Excessive in vitro bacterial lipopolysaccharide-induced production of monokines in cirrhosis

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

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

Presence of MDSC associates with impaired antigen-specific T cell reactivity following COVID-19 vaccination in cirrhotic patients

Background and aims

Cirrhosis entails high risk of serious infections and abated efficiency of vaccination, but the underlying mechanisms are only partially understood. This study aimed at characterizing innate and adaptive immune functions, including antigen-specific T cell responses to COVID-19 vaccination, in patients with compensated and decompensated cirrhosis.

Methods

Immune phenotype and function in peripheral blood from 42 cirrhotic patients and 44 age-matched healthy controls were analysed after two doses of the mRNA-based COVID-19 vaccines [BNT162b2 (Pfizer BioNTech) or mRNA-1273 (Moderna)].

Results

Cirrhotic patients showed significantly reduced blood counts of antigen-presenting dendritic cells (DC) and high counts of monocytic myeloid-derived suppressor cells (M-MDSC) as compared to healthy controls. In addition, monocytic cells recovered from cirrhotic patients showed impaired expression of the antigen-presenting molecule HLA-DR and the co-stimulatory molecule CD86 upon Toll-like receptor (TLR) stimulation. These features were more prominent in patients with decompensated cirrhosis (Child-Pugh classes B & C). Interestingly, while patients with compensated cirrhosis (Child-Pugh class A) showed an inflammatory profile with myeloid cells producing the proinflammatory cytokines IL-6 and TNF, decompensated patients produced reduced levels of these cytokines. Cirrhotic patients, in particular those with more advanced end-stage liver disease, mounted reduced antigen-specific T cell reactivity to COVID-19 vaccination. Vaccine efficiency inversely correlated with levels of M-MDSC.

Conclusion

These results implicate MDSC as mediators of immunosuppression, with ensuing deficiency of vaccine-specific T cell responses, in cirrhosis.

TAM Receptors in the Pathophysiology of Liver Disease

TAM receptors (Tyro3, Axl and MerTK) are a family of tyrosine kinase receptors that are expressed in a variety of cell populations, including liver parenchymal and non-parenchymal cells. These receptors are vital for immune homeostasis, as they regulate the innate immune response by suppressing inflammation via toll-like receptor inhibition and by promoting tissue resolution through efferocytosis. However, there is increasing evidence indicating that aberrant TAM receptor signaling may play a role in pathophysiological processes in the context of liver disease. This review will explore the roles of TAM receptors and their ligands in liver homeostasis as well as a variety of disease settings, including acute liver injury, steatosis, fibrosis, cirrhosis-associated immune dysfunction and hepatocellular carcinoma. A better understanding of our current knowledge of TAM receptors in liver disease may identify new opportunities for disease monitoring as well as novel therapeutic targets. Nonetheless, this review also aims to highlight areas where further research on TAM receptor biology in liver disease is required.

Liver-lung interactions in acute respiratory distress syndrome

Patients with liver diseases are at high risk for the development of acute respiratory distress syndrome (ARDS). The liver is an important organ that regulates a complex network of mediators and modulates organ interactions during inflammatory disorders. Liver function is increasingly recognized as a critical determinant of the pathogenesis and resolution of ARDS, significantly influencing the prognosis of these patients. The liver plays a central role in the synthesis of proteins, metabolism of toxins and drugs, and in the modulation of immunity and host defense. However, the tools for assessing liver function are limited in the clinical setting, and patients with liver diseases are frequently excluded from clinical studies of ARDS. Therefore, the mechanisms by which the liver participates in the pathogenesis of acute lung injury are not totally understood. Several functions of the liver, including endotoxin and bacterial clearance, release and clearance of pro-inflammatory cytokines and eicosanoids, and synthesis of acute-phase proteins can modulate lung injury in the setting of sepsis and other severe inflammatory diseases. In this review, we summarized clinical and experimental support for the notion that the liver critically regulates systemic and pulmonary responses following inflammatory insults. Although promoting inflammation can be detrimental in the context of acute lung injury, the liver response to an inflammatory insult is also pro-defense and pro-survival. A better understanding of the liver–lung axis will provide valuable insights into new diagnostic targets and therapeutic strategies for clinical intervention in patients with or at risk for ARDS.

Pro-adrenomedullin in acute decompensation of liver cirrhosis: relationship with acute-on-chronic liver failure and short-term survival

Background and aim: Acute-on-chronic liver failure (ACLF) is characterized by the presence of acute decompensation (AD) of cirrhosis, organ failures, and high short-term mortality rates. In present study, we explored whether Pro-adrenomedullin (Pro-ADM), a biomarker of sepsis, is a potential marker of outcome in patients admitted for AD or ACLF and whether it might be of additional value to conventional prognostic scoring systems in these patients.Methods: 332 consecutive patients with AD of cirrhosis were prospectively enrolled. Pro-ADM was measured for all patients at baseline. Cox regression analysis was used to evaluate the impact of pro-ADM on short-term survival and developing ACLF during hospital stay.Results: Serum pro-ADM levels were significantly high in non-survivors (p < .001) and showed significant correlation with ALT (r = 0.181, p = .001), INR (r = 0.144, p = .009), TB (r = 0.368, p < .001), Creatinine (r = 0.145, p = .004), MELD score (r = 0.334, p = <.001) and CLI-C OF score (r = 0.375, p= <.001). Serum pro-ADM at admission was shown to be a predictor of 28-day mortality independently of MELD and CLIF-C OF scores. Prognostic models incorporating pro-ADM achieved high C index for predicting 28-day mortality in AD patients of cirrhosis. Moreover, baseline pro-ADM was found to be predictive of ACLF development during hospital stay.Conclusions: Serum pro-ADM levels correlate with multiorgan failure and are independently associated with short-term survival and ACLF development in patients admitted for AD or ACLF.

Diagnostic Value of Presepsin for Bacterial Infection in Cirrhosis: A Pilot Study

INTRODUCTION

Presepsin (or sCD14) has been identified as a protein whose levels increase specifically in the blood of patients with bacterial infections. In this study, we evaluated the clinical performance of sCD14 and its usefulness in the early diagnosis of bacterial infection in decompensated cirrhotic patients.

MATERIALS

Seventy patients were enrolled in this study. The mean age of patients was 49.5 years, and 21 were women and 49 men. The heparinized whole blood for the PATHFAST test was used in the evaluation of bacterial infection (T0). The test was repeated after 48 hours (T1); at 96 hours (T2); at 144 hours (T3); then at 15 days (T4) to monitor the clinical responses to therapeutic interventions.

RESULTS

Forty-nine patients tested positive for sCD14. The mean sCD14 level was 1854 ± 1744 pg/mL. Microbiological findings confirmed the presence of bacterial infections within 84 ± 4.8 h from enrollment in all 49 positive patients. Thirty-eight patients were considered responders to empirical antibiotic therapy with a decrease of presepsin at the different time points, while an increased level of sCD14 was highlighted in 11 patients. When the test was performed, 45% of the patients showed no signs or symptoms of bacterial infection. At 30 days of follow-up 43 patients survived, and 6 patients died from septic shock.

CONCLUSIONS

The PATHFAST test highlighted the presence of infection in a very short time (15 minutes), and the presepsin could be considered an early biomarker in patients with cirrhosis. A greater number of patients are necessary to confirm these data.

Delayed vasopressor initiation is associated with increased mortality in patients with septic shock

PURPOSE

Mortality rate for septic shock, despite advancements in knowledge and treatment, remains high. Treatment includes administration of broad-spectrum antibiotics and stabilization of the mean arterial pressure (MAP) with intravenous fluid resuscitation. Fluid-refractory shock warrants vasopressor initiation. There is a paucity of evidence regarding the timing of vasopressor initiation and its effect on patient outcomes.

MATERIALS AND METHODS

This retrospective, single-centered, cohort study included patients with septic shock from January 2017 to July 2017. Time from initial hypotension to vasopressor initiation was measured for each patient. The primary outcome was 30-day mortality.

