The effect of selective intestinal decontamination on the hyperdynamic circulatory state in cirrhosis. A randomized trial

From Pathophysiology to Practice: Evolving Pharmacological Therapies, Clinical Complications, and Pharmacogenetic Considerations in Portal Hypertension

Background: Portal hypertension is a major complication of chronic liver diseases, leading to serious issues such as esophageal variceal bleeding. The increase in portal vein pressure is driven by both an organic component and a functional component, including tonic contraction of hepatic stellate cells. These processes result in a pathological rise in intrahepatic vascular resistance, stemming from partial impairment of hepatic microcirculation, which is further exacerbated by abnormalities in extrahepatic vessels, including increased portal blood flow. Objectives: This review aims to provide a comprehensive overview of the evolving pharmacological therapies for portal hypertension, with consideration and discussion of pathophysiological mechanisms, clinical complications, and pharmacogenetic considerations, highlighting potential directions for future research. Methods: A review of recent literature was performed to evaluate current knowledge and potential therapeutic strategies in portal hypertension. Results: For over 35 years, non-selective beta-blockers have been the cornerstone therapy for portal hypertension by reducing portal vein inflow as an extrahepatic target, effectively preventing decompensation and variceal hemorrhages. However, since not all patients exhibit an adequate response to non-selective beta-blockers (NSBBs), and some may not tolerate NSBBs, alternative or adjunctive therapies that enhance the effects of NSBBs on portal pressure are being investigated in preclinical and early clinical studies. Conclusions: A better understanding of pharmacogenetic factors and pathophysiological mechanisms could lead to more individualized and effective treatments for portal hypertension. These insights highlight potential directions for future research.

The effect of propranolol on gastrointestinal motility and permeability in patients with cirrhosis and significant portal hypertension

BACKGROUND

Patients with cirrhosis and portal hypertension may have alterations in intestinal barrier resulting in increased susceptibility for infections. We investigated the effect of propranolol in gastrointestinal motility, permeability and bacterial overgrowth in cirrhosis.

METHODS

Patients with cirrhosis and esophageal varices were studied before and after a build-up dose of propranolol according to standard guidelines. Serum TNF-a, IL-6, IL-1b, LPS and bacterial DNA were measured before and during propranolol therapy. Oro-caecal transit time (OCTT) and bacterial overgrowth (BO) have been evaluated with H2 breath testing. Intestinal paracellular (IP), cellular passive non-carrier (ICNC), cellular passive carrier-mediated (ICCM), and gastric permeability (GP) were evaluated by measurement of lactulose, mannitol, D-xylose and sucrose respectively in urine, with high performance liquid chromatography (HPLC).

RESULTS

35 patients with cirrhosis and portal hypertension with median age was 59.6 years (range 42-86) were included in the study. Twenty one had viral hepatitis and 25 were classified as having advanced cirrhosis (Child-Pugh B: 14 or C: 11). Median dose of administrated propranolol was 40 mg/day. After 7 days propranolol treatment BO was resolved in 15 out of 16 patients (93.7%, p = 0.0001) and OCTT was reduced significantly from 180 min to 139 min (SD 58.5, difference - 4 1 min, p = 0.0001). Serum IL-6 levels were reduced in 21/35 (60%) patients from 41.1 to 19 pg/ml (p = 0.01), TNF-a in 10/35 (28.5%) patients from 10.7 to 5.6 pg/ml (p = 0.007) and LPS in 20/35 (57%) from 7.1 to 5.2 mg/L (p = 0.1). No bacterial DNA was detected in serum of all patients either baseline or under propranolol treatment. IP was significantly reduced (0.2 to 0.16, p = 0.04) whereas ICNC (p = 0.9), ICCM (p = 0.4) and GP (p = 0.7) were not affected significantly. Intestinal Permeability (PI) index (Lactulose to Mannitol ratio) was significantly reduced (0.027 to 0.02, p = 0.03).

CONCLUSION

In patients with cirrhosis and portal hypertension, propranolol use is associated with reduction in BO, increase in intestinal motility and amelioration in intestinal permeability. Moreover IL-6 and LPS levels are being decreased in the majority of patients under propranolol.

Liver Cirrhosis: The Immunocompromised State

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

Novel Therapeutic Approaches in Treatment of Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF), a clinical syndrome that can develop at any stage in the progression of cirrhotic liver disease, is characterized by an acute decompensation in liver function with associated multiorgan failure and high short-term mortality. Current evidence points to ACLF being reversible, particularly in those at the lower end of the severity spectrum. However, there are no specific treatments for ACLF, and overall outcomes remain poor. Expedited liver transplantation as a treatment option is limited by organ shortage and a lack of priority allocation for this indication. Other options are therefore urgently needed, and our improved understanding of the condition has led to significant efforts to develop novel therapies. In conclusion, this review aims to summarize the current understanding of the pathophysiological processes involved in the onset, progression, and recovery of ACLF and discuss novel therapies under development.

Presence of NOD2 mutations is not associated with hepatic or systemic hemodynamic abnormalities of cirrhosis

BACKGROUND

Patients with cirrhosis who carry NOD2 mutations are susceptible to bacterial infections. The aim was to evaluate the association of NOD2 mutations with hepatic and systemic hemodynamics in cirrhosis.

PATIENTS AND METHODS

This is a secondary analysis of a prospectively collected database in the context of the screening for the INCA trial (EudraCT 2013-001626-26). This cross-sectional study compared hemodynamic findings according to NOD2 status in 215 patients. Patients were genotyped for NOD2 variants (p.N289S, p.R702W, p.G908R, c.3020insC, rs72796367). Hepatic hemodynamic study and right heart catheterization were performed.

RESULTS

Patients had a median age of 59 (IQR 53-66) years, and 144 (67%) were men. Most patients (64%) were Child-Pugh stage B. Sixty-six patients (31%) carried a NOD2 mutation, which was slightly more common among Child-Pugh stage C (p = 0.05), without differences in MELD [wild-type: 13 (10-16); NOD2 variants 13 (10-18)]. No differences in hepatic and systemic hemodynamics were observed according to NOD2 status. If excluding patients on prophylactic or therapeutic antibiotics, again no association between hepatic or systemic hemodynamics and NOD2 status could be observed.

CONCLUSION

NOD2 mutations are not associated with hepatic or systemic hemodynamic abnormalities in patients with decompensated cirrhosis, suggesting that other mechanisms leading to bacterial translocation predominate.

Prognostic importance of interleukin 2 receptor for patients with a history of cirrhotic variceal bleeding

OBJECTIVES

Variceal hemorrhage is a fatal complication of cirrhosis. In this study, we aimed to investigate the role of serum interleukin 2 receptor (sIL-2R) as a predictive indicator in patients with a previous history of cirrhosis-related variceal bleeding.

METHODS

A total of 340 cirrhotic patients who had experienced variceal bleeding from December 2016 to December 2018 were enrolled, and were randomly assigned to the modeling group and the validation group. The 3-year variceal rebleeding rate and other outcomes including adverse events were analyzed between patients with different sIL-2R levels.

RESULTS

A time-dependent receiver operating characteristic (ROC) curve of variceal rebleeding indicated that sIL-2R had an area under the ROC curve (AUROC] of 0.731 and 0.837 for the modeling and validation groups, respectively, with a cut-off value of 426 U/mL. Kaplan-Meier analysis showed that higher sIL-2R level was related to an increased risk of variceal rebleeding rate (55.33% vs 24.34%, P = 0.024 and 51.28% vs 15.32%, P = 0.049) and decreased 3-year survival rate (91.16% vs 98.92%, P = 0.013 and 90.52% vs 97.50%, P = 0.180) in the modeling and validation groups. Elevated sIL-2R levels were associated with an increased risk of portal vein thrombosis and severe ascites as well as inferior liver function, hypercoagulable state, and increased portal pressure.

