacterial products into the bloodstream inducing a multi-altered immunological status leading to relevant complications. We aimed at evaluating Bifidobacterium pseudocatenulatum CECT7765 effect on the host's macrophage function.

PATIENTS & METHODS

Patients with cirrhosis and ascites were included. Granulocyte-macrophage colony-stimulating factor (GM-CSF) monocyte-derived and ascitic fluid (AF) macrophages were cultured with M-CSF, lipopolysaccharide (LPS) and/or the bifidobacterial strain. Pellets and supernatants were evaluated for gene expression of M1 and M2-related genes and cytokine secretion. Cell surface expression molecules were evaluated by flow cytometry. Kupffer cells from bile duct ligated and CCl4 rats were also evaluated.

RESULTS

Experiments were run on GM-CSF blood-derived and AF macrophages from 10 patients with cirrhosis and 10 healthy donors. Different macrophage morphology was observed by optical microscopy in cells stimulated with bifidobacteria vs. LPS. M2-like expression of CD206, CD163 and CD16 was significantly increased in macrophages after stimulation with the bifidobacterial strain vs. LPS. B. pseudocatenulatum CECT7765 was able to significantly change the cytokine secretion pattern of blood-derived and AF macrophages and Kupffer cells from bile duct ligated and CCl4 cirrhotic rats compared to that induced by LPS. B. pseudocatenulatum CECT7765 was also effective in inducing a phenotype transition and a functional change from an M1- to an M2-related gene expression and cytokine secretion pattern in AF macrophages even after LPS-pretreatment. B. pseudocatenulatum CECT7765 did not reduce AF macrophage bacterial killing capacity.

CONCLUSION

B. pseudocatenulatum CECT7765 induces a morphologic, phenotypic and functional transition towards an anti-inflammatory profile in GM-CSF monocyte-derived and AF macrophages from patients with cirrhosis that may help in controlling sustained inflammation in decompensated cirrhosis.

Decreased Diversity of the Oral Microbiota of Patients with Hepatitis B Virus-Induced Chronic Liver Disease: A Pilot Project

Increasing evidence suggests that altered gut microbiota is implicated in the pathogenesis of hepatitis B virus-induced chronic liver disease (HBV-CLD). However, the structure and composition of the oral microbiota of patients with HBV-CLD remains unclear. High-throughput pyrosequencing showed that decreased oral bacterial diversity was found in patients with HBV-CLD. The Firmicutes/Bacteroidetes ratio was increased significantly, which indicated that dysbiosis of the oral microbiota participated in the process of HBV-CLD development. However, the changing patterns of the oral microbiota in patients with HBV-induced liver cirrhosis (LC) were almost similar to patients with chronic hepatitis B (CHB). HBV infection resulted in an increase in potential H₂S- and CH₃SH-producing phylotypes such as Fusobacterium, Filifactor, Eubacterium, Parvimonas and Treponema, which might contribute to the increased oral malodor. These key oral-derived phylotypes might invade into the gut as opportunistic pathogens and contribute to altering the composition of the gut microbiota. This study provided important clues that dysbiosis of the oral microbiota might be involved in the development of HBV-CLD. Greater understanding of the relationships between the dysbiosis of oral microbiota and the development of HBV-CLD might facilitate the development of non-invasive differential diagnostic procedures and targeted treatments of HBV-CLD patients harbouring specific oral phylotypes.

Acute-on-chronic liver failure: Pathogenesis, prognostic factors and management

Acute-on-chronic liver failure (ACLF) is increasingly recognized as a complex syndrome that is reversible in many cases. It is characterized by an acute deterioration of liver function in the background of a pre-existing chronic liver disease often associated with a high short-term mortality rate. Organ failure (OF) is always associated, and plays a key role in determining the course, and the outcome of the disease. The definition of ACLF remains controversial due to its overall ambiguity, with several disparate criteria among various associations dedicated to the study of liver diseases. Although the precise pathogenesis needs to be clarified, it appears that an altered host response to injury might be a contributing factor caused by immune dysfunction, ultimately leading to a pro-inflammatory status, and eventually to OF. The PIRO concept (Predisposition, Insult, Response and Organ Failure) has been proposed to better approach the underlying mechanisms. It is accepted that ACLF is a different and specific form of liver failure, where a precipitating event is always involved, even though it cannot always be ascertained. According to several studies, infections and active alcoholism often trigger ACLF. Viral hepatitis, gastrointestinal haemorrhage, or drug induced liver injury, which can also provoke the syndrome. This review mainly focuses on the physiopathology and prognostic aspects. We believe these features are essential to further understanding and providing the rationale for improveddisease management strategies.

