Novel treatment options for portal hypertension

Hepatic improvement within 27 days of avenciguat treatment in Child-Pugh A cirrhosis detected by an oral cholate challenge test

New methods for measuring hepatic improvement in clinical trials and the clinic are needed. One new method, HepQuant SHUNT, detected dose-dependent improvements in hepatic function and portal physiology in the phase 1b study (NCT03842761) of avenciguat, an activator of soluble guanylyl cyclase that is being developed for the treatment of portal hypertension. Herein, we examined whether HepQuant Duo, an easy-to-administer test version, could similarly detect the effects of avenciguat. Twenty-three patients with Child-Pugh A cirrhosis and liver stiffness >15 kPa received either a placebo (n = 5) or a maximum twice-daily avenciguat dose of 1, 2, or 3 mg (n = 6 per group) for 28 days. The DuO test was performed at baseline and on days 11 and 27 in each subject. The test involved administering 40 mg of d4-cholate orally, measuring d4-cholate concentrations in serum at 20 and 60 minutes, and calculating portal hepatic filtration rate, disease severity index, portal-systemic shunting (SHUNT%), and hepatic reserve (HR%). Avenciguat demonstrated dose-dependent improvement in all test parameters. Changes from baseline in SHUNT% after 27 days' treatment were 0.1 ± 9.0% for placebo, 1.7 ± 5.5% for 1 mg twice-daily, -3.2 ± 2.7% for 2 mg twice-daily, and -6.1 ± 5.0% for 3 mg twice-daily (paired t test for change from baseline p = 0.98, 0.48, 0.04, and 0.03, respectively). The changes detected by HepQuant DuO were similar to those previously observed and reported for HepQuant SHUNT. The results support further study of avenciguat in treating portal hypertension and spotlight the utility of HepQuant DuO in the development of drug therapy for liver disease. HepQuant DuO facilitates the use of function testing to measure hepatic improvement in clinical trials and the clinic.

Recent Approaches in Portal Hypertension Involving Risk Stratification and Medical Management

Portal hypertension leads to the formation of portosystemic collaterals that divert portal blood to the systemic circulation and bypass the liver, resulting in multiple severe complications. Portal hypertension has classically been diagnosed using invasive methods to calculate the hepatic venous pressure gradient. There has been a recent evolution in portal hypertension pathology emphasizing dynamic changes and integrated pathophysiology, as well as concurrent changes in medical management. There is now a focus on using less-invasive approaches to diagnose portal hypertension and novel treatments that target the various components of evolving portal hypertension pathophysiology. This article details the latest techniques in diagnosing and treating portal hypertension that are becoming cornerstones of portal hypertension management.

The rationale and study design of two phase II trials examining the effects of BI 685,509, a soluble guanylyl cyclase activator, on clinically significant portal hypertension in patients with compensated cirrhosis

BACKGROUND

Clinically significant portal hypertension (CSPH) drives cirrhosis-related complications (i.e. hepatic decompensation). Impaired nitric oxide (NO) bioavailability promotes sinusoidal vasoconstriction, which is the initial pathomechanism of CSPH development. Activation of soluble guanylyl cyclase (sGC), a key downstream effector of NO, facilitates sinusoidal vasodilation, which in turn may improve CSPH. Two phase II studies are being conducted to assess the efficacy of the NO-independent sGC activator BI 685,509 in patients with CSPH due to various cirrhosis aetiologies.

