Elevated soluble tumor necrosis factor receptor 75 concentrations identify patients with liver cirrhosis at risk of death

Mechanisms of immunity in acutely decompensated cirrhosis and acute-on-chronic liver failure

The identification of systemic inflammation (SI) as a central player in the orchestration of acute-on-chronic liver failure (ACLF) has opened new avenues for the understanding of the pathophysiological mechanisms underlying this disease condition. ACLF, which develops in patients with acute decompensation of cirrhosis, is characterized by single or multiple organ failure and high risk of short-term (28-day) mortality. Its poor outcome is closely associated with the severity of the systemic inflammatory response. In this review, we describe the key features of SI in patients with acutely decompensated cirrhosis and ACLF, including the presence of a high blood white cell count and increased levels of inflammatory mediators in systemic circulation. We also discuss the main triggers (i.e. pathogen- and damage-associated molecular patterns), the cell effectors (i.e. neutrophils, monocytes and lymphocytes), the humoral mediators (acute phase proteins, cytokines, chemokines, growth factors and bioactive lipid mediators) and the factors that influence the systemic inflammatory response that drive organ failure and mortality in ACLF. The role of immunological exhaustion and/or immunoparalysis in the context of exacerbated inflammatory responses that predispose ACLF patients to secondary infections and re-escalation of end-organ dysfunction and mortality are also reviewed. Finally, several new potential immunogenic therapeutic targets are debated.

Clinical Implications of Inflammation in Patients With Cirrhosis

Cirrhosis-associated immune dysfunction refers to the concurrent systemic inflammation and immunoparesis evident across the disease spectrum of chronic liver disease, ranging from the low-grade inflammatory plasma milieu that accompanies compensated disease to the intense high-grade inflammatory state with coexistent severe immune paralysis that defines acute decompensation and acute-on-chronic liver failure. Systemic inflammation plays a crucial role in the disease course of cirrhosis and is a key driver for acute decompensation and the progression from compensated to decompensated cirrhosis. Severe systemic inflammation is fundamental to the development of organ dysfunction and failure and, in its most extreme form, acute-on-chronic liver failure. Systemic inflammation propagates the development of hepatic encephalopathy and hepatorenal syndrome-acute kidney injury. It may also be involved in the pathogenesis of further complications such as hepatocellular carcinoma and mental illness. Those patients with the most profound systemic inflammation have the worst prognosis. Systemic inflammation exerts its negative clinical effects through a number of mechanisms including nitric oxide-mediated increased splanchnic vasodilation, immunopathology, and metabolic reallocation.

Beta-blockers in patients with liver cirrhosis: Pragmatism or perfection?

With increasing decompensation, hyperdynamic circulatory disturbance occurs in liver cirrhosis despite activation of vasoconstrictors. Here, the concept of a therapy with non-selective beta-blockers was established decades ago. They lower elevated portal pressure, protect against variceal hemorrhage, and may also have pleiotropic immunomodulatory effects. Recently, the beneficial effect of carvedilol, which blocks alpha and beta receptors, has been highlighted. Carvedilol leads to "biased-signaling" via recruitment of beta-arrestin. This effect and its consequences have not been sufficiently investigated in patients with liver cirrhosis. Also, a number of questions remain open regarding the expression of beta-receptors and its intracellular signaling and the respective consequences in the intra- and extrahepatic tissue compartments. Despite the undisputed role of non-selective beta-blockers in the treatment of liver cirrhosis, we still can improve the knowledge as to when and how beta-blockers should be used in which patients.

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.

Elevated liver stiffness is linked to increased biomarkers of inflammation and immune activation in HIV/hepatitis C virus-coinfected patients

OBJECTIVES

Immune dysregulation is a hallmark of HIV and hepatitis C virus (HCV) infections. We aimed to evaluate the relationship between liver stiffness measurement (LSM) and biomarkers of T-cell activation, bacterial translocation, inflammation, endothelial dysfunction, and coagulopathy in HIV/HCV-coinfected patients.

DESIGN

Cross-sectional study.

METHODS

We studied 238 HIV/HCV-coinfected patients, 32 healthy controls, and 39 HIV-monoinfected patients. Patients were stratified according to LSM into four groups: less than 12.5, 12.5-25, 25-40, and more than 40 kPa. T-cell subsets were measured using flow cytometry and plasma biomarkers using immunoassays.