CONCLUSION

High sIL-2R levels were associated with poor prognosis in cirrhotic patients with previous variceal bleeding.

Antibiotics and probiotics on hepatic venous pressure gradient in cirrhosis: A systematic review and a meta-analysis

Background

Modulation of the gut microbiome could favorably alter the hepatic venous pressure gradient (HVPG) in cirrhosis and portal hypertension (PH).

Aim

This meta-analysis was to evaluate the effects of microbiome-targeted therapies (MTTs) on HVPG in persons with cirrhosis and PH.

Methods

PubMed, The Cochrane Library, Embase, Web of Science and Scopus were searched for randomized clinical trials (RCTs) analyzing the effects on HVPG in people with cirrhosis who received MTTs. Clinical outcomes were pooled using RevMan5.3 software. A trial sequential analysis was applied to calculate the required information size and evaluate the credibility of the meta-analysis results.

Results

A total of six studies were included. MTTs were associated with a reduction of 1.22 mm Hg in HVPG (95% CI: -2.31, -0.14 mmHg, P = 0.03). Subgroup analysis showed a greater reduction with longer duration (-1.88 mmHg;95% CI: -3.23, -0.53; P = 0.006). In the trial sequential analysis of HVPG reduction, the cumulative Z curve crossed the traditional significance boundary without the achievement of required information size (330).

Conclusions

MTTs may be associated with a reduction in HVPG in patients with cirrhosis and PH. Microbiome-targeted therapies merit additional large-sample studies to define the efficacy of HVPG.

Systematic review registration

PROSPERO 2020: CRD4202021609.

Influence of Gut–Liver Axis on Portal Hypertension in Advanced Chronic Liver Disease: The Gut Microbiome as a New Protagonist in Therapeutic Management

Clinically significant portal hypertension is associated with most complications of advanced chronic liver disease (ACLD), including variceal bleeding, ascites, spontaneous bacterial peritonitis, hepatorenal syndrome, and hepatic encephalopathy. Gut dysbiosis is a hallmark of ACLD with portal hypertension and consists of the overgrowth of potentially pathogenic bacteria and a decrease in autochthonous bacteria; additionally, congestion makes the intestinal barrier more permeable to bacteria and their products, which contributes to the development of complications through inflammatory mechanisms. This review summarizes current knowledge on the role of the gut–liver axis in the pathogenesis of portal hypertension, with a focus on therapies targeting portal hypertension and the gut microbiota. The modulation of the gut microbiota on several levels represents a major challenge in the upcoming years; in-depth characterization of the molecular and microbiological mechanisms linking the gut–liver axis to portal hypertension in a bidirectional relationship could pave the way to the identification of new therapeutic targets for innovative therapies in the management of ACLD.

Cirrhotic Patients with Bacterial Infection and Negative Cultures Have a More Advanced Disease and an Increased Short-Term Mortality Rate

BACKGROUND

The negative clinical impact of bacterial infections (BI) in patients with cirrhosis is well documented. In cirrhotic patients, failure to isolate the pathogen is a frequent event, occurring in 30-40% of cases.

AIM

The aim of this study was to compare the clinical characteristics, early (30-day) and short-term (90-day) mortality rates, in a cohort of cirrhotic patients with BI, between those with positive (C-pos) and those with negative (C-neg) microbiological cultures.

METHODS

We retrospectively enrolled 279 consecutive hospitalized cirrhotic patients with BI. Survival and predictors of 30-day and 90-day mortality were assessed by Kaplan-Meier curves and logistic regression analysis, respectively.

RESULTS

Cultures tested negative in 108/279 (38.7%) patients. C-neg patients were more frequently males (p = 0.035), had higher Child-Pugh-Turcotte (CPT; p = 0.007) and model for end-stage liver disease-sodium (MELD-Na; p = 0.043) scores, and had more frequently decompensated liver disease (p = 0.04). Mortality rate was higher in C-neg than in C-pos patients, both at 30 days (22.2% versus 11.7%, p = 0.024) and 90 days (46.3% versus 33.3%, p = 0.030). MELD-Na score and non-selective beta-blockers (NSBBs) were independent risk factors for 30-day and 90-day mortality. In particular, the use of NSBBs was independently associated with a lower 30-day and 90-day mortality risk (OR 0.41, CI95% 0.17-0.94, p = 0.040; and OR 0.43, CI95% 0.25-0.75, p = 0.003, respectively).

CONCLUSIONS

Cirrhotic patients with BI and negative microbiological cultures have significantly higher mortality compared to those with positive cultures. Early mortality and short-term mortality are mainly influenced by the underlying severity of liver disease. In this contest, therapy with NSBBs has a positive impact on short-term survival.

Hepatorenal Syndrome: Pathophysiology

Hepatorenal syndrome (HRS) is defined as a functional renal failure without major histologic changes in individuals with severe liver disease and it is associated with a high mortality rate. Renal hypoperfusion due to marked vasoconstriction as a result of complex circulatory dysfunction has been suggested to be the cornerstone of HRS. Splanchnic and peripheral arterial vasodilation and cirrhotic cardiomyopathy result in effective arterial hypovolemia and compensatory activation of vasoconstrictor mechanisms. The efficacy of current therapeutic strategies targeting this circulatory dysfunction is limited. Increasing evidence suggests a substantial role of systemic inflammation in HRS via either vascular or direct renal effects. Here we summarize the current understanding of HRS pathophysiology.

Endotoxin Translocation and Gut Barrier Dysfunction Are Related to Variceal Bleeding in Patients With Liver Cirrhosis

BACKGROUND

Bacterial infections are associated with the risk of variceal bleeding through complex pathophysiologic pathways.

OBJECTIVES

The primary objective of the present case-control study was to investigate the role of bacterial translocation and intestinal barrier dysfunction in the pathogenesis of variceal bleeding. A secondary objective was to determine independent predictors of key outcomes in variceal bleeding, including bleeding-related mortality.

METHODS

Eighty-four (n = 84) consecutive patients participated in the study, 41 patients with acute variceal bleeding and 43 patients with stable cirrhosis, and were followed up for 6 weeks. Peripheral blood samples were collected at patient admission and before any therapeutic intervention.

RESULTS

Child-Pugh (CP) score (OR: 1.868; p = 0.044), IgM anti-endotoxin antibody levels (OR: 0.954; p = 0.016) and TGF-β levels (OR: 0.377; p = 0.026) were found to be significant predictors of variceal bleeding. Regression analysis revealed that albumin (OR: 0.0311; p = 0.023), CRP (OR: 3.234; p = 0.034) and FABP2 levels (OR:1.000, p = 0.040), CP score (OR: 2.504; p = 0.016), CP creatinine score (OR: 2.366; p = 0.008), end-stage liver disease model (MELD), Na (OR: 1.283; p = 0.033), portal vein thrombosis (OR: 0.075; p = 0.008), hepatocellular carcinoma (OR: 0.060; p = 0.003) and encephalopathy (OR: 0.179; p = 0.045) were significantly associated with 6-week mortality.

CONCLUSIONS

Bacterial translocation and gut barrier impairment are directly related to the risk of variceal bleeding. Microbiota-modulating interventions and anti-endotoxin agents may be promising strategies to prevent variceal bleeding.

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.