METHODS

The 1366.0021 trial (NCT05161481) is a randomised, placebo-controlled, exploratory study that will assess BI 685,509 (moderate or high dose) for 24 weeks in patients with CSPH due to alcohol-related liver disease. The 1366.0029 trial (NCT05282121) is a randomised, open-label, parallel-group, exploratory study that will assess BI 685,509 (high dose) alone in patients with hepatitis B or C virus infection or non-alcoholic steatohepatitis (NASH) and in combination with 10 mg empagliflozin in patients with NASH and type 2 diabetes mellitus for 8 weeks. The 1366.0021 trial will enrol 105 patients, and the 1366.0029 trial will enrol 80 patients. In both studies, the primary endpoint is the change from baseline in hepatic venous pressure gradient (HVPG) until the end of treatment (24 or 8 weeks, respectively). Secondary endpoints include the proportion of patients with an HVPG reduction of > 10% from baseline, the development of decompensation events and the change from baseline in HVPG after 8 weeks in the 1366.0021 trial. In addition, the trials will assess changes in liver and spleen stiffness by transient elastography, changes in hepatic and renal function and the tolerability of BI 685,509.

DISCUSSION

These trials will enable the assessment of the short-term (8 weeks) and longer-term (24 weeks) effects and safety of sGC activation by BI 685,509 on CSPH due to various cirrhosis aetiologies. The trials will use central readings of the diagnostic gold standard HVPG for the primary endpoint, as well as changes in established non-invasive biomarkers, such as liver and spleen stiffness. Ultimately, these trials will provide key information for developing future phase III trials.

TRIAL REGISTRATION

1366.0021: EudraCT no. 2021-001,285-38; ClinicalTrials.gov NCT05161481. Registered on 17 December 2021, https://www.

CLINICALTRIALS

gov/ct2/show/NCT05161481 . 1366.0029: EudraCT no. 2021-005,171-40; ClinicalTrials.gov NCT05282121. Registered on 16 March 2022, https://www.

CLINICALTRIALS

gov/ct2/show/NCT05282121 .

Alcohol-Related Liver Disease: An Overview on Pathophysiology, Diagnosis and Therapeutic Perspectives

Alcohol-related liver disease (ALD) refers to a spectrum of liver manifestations ranging from fatty liver diseases, steatohepatitis, and fibrosis/cirrhosis with chronic inflammation primarily due to excessive alcohol use. Currently, ALD is considered as one of the most prevalent causes of liver disease-associated mortality worldwide. Although the pathogenesis of ALD has been intensively investigated, the present understanding of its biomarkers in the context of early clinical diagnosis is not complete, and novel therapeutic targets that can significantly alleviate advanced forms of ALD are limited. While alcohol abstinence remains the primary therapeutic intervention for managing ALD, there are currently no approved medications for treating ALD. Furthermore, given the similarities and the differences between ALD and non-alcoholic fatty liver disease in terms of disease progression and underlying molecular mechanisms, numerous studies have demonstrated that many therapeutic interventions targeting several signaling pathways, including oxidative stress, inflammatory response, hormonal regulation, and hepatocyte death play a significant role in ALD treatment. Therefore, in this review, we summarized several key molecular targets and their modes of action in ALD progression. We also described the updated therapeutic options for ALD management with a particular emphasis on potentially novel signaling pathways.

Downregulation of Ca2+-Activated Cl- Channel TMEM16A Mediated by Angiotensin II in Cirrhotic Portal Hypertensive Mice

Portal hypertension is defined as an increased pressure in the portal venous system and occurs as a major complication in chronic liver diseases. The pathological mechanism underlying the pathogenesis and development of portal hypertension has been extensively investigated. Vascular tone of portal vein smooth muscles (PVSMs) is regulated by the activities of several ion channels, including Ca²⁺-activated Cl^- (Cl_Ca) channels. TMEM16A is mainly responsible for Cl_Ca channel conductance in vascular smooth muscle cells, including portal vein smooth muscle cells (PVSMCs). In the present study, the functional roles of TMEM16A channels were examined using two experimental portal hypertensive models, bile duct ligation (BDL) mice with cirrhotic portal hypertension and partial portal vein ligation (PPVL) mice with non-cirrhotic portal hypertension. Expression analyses revealed that the expression of TMEM16A was downregulated in BDL-PVSMs, but not in PPVL-PVSMs. Whole-cell Cl_Ca currents were smaller in BDL-PVSMCs than in sham- and PPVL-PVSMCs. The amplitude of spontaneous contractions was smaller and the frequency was higher in BDL-PVSMs than in sham- and PPVL-PVSMs. Spontaneous contractions sensitive to a specific inhibitor of TMEM16A channels, T16A_inh-A01, were reduced in BDL-PVSMs. Furthermore, in normal PVSMs, the downregulation of TMEM16A expression was mimicked by the exposure to angiotensin II, but not to bilirubin. This study suggests that the activity of Cl_Ca channels is attenuated by the downregulation of TMEM16A expression in PVSMCs associated with cirrhotic portal hypertension, which is partly mediated by increased angiotensin II in cirrhosis.