Inflammatory status in human hepatic cirrhosis

This review focuses on new findings about the inflammatory status involved in the development of human liver cirrhosis induced by the two main causes, hepatitis C virus (HCV) infection and chronic alcohol abuse, avoiding results obtained from animal models. When liver is faced to a persistent and/or intense local damage the maintained inflammatory response gives rise to a progressive replacement of normal hepatic tissue by non-functional fibrotic scar. The imbalance between tissue regeneration and fibrosis will determine the outcome toward health recovery or hepatic cirrhosis. In all cases progression toward liver cirrhosis is caused by a dysregulation of mechanisms that govern the balance between activation/homeostasis of the immune system. Detecting differences between the inflammatory status in HCV-induced vs alcohol-induced cirrhosis could be useful to identify specific targets for preventive and therapeutic intervention in each case. Thus, although survival of patients with alcoholic cirrhosis seems to be similar to that of patients with HCV-related cirrhosis (HCV-C), there are important differences in the altered cellular and molecular mechanisms implicated in the progression toward human liver cirrhosis. The predominant features of HCV-C are more related with those that allow viral evasion of the immune defenses, especially although not exclusively, inhibition of interferons secretion, natural killer cells activation and T cell-mediated cytotoxicity. On the contrary, the inflammatory status of alcohol-induced cirrhosis is determined by the combined effect of direct hepatotoxicity of ethanol metabolites and increases of the intestinal permeability, allowing bacteria and bacterial products translocation, into the portal circulation, mesenteric lymph nodes and peritoneal cavity. This phenomenon generates a stronger pro-inflammatory response compared with HCV-related cirrhosis. Hence, therapeutic intervention in HCV-related cirrhosis must be mainly focused to counteract HCV-immune system evasion, while in the case of alcohol-induced cirrhosis it must try to break the inflammatory loop established at the gut-mesenteric lymph nodes-peritoneal-systemic axis.

Mechanisms of decompensation and organ failure in cirrhosis: From peripheral arterial vasodilation to systemic inflammation hypothesis

The peripheral arterial vasodilation hypothesis has been most influential in the field of cirrhosis and its complications. It has given rise to hundreds of pathophysiological studies in experimental and human cirrhosis and is the theoretical basis of life-saving treatments. It is undisputed that splanchnic arterial vasodilation contributes to portal hypertension and is the basis for manifestations such as ascites and hepatorenal syndrome, but the body of research generated by the hypothesis has revealed gaps in the original pathophysiological interpretation of these complications. The expansion of our knowledge on the mechanisms regulating vascular tone, inflammation and the host-microbiota interaction require a broader approach to advanced cirrhosis encompassing the whole spectrum of its manifestations. Indeed, multiorgan dysfunction and failure likely result from a complex interplay where the systemic spread of bacterial products represents the primary event. The consequent activation of the host innate immune response triggers endothelial molecular mechanisms responsible for arterial vasodilation, and also jeopardizes organ integrity with a storm of pro-inflammatory cytokines and reactive oxygen and nitrogen species. Thus, the picture of advanced cirrhosis could be seen as the result of an inflammatory syndrome in contradiction with a simple hemodynamic disturbance.

Acute-on-Chronic Liver Failure

Over the past 2 decades, the concept of acute-on-chronic liver failure (ACLF) has been proposed as an alternate path in the natural history of decompensated cirrhosis. ACLF thus is characterized by the presence of a precipitating event (identified or unidentified) in subjects with underlying chronic liver disease leading to rapid progression of liver injury and ending in multi-organ dysfunction characterized by high short-term mortality. Multiple organ failure and an increased risk for mortality are key to the diagnosis of ACLF. The prevalence of ACLF ranges from 24% to 40% in hospitalized patients. The pathophysiological basis of ACLF can be explained using the following 4-part model: predisposing event, injury caused by a precipitating event, response to injury, and organ failure. Although several mathematic scores have been proposed for identifying outcomes with ACLF, it is as yet unclear whether these organ failure scores are truly prognostic or only reflective of the dying process. Treatment paradigms continue to evolve but consist of early recognition, supportive intensive care, and consideration of liver transplantation before onset of irreversible multiple organ failure.

