Patients with acutely decompensated cirrhosis have a dismal prognosis and frequently progress to acute-on-chronic liver failure, which is characterised by hepatic and extrahepatic organ failure(s). ...The pathomechanisms involved in decompensation and disease progression are still not well understood, and as specific disease-modifying treatments do not exist, research to identify novel therapeutic targets is of the utmost importance. This review amalgamates the latest knowledge on disease mechanisms that lead to tissue injury and extrahepatic organ failure – such as systemic inflammation, mitochondrial dysfunction, oxidative stress and metabolic changes – and marries these with the classical paradigms of acute decompensation to form a single paradigm. With this detailed breakdown of pathomechanisms, we identify areas for future research. Novel disease-modifying strategies that break the vicious cycle are urgently required to improve patient outcomes.
Summary Among the common complication of cirrhosis portal hypertension witnessed a major improvement of prognosis during the past decades. Principally due to the introduction of rational treatments ...based on new pathophysiological paradigms (concepts of thought) developed in the 1980s. The best example being the use of non-selective beta-blockers and of vasopressin analogs, somatostatin, and its analogs. Further refinement in the knowledge of the molecular mechanisms involved in the regulation of both the splanchnic and hepatic circulation has led to the emergence of new treatments, which are based on evidence that show not only structural but also vasoactive components increase the hepatic vascular resistance, as well as of angiogenesis. This knowledge and future improvements will most likely result in more effective treatment of portal hypertension and effective prevention of its complications in early stages.
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•Autophagy maintains liver endothelial cell homeostasis.•Autophagy deficiency in LSEC increases oxidative stress.•Autophagy regulates nitric oxide bioavailability and maintains LSEC ...phenotype.•Impairment of endothelial autophagy enhances endothelial dysfunction and exacerbates fibrosis.
Endothelial dysfunction plays an essential role in liver injury, yet the phenotypic regulation of liver sinusoidal endothelial cells (LSECs) remains unknown. Autophagy is an endogenous protective system whose loss could undermine LSEC integrity and phenotype. The aim of our study was to investigate the role of autophagy in the regulation of endothelial dysfunction and the impact of its manipulation during liver injury.
We analyzed primary isolated LSECs from Atg7control and Atg7endo mice as well as rats after CCl4 induced liver injury. Liver tissue and primary isolated stellate cells were used to analyze liver fibrosis. Autophagy flux, microvascular function, nitric oxide bioavailability, cellular superoxide content and the antioxidant response were evaluated in endothelial cells.
Autophagy maintains LSEC homeostasis and is rapidly upregulated during capillarization in vitro and in vivo. Pharmacological and genetic downregulation of endothelial autophagy increases oxidative stress in vitro. During liver injury in vivo, the selective loss of endothelial autophagy leads to cellular dysfunction and reduced intrahepatic nitric oxide. The loss of autophagy also impairs LSECs ability to handle oxidative stress and aggravates fibrosis.
Autophagy contributes to maintaining endothelial phenotype and protecting LSECs from oxidative stress during early phases of liver disease. Selectively potentiating autophagy in LSECs during early stages of liver disease may be an attractive approach to modify the disease course and prevent fibrosis progression.
Liver endothelial cells are the first liver cell type affected after any kind of liver injury. The loss of their unique phenotype during injury amplifies liver damage by orchestrating the response of the liver microenvironment. Autophagy is a mechanism involved in the regulation of this initial response and its manipulation can modify the progression of liver damage.
Transjugular intrahepatic portosystemic shunt (TIPS) is increasingly used worldwide to treat the complications of portal hypertension in patients with advanced cirrhosis. However, its use is hampered ...by the risk of causing hepatic encephalopathy and of worsening liver function. The reported haemodynamic targets used to guide TIPS are too narrow to be achieved in most cases and are perhaps not entirely adequate nowadays as they were obtained in the pre-covered stent era. We propose that small diameter TIPS – alone or combined to pharmacological therapy or ancillary interventional radiology procedures – may overcome these limitations while maintaining the beneficial effects of the procedure.