Distinct structural and dynamic components of portal hypertension in different animal models and human liver disease etiologies

BACKGROUND AND AIMS

Liver fibrosis is the static and main (70%-80%) component of portal hypertension (PH). We investigated dynamic components of PH by a three-dimensional analysis based on correlation of hepatic collagen proportionate area (CPA) with portal pressure (PP) in animals or HVPG in patients.

APPROACH AND RESULTS

Different animal models (bile duct ligation: n = 31, carbon tetrachloride: n = 12, thioacetamide: n = 12, choline-deficient high-fat diet: n = 12) and patients with a confirmed single etiology of cholestatic (primary biliary cholangitis/primary sclerosing cholangitis: n = 16), alcohol-associated (n = 22), and metabolic (NASH: n = 19) liver disease underwent CPA quantification on liver specimens/biopsies. Based on CPA-to-PP/HVPG correlation, potential dynamic components were identified in subgroups of animals/patients with lower-than-expected and higher-than-expected PP/HVPG. Dynamic PH components were validated in a patient cohort (n = 245) using liver stiffness measurement (LSM) instead of CPA. CPA significantly correlated with PP in animal models (Rho = 0.531; p < 0.001) and HVPG in patients (Rho = 0.439; p < 0.001). Correlation of CPA with PP/HVPG varied across different animal models and etiologies in patients. In models, severity of hyperdynamic circulation and specific fibrosis pattern (portal fibrosis: p = 0.02; septa width: p = 0.03) were associated with PH severity. In patients, hyperdynamic circulation (p = 0.04), vascular dysfunction/angiogenesis (VWF-Ag: p = 0.03; soluble vascular endothelial growth factor receptor 1: p = 0.03), and bile acids (p = 0.04) were dynamic modulators of PH. The LSM-HVPG validation cohort confirmed these and also indicated IL-6 (p = 0.008) and hyaluronic acid (HA: p < 0.001) as dynamic PH components.

CONCLUSIONS

The relative contribution of "static" fibrosis on PH severity varies by type of liver injury. Next to hyperdynamic circulation, increased bile acids, VWF-Ag, IL-6, and HA seem to indicate a pronounced dynamic component of PH in patients.

The Hepatic Sinusoid in Chronic Liver Disease: The Optimal Milieu for Cancer

Simple Summary

During the development of chronic liver disease, the hepatic sinusoid undergoes major changes that further compromise the hepatic function, inducing persistent inflammation and the formation of scar tissue, together with alterations in liver hemodynamics. This diseased background may induce the formation and development of hepatocellular carcinoma (HCC), which is the most common form of primary liver cancer and a major cause of mortality. In this review, we describe the ways in which the dysregulation of hepatic sinusoidal cells—including liver sinusoidal cells, Kupffer cells, and hepatic stellate cells—may have an important role in the development of HCC. Our review summarizes all of the known sinusoidal processes in both health and disease, and possible treatments focusing on the dysregulation of the sinusoid; finally, we discuss how some of these alterations occurring during chronic injury are shared with the pathology of HCC and may contribute to its development.