Neutrophil dysfunction in patients with liver cirrhosis

Liver cirrhosis is the final stage of chronic liver disease of any causes, in which the defensive reaction to infections is reducing. Patients with liver cirrhosis are at an increased risk of infections, sepsis and death. Neutrophils are an essential component of the innate immune response and the first line of defense to resist all kinds of detrimental factor, and participate in specific immunity. Immune dysfunction in cirrhosis is associated with neutrophil dysfunction. This paper reviews the neutrophil dysfunction and its pathogenesis in liver cirrhosis.

Clinical and pathophysiological consequences of alterations in the microbiome in cirrhosis

Cirrhosis is a major cause of mortality worldwide. Exponential rises in prevalence have been observed secondary to increases in obesity and alcohol consumption. Multiple lines of evidence implicate gut-derived bacteria and bacterial ligands as a central driver of pathogenesis. Recent developments in culture-independent techniques have facilitated a more accurate description of microbiome composition in cirrhosis and led to the description of measures of dysbiosis shown to be associated with disease. More importantly, metagenomic studies are adding to an understanding of the functional contribution of the microbiota and may prove to be a more clinically relevant biomarker than phylogenetic studies. Much like other dysbiotic states such as inflammatory bowel disease, the microbiota in cirrhosis is characterized by a low microbial and genetic diversity. Therapeutic strategies to diminish this process are currently limited to selective intestinal decontamination with antibiotics. This review summarizes the available data and develops a framework for the use of current and future treatment strategies to diminish the consequences of dysbiosis in cirrhosis. Interventional strategies to bind bacterial products in the gut lumen and blood, and modulate the magnitude of host sensing mechanisms remain an unmet clinical need. A greater understanding of the host-microbiota interaction in cirrhosis is of key importance to inform future interventional strategies to diminish the currently escalating burden of the disease.

Salivary microbiota reflects changes in gut microbiota in cirrhosis with hepatic encephalopathy

Altered gut microbiome is associated with systemic inflammation and cirrhosis decompensation. However, the correlation of the oral microbiome with inflammation in cirrhosis is unclear. Our aim was to evaluate the oral microbiome in cirrhosis and compare with stool microbiome. Outpatients with cirrhosis (with/without hepatic encephalopathy [HE]) and controls underwent stool/saliva microbiome analysis (for composition and function) and also systemic inflammatory evaluation. Ninety-day liver-related hospitalizations were recorded. Salivary inflammation was studied using T helper 1 cytokines/secretory immunoglobulin A (IgA), histatins and lysozyme in a subsequent group. A total of 102 patients with cirrhosis (43 previous HE) and 32 age-matched controls were included. On principal component analysis (PCA), stool and saliva microbiome clustered far apart, showing differences between sites as a whole. In salivary microbiome, with previous HE, relative abundance of autochthonous families decreased whereas potentially pathogenic ones (Enterobacteriaceae, Enterococcaceae) increased in saliva. Endotoxin-related predicted functions were significantly higher in cirrhotic saliva. In stool microbiome, relative autochthonous taxa abundance reduced in previous HE, along with increased Enterobacteriaceae and Enterococcaceae. Cirrhotic stool microbiota demonstrated a significantly higher correlation with systemic inflammation, compared to saliva microbiota, on correlation networks. Thirty-eight patients were hospitalized within 90 days. Their salivary dysbiosis was significantly worse and predicted this outcome independent of cirrhosis severity. Salivary inflammation was studied in an additional 86 age-matched subjects (43 controls/43 patients with cirrhosis); significantly higher interleukin (IL)-6/IL-1β, secretory IgA, and lower lysozyme, and histatins 1 and 5 were found in patients with cirrhosis, compared to controls.