RESULTS

Of 530 patients screened,119 patients were included. There were no differences in baseline patient characteristics. Thirty-day mortality was higher in patients who received vasopressors after 6 h (51.1% vs 25%, p < .01). Patients who received vasopressors within the first 6 h had more vasopressor-free hours at 72 h (34.5 h vs 13.1, p = .03) and shorter time to MAP of 65 mmHg (1.5 h vs 3.0, p < .01).

CONCLUSION

Vasopressor initiation after 6 h from shock recognition is associated with a significant increase in 30-day mortality. Vasopressor administration within 6 h was associated with shorter time to achievement of MAP goals and higher vasopressor-free hours within the first 72 h.

Cirrhotic Patients Admitted to the ICU With Septic Shock: Factors Predicting Short and Long-Term Outcome

Cirrhotic patients with septic shock have a poor prognosis in ICU compared to general population of critically ill patients. Little is known about long-term outcome in these patients. We performed a retrospective analysis of a prospective cohort of cirrhotic patients with septic shock. The aim of this study was to describe both short and long-term outcomes and to evaluate factors predicting mortality. Data from 149 patients were analyzed (mean age: 60 ± 11 years, sex ratio: 2.4). Mortality rate in the ICU was 54% and at 1 year it was 73%. Among factors associated with adverse outcome, independent factors predicting ICU mortality were early need for renal replacement therapy (odds ratios, OR 13.95, 95% confidence interval, CI 3.30; 59.03) and arterial lactate >5 mmol.L (OR 7.27, 95% CI 2.92; 18.10), and early use of mechanical ventilation (OR 3.05, 95% CI 1.08; 8.58). For 1-year mortality, independent prognostic factors were the need for renal replacement therapy during ICU stay (OR 9.60, 95% CI 2.90; 31.82), prothrombin time ≤40% (OR 3.47, 95% CI 1.43; 8.43), and Charlson score (OR 1.36 per point, 95% CI 1.11; 1.67). The results emphasize the poor prognosis of cirrhotic patients with septic shock admitted to the ICU. The need for organ supports appears to be a better predictor of short-term outcome than the underlying hepatic disease. Renal replacement therapy is associated with both short and long-term outcomes.

Liver and Steroid Hormones-Can a Touch of p53 Make a Difference?

The liver is the main metabolic organ in the body, serving as a significant hormonal secretory gland and functioning to maintain hormone balance and homeostasis. Steroid hormones regulate various biological pathways, mainly in the reproductive system and in many metabolic processes. The liver, as well as steroid hormones, contribute significantly, through functional intertwine, to homeostasis maintenance, and proper responses during stress. Malfunction of either has a significant impact on the other and may lead to severe liver diseases as well as to several endocrine syndromes. Thus, the regulation on liver functions as on steroid hormones levels and activities is well-controlled. p53, the well-known tumor suppressor gene, was recently found to regulate metabolism and general homeostasis processes, particularly within the liver. Moreover, p53 was shown to be involved in steroid hormones regulation. In this review, we discuss the bi-directional regulation of the liver and the steroid hormones pointing to p53 as a novel regulator in this axis. A comprehensive understanding of the molecular mechanisms of this axis may help to prevent and treat related disease, especially with the increasing exposure of the population to environmental steroid hormones and steroid hormone-based medication.

Management of Infectious Complications Associated with Acute-on-Chronic Liver Failure

Introduction

Acute-on-chronic liver failure (ACLF) is associated with a high susceptibility to infections leading to complications and poor prognosis. The sensitized immune system overwhelmingly responds to invading bacteria leading to organ damage. After resolution of infection or prolonged disease duration, the phagocytic system becomes irresponsive with a reduced bacterial clearance capacity promoting secondary infection.

Methods

This review focuses on the best management strategies for patients with ACLF and infections. Using the following terms, an extensive literature research on the Medline database was performed: 'acute-on-chronic liver failure', 'infection', 'ACLF', 'bacteria', 'multi-resistance'.

Results

Analysis of the literature confirmed that delayed diagnosis and treatment of infections in patients with ACLF results in a poor prognosis. Patients with ACLF should be considered as having a potential infection and should undergo a complete screening for sepsis. Once biochemical analysis indicates a potential infection, such as abnormal levels of C-reactive protein and procalcitonin, antibiotic treatment should be initiated immediately without microbiological culture results. For community-acquired infections third-generation cephalosporins are still the first choice, whereas in the nosocomial setting antibiotics with broader spectrum, such as piperacillin/combactam or carbapenems ± glycopeptides, are preferred. The patient should be re-assessed 48 h after treatment initiation in order to tailor the treatment. Non-response is suspicious, likely due to bacterial resistance or fungal infection, which should be considered when choosing further treatment strategies. Albumin substitution to prevent hepatorenal syndrome and to improve patients' outcome is mandatory in patients with spontaneous bacterial peritonitis. Prophylactic antibiotic therapy is suitable to prevent infections in high-risk patients.

Conclusion

The screening for infections and its treatment is an essential part of managing patients with ACLF. In order to improve patients' prognosis, antibiotic treatment should be initiated once an infection is suspected. However, preventive strategies are already established and should be applied according to the guidelines.

Clarifying the role of C-reactive protein as a bacterial infection predictor in decompensated cirrhosis

INTRODUCTION

Bacterial infections are frequent in cirrhosis and may induce other deleterious complications. Ultrasensitive C-reactive protein (US-CRP), like other acute-phase proteins, is often considered useful in predicting bacterial infection in decompensated cirrhosis. However, US-CRP's reliability remains inconclusive, as inflammation in cirrhosis causes US-CRP synthesis independently of infection. The aim of this study was to clarify US-CRP's role as an infection predictor in decompensated cirrhosis.

PATIENTS AND METHODS

This was a prospective single-center study with systematic inclusion of cirrhotic patients admitted because of decompensation.

RESULTS

A total of 118 patients were enrolled, of whom 47 (39.8%) had an overt infection, defined by clinical and laboratory/imaging criteria. Within those, 17 had infection confirmed by culture bacterial identification. Escherichia coli was the most frequent isolated bacteria. Seventeen patients had spontaneous bacterial peritonitis, but only four (23.5%) had positive ascitic fluid cultures. US-CRP levels were significantly higher in cases of overt infection and positive culture groups than the no infection group (median: 4.14 and 6.40 vs. 1.11 mg/dl, P<0.0001 for both). When considering both overt infection and positive culture groups, the US-CRP values of area under the curve as an infection predictor were, respectively, 0.824 and 0.870, P<0.0001 for both, with associated cutoff values of 2.40 and 3.92 mg/dl, and sensitivity and specificity of 78.7/74.6 and 82.4/79.2%, respectively.

CONCLUSION

The ideal US-CRP infection confirmatory cutoff is probably situated between 2.40 and 3.92 mg/dl. However, as infection is somewhat concealed and hazardous in cirrhotic patients, if not considered with lower US-CRP levels according to specific clinic scenarios, it should be carefully considered, at least, if US-CRP is greater than 2.40 mg/dl (0.5 mg/dl normal upper cutoff).

Sepsis in alcohol-related liver disease

Alcohol-related liver disease (ALD) remains the most important cause of death due to alcohol. Infections, particularly bacterial infections, are one of the most frequent and severe complications of advanced ALDs, such as alcoholic cirrhosis and severe alcoholic hepatitis (sAH). The specific mechanisms responsible for this altered host defence are yet to be deciphered. The aim of the present study is to review the current knowledge of infectious complications in ALD and its pathophysiological mechanisms, distinguishing the role of alcohol consumption and the contribution of different forms of ALD. To date, corticosteroids are the only treatment with proven efficacy in sAH, but their impact on the occurrence of infections remains controversial. The combination of an altered host defence and corticosteroid treatment in sAH has been suggested as a cause of opportunistic fungal and viral infections. A high level of suspicion with systematic screening and prompt, adequate treatment are warranted to improve outcomes in these patients. Prophylactic or preemptive strategies in this high-risk population might be a preferable option, because of the high short-term mortality rate despite adequate therapies. However, these strategies should be assessed in well-designed trials before clinical implementation.