RESULTS

HIV/HCV-coinfected patients had higher biomarker levels of immune activation in peripheral blood [T-cell activation (CD4CD38 and CD8CD38), bacterial translocation (soluble CD14), inflammation [IL-1b, IL-6, IL-8, IL-18, IFN-γ-inducible protein 10 (IP-10)] endothelial dysfunction [soluble vascular cell adhesion molecule 1 (sVCAM1), soluble intercellular cell adhesion molecule 1 (sICAM1), and soluble tumor necrosis factor receptor 1 (sTNFR1)], and coagulopathy (plasminogen activator inhibitor-1)] than healthy controls and HIV-monoinfected patients. Moreover, in HIV/HCV-coinfected patients, a direct relationship between LSM and immune activation [T-cell activation (CD8CD38 bacterial translocation (lipopolysaccharide), inflammation (IL-8, IP-10), endothelial dysfunction (sVCAM1, sICAM1, and sTNFR1), and coagulopathy (D-dimer)] was found. Subsequently, patients were stratified into different fibrosis stages, finding that patients with cirrhosis who had LSM at least 40 kPa showed higher biomarker values of immune activation [T-cell activation (CD4CD38 and CD8CD38), bacterial translocation (lipopolysaccharide), inflammation (IL-8, IL-6, IP-10), endothelial dysfunction (sVCAM1, sICAM1, and sTNFR1), and coagulopathy (D-dimer)] than patients from the other three groups (<12.5, 12.5-25, and 25-40 kPa).

CONCLUSION

T-cell activation, bacterial translocation, inflammation, endothelial dysfunction, and coagulopathy increased with the severity of liver fibrosis in HIV/HCV-coinfected patients, particularly in patients who had LSM at least 40 kPa.

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.

Combined Intraperitoneal and Intrathecal Etanercept Reduce Increased Brain Tumor Necrosis Factor-Alpha and Asymmetric Dimethylarginine Levels and Rescues Spatial Deficits in Young Rats after Bile Duct Ligation

BACKGROUND

Rats subjected to bile duct ligation (BDL) exhibit increased systemic oxidative stress and brain dysfunction characteristic of hepatic encephalopathy (HE), including fatigue, neurotransmitter alterations, cognitive and motor impairment, and brain inflammation. The levels of tumor necrosis factor-alpha (TNF-α) and asymmetric dimethylarginine (ADMA) are both increased in plasma and brain in encephalopathy induced by chronic liver failure. This study first determined the temporal profiles of TNF-α and ADMA in the plasma, brain cortex, and hippocampus in young BDL rats. Next, we examined whether etanercept was beneficial in preventing brain damage.

METHODS

Young rats underwent sham ligation or BDL at day 17 ± 1 for 4 weeks. Treatment group rats were administered etanercept (10 mg/kg) intraperitoneally (IP) three times per week with or without etanercept (100 μg) intrathecally (IT) three times in total.

RESULTS

We found increased plasma TNF-α, soluble tumor necrosis factor receptor 1 (sTNFR1), soluble tumor necrosis factor receptor 2 (sTNFR2), and ADMA levels, increased cortical TNF-α mRNA and protein and ADMA, and hippocampal TNF-α mRNA and protein, and spatial defects in young BDL rats. The increase in cortex TNF-α mRNA and ADMA were reduced by IP etanercept or combined IP and IT etanercept. Dually IP/IT etanercept administration reduced the increased cortical and hippocampal TNF-α mRNA and protein level as well as spatial deficits.

CONCLUSIONS

We conclude that combined intraperitoneal and intrathecal etanercept reduce increased brain TNF-α and ADMA levels and rescues spatial deficits in young rats after BDL.

Soluble tumor necrosis factor receptors as predictors of 1-year mortality and renal dysfunction after liver transplantation

BACKGROUND

Several risk factors influence survival after liver transplantation (LT). Some research has demonstrated a relationship between soluble tumor necrosis factor receptors (sTNFRs) and worse clinical liver disease outcomes, but there are no data showing an association between sTNFRs and outcomes after LT. The primary aim of this study was to determine whether an association exists between perioperative sTNFRs and renal dysfunction or mortality after LT.

METHODS

Data were collected prospectively from 122 patients submitted to deceased-donor orthotopic LT. Blood samples were collected at seven different perioperative times and analyzed by ELISA. The statistical analysis included univariate analysis followed by logistic regression. The predictive value of significant variables was assessed using ROC curves.