Targeting Gut–Liver Axis for Treatment of Liver Fibrosis and Portal Hypertension

Antifibrotic therapies for the treatment of liver fibrosis represent an unconquered area of drug development. The significant involvement of the gut microbiota as a driving force in a multitude of liver disease, be it pathogenesis or fibrotic progression, suggest that targeting the gut–liver axis, relevant signaling pathways, and/or manipulation of the gut’s commensal microbial composition and its metabolites may offer opportunities for biomarker discovery, novel therapies and personalized medicine development. Here, we review potential links between bacterial translocation and deficits of host-microbiome compartmentalization and liver fibrosis that occur in settings of advanced chronic liver disease. We discuss established and emerging therapeutic strategies, translated from our current knowledge of the gut–liver axis, targeted at restoring intestinal eubiosis, ameliorating hepatic fibrosis and rising portal hypertension that characterize and define the course of decompensated cirrhosis.

Bile Acids, Liver Cirrhosis, and Extrahepatic Vascular Dysfunction

The bile acid pool with its individual bile acids (BA) is modulated in the enterohepatic circulation by the liver as the primary site of synthesis, the motility of the gallbladder and of the intestinal tract, as well as by bacterial enzymes in the intestine. The nuclear receptor farnesoid X receptor (FXR) and Gpbar1 (TGR5) are important set screws in this process. Bile acids have a vasodilatory effect, at least according to in vitro studies. The present review examines the question of the extent to which the increase in bile acids in plasma could be responsible for the hyperdynamic circulatory disturbance of liver cirrhosis and whether modulation of the bile acid pool, for example, via administration of ursodeoxycholic acid (UDCA) or via modulation of the dysbiosis present in liver cirrhosis could influence the hemodynamic disorder of liver cirrhosis. According to our analysis, the evidence for this is limited. Long-term studies on this question are lacking.

Regression of portal hypertension: underlying mechanisms and therapeutic strategies

Portal hypertension is the main non-neoplastic complication of chronic liver disease, being the cause of important life-threatening events including the development of ascites or variceal bleeding. The primary factor in the development of portal hypertension is a pathological increase in the intrahepatic vascular resistance, due to liver microcirculatory dysfunction, which is subsequently aggravated by extra-hepatic vascular disturbances including elevation of portal blood inflow. Evidence from pre-clinical models of cirrhosis has demonstrated that portal hypertension and chronic liver disease can be reversible if the injurious etiological agent is removed and can be further promoted using pharmacological therapy. These important observations have been partially demonstrated in clinical studies. This paper aims at providing an updated review of the currently available data regarding spontaneous and drug-promoted regression of portal hypertension, paying special attention to the clinical evidence. It also considers pathophysiological caveats that highlight the need for caution in establishing a new dogma that human chronic liver disease and portal hypertension is reversible.

The Clinical Impact of Cirrhosis on the Hospital Outcomes of Patients Admitted With Influenza Infection: Propensity Score Matched Analysis of 2011-2017 US Hospital Data

BACKGROUND/OBJECTIVES

Patients with cirrhosis have liver-related immune dysfunction that potentially predisposes the patients to increased influenza infection risk. Our study evaluates this cross-sectional relationship using a national registry of hospital patients.

METHODS

This study included the 2011-2017 National Inpatient Sample database. From this, respiratory influenza cases were isolated and stratified using the presence of cirrhosis into a cirrhosis-present study cohort and cirrhosis-absent controls; propensity score matching method was used to match the controls to the study cohort (cirrhosis-present) using a 1:1 matching ratio. The endpoints included mortality, length of stay, hospitalization costs, and influenza-related complications.

RESULTS

Following the match, there were 2,040 with cirrhosis and matched 2,040 without cirrhosis admitted with respiratory influenza infection. Compared to the controls, cirrhosis patients had higher in-hospital mortality (7.79 vs 3.43% p < 0.001, OR 2.38 95% CI 1.78-3.17), longer length of stay (7.25 vs 6.52 d p < 0.001), higher hospitalization costs ($70,009 vs $65,035 p < 0.001), and were more likely be discharged to a skilled nursing facility and home healthcare (vs routine home discharges). In terms of influenza-related complications, the cirrhosis cohort had higher rates of sepsis (29.8 vs 22% p < 0.001, OR 1.51 95% CI 1.31-1.74). In the multivariate regression analysis, cirrhosis was associated with higher mortality (p < 0.001, aOR 2.31 95% CI 1.59-3.35) and length of stay (p = 0.018, aOR 1.03 95% CI 1.01-1.06). In subgroup analysis of patients with decompensated (n = 597) versus compensated cirrhosis (n = 1443), those with decompensated cirrhosis had higher rates of in-hospital mortality (12.7 vs 5.75% p < 0.001, OR 2.39 95% CI 1.72-3.32), length of stay (8.85 vs 6.59 d p < 0.001), and hospitalization costs ($92,858 vs $60,556 p < 0.001). In the multivariate analysis, decompensated cirrhosis was associated with increased mortality (p < 0.001, aOR 2.86 95% CI 1.90-4.32).

CONCLUSION

This study shows the presence of cirrhosis to result in higher hospital mortality and postinfluenza complications in patients with influenza infection.

Primary prevention of bleeding from esophageal varices in patients with liver cirrhosis: An update and review of the literature

All patients with liver cirrhosis and portal hypertension should be stratified by risk groups to individualize different therapeutic strategies to increase the effectiveness of treatment. In this regard, the development of primary prophylaxis of variceal bleeding and its management according to the severity of portal hypertension may be promising. This paper is to describe the modern principles of primary prophylaxis of esophageal variceal bleeding in patients with liver cirrhosis. The PubMed and EMbase databases, Web of Science, Google Scholar, and the Cochrane Database of Systematic Reviews were used to search for relevant publications from 1999 to 2019. The results suggested that depending on the severity of portal hypertension, patients with cirrhosis should be divided into those who need preprimary prophylaxis, which aims to prevent the formation of esophageal varices, and those who require measures that aim to prevent esophageal variceal bleeding. In subclinical portal hypertension, therapy should be etiological and pathogenetic. Cirrhosis with clinically significant portal hypertension should receive nonselective β-blockers if they have small esophageal varices and risk factors for variceal bleeding. Nonselective β-blockers are the first-line drugs for the primary prevention of bleeding from medium to large-sized esophageal varices. Endoscopic band ligation is indicated for the patients who are intolerant to nonselective β-blockers or in the case of contraindications to pharmacological therapy. In summary, the stratification of cirrhotic patients by the severity of portal hypertension and an individual approach to the choice of treatment may increase the effectiveness of therapy as well as improve survival rate of these patients.

Effect of poorly absorbable antibiotics on hepatic venous pressure gradient in cirrhosis: A systematic review and meta-analysis

BACKGROUND

The effects of poorly/non-absorbable antibiotics on hepatic venous pressure gradient (HVPG) are debated.

AIM

To analyze the effects of rifaximin or norfloxacin on HVPG and on markers of bacterial translocation and proinflammatory cytokines.

METHODS

We performed a systematic search of randomized clinical trials (RCTs) involving patients with cirrhosis and portal hypertension, assessing the effect of rifaximin or norfloxacin vs control on HVPG. Pooled analyses were based on random-effects models, heterogeneity was assessed by Cochran's Q, I² statistic and subgroup analyses.

RESULTS

Five studies (215 patients) were included. Risk of bias was high in three. We found no significant differences using antibiotics versus control. The summary mean difference in HVPG was of -0.55 mmHg (95%CI:-1.52, 0.42; P = 0.27), with moderate heterogeneity (P = 0.15; I² = 40%). RCTs with longer therapy (60-90 days) used non-selective-beta-blockers (NSBB) in both antibiotics and control arms. Subgroup analysis showed a significantly greater reduction in HVPG in the combination arm over controls (mean difference -1.46 mmHg [95%CI: -2.63, -0.28; P = 0.01]) with no heterogeneity (P = 0.46; I² = 0%). Serum lipopolysaccharide-binding protein (LBP) significantly decreased with antibiotics, but with high heterogeneity (P < 0.001; I² = 92%).