CONCLUSIONS

Dysbiosis, represented by reduction in autochthonous bacteria, is present in both saliva and stool in patients with cirrhosis, compared to controls. Patients with cirrhosis have impaired salivary defenses and worse inflammation. Salivary dysbiosis was greater in patients with cirrhosis who developed 90-day hospitalizations. These findings could represent a global mucosal-immune interface change in cirrhosis.

Intestinal barrier dysfunction in cirrhosis: Current concepts in pathophysiology and clinical implications

The intestinal lumen is a host place for a wide range of microbiota and sets a unique interplay between local immune system, inflammatory cells and intestinal epithelium, forming a physical barrier against microbial invaders and toxins. Bacterial translocation is the migration of viable or nonviable microorganisms or their pathogen-associated molecular patterns, such as lipopolysaccharide, from the gut lumen to the mesenteric lymph nodes, systemic circulation and other normally sterile extraintestinal sites. A series of studies have shown that translocation of bacteria and their products across the intestinal barrier is a commonplace in patients with liver disease. The deterioration of intestinal barrier integrity and the consulting increased intestinal permeability in cirrhotic patients play a pivotal pathophysiological role in the development of severe complications as high rate of infections, spontaneous bacterial peritonitis, hepatic encephalopathy, hepatorenal syndrome, variceal bleeding, progression of liver injury and hepatocellular carcinoma. Nevertheless, the exact cellular and molecular mechanisms implicated in the phenomenon of microbial translocation in liver cirrhosis have not been fully elucidated yet.

Role of systemic inflammation in cirrhosis: From pathogenesis to prognosis

The natural history of cirrhosis can be divided into an initial stage, known as compensated cirrhosis, and an advanced stage which encompasses both decompensated cirrhosis and acute-on-chronic liver failure (ACLF). The latter syndrome has been recently described as an acute deterioration of liver function in patients with cirrhosis, which is usually triggered by a precipitating event and results in the failure of one or more organs and high short-term mortality rates. Each stage is characterized by distinctive clinical manifestations and prognoses. One of the key elements involved in cirrhosis physiopathology is systemic inflammation, recently described as one of the components in the cirrhosis-associated immune dysfunction syndrome. This syndrome refers to the combination of immune deficiency and exacerbated inflammation that coexist during the course of cirrhosis and relates to the appearance of clinical complications. Since systemic inflammation is often difficult to assess in cirrhosis patients, new objective, reproducible and readily-available markers are needed in order to optimize prognosis and lengthen survival. Thus, surrogate serum markers and clinical parameters of systemic inflammation have been sought to improve disease follow-up and management, especially in decompensated cirrhosis and ACLF. Leukocyte counts (evaluated as total leukocytes, total eosinophils or neutrophil:lymphocyte ratio) and plasma levels of procalcitonin or C-reactive protein have been proposed as prognostic markers, each with advantages and shortcomings. Research and prospective randomized studies that validate these and other markers are clearly warranted.

Mechanisms of susceptibility to bacterial infections in cirrhotic patients

Bacterial infections are very common in cirrhotic patients, and the incidence is 4-5 times higher than that in the general population. The mechanisms of susceptibility to bacterial infections in cirrhotic patients include intestinal bacterial overgrowth, bacterial translocation, increased number of potentially pathogenic bacteria accompanied by reduced number of beneficial bacteria; small bowel motility disturbances and delayed gut transit, increased intestinal permeability; genetic predisposition to bacterial infections; immunodeficiency accompanied by persistent activation of the immune cells with production of pro-inflammatory cytokines. In this paper, we will discuss the mechanisms of susceptibility to bacterial infections in cirrhotic patients.

Sorting out cirrhosis: mechanisms of non-response to hepatitis C therapy

Although cirrhosis has long been recognized as an important negative predictor of treatment response for hepatitis C virus (HCV) therapy, the mechanisms underlying this association remain relatively poorly understood. Treatment has progressed rapidly with the introduction of highly effective all-oral therapies, with promising outcomes even in patients with advanced cirrhosis. However, even with the new therapies, it is clear that patients with cirrhosis require special attention. Efficacy continues to be somewhat reduced compared to non-cirrhotic patients and safety is an important concern. In this review, we explore the reasons for treatment non-response in patients with cirrhosis. We focus on how cirrhosis impacts on four important areas including drug delivery, drug uptake and metabolism, immune responses and drug toxicity with examples from the clinical and basic literature. Fortunately, as treatment continues to progress, many of the challenges of treating patients with cirrhosis will become less and less problematic.