RESULTS

One-month and 1-year LT survivals were 91% and 81%, respectively. Increased levels of soluble tumor necrosis factor receptor 1 (sTNF-R1) after 24h of graft perfusion were associated with postoperative Renal Replacement Therapy (RRT) (OR 1.25) and 1-year mortality (OR 1.1). RRT was associated with 30-day and 1-year LT mortality, with OR 19.78 and 45.45, respectively.

CONCLUSION

A higher sTNF-R1 level measured 24h after graft perfusion is an independent predictor of RRT and 1-year mortality after LT.

Child-Pugh Versus MELD Score for the Assessment of Prognosis in Liver Cirrhosis: A Systematic Review and Meta-Analysis of Observational Studies

Child-Pugh and MELD scores have been widely used for the assessment of prognosis in liver cirrhosis. A systematic review and meta-analysis aimed to compare the discriminative ability of Child-Pugh versus MELD score to assess the prognosis of cirrhotic patients.PubMed and EMBASE databases were searched. The statistical results were summarized from every individual study. The summary areas under receiver operating characteristic curves, sensitivities, specificities, positive and negative likelihood ratios, and diagnostic odds ratios were also calculated.Of the 1095 papers initially identified, 119 were eligible for the systematic review. Study population was heterogeneous among studies. They included 269 comparisons, of which 44 favored MELD score, 16 favored Child-Pugh score, 99 did not find any significant difference between them, and 110 did not report the statistical significance. Forty-two papers were further included in the meta-analysis. In patients with acute-on-chronic liver failure, Child-Pugh score had a higher sensitivity and a lower specificity than MELD score. In patients admitted to ICU, MELD score had a smaller negative likelihood ratio and a higher sensitivity than Child-Pugh score. In patients undergoing surgery, Child-Pugh score had a higher specificity than MELD score. In other subgroup analyses, Child-Pugh and MELD scores had statistically similar discriminative abilities or could not be compared due to the presence of significant diagnostic threshold effects.Although Child-Pugh and MELD scores had similar prognostic values in most of cases, their benefits might be heterogeneous in some specific conditions. The indications for Child-Pugh and MELD scores should be further identified.

Cirrhosis-associated immune dysfunction: distinctive features and clinical relevance

The term cirrhosis-associated immune dysfunction refers to the main syndromic abnormalities of immune function, immunodeficiency and systemic inflammation that are present in cirrhosis. The course of advanced cirrhosis, regardless of its aetiology, is complicated by cirrhosis-associated immune dysfunction and this constitutes the pathophysiological hallmark of an increased susceptibility to bacterial infection, distinctive of the disease. Cirrhosis impairs the homeostatic role of the liver in the systemic immune response. Damage to the reticulo-endothelial system compromises the immune surveillance function of the organ and the reduced hepatic synthesis of proteins, involved in innate immunity and pattern recognition, hinders the bactericidal ability of phagocytic cells. Systemic inflammation, in form of activated circulating immune cells and increased serum levels of pro-inflammatory cytokines, is the result of persistent episodic activation of circulating immune cells from damage-associated molecular patterns, released from necrotic liver cells and, as cirrhosis progresses, from pathogen-associated molecular patterns, released from the leaky gut. Cirrhosis-associated immune dysfunction phenotypes switch from predominantly "pro-inflammatory" to predominantly "immunodeficient" in patients with stable ascitic cirrhosis and in patients with severely decompensated cirrhosis and extra-hepatic organ failure (e.g. acute-on-chronic liver failure), respectively. These cirrhosis-associated immune dysfunction phenotypes represent the extremes of a spectrum of reversible dynamic events that take place during the course of cirrhosis. Systemic inflammation can affect the functions of tissue somatic cells and modify the clinical manifestation of cirrhosis. The best characterized example is the contribution of systemic inflammation to the haemodynamic derangement of cirrhosis, which correlates negatively with prognosis.

Vitamin D deficiency is associated with mortality in patients with advanced liver cirrhosis

BACKGROUND

Chronic liver disease is the fifth most common cause of mortality in Europe. Recently, vitamin D deficiency has been associated with an increased risk of mortality in the general population. As patients with advanced liver disease frequently exhibit vitamin D deficiency, we assessed for a possible association of vitamin D deficiency with survival in a cohort of patients with advanced liver disease.

METHODS

Sixty-five patients with liver cirrhosis (median age, 58 years; range, 19-76 years; 66% male; Child-Pugh stage C, 46%) were included in our prospective single-centre survival study. Serum 25-hydroxyvitamin D concentrations were measured by chemiluminescence immunoassay. The optimal cut-off was determined using receiver operating characteristic (ROC) and Kaplan-Meier analysis. Chi-square statistics and multivariate binary logistic regression analysis were also conducted.