CONCLUSIONS

Rifaximin or norfloxacin did not significantly reduce HVPG in patients with cirrhosis and portal hypertension. Studies using antibiotic for longer periods on top of NSBB showed a significant decrease in HVPG.

Is small intestinal bacterial overgrowth a cause of hyperdynamic circulation in cirrhosis?

BACKGROUND/AIMS

Small intestinal bacterial overgrowth (SIBO) and hemodynamic changes are common in cirrhosis. We wanted to examine our hypothesis whether SIBO leads to hemodynamic changes in cirrhosis.

MATERIALS AND METHODS

A total of 50 patients with cirrhosis and 15 healthy controls were enrolled in a pilot prospective study. All participants underwent the lactulose hydrogen breath test for SIBO and echocardiography with a simultaneous assessment of blood pressure and heart rate. Cardiac output and systemic vascular resistance were calculated.

RESULTS

Study participants with SIBO had a lower systolic blood pressure and systemic vascular resistance compared to those without SIBO and to healthy controls (110.2±12.3 mmHg vs. 126.2±21.0 mmHg and 121.2±9.8 mmHg; p=0.005 and p=0.011, respectively; 1312±352 dyn•s•cm-5 vs. 1704±424 dyn•s•cm-5 and 1648±272 dyn•s•cm-5; p=0.001 and p=0.006, respectively), but a higher cardiac output (5.38±1.41 l/min vs. 4.52±1.03 l/min and 4.40±0.68 l/min; p=0.034 and p=0.041, respectively) and C-reactive protein (10.5[1.2-16.5] mg/l vs. 2.8[0.6-9.1] mg/l; p=0.028; no comparison with healthy controls). There were no significant differences between patients without SIBO and healthy controls with regard to systolic blood pressure (p=0.554), systemic vascular resistance (p=0.874), and cardiac output (p=0.795). SIBO was associated with vasodilation and hyperdynamic circulation in decompensated cirrhosis (p=0.002; p=0.012), but not in compensated cirrhosis (p=1.000; p=0.474).

CONCLUSIONS

SIBO is associated with hyperdynamic circulation and other hemodynamic changes in cirrhosis and may be a principal factor causing these through systemic inflammation.

Ascites and Hepatorenal Syndrome

Ascites occurs in up to 70% of patients during the natural history of cirrhosis. Management of uncomplicated ascites includes sodium restriction and diuretic therapy, whereas that for refractory ascites (RA) is regular large-volume paracentesis with transjugular intrahepatic portosystemic shunt being offered in appropriate patients. Renal impairment occurs in up to 50% of patients with RA with type 1 hepatorenal syndrome (HRS) being most severe. Liver transplant remains the definitive treatment of eligible candidates with HRS, whereas combined liver and kidney transplant should be considered in patients requiring dialysis for more than 4 to 6 weeks or those with underlying chronic kidney disease.

Gut-liver axis signaling in portal hypertension

Portal hypertension (PHT) in advanced chronic liver disease (ACLD) results from increased intrahepatic resistance caused by pathologic changes of liver tissue composition (structural component) and intrahepatic vasoconstriction (functional component). PHT is an important driver of hepatic decompensation such as development of ascites or variceal bleeding. Dysbiosis and an impaired intestinal barrier in ACLD facilitate translocation of bacteria and pathogen-associated molecular patterns (PAMPs) that promote disease progression via immune system activation with subsequent induction of proinflammatory and profibrogenic pathways. Congestive portal venous blood flow represents a critical pathophysiological mechanism linking PHT to increased intestinal permeability: The intestinal barrier function is affected by impaired microcirculation, neoangiogenesis, and abnormal vascular and mucosal permeability. The close bidirectional relationship between the gut and the liver has been termed “gut-liver axis”. Treatment strategies targeting the gut-liver axis by modulation of microbiota composition and function, intestinal barrier integrity, as well as amelioration of liver fibrosis and PHT are supposed to exert beneficial effects. The activation of the farnesoid X receptor in the liver and the gut was associated with beneficial effects in animal experiments, however, further studies regarding efficacy and safety of pharmacological FXR modulation in patients with ACLD are needed. In this review, we summarize the clinical impact of PHT on the course of liver disease, discuss the underlying pathophysiological link of PHT to gut-liver axis signaling, and provide insight into molecular mechanisms that may represent novel therapeutic targets.

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.

Dysfunctional Immune Response in Acute-on-Chronic Liver Failure: It Takes Two to Tango

Acute-on-chronic liver failure (ACLF) is characterized by the acute decompensation of cirrhosis associated with organ failure and high short-term mortality. The key event in the pathogenesis is a dysfunctional immune response arising from exacerbation of the two main immunological alterations already present in cirrhosis: systemic inflammation and immune cell paralysis. High-grade systemic inflammation due to predominant activation and dysregulation of the innate immune response leads to the massive release of cytokines. Recognition of acutely increased pathogen and damage-associated molecular patterns by specific receptors underlies its pathogenesis and contributes to tissue damage and organ failure. In addition, an inappropriate compensatory anti-inflammatory response over the course of ACLF, along with the exhaustion and dysfunction of both the innate and adaptive immune systems, leads to functional immune cell paralysis. This entails a high risk of infection and contributes to a poor prognosis. Therapeutic approaches seeking to counteract the immune alterations present in ACLF are currently under investigation.

Potential mechanisms linking gut microbiota and portal hypertension

Gut microbiota is the largest collection of commensal micro-organisms in the human body, engaged in reciprocal cellular and molecular interactions with the liver. This mutually beneficial relationship may break down and result in dysbiosis, associated with disease phenotypes. Altered composition and function of gut microbiota has been implicated in the pathobiology of nonalcoholic fatty liver disease (NAFLD), a prevalent condition linked to obesity, insulin resistance and endothelial dysfunction. NAFLD may progress to cirrhosis and portal hypertension, which is the result of increased intrahepatic vascular resistance and altered splanchnic circulation. Gut microbiota may contribute to rising portal pressure from the earliest stages of NAFLD, although the significance of these changes remains unclear. NAFLD has been linked to lower microbial diversity and weakened intestinal barrier, exposing the host to bacterial components and stimulating pathways of immune defence and inflammation. Moreover, disrupted host-microbial metabolic interplay alters bile acid signalling and the release of vasoregulatory gasotransmitters. These perturbations become prominent in cirrhosis, increasing the risk of clinically significant portal hypertension and leading to bacterial translocation, sepsis and acute-on-chronic liver failure. Better understanding of the gut-liver axis and identification of novel microbial molecular targets may yield specific strategies in the prevention and management of portal hypertension.

An update on the pathogenesis and clinical management of cirrhosis with refractory ascites

Ascites commonly complicates cirrhosis, becoming refractory to treatment with diuretics and sodium restriction in approximately 10% of patients. Pathogenesis of refractory ascites (RA) is multifactorial, the common final pathway being renal hypoperfusion and avid sodium retention. Refractory ascites has a negative prognostic implication in the natural history of cirrhosis. Management of RA include sodium restriction and regular large volume paracentesis (LVP) with albumin infusions, preventing paracentesis-induced circulatory dysfunction. In appropriate setting, transjugular intrahepatic porto-systemic shunt (TIPS) can be considered. Ascites clearance with TIPS can lead to nutritional improvement, avoiding sarcopenia. Liver transplantation (LT) remains the definitive treatment for eligible candidates. Areas covered: Our review summarizes current updates on pathogenesis and clinical management of RA including potential future therapeutic options such as the automated slow-flow ascites pump, chronic outpatient albumin infusion and cell-free and concentrated ascites reinfusion therapy. Expert commentary: Standard of care in patients with RA include LVP with albumin replacement and prompt referral for LT where indicated. Other novel therapeutic options on the horizon include automated low-flow ascites pump and cell-free, concentrated albumin reinfusion therapy.