Abstract

The liver sinusoids are a unique type of microvascular beds. The specialized phenotype of sinusoidal cells is essential for their communication, and for the function of all hepatic cell types, including hepatocytes. Liver sinusoidal endothelial cells (LSECs) conform the inner layer of the sinusoids, which is permeable due to the fenestrae across the cytoplasm; hepatic stellate cells (HSCs) surround LSECs, regulate the vascular tone, and synthetize the extracellular matrix, and Kupffer cells (KCs) are the liver-resident macrophages. Upon injury, the harmonic equilibrium in sinusoidal communication is disrupted, leading to phenotypic alterations that may affect the function of the whole liver if the damage persists. Understanding how the specialized sinusoidal cells work in coordination with each other in healthy livers and chronic liver disease is of the utmost importance for the discovery of new therapeutic targets and the design of novel pharmacological strategies. In this manuscript, we summarize the current knowledge on the role of sinusoidal cells and their communication both in health and chronic liver diseases, and their potential pharmacologic modulation. Finally, we discuss how alterations occurring during chronic injury may contribute to the development of hepatocellular carcinoma, which is usually developed in the background of chronic liver disease.

Farnesoid X Receptor as Target for Therapies to Treat Cholestasis-Induced Liver Injury

Recent studies on liver disease burden worldwide estimated that cirrhosis is the 11th most common cause of death globally, and there is a great need for new therapies to limit the progression of liver injuries in the early stages. Cholestasis is caused by accumulation of hydrophobic bile acids (BA) in the liver due to dysfunctional BA efflux or bile flow into the gall bladder. Therefore, strategies to increase detoxification of hydrophobic BA and downregulate genes involved in BA production are largely investigated. Farnesoid X receptor (FXR) has a central role in BA homeostasis and recent publications revealed that changes in autophagy due to BA-induced reactive oxygen species and increased anti-oxidant response via nuclear factor E2-related factor 2 (NRF2), result in dysregulation of FXR signaling. Several mechanistic studies have identified new dysfunctions of the cholestatic liver at cellular and molecular level, opening new venues for developing more performant therapies.

Pathophysiology and Management of Variceal Bleeding

Cirrhosis is the fifth leading cause of death in adults. Advanced cirrhosis can cause significant portal hypertension (PH), which is responsible for many of the complications observed in patients with cirrhosis, such as varices. If portal pressure exceeds a certain threshold, the patient is at risk of developing life-threatening bleeding from varices. Variceal bleeding has a high incidence among patients with liver cirrhosis and carries a high risk of mortality and morbidity. The management of variceal bleeding is complex, often requiring a multidisciplinary approach involving pharmacological, endoscopic, and radiologic interventions. In terms of management, three stages can be considered: primary prophylaxis, active bleeding, and secondary prophylaxis. The main goal of primary and secondary prophylaxis is to prevent variceal bleeding. However, active variceal bleeding is a medical emergency that requires swift intervention to stop the bleeding and achieve durable hemostasis. We describe the pathophysiology of cirrhosis and PH to contextualize the formation of gastric and esophageal varices. We also discuss the currently available treatments and compare how they fare in each stage of clinical management, with a special focus on drugs that can prevent bleeding or assist in achieving hemostasis.

CARVEDILOL AS PRIMARY PROPHYLAXIS FOR GASTRIC VARICEAL BLEEDING IN PORTAL HYPERTENSION MODEL IN RATS

Background:

Portal hypertension (PH) can be measured indirectly through a hepatic vein pressure gradient greater than 5 mmHg. Cirrhosis is the leading cause for PH and can present as complications ascites, hepatic dysfunction, renal dysfunction, and esophagogastric varices, characterizing gastropathy.

Aim:

To evaluate the use of carvedilol as primary prophylaxis in the development of collateral circulation in rats submitted to the partial portal vein ligament (PPVL) model.

Method:

This is a combined qualitative and quantitative experimental study in which 32 Wistar rats were divided into four groups (8 animals in each): group I - cirrhosis + carvedilol (PPVL + C); group II - cirrhosis + vehicle (PPVL); group III - control + carvedilol (SO-sham-operated + C); group IV - control + vehicle (SO-sham-operated). After seven days of the surgical procedure (PPVL or sham), carvedilol (10 mg/kg) or vehicle (1 mL normal saline) were administered to the respective groups daily for seven days.