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

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

Adipokines in Liver Cirrhosis

Liver fibrosis can progress to cirrhosis, which is considered a serious disease. The Child-Pugh score and the model of end-stage liver disease score have been established to assess residual liver function in patients with liver cirrhosis. The development of portal hypertension contributes to ascites, variceal bleeding and further complications in these patients. A transjugular intrahepatic portosystemic shunt (TIPS) is used to lower portal pressure, which represents a major improvement in the treatment of patients. Adipokines are proteins released from adipose tissue and modulate hepatic fibrogenesis. These proteins affect various biological processes that are involved in liver function, including angiogenesis, vasodilation, inflammation and deposition of extracellular matrix proteins. The best studied adipokines are adiponectin and leptin. Adiponectin protects against hepatic inflammation and fibrogenesis, and leptin functions as a profibrogenic factor. These and other adipokines are supposed to modulate disease severity in patients with liver cirrhosis. Consequently, circulating levels of these proteins have been analyzed to identify associations with parameters of hepatic function, portal hypertension and its associated complications in patients with liver cirrhosis. This review article briefly addresses the role of adipokines in hepatitis and liver fibrosis. Here, studies having analyzed these proteins in systemic blood in cirrhotic patients are listed to identify adipokines that are comparably changed in the different cohorts of patients with liver cirrhosis. Some studies measured these proteins in systemic, hepatic and portal vein blood or after TIPS to specify the tissues contributing to circulating levels of these proteins and the effect of portal hypertension, respectively.

Interaction between periodontitis and liver diseases

Periodontitis is an oral disease that is highly prevalent worldwide, with a prevalence of 30–50% of the population in developed countries, but only ~10% present with severe forms. It is also estimated that periodontitis results in worldwide productivity losses amounting to ~54 billion USD yearly. In addition to the damage it causes to oral health, periodontitis also affects other types of disease. Numerous studies have confirmed the association between periodontitis and systemic diseases, such as diabetes, respiratory disease, osteoporosis and cardiovascular disease. Increasing evidence also indicated that periodontitis may participate in the progression of liver diseases, such as non-alcoholic fatty liver disease, cirrhosis and hepatocellular carcinoma, as well as affecting liver transplantation. However, to the best of our knowledge, there are currently no reviews elaborating upon the possible links between periodontitis and liver diseases. Therefore, the current review summarizes the human trials and animal experiments that have been conducted to investigate the correlation between periodontitis and liver diseases. Furthermore, in the present review, certain mechanisms that have been postulated to be responsible for the role of periodontitis in liver diseases (such as bacteria, pro-inflammatory mediators and oxidative stress) are considered. The aim of the review is to introduce the hypothesis that periodontitis may be important in the progression of liver disease, thus providing dentists and physicians with an improved understanding of this issue.

Acute-on-chronic liver failure in cirrhosis

The definition of acute-on-chronic liver failure (ACLF) remains contested. In Europe and North America, the term is generally applied according to the European Association for the Study of the Liver-Chronic Liver Failure (EASL-CLIF) Consortium guidelines, which defines this condition as a syndrome that develops in patients with cirrhosis and is characterized by acute decompensation, organ failure and high short-term mortality. One-third of patients who are hospitalized for acute decompensation present with ACLF at admission or develop the syndrome during hospitalization. ACLF frequently occurs in a closed temporal relationship to a precipitating event, such as bacterial infection or acute alcoholic, drug-induced or viral hepatitis. However, no precipitating event can be identified in approximately 40% of patients. The mechanisms of ACLF involve systemic inflammation due to infections, acute liver damage and, in cases without precipitating events, probably intestinal translocation of bacteria or bacterial products. ACLF is graded into three stages (ACLF grades 1-3) on the basis of the number of organ failures, with higher grades associated with increased mortality. Liver and renal failures are the most common organ failures, followed by coagulation, brain, circulatory and respiratory failure. The 28-day mortality rate associated with ACLF is 30%. Depending on the grade, ACLF can be reversed using standard therapy in only 16-51% of patients, leaving a considerable proportion of patients with ACLF that remains steady or progresses. Liver transplantation in selected patients with ACLF grade 2 and ACLF grade 3 increases the 6-month survival from 10% to 80%.

The pathophysiology of thrombocytopenia in chronic liver disease

Thrombocytopenia is the most common hematological abnormality encountered in patients with chronic liver disease (CLD). In addition to being an indicator of advanced disease and poor prognosis, it frequently prevents crucial interventions. Historically, thrombocytopenia has been attributed to hypersplenism, which is the increased pooling of platelets in a spleen enlarged by congestive splenomegaly secondary to portal hypertension. Over the past decade, however, there have been significant advances in the understanding of thrombopoiesis, which, in turn, has led to an improved understanding of thrombocytopenia in cirrhosis. Multiple factors contribute to the development of thrombocytopenia and these can broadly be divided into those that cause decreased production, splenic sequestration, and increased destruction. Depressed thrombopoietin levels in CLD, together with direct bone marrow suppression, result in a reduced rate of platelet production. Thrombopoietin regulates both platelet production and maturation and is impaired in CLD. Bone marrow suppression can be caused by viruses, alcohol, iron overload, and medications. Splenic sequestration results from hypersplenism. The increased rate of platelet destruction in cirrhosis also occurs through a number of pathways: increased shear stress, increased fibrinolysis, bacterial translocation, and infection result in an increased rate of platelet aggregation, while autoimmune disease and raised titers of antiplatelet immunoglobulin result in the immunologic destruction of platelets. An in-depth understanding of the complex pathophysiology of the thrombocytopenia of CLD is crucial when considering treatment strategies. This review outlines the recent advances in our understanding of thrombocytopenia in cirrhosis and CLD.

Thalidomide Improves the Intestinal Mucosal Injury and Suppresses Mesenteric Angiogenesis and Vasodilatation by Down-Regulating Inflammasomes-Related Cascades in Cirrhotic Rats

Background and Aims

By blocking TNFα-related effects, thalidomide not only inhibits hepatic fibrogenesis but improves peripheral vasodilatation and portal hypertension in cirrhotic rats. Nonetheless, the investigation of thalidomide's effects on splanchnic and collateral microcirculation has been limited. Our study explored the roles of intestinal and mesenteric TNFα along with inflammasome-related pathway in relation to cirrhosis and the splanchnic/collateral microcirculation.

Methods

Using in vivo and in vitro approaches, mechanisms of the effects of thalidomide on intestinal and mesenteric inflammatory, vasodilatory and angiogenic cascades-related abnormalities were explored in cirrhotic rats that had received 1-month thalidomide (C-T) treatment.

Results

In cirrhotic rats, high tumor necrosis factor (TNF)α, vascular endothelial growth factor (VEGF) and nitric oxide (NO)x levels were associated with the NOD-like receptors protein 3 (NLRP3), IL-1β and caspase-1 inflammasome over-expression in splenorenal shunt and mesenteric tissues. The thalidomide-related inhibition of mesenteric and splenorenal shunt inflammasome expression was accompanied by a significantly decreased intestinal mucosal injury and inflammasome immunohistochemical staining expression. Suppression of various angiogenic cascades, namely VEGF-NOS-NO, was paralleled by a decrease in mesenteric angiogenesis as detected by CD31 immunofluorescence staining and by reduced portosystemic shunting (PSS) in C-T rats. The down-regulation of the mesenteric and collateral vasodilatory VEGF-NOS-NO cascades resulted in a correction of vasoconstrictive hypo-responsiveness and in an attenuation of vasodilatory hyper-responsiveness when analyzed by in situ perfusion of the superior mesenteric arterial (SMA) and portosystemic collaterals. There was also a decrease in SMA blood flow and an increase in SMA resistance in the C-T rats. Additionally, acute incubation with thalidomide abolished TNFα-augmented VEGF-mediated migration of and tube formation of human umbilical vein endothelial cells, which was accompanied by corresponding changes in inflammatory and angiogenic substances release.