RESULTS

Median serum vitamin D levels were 8·2 ng/mL (range <4·0-95·8 ng/mL). Overall, 48% of patients (31/65) died during a 24-month follow-up period. ROC analysis determined a vitamin D level of 6·0 ng/mL as optimal cut-off for discriminating survivors from nonsurvivors. Kaplan-Meier analysis of survival confirmed low vitamin D levels as significant predictor of death (P = 0·012). Finally, multivariate analysis identified low vitamin D levels (OR = 6·3; 95% CI, 1·2-31·2; P = 0·012) and MELD scores (OR = 1·4; 95% CI, 1·2-1·7; P < 0·001) as independent predictors of survival.

CONCLUSION

Low vitamin D levels are associated with increased mortality in patients with advanced liver disease. Thus, serum levels of vitamin D might represent a critical marker of survival in advanced liver cirrhosis.

Soluble TNF-alpha-receptors I are prognostic markers in TIPS-treated patients with cirrhosis and portal hypertension

Background

TNFα levels are increased in liver cirrhosis even in the absence of infection, most likely owing to a continuous endotoxin influx into the portal blood. Soluble TNFα receptors (sTNFR type I and II) reflect release of the short-lived TNFα, because they are cleaved from the cells after binding of TNFα. The aims were to investigate the circulating levels of soluble TNFR-I and -II in cirrhotic patients receiving TIPS.

Methods

Forty-nine patients with liver cirrhosis and portal hypertension (12 viral, 37 alcoholic) received TIPS for prevention of re-bleeding (n = 14), therapy-refractory ascites (n = 20), or both (n = 15). Portal and hepatic venous blood was drawn in these patients during the TIPS procedure and during the control catheterization two weeks later. sTNFR-I and sTNFR-II were measured by ELISA, correlated to clinical and biochemical characteristics.

Results

Before TIPS insertion, sTNFR-II levels were lower in portal venous blood than in the hepatic venous blood, as well as in portal venous blood after TIPS insertion. No significant differences were measured in sTNFR-I levels. Hepatic venous levels of sTNFR-I above 4.5 ng/mL (p = 0.036) and sTNFR-II above 7 ng/mL (p = 0.05) after TIPS insertion were associated with decreased survival. A multivariate Cox-regression survival analysis identified the hepatic venous levels of sTNFR-I (p = 0.004) two weeks after TIPS, and Child score (p = 0.002) as independent predictors of mortality, while MELD-score was not.

Conclusion

Hepatic venous levels of sTNFR-I after TIPS insertion may predict mortality in patients with severe portal hypertension.

Nucleotide-binding oligomerization domain containing 2 (NOD2) variants are genetic risk factors for death and spontaneous bacterial peritonitis in liver cirrhosis

Spontaneous bacterial peritonitis (SBP), a severe complication in patients with advanced liver cirrhosis, has been attributed to bacterial translocation from the intestine. Variants of the NOD2 (nucleotide-binding oligomerization domain containing 2) gene have been associated with impaired mucosal barrier function in Crohn disease. We hypothesized that the risk of acquiring SBP is increased in patients with cirrhosis carrying NOD2 variants. We recruited 150 nonselected patients with liver cirrhosis and ascites admitted to our unit, monitored survival, and recorded the development of SBP prospectively and retrospectively. SBP was defined as the presence of polymorphonuclear neutrophil (PMN) cells >250 per microL of ascitic fluid. Patients were genotyped for the NOD2 variants p.R702W, p.G908R, and c.3020insC. During a median follow-up of 155 days, 54 patients (36%) died and SBP was diagnosed in 30 patients (20%). The occurrence of SBP was increased significantly (P = 0.008) in carriers of NOD2 variants (odds ratio [OR] = 3.06). Retrospectively, SBP was observed in 22 additional patients, and the combined prospective and retrospective analysis substantiated the association between NOD2 and SBP (P = 0.004; OR = 2.98). Of note, carriers of NOD2 risk alleles showed a significantly (P = 0.007) reduced mean survival time (274 days) in comparison to patients with wildtype genotypes (395 days).

CONCLUSION

Common NOD2 variants linked previously to impaired mucosal barrier function may be genetic risk factors for death and SBP. These findings might serve to identify patients with cirrhotic ascites eligible for preemptive antibiotic treatment.