Results:

The histological analysis showed no hepatic alteration in any group and a decrease in edema and vasodilatation in the PPVL + C group. The laboratory evaluation of liver function did not show a statistically significant change between the groups.

Conclusion:

Carvedilol was shown to have a positive effect on gastric varices without significant adverse effects.

Phosphodiesterases in the Liver as Potential Therapeutic Targets of Cirrhotic Portal Hypertension

Liver cirrhosis is a frequent condition with high impact on patients' life expectancy and health care systems. Cirrhotic portal hypertension (PH) gradually develops with deteriorating liver function and can lead to life-threatening complications. Other than an increase in intrahepatic flow resistance due to morphological remodeling of the organ, a functional dysregulation of the sinusoids, the smallest functional units of liver vasculature, plays a pivotal role. Vascular tone is primarily regulated by the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, wherein soluble guanylate cyclase (sGC) and phosphodiesterase-5 (PDE-5) are key enzymes. Recent data showed characteristic alterations in the expression of these regulatory enzymes or metabolite levels in liver cirrhosis. Additionally, a disturbed zonation of the components of this pathway along the sinusoids was detected. This review describes current knowledge of the pathophysiology of PH with focus on the enzymes regulating cGMP availability, i.e., sGC and PDE-5. The results have primarily been obtained in animal models of liver cirrhosis. However, clinical and histochemical data suggest that the new biochemical model we propose can be applied to human liver cirrhosis. The role of PDE-5 as potential target for medical therapy of PH is discussed.

Plasma Nogo-A and placental growth factor levels are associated with portal hypertension in patients with liver cirrhosis

BACKGROUND

Clinically significant portal hypertension (CSPH) and severe portal hypertension (SPH) increase the risk for decompensation and life-threatening complications in liver cirrhosis. Pathologic angiogenesis might contribute to the formation of these conditions. Placental growth factor (PlGF) and Nogo-A protein are biomarkers of pathological angiogenesis, but data on their role in liver cirrhosis and portal hypertension is scarce.

AIM

To determine plasma levels of PlGF and Nogo-A in patients with liver cirrhosis, CSPH, SPH and potential to predict portal hypertension.

METHODS

A cohort of 122 patients with hepatitis C virus and/or alcohol-induced liver cirrhosis with characterized hepatic venous pressure gradient (HVPG) were included in the study. Demographic data, medical history, Child-Turcotte-Pugh and Model of End Stage liver disease score, clinical chemistry, liver stiffness values were recorded on the day of the procedure prior HVPG measurement. The degree of portal hypertension was determined by the invasive HVPG measurement. Nogo-A and PlGF plasma levels were evaluated using enzyme linked immunosorbent assay. The control group consisted of 30 healthy age- and sex- matched individuals.

RESULTS

Peripheral PlGF levels were higher and Nogo-A levels were lower in patients with liver cirrhosis (23.20 vs 9.85; P < 0.0001 and 2.19 vs 3.12; P = 0.004 respectively). There was a positive linear correlation between peripheral levels of PlGF and HVPG (r = 0.338, P = 0.001) and negative linear correlation between the peripheral Nogo-A levels and HVPG (r = -0.267, P = 0.007). PlGF levels were higher in CSPH and SPH (P = 0.006; P < 0.0001) whereas Nogo-A levels were lower (P = 0.01; P < 0.033). Area under the curve for the diagnosis of CSPH for PlGF was 0.68 (P = 0.003) and for Nogo-A - 0.67 (P = 0.01); for SPH 0.714 (P < 0.0001) and 0.65 (P = 0.014) respectively. PlGF levels were higher and Nogo-A levels were lower in patients with esophageal varices (P < 0.05). PlGF cut-off value of 25 pg/mL distinguished patients with CSPH at 55.7% sensitivity and 76.7% specificity; whereas Nogo-A cut-off value of 1.12 ng/mL was highly specific (93.1%) for the diagnosis of CSPH.