Conclusions

The suppression of inflammasome over-expression by chronic thalidomide treatment ameliorates inflammatory, angiogenic and vasodilatory cascades-related pathogenic changes in the splanchnic and collateral microcirculation of cirrhotic rats. Thalidomide seems to be a promising agent that might bring about beneficial changes to the disarrangements of peripheral, hepatic, splanchnic and collateral systems in cirrhosis.

Gut dysbiosis in acute-on-chronic liver failure and its predictive value for mortality

BACKGROUND

Bacterial translocation from the gut plays an important role in the pathophysiology of acute-on-chronic liver failure (ACLF). However, gut dysbiosis in ACLF was not widely documented in previous studies.

AIM

This research characterized the fecal microbiota in patients with ACLF and analyzed the temporal stability of gut microbiota during illness.

METHODS

Fecal microbiota of 79 ACLF patients (42 patients were followed in the next 4 weeks after the first visit for longitudinal study) and 50 healthy controls was analyzed by 16S ribosomal DNA pyrosequencing.

RESULTS

There was a marked difference between the ACLF group and the control group. The overall microbial diversity and richness were significantly lower in ACLF than in controls. ACLF patients had lower abundance of Bacteroidaceae, Ruminococcaceae, and Lanchnospiraceae, but higher abundance of Pasteurellaceae, Streptococcaceae, and Enterecoccaceae. The relative abundance of Lachnospiraceae was obviously decreased in ACLF patients with hepatic encephalopathy. The gut microbiota kept relatively stable in a short term after the onset of ACLF. The use of antibiotics only showed moderate impacts on the gut microbiota. The relative abundance of Pasteurellaceae and Model of End Stage Liver Disease score were independent factors predicting mortality rate. Network analysis comparison showed robust correlations between specific bacterial families (Ruminococcaceae and Lachnospiraceae) and inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor alpha, IL-2) in ACLF patients.

CONCLUSIONS

These data suggest gut dysbiosis in ACLF and its predictive value for mortality. The results thus open up the possibility of designing diagnostic biomarkers and targeted probiotics aimed at decreasing mortality in ACLF.

Role of Infections in Acute-on-Chronic Liver Failure

Patients with cirrhosis are prone to developing bacterial infections. Moreover, bacterial infection is the most common identifiable trigger of acute-on-chronic liver failure (ACLF), which is characterized by organ failures and a high risk of death. There is evidence of an excessive immune response of the host as a major mechanism leading to the development of organ failures in patients with cirrhosis. However, a role for direct tissue damage caused by bacterial toxins and virulence factors cannot be excluded. Failed tolerance mechanisms may also contribute to organ failures, although the involved mechanisms are unclear. A proportion of patients with infection-related ACLF have a prolonged stay in the intensive care unit. These patients have immune suppression, increased risk of superinfection and poor outcome. Immune suppression might be a consequence of the first infection episode that has led patients to be admitted to hospital.

Acute-on-chronic liver failure: A new syndrome that will re-classify cirrhosis

Acute-on-chronic liver failure (ACLF) is a recently recognized syndrome characterized by acute decompensation (AD) of cirrhosis and organ/system failure(s) (organ failure: liver, kidney, brain, coagulation, circulation and/or respiration) and extremely poor survival (28-day mortality rate 30-40%). ACLF occurs in relatively young patients. It is especially frequent in alcoholic- and untreated hepatitis B associated-cirrhosis, in addition it is related to bacterial infections and active alcoholism, although in 40% of cases no precipitating event can be identified. It may develop at any time during the course of the disease in the patient (from compensated to long-standing cirrhosis). The development of ACLF occurs in the setting of a systemic inflammation, the severity of which correlates with the number of organ failures and mortality. Systemic inflammation may cause ACLF through complex mechanisms including an exaggerated inflammatory response and systemic oxidative stress to pathogen- or danger/damage-associated molecular patterns (immunopathology) and/or alteration of tissue homeostasis to inflammation caused either by the pathogen itself or through a dysfunction of tissue tolerance. A scoring system composed of three scores (CLIF-C OFs, CLIF-C AD, and CLIF-C ACLFs) specifically designed for patients with AD, with and without ACLF, allows a step-wise algorithm for a rational indication of therapy. The management of ACLF should be carried out in enhanced or intensive care units. Current therapeutic measures comprise the treatment for associated complications, organ failures support and liver transplantation.

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.

Bacterial infections in cirrhosis: a position statement based on the EASL Special Conference 2013

Bacterial infections are very common and represent one of the most important reasons of progression of liver failure, development of liver-related complications, and mortality in patients with cirrhosis. In fact, bacterial infections may be a triggering factor for the occurrence of gastrointestinal bleeding, hypervolemic hyponatremia, hepatic encephalopathy, kidney failure, and development of acute-on-chronic liver failure. Moreover, infections are a very common cause of repeated hospitalizations, impaired health-related quality of life, and increased healthcare costs in cirrhosis. Bacterial infections develop as a consequence of immune dysfunction that occurs progressively during the course of cirrhosis. In a significant proportion of patients, infections are caused by gram-negative bacteria from intestinal origin, yet gram-positive bacteria are a frequent cause of infection, particularly in hospitalized patients. In recent years, infections caused by multidrug-resistant bacteria are becoming an important clinical problem in many countries. The reduction of the negative clinical impact of infections in patients with cirrhosis may be achieved by a combination of prophylactic measures, such as administration of antibiotics, to reduce the occurrence of infections in high-risk groups together with early identification and management of infection once it has developed. Investigation on the mechanisms of altered gut microflora, translocation of bacteria, and immune dysfunction may help develop more effective and safe methods of prevention compared to those that are currently available. Moreover, research on biomarkers of early infection may be useful in early diagnosis and treatment of infections. The current manuscript reports an in-depth review and a position statement on bacterial infections in cirrhosis.

Correction of all-trans retinoic acid deficiency in alcoholic cirrhosis lessens the excessive inflammatory monocyte response: a translational study

BACKGROUND & AIMS

Patients with alcoholic liver disease (ALD) have vitamin A (VA) deficiency and an enhanced immune response associated with disease severity. All-trans retinoic acid (ATRA), a VA-active metabolite, has anti-inflammatory effects and its deficiency could contribute to the exacerbated proinflammatory reaction. The aim of this study was to investigate the effects of ATRA/VA deficiency and supplementation on the monocyte response in ALD.

METHODS

Vitamin A and ATRA plasma levels were quantified in ALD patients and healthy subjects (HS). The in vitro effect of ATRA on lipopolysaccharide (LPS)-induced TNF-α production by human peripheral blood mononuclear cells (PBMC) was assessed by ELISA and RT-PCR. The activation pattern of peritoneal macrophages (PerMΦ) and circulating monocytes isolated from VA-deficient mice and ALD patients, respectively, was evaluated by flow cytometry, quantification of TNF-α and NO2 production.

RESULTS

Alcoholic liver disease patients (n = 85) showed plasmatic VA deficiency that was correlated with scores of severity and with the hepatic venous pressure gradient. ATRA levels correlated significantly with VA levels. In vitro, ATRA pretreatment decreased the overproduction of TNF-α by LPS-stimulated PBMC of ALD patients. In vivo, VA deficiency in mice was associated with increased activation of PerMΦ, while oral ATRA supplementation normalized it.

CONCLUSION

For the first time, we show that VA/ATRA deficiencies in ALD patients are associated with disease severity. Furthermore, our data strongly suggest that the VA deficiency observed in ALD patients might participate in the pathophysiology of the disease by priming immune cells, and that ATRA supplementation could downregulate the deleterious proinflammatory state in cirrhosis and might thus be of therapeutic use.