Future Pharmacological Therapies of Portal Hypertension

PURPOSE OF REVIEW

To provide an overview of recent pharmacological treatments for portal hypertension evaluated in early clinical trials, with particular emphasis on the pathophysiological basis of their use.

RECENT FINDINGS

In patients with compensated cirrhosis, even small decreases in portal pressure (as small as 1 mmHg) are associated with a lower probability of decompensation. In patients with decompensated cirrhosis, portal pressure "response" to non-selective beta-blocker (NSBB) therapy is associated with a lower mortality. When present, significant portal hypertension persists even after elimination of the etiology of cirrhosis and this justifies the continued development of new drugs that target portal hypertension.

SUMMARY

Over several decades we have gained great depth in the understanding of portal hypertension, its mechanisms and complications. NSBBs, which act by reducing portal venous inflow (an extrahepatic target), are effective in reducing portal pressure and have been the mainstay of therapy for portal hypertension in the last 35 years -being effective in preventing decompensation and variceal hemorrhage. However, because not all patients will have a sufficient response to NSBB and some may be intolerant to NSBB, alternative drugs or drugs that will augment the effect of NSBB on portal pressure are being tested in pre-clinical and early-clinical trials. Many of these drugs target more than one of the intrahepatic or extrahepatic mechanisms implicated in the pathogenesis of portal hypertension in cirrhosis. Out of these proposed therapies, statins have emerged as the most promising new pharmacological therapy for the treatment of portal hypertension.

Serum Angiopoietin-2 Predicts Mortality and Kidney Outcomes in Decompensated Cirrhosis

Acute kidney injury in decompensated cirrhosis has limited therapeutic options, and novel mechanistic targets are urgently needed. Angiopoietin-2 is a context-specific antagonist of Tie2, a receptor that signals vascular quiescence. Considering the prominence of vascular destabilization in decompensated cirrhosis, we evaluated Angiopoietin-2 to predict clinical outcomes. Serum Angiopoietin-2 was measured serially in a prospective cohort of hospitalized patients with decompensated cirrhosis and acute kidney injury. Clinical characteristics and outcomes were examined over a 90-day period and analyzed according to Angiopoietin-2 levels. Primary outcome was 90-day mortality. Our study included 191 inpatients (median Angiopoietin-2 level 18.2 [interquartile range 11.8, 26.5] ng/mL). Median Model for End-Stage Liver Disease (MELD) score was 23 [17, 30] and 90-day mortality was 41%. Increased Angiopoietin-2 levels were associated with increased mortality (died 21.9 [13.9, 30.3] ng/mL vs. alive 15.2 [9.8, 23.0] ng/mL; P < 0.001), higher Acute Kidney Injury Network stage (stage I 13.4 [9.8, 20.1] ng/mL vs. stage II 20.0 [14.1, 26.2] ng/mL vs. stage III 21.9 [13.0, 29.5] ng/mL; P = 0.002), and need for renal replacement therapy (16.5 [11.3, 23.6] ng/mL vs. 25.1 [13.3, 30.3] ng/mL; P = 0.005). The association between Angiopoietin-2 and mortality was significant in unadjusted and adjusted Cox regression models (P ≤ 0.001 for all models), and improved discrimination for mortality when added to MELD score (integrated discrimination increment 0.067; P = 0.001). Conclusion: Angiopoietin-2 was associated with mortality and other clinically relevant outcomes in a cohort of patients with decompensated cirrhosis with acute kidney injury. Further experimental study of Angiopoietin/Tie2 signaling is warranted to explore its potential mechanistic and therapeutic role in this population.

Bacterial translocation in patients with liver cirrhosis: physiology, clinical consequences, and practical implications

The gut liver axis is an operative unit that works to protect the human body against potentially harmful substances and microorganisms, maintaining the homeostasis of the immune system. Liver cirrhosis profoundly alters this complex system. The intestine becomes more permeable allowing the translocation of bacteria, bacterial products and fragments into the portal circulation, triggering an abnormal local and systemic inflammatory response and a condition of perpetual immunologic alarm. This immune-inflammatory disorder related to dysbiosis is involved in the development of liver damage and liver cirrhosis complications and increases intestinal permeability in a vicious circle. Areas covered: The most relevant studies on bacterial translocation, the mechanism of intestinal barrier dysfunction and its consequences in patients with liver cirrhosis have been revised through a PubMed search. Data have been discussed with particular regard to their significance in clinical practice. Expert commentary: The assessment of bacterial translocation and intestinal permeability is not currently used in clinical practice but may be useful to stratify patients' prognosis.

Rifaximin and Propranolol Combination Therapy Is More Effective than Propranolol Monotherapy for the Reduction of Portal Pressure: An Open Randomized Controlled Pilot Study

Background/Aims

Non-selective beta blockers (NSBBs) are currently the only accepted regimen for preventing portal hypertension (PHT)-related complications. However, the effect of NSBBs is insufficient in many cases. Bacterial translocation (BT) is one of the aggravating factors of PHT in cirrhosis; therefore, selective intestinal decontamination by rifaximin is a possible therapeutic option for improving PHT. We investigated whether the addition of rifaximin to propranolol therapy can improve hepatic venous pressure gradient (HVPG) response.

Methods

Sixty-four cirrhosis patients were randomly assigned to propranolol monotherapy (n=48) versus rifaximin and propranolol combination therapy (n=16). Baseline and post-treatment HVPG values, BT-related markers (lipopolysaccharide [LPS], LPS-binding protein [LBP], interleukin-6 [IL-6], and tumor necrosis factor α [TNF-α]), serological data, and adverse event data were collected. HVPG response rate was the primary endpoint.

Results

Combination therapy was associated with better HVPG response rates than monotherapy (56.2% vs 87.5%, p=0.034). In combination therapy, posttreatment BT-related markers were significantly decreased (LPS, p=0.005; LBP, p=0.005; IL-6, p=0.005; TNF-α, p=0.047).

Conclusions

Rifaximin combination therapy showed an additive effect in improving PHT compared to propranolol monotherapy. These pilot data suggest that the addition of rifaximin to NSBBs could be a good therapeutic option for overcoming the limited effectiveness of NSBBs.

Managing portal hypertension in patients with liver cirrhosis

Portal hypertension is one cause and a part of a dynamic process triggered by chronic liver disease, mostly induced by alcohol or incorrect nutrition and less often by viral infections and autoimmune or genetic disease. Adequate staging - continuously modified by current knowledge - should guide the prevention and treatment of portal hypertension with defined endpoints. The main goals are interruption of etiology and prevention of complications followed, if necessary, by treatment of these. For the past few decades, shunts, mostly as intrahepatic stent bypass between portal and hepatic vein branches, have played an important role in the prevention of recurrent bleeding and ascites formation, although their impact on survival remains ambiguous. Systemic drugs, such as non-selective beta-blockers, statins, or antibiotics, reduce portal hypertension by decreasing intrahepatic resistance or portal tributary blood flow or by blunting inflammatory stimuli inside and outside the liver. Here, the interactions among the gut, liver, and brain are increasingly examined for new therapeutic options. There is no general panacea. The interruption of initiating factors is key. If not possible or if not possible in a timely manner, combined approaches should receive more attention before considering liver transplantation.