Idiopathic portal hypertension (IPH) is a rare cause of intrahepatic portal hypertension. Data on natural history and prognosis of IPH are limited. We sought to describe the complications and ...long‐tem outcome of IPH by retrospectively studying 69 biopsy‐proven cases of IPH. Mean duration of follow‐up was 6.7 ± 4.6 years. All patients had evidence of portal hypertension (PH) at diagnosis, and 42% were symptomatic. Variceal bleeding (VB) was the most common manifestation. In those without bleeding at diagnosis, 74% had varices at first endoscopy. In those with large varices, the 1‐year probability of first bleeding despite primary prophylaxis was 9%. The 1‐year probability of rebleeding was 22%. Ascites and hepatic encephalopathy was documented in 26% and 7% of patients, respectively, at least once during the clinical course. The 1‐year probability of developing portal vein thrombosis (PVT) was 9%, and 53% of patients receiving anticoagulation achieved recanalization. Human immunodeficiency virus (HIV) infection and VB at diagnosis were the independent predictors of PVT. Seven patients died (6 as a result of an IPH‐related cause) and 2 were transplanted. Probability of liver transplantation–free survival was 82% at 10 years. Presence of a severe associated disorder and ascites as a presenting symptom were associated with poor survival. Conclusion: Variceal bleeding is a major complication of IPH. Using, in IPH patients, the same management approach for PH as in cirrhosis is safe and maintains a low incidence of first bleeding and rebleeding in IPH patients. PVT is a frequent complication, particularly in those with HIV infection. Despite several complications, overall survival of patients with IPH is considerably good. (Hepatology 2014;59:2276–2285)
Portal hypertension is the main cause of complications in patients with chronic liver disease. Over the past 25 years, progress in the understanding of the pathophysiology of portal hypertension was ...followed by the introduction of an effective pharmacological therapy, consisting mainly of treatments aimed at correcting the increased splanchnic blood flow. It is only recently that this paradigm has been changed. Progress in our knowledge of the mechanisms of increased resistance to portal blood flow, of the formation of portal-systemic collaterals, and of mechanisms other than vasodilatation maintaining the increased splanchnic blood flow have opened entirely new perspectives for developing more effective treatment strategies. This is the aim of the current review, which focuses on: (a) the modulation of hepatic vascular resistance by correcting the increased hepatic vascular tone due to hepatic endothelial dysfunction, and (b) correcting the abnormal angiogenesis associated with portal hypertension, which contributes to liver inflammation and fibrogenesis, to the hyperkinetic splanchnic circulation, and to the formation of portal-systemic collaterals and varices.
Beta-blockers have been studied for the prevention of variceal bleeding and, more recently, for the prevention of all-cause decompensation. Some uncertainties regarding the benefit of beta-blockers ...for the prevention of decompensation remain. Bayesian analyses enhance the interpretation of trials. The purpose of this study was to provide clinically meaningful estimates of both the probability and magnitude of the benefit of beta-blocker treatment across a range of patient types.
We undertook a Bayesian reanalysis of PREDESCI incorporating 3 priors (moderate neutral, moderate optimistic, and weak pessimistic). The probability of clinical benefit was assessed considering the prevention of all-cause decompensation. Microsimulation analyses were done to determine the magnitude of the benefit. In the Bayesian analysis, the probability that beta-blockers reduce all-cause decompensation was >0.93 for all priors. The Bayesian posterior hazard ratios (HR) for decompensation ranged from 0.50 (optimistic prior, 95% credible interval 0.27-0.93) to 0.70 (neutral prior, 95% credible interval 0.44-1.12). Exploring the benefit of treatment using microsimulation highlights substantial treatment benefits. For the neutral prior derived posterior HR and a 5% annual incidence of decompensation, at 10 years, an average of 497 decompensation-free years per 1000 patients were gained with treatment. In contrast, at 10 years 1639 years per 1000 patients were gained from the optimistic prior derived posterior HR and a 10% incidence of decompensation.