Gene- and exon-expression profiling reveals an extensive LPS-induced response in immune cells in patients with cirrhosis

BACKGROUND & AIMS

Lipopolysaccharide (LPS)-expressing bacteria cause severe inflammation in cirrhotic patients. The global gene response to LPS is unknown in cirrhotic immune cells.

METHODS

Gene-expression profiling using Affymetrix Human Exon Array analyzed the expression of 14,851 genes in LPS-stimulated peripheral blood mononuclear cells (PBMCs) from 4 patients with cirrhosis and 4 healthy subjects. We performed validation studies using RT-qPCR in LPS-stimulated PBMCs from 52 patients and 9 healthy subjects and investigated the association of gene induction with mortality in 26 patients.

RESULTS

Gene-expression profiling of LPS-stimulated cirrhotic cells showed 509 upregulated genes and 1588 downregulated genes. In LPS-stimulated "healthy" cells, 952 genes were upregulated and 838 genes downregulated. The 741 LPS-regulated genes shared by cirrhotic and "healthy" cells were involved in cytokine production/activity and induction of "immune paralysis". Comparison of functions associated with the 1356 genes, specifically regulated by LPS in cirrhotic cells, to functions of the 1049 genes, specifically regulated in "healthy" cells, allowed to define a cirrhosis-specific phenotype. Unlike in "healthy" cells, LPS failed to induce an interferon-mediated program in cirrhotic cells. In cirrhotic PBMCs, LPS specifically induced certain molecules involved in apoptosis and downregulated molecules involved in endocytic trafficking. RT-qPCR experiments showed that LPS-stimulated cirrhotic PBMCs had an enhanced induction of certain proinflammatory cytokines and chemokines. In the prognosis study, higher ex vivo LPS-induction of the inflammatory genes IL6 and CXCL5 was a significant predictor of mortality.

CONCLUSIONS

Our results show that LPS-stimulated cirrhotic PBMCs exhibit an extensive and often unexpected transcriptional response.

Increased survival of cirrhotic patients with septic shock

Introduction

The overall outcome of septic shock has been recently improved. We sought to determine whether this survival gain extends to the high-risk subgroup of patients with cirrhosis.

Methods

Cirrhotic patients with septic shock admitted to a medical intensive care unit (ICU) during two consecutive periods (1997-2004 and 2005-2010) were retrospectively studied.

Results

Forty-seven and 42 cirrhotic patients presented with septic shock in 1997-2004 and 2005-2010, respectively. The recent period differed from the previous one by implementation of adjuvant treatments of septic shock including albumin infusion as fluid volume therapy, low-dose glucocorticoids, and intensive insulin therapy. ICU and hospital survival markedly improved over time (40% in 2005-2010 vs. 17% in 1997-2004, P = 0.02 and 29% in 2005-2010 vs. 6% in 1997-2004, P = 0.009, respectively). Furthermore, this survival gain in the latter period was sustained for 6 months (survival rate 24% in 2005-2010 vs. 6% in 1997-2004, P = 0.06). After adjustment with age, the liver disease stage (Child-Pugh score), and the critical illness severity score (SOFA score), ICU admission between 2005 and 2010 remained an independent favorable prognostic factor (odds ratio (OR) 0.09, 95% confidence interval (CI) 0.02-0.4, P = 0.004). The stage of the underlying liver disease was also independently associated with hospital mortality (Child-Pugh score: OR 1.42 per point, 95% CI 1.06-1.9, P = 0.018).

Conclusions

In the light of advances in management of both cirrhosis and septic shock, survival of such patients substantially increased over recent years. The stage of the underlying liver disease and the related therapeutic options should be included in the decision-making process for ICU admission.

Alcohol, liver, systemic inflammation and skin: a focus on patients with psoriasis

Emerging evidence suggests that excessive alcohol consumption is associated with psoriasis. In alcoholics, antipsoriatic treatments are less efficient, but more toxic and an additional challenge is poor therapeutic compliance. There is a correlation between excess alcohol intake and increased risk of infections, but on the other hand alcohol and its metabolites can trigger a persistent systemic inflammation, mediated by pro-inflammatory cytokines released from activated Kupffer cells in the liver and from monocytes in the circulation. Ethanol and its metabolites can also enhance lymphocyte and keratinocyte activation and proliferation and can increase the mRNA levels of genes characteristic for proliferating keratinocytes. In this review, we discuss the mechanisms by which alcohol contributes to psoriasis development focusing on liver, systemic inflammation and skin.

Hepatic expression of CCL2 in alcoholic liver disease is associated with disease severity and neutrophil infiltrates

Serum levels and liver expression of CCL2 are increased in patients with alcoholic hepatitis (AH). In an experimental model of alcoholic liver disease (ALD), CCL2 was implicated in proinflammatory cytokines activation and hepatic lipid metabolism, but its role in human disease is currently unknown. In a large cohort of ALD patients, we analysed plasma levels and liver expression of CCL2 and their association with liver disease severity and histological lesions. We also studied the relationship between -2518 A > G CCL2 and CCR2 190 A/G polymorphisms and severity of ALD. We show that CCL2 plasma levels are increased in ALD patients compared with healthy subjects. AH patients had significantly higher plasma levels and hepatic expression of CCL2 than patients without AH. Plasma levels and hepatic expression of CCL2 were associated with disease severity. CCL2 liver expression was correlated with neutrophil infiltrate and interleukin (IL)-8 expression, but not with steatosis. Moreover, there were more G-allele carriers of -2518 A > G CCL2 polymorphism in severe AH patients than in other ALD patients. Our results demonstrate that CCL2 is increased in ALD, particularly in severe forms, and suggest a role for CCL2 in the pathogenesis of ALD via neutrophil recruitment.

Management of bacterial infections in cirrhosis

Bacterial infections are very frequent in advanced cirrhosis and become the first cause of death of these patients. Despite numerous experimental data and significant advances in the understanding of the pathogenesis of sepsis in cirrhosis, the outcome remains poor. Classical diagnostic parameters such as C-reactive protein and SIRS criteria have less diagnostic capacity in the cirrhotic population, often delaying the diagnosis and the management of bacterial infection. Prompt and appropriate empirical antibiotic treatment of infection and early resuscitation of patients with severe sepsis or septic shock are essential in determining patient's outcome. A strategy of careful restriction of prophylactic antibiotics to the high-risk populations could reduce the spread of multidrug resistant bacteria. This review is focused on the currently recommended diagnostic, therapeutic and prophylactic strategies for bacterial infections in the cirrhotic population.

Circulating endotoxin and interleukin-6 levels are associated with Doppler-evaluated pulmonary vascular resistance in cirrhotic patients

PURPOSE

Endotoxin and interleukin-6 levels (IL-6) have been involved in the development of pulmonary hypertension (PH) in non-cirrhotic experimental models and subjects. High circulating levels of both substances have been detected in cirrhosis. The association between circulating endotoxin and IL-6 levels and echocardiographically evaluated pulmonary vascular resistance (PVR) in cirrhotic patients are investigated.

METHODS

Thirty-seven cirrhotic patients were studied: 25 with PVR <120 dynes s cm(-5) (group 1) and 12 with PVR >120 dynes s cm(-5) (group 2). Plasma endotoxin and serum IL-6 levels were measured. The PVR and cardiac output (CO) by Doppler ultrasound, mean arterial pressure (MAP), and systemic vascular resistance (SVR) as the ratio MAP/CO were evaluated.