Microbiota and the liver

The gut microbiome outnumbers the human genome by 150-fold and plays important roles in metabolism, immune system education, tolerance development, and prevention of pathogen colonization. Dysbiosis has been associated with nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), and alcoholic liver disease (ALD) as well as cirrhosis and complications. This article provides an overview of this relationship. Liver Transplantation 24 539-550 2018 AASLD.

The pathophysiology of arterial vasodilatation and hyperdynamic circulation in cirrhosis

Patients with cirrhosis and portal hypertension often develop complications from a variety of organ systems leading to a multiple organ failure. The combination of liver failure and portal hypertension results in a hyperdynamic circulatory state partly owing to simultaneous splanchnic and peripheral arterial vasodilatation. Increases in circulatory vasodilators are believed to be due to portosystemic shunting and bacterial translocation leading to redistribution of the blood volume with central hypovolemia. Portal hypertension per se and increased splanchnic blood flow are mainly responsible for the development and perpetuation of the hyperdynamic circulation and the associated changes in cardiovascular function with development of cirrhotic cardiomyopathy, autonomic dysfunction and renal dysfunction as part of a cardiorenal syndrome. Several of the cardiovascular changes are reversible after liver transplantation and point to the pathophysiological significance of portal hypertension. In this paper, we aimed to review current knowledge on the pathophysiology of arterial vasodilatation and the hyperdynamic circulation in cirrhosis.

Management of bacterial infection in the liver transplant candidate

Bacterial infection (BI) is a common cause of impairment of liver function in patients with cirrhosis, especially in the liver transplant candidates. These patients share an immunocompromised state and increased susceptibility to develop community and hospital-acquired infections. The changing epidemiology of BI, with an increase of multidrug resistant strains, especially in healthcare-associated settings, represents a critical issue both in the waiting list and in the post-operative management. This review focused on the role played by BI in patients awaiting liver transplantation, evaluating the risk of drop-out from the waiting list, the possibility to undergo liver transplantation after recovery from infection or during a controlled infection.

Rifaximin has minor effects on bacterial composition, inflammation, and bacterial translocation in cirrhosis: A randomized trial

BACKGROUND AND AIM

Decompensated cirrhosis is characterized by disturbed hemodynamics, immune dysfunction, and high risk of infections. Translocation of viable bacteria and bacterial products from the gut to the blood is considered a key driver in this process. Intestinal decontamination with rifaximin may reduce bacterial translocation (BT) and decrease inflammation. A randomized, placebo-controlled trial investigated the effects of rifaximin on inflammation and BT in decompensated cirrhosis.

METHODS

Fifty-four out-patients with cirrhosis and ascites were randomized, mean age 56 years (± 8.4), and model for end-stage liver disease score 12 (± 3.9). Patients received rifaximin 550-mg BD (n = 36) or placebo BD (n = 18). Blood and fecal (n = 15) sampling were conducted at baseline and after 4 weeks. Bacterial DNA in blood was determined by real-time qPCR 16S rRNA gene quantification. Bacterial composition in feces was analyzed by 16S rRNA gene sequencing.

RESULTS

Circulating markers of inflammation, including tumor necrosis factor alpha, interleukins 6, 10, and 18, stromal cell-derived factor 1-α, transforming growth factor β-1, and high sensitivity C-reactive protein, were unaltered by rifaximin treatment. Rifaximin altered abundance of bacterial taxa in blood marginally, only a decrease in Pseudomonadales was observed. In feces, rifaximin decreased bacterial richness, but effect on particular species was not observed. Subgroup analyses on patients with severely disturbed hemodynamics (n = 34) or activated lipopolysaccharide binding protein (n = 37) revealed no effect of rifaximin.

CONCLUSION

Four weeks of treatment with rifaximin had no impact on the inflammatory state and only minor effects on BT and intestinal bacterial composition in stable, decompensated cirrhosis (NCT01769040).

Rifaximin for the prevention of spontaneous bacterial peritonitis and hepatorenal syndrome in cirrhosis: a systematic review and meta-analysis

Prophylactic antibiotics have been recommended in patients with a previous history of spontaneous bacterial peritonitis (SBP). Recently, there has been interest in the use of rifaximin for the prevention of SBP and hepatorenal syndrome (HRS). We conducted a meta-analysis to evaluate this association of rifaximin. We searched several databases from inception through 24 January 2017, to identify comparative studies evaluating the effect of rifaximin on the occurrence of SBP and HRS. We performed predetermined subgroup analyses based on the type of control group, design of the study, and type of prophylaxis. Pooled odds ratios (ORs) were calculated using a random effects model. We included 13 studies with 1703 patients in the meta-analysis of SBP prevention. Pooled OR [95% confidence interval (CI)] was 0.40 (95% CI: 0.22-0.73) (I=58%). On sensitivity analysis, adjusted OR was 0.29 (95% CI: 0.20-0.44) (I=0%). The results of the subgroup analysis based on type of control was as follows: in the quinolone group, pooled OR was 0.42 (95% CI: 0.14-1.25) (I=55%), and in the no antibiotic group, pooled OR was 0.40 (95% CI: 0.18-0.86) (I=64%). However, with sensitivity analysis, benefit of rifaximin was demonstrable; pooled ORs were 0.32 (95% CI: 0.17-0.63) (I=0%) and 0.28 (95% CI: 0.17-0.45) (I=0%) for the comparison with quinolones and no antibiotics, respectively. Pooled OR based on randomized controlled trials was 0.41 (95% CI: 0.22-0.75) (I=13%). For the prevention of HRS, the pooled OR was 0.25 (95% CI: 0.13-0.50) (I=0%). Rifaximin has a protective effect against the development of SBP in cirrhosis. However, the quality of the evidence as per the GRADE framework was very low. Rifaximin appeared effective for the prevention of HRS.

Novel treatment options for portal hypertension

Portal hypertension is most frequently associated with cirrhosis and is a major driver for associated complications, such as variceal bleeding, ascites or hepatic encephalopathy. As such, clinically significant portal hypertension forms the prelude to decompensation and impacts significantly on the prognosis of patients with liver cirrhosis. At present, non-selective β-blockers, vasopressin analogues and somatostatin analogues are the mainstay of treatment but these strategies are far from satisfactory and only target splanchnic hyperemia. In contrast, safe and reliable strategies to reduce the increased intrahepatic resistance in cirrhotic patients still represent a pending issue. In recent years, several preclinical and clinical trials have focused on this latter component and other therapeutic avenues. In this review, we highlight novel data in this context and address potentially interesting therapeutic options for the future.

Bacterial load and cytokine profile in patients with cirrhosis following therapy with proton pump inhibitors: a prospective cohort study

BACKGROUND

The aim of this study was to explore the presence of bacterial products and the cytokine profile in outpatients with cirrhosis before and after short-term (4-8 weeks) administration of proton pump inhibitors (PPIs).

METHODS

Seventeen patients with cirrhosis-male/female: 12/5; age: median 59.2 years (49-65); etiology: HBV±HDV 23.5%, HCV 17.7%, alcohol 41.2%, other 17.6%; Child-Pugh score: median 7.5 (5-12); Model for End-stage Liver Disease: 10.5 (7-21); ascites (%): 3 (17.7)-attending the outpatient clinics were included. None had hepatocellular carcinoma. Indications for PPIs were: esophagitis (n=6, 35.3%), peptic ulcer (n=10, 58.6%) and other (n=1, 5.9%). Bacterial DNA in serum and the levels of endotoxin, lipopolysaccharide binding protein, transforming growth factor-β, interleukin -1β, -6, -8, -12, -10, tumor necrosis factor-α and nitric oxide were assessed at baseline (time 1) and at the end of treatment (time 2). The Wilcoxon signed rank test was used to evaluate significant differences in the parameters assayed before and after PPI administration.