Beta-blocker treatment is associated with a high probability of clinical benefit. This likely translates to a substantial gain in decompensation-free life years at the population level.
Background & Aims Resveratrol, a polyphenol found in a variety of fruits, exerts a wide range of beneficial effects on the endothelium, regulates multiple vasoactive substances and decreases ...oxidative stress, factors involved in the pathophysiology of portal hypertension. Our study aimed at evaluating the effects of resveratrol on hepatic and systemic hemodynamics, hepatic endothelial dysfunction, and hepatic fibrosis in CCl4 cirrhotic rats. Methods Resveratrol (10 and 20 mg/kg/day) or its vehicle was administered to cirrhotic rats for two weeks and hepatic and systemic hemodynamics were measured. Moreover, we evaluated endothelial function by dose-relaxation curves to acetylcholine, hepatic NO bioavailability and TXA2 production. We also evaluated liver fibrosis by Sirius Red staining of liver sections, collagen-1, NFκB , TGFβ mRNA expression, and desmin and α-smooth muscle actin (α-SMA) protein expression, as a surrogate of hepatic stellate cell activation. Results Resveratrol administration significantly decreased portal pressure compared to vehicle (12.1 ± 0.9 vs. 14.3 ± 2.2 mmHg; p <0.05) without significant changes in systemic hemodynamics. Reduction in portal pressure was associated with an improved vasodilatory response to acetylcholine, with decreased TXA2 production, increased endothelial NO, and with a significant reduction in liver fibrosis. The decrease in hepatic fibrosis was associated with a reduced collagen-1, TGFβ , NFκB mRNA expression and desmin and α-SMA protein expression. Conclusions Resveratrol administration reduces portal pressure, hepatic stellate cell activation and liver fibrosis, and improves hepatic endothelial dysfunction in cirrhotic rats, suggesting it may be a useful dietary supplement in the treatment of portal hypertension in patients with cirrhosis.
In cirrhosis, increased intrahepatic vascular resistance (IHVR) is the primary factor for portal hypertension (PH) development. Hepatic stellate cells (HSCs) play a major role increasing IHVR ...because, when activated, they are contractile and promote fibrogenesis. Protease‐activated receptors (PARs) can activate HSCs through thrombin and factor Xa, which are known PAR agonists, and cause microthrombosis in liver microcirculation. This study investigates the effects of the oral anticoagulant, rivaroxaban (RVXB), a direct antifactor Xa, on HSC phenotype, liver fibrosis (LF), liver microthrombosis, and PH in cirrhotic rats. Hepatic and systemic hemodynamic, nitric oxide (NO) bioavailability, LF, HSC activation, and microthrombosis were evaluated in CCl4 and thioacetamide‐cirrhotic rats treated with RVXB (20 mg/kg/day) or its vehicle for 2 weeks. RVXB significantly decreased portal pressure (PP) in both models of cirrhosis without changes in portal blood flow, suggesting a reduction in IHVR. RVXB reduced oxidative stress, improved NO bioavailability, and ameliorated endothelial dysfunction. Rivaroxaban deactivated HSC, with decreased alpha‐smooth muscle actin and mRNA expression of other HSC activation markers. Despite this marked improvement in HSC phenotype, no significant changes in LF were identified. RVXB markedly reduced fibrin deposition, suggesting reduced intrahepatic microthrombosis. Conclusion: RVXB decreases PP in two rat models of cirrhosis. This effect is mostly associated with decreased IHVR, enhanced NO bioavailability, HSC deactivation, and reduced intrahepatic microthrombosis. Our findings suggest that RVXB deserves further evaluation as a potential treatment for cirrhotic PH. (Hepatology 2017;65:2031‐2044).
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