CONCLUSION

Plasma PlGF levels were higher while Nogo-A levels were lower in patients with liver cirrhosis and portal hypertension. Biomarkers showed moderate predictive value in determining CSPH and SPH.

Simultaneous radiofrequency ablation combined with laparoscopic splenectomy: a safe and effective way for patients with hepatocellular carcinoma complicated with cirrhosis and hypersplenism

Purpose: This study aimed to evaluate the safety and effectiveness of simultaneous radiofrequency ablation (RFA) combined with laparoscopic splenectomy (Lap-Sp) for patients with hepatocellular carcinoma (HCC) complicated with cirrhosis and hypersplenism.Material and methods: Between January 2013 and June 2014, 42 patients with primary HCC complicated with cirrhosis and hypersplenism who underwent simultaneous RFA combined with Lap-Sp were enrolled at the Department of General Surgery, Beijing Di Tan Hospital. The median number of tumors ablated using RFA was one (range 1-3), and the median sum of the maximum diameter of tumors was 2.5 cm (range 1.2-5.4 cm). The related indicators before and after surgery, complications, and long-term effects were retrospectively analyzed.Results: The median operative time for 42 patients undergoing simultaneous RFA combined with Lap-Sp was 4.5 h (range 2.5-8.5 h), and the median blood loss was 120 mL (range 5-2200 mL). The incidence of moderate-to-severe postoperative complications and the perioperative mortality after surgery were 31.0 and 0%, respectively. The disease-free survival rate for one, three, and five years was 73.8, 19.7, and 16.4%, respectively. The overall survival rate was 90.5, 73.3, and 60.4%, respectively.Conclusion: Simultaneous RFA combined with Lap-Sp was safe and effective for patients with HCC complicated with cirrhosis and hypersplenism.

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.

Invasive Hemodynamic Characterization of the Portal-hypertensive Syndrome in Cirrhotic Rats

This is a detailed protocol describing invasive hemodynamic measurements in cirrhotic rats for the characterization of portal hypertensive syndrome. Portal hypertension (PHT) due to cirrhosis is responsible for the most severe complications in patients with liver disease. The full picture of the portal hypertensive syndrome is characterized by increased portal pressure (PP) due to the increased intrahepatic vascular resistance (IHVR), hyperdynamic circulation, and increased splanchnic blood flow. Progressive splanchnic arterial vasodilation and increased cardiac output with elevated heart rate (HR) but low arterial pressure characterizes the portal hypertensive syndrome. Novel therapies are currently being developed that aim to decrease PP by either targeting IHVR or increased splanchnic blood flow - but side effects on systemic hemodynamics may occur. Thus, a detailed characterization of portal venous, splanchnic, and systemic hemodynamic parameters, including measurement of PP, portal venous blood flow (PVBF), mesenteric arterial blood flow, mean arterial pressure (MAP), and HR is needed for preclinical evaluation of the efficacy of novel treatments for PHT. Our video article provides the reader with a structured protocol for performing invasive hemodynamic measurements in cirrhotic rats. In particular, we describe the catheterization of the femoral artery and the portal vein via an ileocolic vein and the measurement of portal venous and splanchnic blood flow via perivascular Doppler-ultrasound flow probes. Representative results of different rat models of PHT are shown.

The soluble guanylate cyclase stimulator riociguat reduces fibrogenesis and portal pressure in cirrhotic rats