RESULTS

No patients developed infection during the study period. Bacterial DNA was not detected before or after treatment. No significant differences were observed between the concentrations of any indices between times 1 and 2 (P>0.05). Subgroup analysis according to Child-Pugh stage yielded similar results.

CONCLUSION

Short-term administration of PPIs had no effect on bacterial DNA, bacterial products or cytokine concentrations in patients with liver cirrhosis.

Rifaximin Decreases the Incidence and Severity of Acute Kidney Injury and Hepatorenal Syndrome in Cirrhosis

BACKGROUND

While the effects of rifaximin have been shown to be protective against acute kidney injury (AKI) and hepatorenal syndrome (HRS) in alcohol-induced cirrhosis, its long-term effects on the renal function of other cirrhotic patients are unknown.

AIM

To examine the long-term effects of rifaximin on the renal function of patients with cirrhosis from various etiologies.

METHODS

In a retrospective study, we examined cirrhotic patients at the University of Chicago Liver Clinic from January 1, 2011, to December 31, 2014. The study enrolled patients on rifaximin for ≥90 days, who were then matched by age, gender, and MELD score to a control group. Patients with malignancy and renal replacement therapy (RRT) at baseline were excluded. Data were censored at the last follow-up, termination of rifaximin therapy, initiation of RRT, death, or liver transplant.

RESULTS

Eighty-eight rifaximin cases were identified and matched to 88 control cases. Baseline characteristics were similar, with the exceptions of more prevalent long-term midodrine use (≥90 days) (17.0 vs 4.5 %, p = 0.01) and baseline ascites (37.5 vs 23.8 %, p = 0.05) in the rifaximin group. There was no difference in the frequency of infections, deaths, liver transplants, or hospitalizations. After controlling for cofounders, the incidence rate ratio of AKI (IRR 0.71, p = 0.02) and HRS (IRR 0.21, p = 0.02), as well as the risk of requiring RRT (OR 0.23, p = 0.01), was lower in the rifaximin group.

CONCLUSIONS

Long-term use of rifaximin is associated with a decrease incidence of AKI and HRS and a decrease risk of requiring RRT in a general population of cirrhotic patients.

Efficacy and safety of alternating norfloxacin and rifaximin as primary prophylaxis for spontaneous bacterial peritonitis in cirrhotic ascites: a prospective randomized open-label comparative multicenter study

BACKGROUND AND AIM

Primary prevention of spontaneous bacterial peritonitis (SBP) is an important strategy to reduce morbidity and mortality in cirrhotic patients with ascites. Efficacy and safety of alternating rifaximin and norfloxacin as primary prophylaxis is questionable.

METHODS

Three hundred thirty-four cirrhotic patients with high SAAG (≥1.1) ascites, protein level in ascitic fluid less than 1.5 g/dL with advanced liver disease (Child-Pugh score >9 points with serum bilirubin level >3 mg/dL) or renal impairment (serum creatinine level >1.2 mg/dL, blood urea nitrogen level >25 mg/dL, or serum sodium level <130 mEq/L) were included in an open-label, randomized study aimed at comparing alternating use of norfloxacin and rifaximin vs. norfloxacin or rifaximin alone as primary prophylaxis for SBP. Both intention-to-treat and per-protocol efficacy analyses were done after 6 months of treatment by assessment of ascitic fluid neutrophil count. Safety analysis was done for all intention-to-treat populations.

RESULTS

Alternating norfloxacin and rifaximin showed superior prophylaxis by intention-to-treat (74.7 vs. 56.4% vs. 68.3%, p < 0.048). Pairwise analysis showed that alternating regimen had lower probability to develop SBP when compared to a norfloxacin-based regimen in intention-to-treat (p = 0.016) and per protocol analysis (p = 0.039). There was no difference among the studied groups regarding the incidence and severity of adverse events reported.

CONCLUSIONS

Alternating norfloxacin- and rifaximin-based primary prophylaxis for SBP showed higher efficacy with the same safety profile when compared with monotherapy of norfloxacin.

Microbiome and bacterial translocation in cirrhosis

Qualitative and quantitative changes in gut microbiota play a very important role in cirrhosis. Humans harbour around 100 quintillion gut bacteria, thus representing around 10 times more microbial cells than eukaryotic ones. The gastrointestinal tract is the largest surface area in the body and it is subject to constant exposure to these living microorganisms. The existing symbiosis, proven by the lack of proinflammatory response against commensal bacteria, implies the presence of clearly defined communication lines that contribute to the maintenance of homeostasis of the host. Therefore, alterations of gut flora seem to play a role in the pathogenesis and progress of multiple liver and gastrointestinal diseases. This has made its selective modification into an area of high therapeutic interest. Bacterial translocation is defined as the migration of bacteria or bacterial products from the intestines to the mesenteric lymph nodes. It follows that alteration in gut microbiota have shown importance, at least to some extent, in the pathogenesis of several complications arising from terminal liver disease, such as hepatic encephalopathy, portal hypertension and spontaneous bacterial peritonitis. This review sums up, firstly, how liver disease can alter the common composition of gut microbiota, and secondly, how this alteration contributes to the development of complications in cirrhosis.

[Aspects of pathogenetc pharmacotherapy for portal hypertension in liver cirrhosis]

The review of literature considers the principles of medical treatment for portal hypertension in liver cirrhosis, which are based on the current views of its development mechanisms. It describes both current pharmacotherapy methods for portal hypertension and drugs, the efficacy of which is being investigated.

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

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

Clinical and pathophysiological consequences of alterations in the microbiome in cirrhosis

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

Challenges and Management of Liver Cirrhosis: Pathophysiology of Renal Dysfunction in Cirrhosis

Kidney dysfunction is a common complication of patients with advanced cirrhosis and is associated with poor prognosis. Patients with advanced cirrhosis show circulatory dysfunction characterized by reduced systemic vascular resistance due to splanchnic arterial vasodilation, which is caused by portal hypertension. The progressive reduction in systemic vascular resistance leads to effective arterial hypovolemia. In order to maintain arterial pressure within normal limits in this setting, there is activation of systemic vasoconstrictor systems, including the renin-angiotensin-aldosterone system, sympathetic nervous system and, in late stages, nonosmotic hypersecretion of vasopressin. Although these systems have positive effects in maintaining arterial pressure, they have a negative influence on kidney function, leading to the retention of sodium and solute-free water, and in late stages of the disease an intense kidney vasoconstriction develops, leading to decrease of the glomerular filtration rate and the development of hepatorenal syndrome (HRS). Moreover, bacterial translocation and the existence of a systemic inflammatory state in patients with advanced cirrhosis may play a role in the impairment of circulatory function. HRS is a unique cause of kidney failure of functional origin that develops in patients with cirrhosis. However, besides HRS, patients with cirrhosis may develop kidney failure due to other causes, including bacterial infections, prerenal kidney failure, shock, use of nephrotoxic drugs or intrinsic kidney diseases. Considering the existence of circulatory dysfunction and some degree of kidney vasoconstriction, patients with advanced cirrhosis have fragile kidney function and are susceptible to easily developing kidney failure associated with other complications of the disease, particularly bacterial infections and gastrointestinal bleeding.