RESULTS

Child-Pugh scores, MAP, CO, and SVR were similar in both groups. Endotoxin levels were correlated significantly with IL-6 levels (r = 0.342; P = 0.03). Endotoxin and IL-6 levels were significantly higher in group 2 compared to group 1 (2.26 [0.39-8.4] vs. 0.85 [0.37-7.6] EU/mL; P = 0.04 and 37.4 [7.85-106.5] vs. 8.36 [3.15-53.7] pg/mL; P < 0.001, respectively). The PVR was correlated significantly with endotoxin levels in group 2 (r = 0.587; P = 0.04) and with IL-6 levels in group 1 (r = 0.529; P = 0.01) and group 2 (r = 0.760; P = 0.004), respectively.

CONCLUSIONS

Our results suggest that endotoxin and IL-6 may contribute to cirrhosis-associated PH. In this regard, modulation of these substances could improve pulmonary pressures in cirrhotic patients.

Endotoxin and tumor necrosis factor-receptor levels in portal and hepatic vein of patients with alcoholic liver cirrhosis receiving elective transjugular intrahepatic portosystemic shunt

BACKGROUND/AIMS

In cirrhosis portal hypertension can promote bacterial translocation and increase serum endotoxin levels. Vice versa, endotoxin aggravates portal hypertension by induction of systemic and splanchnic vasodilation, and by triggering hepatic inflammatory response via tumor necrosis factor α (TNFα). However, the hepatic elimination of endotoxin in cirrhotic patients with severe portal hypertension, in the absence of acute complications, has not been investigated so far.

METHODS

Twenty patients with alcoholic liver cirrhosis received transjugular intrahepatic portosystemic shunt at an event-free interval for either refractory ascites or recurrent bleeding. During the transjugular intrahepatic portosystemic shunt procedure portal and hepatic venous blood samples were obtained and endotoxin levels were measured by a chromogenic limulus-assay. In 16 of these patients an enzyme-linked immunosorbent assay was used to measure levels of the soluble TNFα-receptors sTNF-R55 and sTNF-R75.

RESULTS

Portal venous endotoxin levels correlated with portal vein velocity (P=0.03) and arterial systolic blood pressure (P=0.007). Portal endotoxin levels correlated with portal venous sTNF-R75-levels (P=0.039; r=0.521) and hepatic venous sTNF-R55-levels (P=0.009; r=0.669). Hepatic venous levels of both sTNF-R55 and sTNF-R75 correlated directly with the model for end-stage liver disease-score, and inversely with cholinesterase. However, we did not find significant differences in endotoxin levels nor in sTNF-R55-levels and sTNF-R75-levels between portal and hepatic venous blood.

CONCLUSION

Endotoxin levels correlated with hemodynamic derangement in cirrhotic severe portal hypertension, and with levels of soluble TNFα-receptors. Soluble TNFα-receptor levels correlated with the severity of liver dysfunction. However, in this study an endotoxin concentration gradient across the liver was absent, suggesting negligible primary hepatic endotoxin elimination in the absence of complications.

Glycogen synthase kinase 3 involvement in the excessive proinflammatory response to LPS in patients with decompensated cirrhosis

BACKGROUND & AIMS

In decompensated cirrhosis, the early innate immune response to the Toll-like receptor 4 (TLR4) agonist, lipopolysaccharides (LPS), is characterized by a hyper-production of pro-inflammatory cytokines and hypo-production of the anti-inflammatory cytokine IL-10. In LPS-stimulated non-cirrhotic immune cells, the constitutively active glycogen synthase kinase (GSK) 3 favors pro- vs. anti-inflammatory cytokines, by acting on gene induction. However, in these cells, TLR4 dampens its own pro-inflammatory response by inducing early (within minutes) AKT-mediated phosphorylation of GSK3β (one of two GSK3 isoforms) on Ser9. Phosphorylation of GSK3β (Ser9) inhibits its activity, decreases pro-inflammatory cytokines, and increases IL-10. Thus, we investigated the role of GSK3 in LPS-induced cytokine production by peripheral blood mononuclear cells (PBMCs) or monocytes from patients with advanced cirrhosis and normal subjects.

METHODS

Cells were pre-incubated with or without GSK3 inhibitor (SB216763 or lithium chloride) for 1h and then stimulated with LPS. Cytokine production was assessed at mRNA and secreted proteins levels, by real-time RT-PCR at 1h and ELISA at 20 h, respectively. GSK3β phosphorylation was assessed using Western blotting.

RESULTS

In cirrhotic and normal PBMCs pretreated with GSK3 inhibitors, LPS-induced production of pro-inflammatory proteins TNF-α and IL-12p40 was significantly decreased while that of IL-10 was increased. LPS-induced, AKT-mediated phosphorylation of GSK3β on Ser9 found in normal monocytes, was abolished in cirrhotic cells.

CONCLUSIONS

GSK3 is involved in the early TLR4-mediated pro-inflammatory response in patients with decompensated cirrhosis. This was associated with a defect in AKT-mediated GSK3β phosphorylation resulting in unrestricted 'pro-inflammatory' activity of the enzyme.

Critical role of the liver in the induction of systemic inflammation in rats with preascitic cirrhosis

Systemic activation of the inflammatory immune system contributes to the progression of cirrhosis with ascites. Immune cells become activated after interacting at the mesenteric lymph nodes (MLNs) with bacteria translocated from the gut, and thereafter reach the bloodstream through recirculation. It is unknown whether systemic activation of the immune system is present in pre-ascitic cirrhosis, in which gut bacterial translocation has not been described. The purpose of this study was to determine whether systemic activation of the immune system initiates in rats with compensated carbon tetrachloride (CCl(4))-induced cirrhosis, and if so to establish the activation site of immune cells. We studied the activation status of immune cells in peripheral blood, MLNs, and hepatic lymph nodes (HLNs). Systemic inflammation was present in rats with cirrhosis, as shown by expansion (P < 0.01) of circulating total and inflammatory monocytes and recently activated CD134(+) T helper (T(h)) cells. The same populations of cells were increased (P < 0.01) in MLNs and HLNs. Bacterial translocation was absent in rats with cirrhosis or control rats, but bacterial DNA fragments were present in the MLNs of 54% of rats with cirrhosis. The liver was the source of activated immune cells present in the blood, as shown by the direct correlation between activated T(h) cells in the blood and HLNs, but not in MLNs, and the normalization by gut decontamination with antibiotics of activated cells in MLNs, but not in the blood or HLNs.

CONCLUSION

In experimental cirrhosis, systemic activation of the immune system occurs before ascites development and is driven by recirculation of cells activated in HLNs. In addition, in compensated cirrhosis, bacterial DNA fragments reach the MLNs, where they elicit a local inflammatory response.

Bacterial DNA translocation is associated with systemic circulatory abnormalities and intrahepatic endothelial dysfunction in patients with cirrhosis

Presence of bacterial DNA in noninfected patients with cirrhosis and ascites is associated with a marked inflammatory response including activation of the inducible form of nitric oxide synthase and release of nitric oxide, similar to that observed in patients with spontaneous bacterial peritonitis. Although presence of bacterial DNA is associated with an impaired prognosis, no information is available regarding its hemodynamic consequences. Systemic and hepatic hemodynamics before and after a liquid test meal were assessed in a series of 75 noninfected patients with cirrhosis (55 with ascites). Bacterial DNA was measured by polymerase chain reaction. Bacterial DNA was detected only in patients with ascites. Clinical data and liver function were similar in ascitic patients with presence (n = 21) or absence of bacterial DNA (n = 34). Bacterial-DNA(+) patients had significantly lower mean arterial pressure (P = 0.002) and systemic vascular resistance (P = 0.03) than bacterial-DNA(-) patients. Cardiac output, cardiopulmonary pressures, hepatic venous pressure gradient (HVPG), and hepatic blood flow were similar in both groups. Thirty minutes after the test meal, in response to increased blood flow caused by postprandial hyperemia, there was a significantly greater increase in HVPG and impaired hepatic vasorelaxation in bacterial-DNA(+) as compared with bacterial-DNA(-) patients, which indicates hepatic endothelial dysfunction. Indeed, the increase in HVPG after the test meal significantly correlated with serum bacterial DNA concentration.