In cirrhotic patients, portal hypertension (PHT) deteriorates survival, yet treatment options are limited. A major contributor to increased intrahepatic vasoconstriction in PHT is dysfunctional nitric-oxide signaling. Soluble guanylate cyclase (sGC) is the receptor of nitric-oxide and can be stimulated by riociguat. Riociguat is approved for pulmonary hypertension but has not been studied in liver cirrhosis. In this study we assessed the effects of riociguat on PHT and liver fibrosis in cholestatic (bile duct ligation, BDL) and toxic (carbon-tetrachloride, CCl4) rat models. In cirrhotic livers sGC expression was upregulated. In BDL rats, riociguat reduced liver fibrosis and decreased portal pressure without affecting systemic hemodynamics. In an early BDL disease stage, riociguat decreased bile duct proliferation, improved sinusoidal vascular dysfunction and inhibited angiogenesis. In advanced BDL riociguat exhibited anti-inflammatory effects. In CCl4 rats the beneficial effects of riociguat treatment were less pronounced and confined to an early disease stage. Similarly, in patients with cholestatic cirrhosis and PHT nitrates (that induce sGC activity) decreased portal pressure more effectively than in patients with non-cholestatic etiology. We also found an improvement of transaminases in patients with pulmonary hypertension receiving riociguat. Our findings support the clinical development of sGC stimulators in patients with cirrhotic PHT.

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.

Clinical significance of small-bowel villous edema in patients with liver cirrhosis: A capsule endoscopy study

BACKGROUND AND AIM

The relationship between the presence of villous edema (VE) in portal hypertensive enteropathy and clinical factors remains unclear. The aim of this study was to reveal the clinical factors related to VE in patients with liver cirrhosis (LC), and investigate the clinical significance of VE.

METHODS

Between February 2009 and September 2016, 363 consecutive patients with LC underwent capsule endoscopy for diagnosing portal hypertensive enteropathy at Hiroshima University Hospital. We evaluated the relationship between the presence of VE and patients' clinical characteristics, findings of esophagogastroduodenoscopy and computed tomography, and survival time.

RESULTS

Villous edema was observed in 131 patients (36%), and severe lesions were found in 71 (20%). The presence of VE was significantly greater in patients with Child-Pugh classification B or C, esophageal varices, portal hypertensive gastropathy (PHG), ascites, portal vein thrombosis (PVT), and splenomegaly. In multivariate analysis, Child-Pugh class B or C, esophageal varices, PVT, and splenomegaly were significant predictive factors for the presence of VE. Severe VE was significantly greater in patients with Child-Pugh class B or C, serum albumin level ≤ 3.2 mg/dL, PHG, and PVT. In multivariate analysis, PHG, Child-Pugh class B or C, PVT, were significant predictive factors for severe VE.

CONCLUSIONS

Clinical factors related to portal hypertension were significantly correlated with VE. In particular PVT was correlated with the appearance and exacerbation of VE. Periodic capsule endoscopy in LC patients may lead to early detection of portal hypertension and PVT.

Origins of Portal Hypertension in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) advanced to cirrhosis is often complicated by clinically significant portal hypertension, which is primarily caused by increased intrahepatic vascular resistance. Liver fibrosis has been identified as a critical determinant of this process. However, there is evidence that portal venous pressure may begin to rise in the earliest stages of NAFLD when fibrosis is far less advanced or absent. The biological and clinical significance of these early changes in sinusoidal homeostasis remains unclear. Experimental and human observations indicate that sinusoidal space restriction due to hepatocellular lipid accumulation and ballooning may impair sinusoidal flow and generate shear stress, increasingly disrupting sinusoidal microcirculation. Sinusoidal endothelial cells, hepatic stellate cells, and Kupffer cells are key partners of hepatocytes affected by NAFLD in promoting endothelial dysfunction through enhanced contractility, capillarization, adhesion and entrapment of blood cells, extracellular matrix deposition, and neovascularization. These biomechanical and rheological changes are aggravated by a dysfunctional gut-liver axis and splanchnic vasoregulation, culminating in fibrosis and clinically significant portal hypertension. We may speculate that increased portal venous pressure is an essential element of the pathogenesis across the entire spectrum of NAFLD. Improved methods of noninvasive portal venous pressure monitoring will hopefully give new insights into the pathobiology of NAFLD and help efforts to identify patients at increased risk for adverse outcomes. In addition, novel drug candidates targeting reversible components of aberrant sinusoidal circulation may prevent progression in NAFLD.