Portal vein thrombosis in cirrhosis: Controversies and latest developments

Portal vein thrombosis (PVT) is encountered in liver cirrhosis, particularly in advanced disease. It has been a feared complication of cirrhosis, attributed to significant worsening of liver disease, poorer clinical outcomes and potential inoperability at liver transplantation; also catastrophic events such as acute intestinal ischaemia. Optimal management of PVT has not yet been addressed in any consensus publication. We review current literature on PVT in cirrhosis; its prevalence, pathophysiology, diagnosis, impact on the natural history of cirrhosis and liver transplantation, and management. Studies were identified by a search strategy using MEDLINE and Google Scholar. The incidence of PVT increases with increasing severity of liver disease: less than 1% in well-compensated cirrhosis, 7.4%-16% in advanced cirrhosis. Prevalence in patients undergoing liver transplantation is 5%-16%. PVT frequently regresses instead of uniform thrombus progression. PVT is not associated with increased risk of mortality. Optimal management has not been addressed in any consensus publication. We propose areas for future research to address unresolved clinical questions.

Hepatic encephalopathy in acute-on-chronic liver failure

The presence of hepatic encephalopathy (HE) within 4 weeks is part of the criteria for defining acute-on-chronic liver failure (ACLF). The pathophysiology of HE is complex, and hyperammonemia and cerebral hemodynamic dysfunction appear to be central in the pathogenesis of encephalopathy. Recent data also suggest that inflammatory mediators may have a significant role in modulating the cerebral effect of ammonia. Multiple prospective and retrospective studies have shown that hepatic encephalopathy in ACLF patients is associated with higher mortality, especially in those with grade III-IV encephalopathy, similar to that of acute liver failure (ALF). Although significant cerebral edema detected by CT in ACLF patients appeared to be less common, specialized MRI imaging was able to detect cerebral edema even in low grade HE. Ammonia-focused therapy constitutes the basis of current therapy, as in the treatment of ALF. Emerging treatment strategies focusing on modulating the gut-liver-circulation-brain axis are discussed.

Contemporary concepts of the medical therapy of portal hypertension under liver cirrhosis

Severe complications of liver cirrhosis are mostly related to portal hypertension. At the base of the pathogenesis of portal hypertension is the increase in hepatic vascular resistance to portal blood flow with subsequent development of hyperdynamic circulation, which, despite of the formation of collateral circulation, promotes progression of portal hypertension. An important role in its pathogenesis is played by the rearrangement of vascular bed and angiogenesis. As a result, strategic directions of the therapy of portal hypertension under liver cirrhosis include selectively decreasing hepatic vascular resistance with preserving or increasing portal blood flow, and correcting hyperdynamic circulation and pathological angiogenesis, while striving to reduce the hepatic venous pressure gradient to less than 12 mmHg or 20% of the baseline. Over the last years, substantial progress in understanding the pathophysiological mechanisms of hemodynamic disorders under liver cirrhosis has resulted in the development of new drugs for their correction. Although the majority of them have so far been investigated only in animal experiments, as well as at the molecular and cellular level, it might be expected that the introduction of the new methods in clinical practice will increase the efficacy of the conservative approach to the prophylaxis and treatment of portal hypertension complications. The purpose of the review is to describe the known methods of portal hypertension pharmacotherapy and discuss the drugs that may affect the basic pathogenetic mechanisms of its development.

A matched cross-sectional study of the association between circulating tissue factor activity, immune activation and advanced liver fibrosis in hepatitis C infection

Background

Tissue factor (TF) is a protein that mediates the initiation of the coagulation cascade. TF expression is increased in patients with poorly-controlled HIV, and may be associated with increased immune activation that leads to cardiovascular morbidity. The role of TF in immune activation in liver disease in hepatitis C virus (HCV)-monoinfection and HIV/HCV-coinfection has not been explored.

Methods

Fifty-nine patients were stratified: A) HIV-monoinfection (N = 15), B) HCV-monoinfection with chronic hepatitis C (CHC) (N = 15), C) HIV/HCV-coinfection with CHC (N = 14), and D) HIV/HCV-seropositive with cleared-HCV (N = 15). All HIV+ patients had undetectable HIV viremia. Whole blood was collected for CD4/CD8 immune activation markers by flow cytometry and plasma was assayed for microparticle TF (MPTF) activity. Subjects underwent transient elastography (TE) to stage liver fibrosis. Undetectable versus detectable MPTF was compared across strata using Fisher's Exact test.

Results

MPTF activity was more frequently detected among patients with HCV-monoinfection (40%), compared to HIV-monoinfection and HIV/HCV-seropositive with cleared HCV (7%) and HIV/HCV-coinfection with CHC (14%) (p = 0.02). Mean TE-derived liver stiffness score in kPa was higher in patients with detectable MPTF (12.4 ± 8.5) than those with undetectable MPTF (6.4 ± 3.0) (p = 0.01). Mean CD4 + HLADR+ and CD4 + CD38-HLADR+ expression were higher in those with detectable MPTF (44 ± 9.8% and 38 ± 8.7%, respectively) than those with undetectable MPTF (36 ± 11% and 31 ± 10.4% respectively) (p = 0.05 and 0.04 respectively).

Conclusions

HCV-monoinfection and HIV/HCV-coinfection with CHC were associated with MPTF activity. MPTF activity is also associated with advanced liver fibrosis and with CD4 + HLADR+ immune activation.

Appropriate and timely antimicrobial therapy in cirrhotic patients with spontaneous bacterial peritonitis-associated septic shock: a retrospective cohort study

BACKGROUND

Spontaneous bacterial peritonitis (SBP)-associated septic shock carries significant mortality in cirrhosis.

AIM

To determine whether practice-related aspects of antimicrobial therapy contribute to high mortality.

METHODS

Retrospective cohort study of all (n = 126) cirrhotics with spontaneous bacterial peritonitis (neutrophil count >250 or positive ascitic culture)-associated septic shock (1996-2011) from an international, multicenter database. Appropriate antimicrobial therapy implied either in vitro activity against a subsequently isolated pathogen (culture positive) or empiric management consistent with broadly accepted norms (culture negative).

RESULTS

Overall hospital mortality was 81.8%. Comparing survivors (n = 23) with non-survivors (n = 103), survivors had lower Acute Physiology and Chronic Health Evaluation (APACHEII) (mean ± s.d.; 22 ± 7 vs. 32 ± 8) and model for end-stage liver disease (MELD) (24 ± 9 vs. 34 ± 11) scores and serum lactate on admission (4.9 ± 3.1 vs. 8.9  ± 5.3), P < 0.001 for all. Survivors were less likely to receive inappropriate initial antimicrobial therapy (0% vs. 25%, P = 0.013) and received appropriate antimicrobial therapy earlier [median 1.8 (1.1-5.2) vs. 9.5 (3.9-14.3) h, P < 0.001]. After adjusting for covariates, APACHEII [OR, odds ratio 1.45 (1.04-2.02) per 1 unit increment, P = 0.03], lactate [OR 2.34 (1.04-5.29) per unit increment, P = 0.04] and time delay to appropriate antimicrobials [OR 1.86 (1.10-3.14) per hour increment, P = 0.02] were significantly associated with increased mortality.

CONCLUSIONS

Cirrhotic patients with septic shock secondary to spontaneous bacterial peritonitis have high mortality (>80%). Each hour of delay in appropriate antimicrobial therapy was associated with a 1.86 times increased hospital mortality. Admission APACHEII and serum lactate also significantly impacted hospital mortality. Earlier initiation of appropriate antimicrobial therapy could substantially improve outcome.