CONCLUSION

Presence of bacterial DNA, a marker of bacterial translocation, is associated with aggravation of peripheral vasodilation and with worsening of intrahepatic endothelial dysfunction.

Protective effects of quercetin on liver injury induced by ethanol

Quercetin, a natural compound of multiple origins, has broad biopharmacological effects, such as antioxidant, directly scavenging free radical, and hepatoprotectivity effects. This study is designed to investigate the interveneous effect of quercetin on liver injury induced by ethanol in rats. The rats that were orally treated with 50% ethanol for continuous ten days, which resulted in cell necrosis, fibrosis and inflammatory infiltration, were included in this study. Higher contents of AST, ALT ADH, γ-GT, TG in plasma and MDA in liver tissue, and lower content of GSH in liver tissue were highlighted in ethanol-treated rats when compared with healthy ones. The levels of cytokines such as IL-1β, IL-1, IL-6, IL-8, and TNF-α in rats plasma were also significantly enhanced, and level of IL-10 was obviously lowered through ethanol treatment. By preventive and synchronism treatment with quercetin for fourteen days, the contents of AST, ALT ADH, γ-GT, TG and MDA, and levels of IL-1β, IL-1, IL-6, IL-8, and TNF-α were significantly reduced, whereas GSH and level of IL-10 were obviously increased. It may be deduced that quercetin, by multiple mechanisms interplay, demonstrated somewhat protective effect on liver injury induced by ethanol in rats.

Severe sepsis in cirrhosis

Sepsis is physiologically viewed as a proinflammatory and procoagulant response to invading pathogens. There are three recognized stages in the inflammatory response with progressively increased risk of end-organ failure and death: sepsis, severe sepsis, and septic shock. Patients with cirrhosis are prone to develop sepsis, sepsis-induced organ failure, and death. There is evidence that in cirrhosis, sepsis is accompanied by a markedly imbalanced cytokine response ("cytokine storm"), which converts responses that are normally beneficial for fighting infections into excessive, damaging inflammation. Molecular mechanisms for this excessive proinflammatory response are poorly understood. In patients with cirrhosis and severe sepsis, high production of proinflammatory cytokines seems to play a role in the worsening of liver function and the development of organ/system failures such as shock, renal failure, acute lung injury or acute respiratory distress syndrome, coagulopathy, or hepatic encephalopathy. In addition, these patients may have sepsis-induced hyperglycemia, defective arginine-vasopressin secretion, adrenal insufficiency, or compartmental syndrome. In patients with cirrhosis and spontaneous bacterial peritonitis (SBP), early use of antibiotics and intravenous albumin administration decreases the risk for developing renal failure and improves survival. There are no randomized studies that have been specifically performed in patients with cirrhosis and severe sepsis to evaluate treatments that have been shown to improve outcome in patients without cirrhosis who have severe sepsis or septic shock. These treatments include recombinant human activated C protein and protective-ventilation strategy for respiratory failure. Other treatments should be evaluated in the cirrhotic population with severe sepsis including the early use of antibiotics in "non-SBP" infections, vasopressor therapy, hydrocortisone, renal-replacement therapy and liver support systems, and selective decontamination of the digestive tract or oropharynx.

Downregulation of cyclooxygenase-1 is involved in gastric mucosal apoptosis via death signaling in portal hypertensive rats

Portal hypertension (PHT) gastropathy is a frequent complication of liver cirrhosis and one of the leading causes of death from cirrhosis. Apoptosis is widely considered to be an active energy-dependent mode of cell death and a distinct entity from necrotic cell death. It is unclear whether gastric mucosal apoptosis is involved in PHT gastropathy. Prostaglandins (PGs) produced through cyclooxygenase (COX) are thought to play a key role in protection of the gastrointestinal mucosa from injury and apoptosis. However, the role of COX in PHT gastropathy is still not clearly understood. The aims of this study were to investigate whether (1) gastric mucosal apoptosis is involved in PHT gastropathy and (2) downregulation of COX contributes to this apoptosis. In this study, we show that gastric mucosal apoptosis was remarkably increased while mucosal proliferation was inhibited in PHT rats. Gastric mucosal COX-1 was significantly suppressed at both the mRNA and protein levels, and PGE(2) was reduced in PHT rats. Further, PGE(2) treatment suppressed gastric mucosal apoptosis in PHT rats. However, gastric mucosal COX-2 levels did not differ between sham-operated rats and PHT rats. Gastric mucosal levels of tumor necrosis factor-alpha (TNF-alpha) and Fas ligand, but not TNF-related apoptosis-inducing ligand, were increased, and activated caspase-8 and caspase-3 levels were upregulated in PHT rats. The release of cytochrome c from the mitochondria to the cytosol was not observed in PHT rats. Our data indicate that downregulation of COX-1 is involved in gastric mucosal apoptosis via death signaling-mediated type-I cell death in PHT rats.

Chronic antigenic stimuli as a possible explanation for the immunodepression caused by liver cirrhosis

The objectives of this work were the analysis of the functional characteristics of circulating monocytes and T lymphocytes in patients with liver cirrhosis, and evaluation of the relationship with an increased exposure to antigens due to bacterial translocation. Forty patients with liver cirrhosis (20 with compensated cirrhosis and 20 with ascitic decompensation) and 20 healthy control subjects were studied. Bacterial translocation was evaluated by serum levels of lipopolysaccharide binding protein (LBP). Macrophage activation was studied by CD40 antigen expression. T lymphocytes were analysed for activation (CD25(+), CD122(+)), effector function (CD8(+)CD45RO(+)CD57(+)), apoptosis (CD95(+)) and regulatory abilities, either by analysis of the membrane expression of co-stimulatory molecules CD80, CD86 and CD28, or by quantification of regulatory T cells CD4(+)CD25(high)forkhead box P3 (FoxP3). The percentage of activated monocytes and T lymphocytes in patients was increased significantly. The proportions of effector senescent cells and of those near to apoptosis were also significantly higher. With respect to these proportions, there were no significant differences between patients in function of the presence or absence of decompensation or in function of the increased or normal values of LBP. Conversely, those patients with elevated levels of LBP presented a significantly higher frequency of regulatory T cells than those with normal levels. In conclusion, patients with liver cirrhosis showed an intensive activation state with a higher percentage of cells committed to activation-induced death, even in non-advanced stages. It is possible that bacterial permeability and endotoxaemia contribute to the expansion of those lymphocyte populations implicated in the prevention of a more severe antigen-induced immunopathology.

Protein array technology to investigate cytokine production by monocytes from patients with advanced alcoholic cirrhosis: An ex vivo pilot study

AIM

In patients with advanced cirrhosis, little is known about the ability of peripheral blood monocytes to spontaneously produce signaling proteins such as cytokines. The aim of this ex vivo study was to evaluate cytokine production under baseline conditions and after stimulation by lipopolysaccharide (LPS), a toll-like receptor (TLR) agonist.

METHODS

Peripheral blood monocytes were isolated from patients with advanced alcoholic cirrhosis (without ongoing bacterial infections) and normal subjects. Cells were left unstimulated or were stimulated with LPS. The abundance of 24 cytokines was measured using a filter-based, arrayed sandwich enzyme-linked immunosorbent assay (ELISA) in the supernatant of cultured monocytes.

RESULTS

Cirrhotic monocytes spontaneously produced six proteins (TNF-alpha, IL-6, IL-8, MCP-1, RANTES and Gro), whereas normal monocytes produced only small amounts of IL-8 and RANTES. Analyses with the online gene set analysis toolkit WebGestalt (http://bioinfo.vanderbilt.edu/webgestalt) found enrichment for the six proteins in the human gene ontology subcategory (http://www.geneontology.org), Kyoto Encyclopedia of Genes and Genome pathways (http://www.genome.ad.jp/kegg/) and BioCarta pathways (http://www.biocarta.com/genes/index.asp) consistent with a proinflammatory phenotype of cirrhotic monocytes resulting from activated TLR signaling. Interestingly, LPS-elicited TLR engagement further increased the production of the six proteins and did not induce the secretion of any others, in particular the anti-inflammatory cytokine IL-10. LPS-stimulated normal monocytes produced TNF-alpha, IL-6, IL-8, MCP-1, RANTES, Gro and IL-10.