Impact of clinically evident portal hypertension on the course of hepatocellular carcinoma in patients listed for liver transplantation

Liver transplantation (LT) is the best curative treatment for early hepatocellular carcinoma (HCC) in patients with cirrhosis. However, the current shortage of organs causes prolonged waiting times and poorer intention-to-treat (ITT) survival (i.e., after listing) owing to tumor progression and dropout. Portal hypertension (PH) is a recognized risk factor of HCC development in patients with cirrhosis and its recurrence after resection. The aim of this study was to evaluate the potential impact of PHT on the results of LT on an ITT basis. Patients with cirrhosis listed for LT for HCC were included and their outcomes after listing were compared according to the presence or absence of PH defined as presence of esophageal varices or ascites or low platelet count and splenomegaly. Among 243 consecutively listed patients, 70% were affected by PH, which was associated with a significantly higher risk of tumor progression (38% vs. 22%; P = 0.017) and a higher risk of dropout (22% vs. 8%; P = 0.01). Transarterial chemoembolization (TACE) was similarly applied to the two groups (60% vs. 67%; P = 0.325). An absence of TACE was the only other independent risk factor of dropout owing to tumor progression. Under an ITT analysis, PH reduced overall survival (OS), but there was no difference in OS and time to recurrence post-LT. The only pathological feature that could potentially explain this observation was the lower complete response to TACE in the PHT group (12% vs. 36%; P = 0.001).

CONCLUSION

PH should be regarded as a major risk factor of dropout owing to tumor progression and should be taken into consideration when managing patients with HCC who are waiting for LT.

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

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

Treatment to improve acute kidney injury in cirrhosis

OPINION STATEMENT

Acute kidney injury (AKI) is an ominous complication of decompensated cirrhosis, which can be fatal if not treated promptly. It is important that clinicians recognize that AKI has occurred and institute timely treatment. Recent establishment of diagnostic criteria and treatment guidelines are most useful, and these will be further refined as treatments are being modified to improve patient outcome. To manage such a patient, firstly, the cause of the AKI needs to be identified and any precipitating factors corrected. Bacterial infections are a common cause of AKI in cirrhosis, and it is recommended to offer empirical antibiotics in cases of suspicious bacterial infection until all the cultures are negative. Patients should be given albumin infusion in doses of 1 g/kg of body weight for at least 2 days. This can improve the filling of the central circulation, and also absorb many of the bacterial products or inflammatory cytokines that play a role in mediating the renal dysfunction. Often, albumin infusion alone may be sufficient to reverse the AKI. For patients who have acute or type 1 hepatorenal syndrome (HRS1), which is a special form of AKI, pharmacotherapy in the form of vasoconstrictor will be needed. The vasoconstrictor can be terlipressin, norepinephrine, or midodrine, depending on the local availability of drugs or facilities. Currently, approximately 40 % of patients will respond to a combination of vasoconstrictor and albumin. All patients with HRS1 should be assessed for liver transplant. If accepted for liver transplantation, those patients who do not respond to vasocontrictors and albumin need to be started on renal replacement therapy, which otherwise has no place in the treatment of HRS1. Once listed, liver transplantation should occur promptly, preferable under 2 weeks. Otherwise, the chances for renal recovery after liver transplant are significantly reduced, necessitating a renal transplant at the future date.

Hematogenous dissemination of Candida dubliniensis causing spondylodiscitis and spinal abscess in a HIV-1 and HCV-coinfected patient

We report a case of spondylodiscitis and spinal abscess following haematogenous dissemination of the emerging yeast Candida dubliniensis in a human immunodeficiency virus-1 (HIV-1) and hepatitis C virus (HCV)-coinfected patient. Although C. dubliniensis is considered less virulent compared to its closest known relative Candida albicans, reports of severe fungal infections are increasing. This case indicates that the pathogenicity of C. dubliniensis may be higher than previously believed. Therefore fungal infections caused by this dimorph fungus should be kept in mind in immunocompromised patients with spondylodiscitis and spinal abscess.