CONCLUSION

In patients with advanced cirrhosis, peripheral blood monocytes spontaneously produce proinflammatory cytokines, presumably in response to unrestricted TLR signaling.

An inhibitor of interleukin-6 trans-signalling, sgp130, contributes to impaired acute phase response in human chronic liver disease

In chronic liver disease, high circulating interleukin (IL)-6 contrasts with a poor acute phase response. We evaluated the impact of liver and circulating IL-6-receptor (IL-6R) forms on IL-6 bioactivity in chronic liver disease. IL-6, soluble IL-6-receptor and sgp130 levels were assayed in plasma from 45 patients with alcoholic liver disease, 84 with hepatitis C virus (HCV) infection undergoing transjugular liver biopsies and 15 healthy subjects. IL-6R mRNA was quantified on liver extracts from 54 patients with alcoholic liver disease with or without cirrhosis and 18 HCV-infected patients. The effect of gp130-Fc on fibrinogen secretion induced by IL-6 trans-signalling was evaluated on hepatocyte cultures. Levels of plasma IL-6 and sgp130, but not soluble IL-6R, increased with the stage of chronic liver disease, and correlated significantly with disease severity. Alcoholic liver disease patients had higher plasma IL-6 levels than hepatitis C, but lower liver IL-6R expression. In alcoholic and HCV-related liver diseases, liver IL-6R expression decreased with advanced fibrosis stage. In vitro, on hepatocytes, gp130-Fc blunted the acute phase response while soluble IL-6R enhanced IL-6 stimulation. In advanced chronic liver disease, high plasma IL-6 is associated with low liver IL-6R expression. This situation enables high plasma sgp130 to act as a major negative regulator of liver IL-6 trans-signalling, as demonstrated functionally here on hepatocytes. This might explain the poor acute phase response induced by IL-6 in chronic liver disease.

The interleukin-17 pathway is involved in human alcoholic liver disease

Immune dysregulations in alcoholic liver diseases are still unclear, especially regarding alcoholic hepatitis inflammatory burst. Interleukin-17 (IL-17) is known to enhance neutrophil recruitment. We studied the IL-17 pathway in alcoholic cirrhosis and alcoholic hepatitis. Patients with alcoholic liver disease were compared with patients with chronic hepatitis C virus (HCV) infection or autoimmune liver disease and with healthy controls. IL-17 plasma levels and peripheral blood mononuclear cell secretion were assessed by enzyme-linked immunosorbent assay (ELISA) and T cell phenotype by flow cytometry. IL-17 staining and co-staining with CD3 and myeloperoxidase were performed on liver biopsy specimens. IL-17 receptor expression was studied on liver biopsies and in human hepatic stellate cells as well as their response to recombinant IL-17 by chemotaxis assays. IL-17 plasma levels were dramatically increased in alcoholic liver disease patients. Peripheral blood mononuclear cells of patients with alcoholic liver disease produced higher amounts of IL-17, and their CD4(+) T lymphocytes disclosed an IL-17-secreting phenotype. In the liver, IL-17-secreting cells contributed to inflammatory infiltrates in alcoholic cirrhosis, and alcoholic hepatitis foci disclosed many IL-17(+) cells, including T lymphocytes and neutrophils. In alcoholic liver disease, liver IL-17(+) cells infiltrates correlated to model for end-stage liver disease score, and in alcoholic hepatitis to modified discriminant function. IL-17 receptor was expressed in alcoholic liver disease by hepatic stellate cells, and these cells recruited neutrophils after IL-17 stimulation in a dose-dependent manner through IL-8 and growth related oncogen alpha (GRO-alpha) secretion in vitro.

CONCLUSION

Human alcoholic liver disease is characterized by the activation of the IL-17 pathway. In alcoholic hepatitis, liver infiltration with IL-17-secreting cell infiltrates is a key feature that might contribute to liver neutrophil recruitment. (Clinical trials number NCT00610597).

Ex vivo effects of high-density lipoprotein exposure on the lipopolysaccharide-induced inflammatory response in patients with severe cirrhosis

High-density lipoproteins (HDL) are known to neutralize lipopolysaccharide (LPS). Because patients with cirrhosis have lower HDL levels, this may contribute to LPS-induced ex vivo monocyte overproduction of proinflammatory cytokines. However, the effects of HDL on cytokine production by monocytes from patients with cirrhosis have never been studied. The aim of this study was to determine the effects of HDL on LPS-induced proinflammatory cytokine production in whole blood and isolated monocytes from patients with severe cirrhosis and controls. Plasma levels of HDL and cytokines were determined. The effects of reconstituted HDL (rHDL) on LPS-induced cytokine production in whole blood were assessed by cytokine array and on tumor necrosis factor alpha (TNF-alpha) and interleukin-10 (IL-10) production in isolated monocytes. Plasma HDL levels were significantly lower in patients with cirrhosis than in controls. Plasma levels of TNF-alpha and IL-6 were significantly higher in patients with cirrhosis than in controls. Incubation of rHDL with whole blood prevented LPS-induced TNF-alpha and IL-6 overproduction in patients with cirrhosis. LPS-induced TNF-alpha production and CD14 expression were significantly more marked in cirrhotic monocytes than in control monocytes, and both decreased significantly after rHDL incubation. LPS-induced down-regulation of scavenger receptor, class B, type I (SR-BI) expression was abolished in cirrhotic monocytes.

CONCLUSIONS

This study shows that rHDL abolishes the LPS-induced overproduction of proinflammatory cytokines in whole blood from patients with severe cirrhosis. These results were confirmed in isolated monocytes from these patients. This suggests that administration of rHDL might be a useful strategy for the treatment of cirrhosis to limit LPS-induced cytokine overproduction.

Probiotic yogurt for the treatment of minimal hepatic encephalopathy

OBJECTIVES

Minimal hepatic encephalopathy (MHE), the preclinical stage of overt hepatic encephalopathy (OHE), is a significant condition affecting up to 60% of cirrhotics. All MHE therapies modify gut microflora, but consensus regarding MHE treatment and long-term adherence studies is lacking. The aim was to determine the effect of probiotic supplementation in the form of a food item, probiotic yogurt, on MHE reversal and adherence.

METHODS

Nonalcoholic MHE cirrhotics (defined by a standard psychometric battery) were randomized with unblinded allocation to receive probiotic yogurt (with proven culture stability) or no treatment (no Rx) for 60 days in a 2:1 ratio. Quality of life (short form [SF]-36), adherence, venous ammonia, model of end-stage liver disease (MELD) scores, and inflammatory markers (tumor necrosis factor [TNF]-alpha, interleukin [IL]-6) were also measured. Outcomes were MHE reversal using blinded scoring, OHE development, and adherence.

RESULTS

Twenty-five patients (17 yogurt, 8 no Rx; 84% Child class A) were enrolled. A significantly higher percentage of yogurt patients reversed MHE compared to no Rx patients (71%vs 0%, P= 0.003, intention-to-treat). Yogurt patients demonstrated a significant improvement in number connection test-A (NCT-A), block design test (BDT), and digit symbol test (DST) compared to baseline/no Rx group. Twenty-five percent of no Rx versus 0% of yogurt patients developed OHE during the trial. Eighty-eight percent of yogurt patients were adherent. No adverse effects or change in covariates were observed. All patients who completed the yogurt arm were agreeable to continue yogurt for 6 months if needed.

CONCLUSIONS

This trial demonstrated a significant rate of MHE reversal and excellent adherence in cirrhotics after probiotic yogurt supplementation with potential for long-term adherence.