Cirrhosis regression: extrahepatic angiogenesis and liver hyperarterialization persist

Persistent varices in cured patients: Understanding the role of hepatic venous pressure gradient

Background & Aims

Etiologic factor removal (ER) drives recompensation and improves portal hypertension in cirrhosis. Esophageal varices (EV) and portosystemic shunts (PSS) have been found in patients despite hepatic venous pressure gradient (HVPG) dropping below 10 mmHg after ER, questioning HVPG accuracy in reflecting true portal pressure in the setting of ER. We aim to evaluate the correlation of HVPG with direct portal pressure (DPP) in patients with persistence of EV after ER despite HVPG <10 mmHg.

Methods

This is a bicentric 'proof of concept' study evaluating HVPG and ultrasound-guided percutaneous DPP in patients with HCV or alcohol-related cirrhosis with persistent varices and HVPG <10 mmHg after at least 5 years of ER.

Results

Seven patients with HCV and three with alcohol-related cirrhosis with persistent varices and HVPG <10 mmHg after at least 5 years of ER were included. At evaluation, all patients had a patent portal vein and were compensated. The median platelet count was 129.5 (IQR 95-145) × 109/ml, and the median liver stiffness measurement was 16.15 (IQR 14.4-22.3) kPa. In five patients, EV remained the same size (two large and three small), and five downsized to small after ER. Wedge hepatic vein pressure (median 19 [IQR 16.5-20] mmHg) and portal pressure (median 18 [IQR 15-19.5] mmHg) had an excellent correlation (R = 0.93, p <0.0001). Portal pressure gradient (PPG) confirmed the absence of clinically significant portal hypertension as identified by HVPG across all the patients.

Conclusions

HVPG accurately reflects PPG in the context of HCV and alcohol-related cirrhosis regression. After ER, EV may persist despite HVPG <10 mmHg. The benefit of prophylaxis in patients with EV and HVPG <10 mmHg is unknown. Future studies with clinical endpoints are needed to validate our findings.

Impact and implications

Despite a favorable evolution after the removal of the etiologic factor, varices persist in some patients, and there is a lack of concise guidelines for the evaluation and management of portal hypertension in this population. Our research underscores the persistence of varices in the absence of clinically significant portal hypertension and significantly demonstrates the accuracy of hepatic venous pressure gradient (HVPG) in reflecting portal vein pressure in this specific patient group. These findings emphasize the crucial role of HVPG in the assessment of portal hypertension after etiologic factor removal and lay the groundwork for further investigation into clinical outcomes and the necessity of non-selective beta-blockers in individuals with persistent varices after the removal of etiologic factor.

Angiopoietin 2 levels decrease after HCV-cure and reflect the evolution of portal hypertension

BACKGROUND

Portal hypertension (PH) does not resolve in a considerable proportion of patients who achieved HCV-cure.

AIMS

To investigate (i)whether HCV-cure impacts cytokines that orchestrate angiogenesis (i.e.,Ang1/Ang2/VEGF) and fibrogenesis (i.e.,PDGF/TGF-β) and (ii)whether their changes reflect PH-evolution and its complications.

METHODS

We measured plasma levels of cytokines and von Willebrand factor (VWF) and assessed hepatic venous pressure gradient (HVPG) before/after HCV-cure in 66 patients with pre-treatment PH and 23 patients without advanced disease, who served as controls.

RESULTS

Following HCV-cure, we observed a decrease in Ang2/TGF-β, but no changes in the other cytokines. The differences in circulating cytokine profiles in PH patients persisted after removing the primary etiological factor. Patients with pre-treatment HVPG≥10 mmHg with HVPG-reduction≥10% had a more pronounced relative decrease in Ang2. Finally, post-treatment Ang2 predicted FU-HVPG≥16 mmHg/decompensation with AUROC-values of 0.804/0.835.

CONCLUSIONS

HCV-cure decreases circulating Ang2 - a mediator/indicator of dysangiogenesis/endothelial dysfunction, as well as TGF-β - a profibrogenic cytokine. The dynamics of Ang2 mirrored those of PH, rendering FU-Ang2 a non-invasive test for pronounced PH at FU that also predicts hepatic decompensation. The pathophysiological significance of the persistently altered cytokine levels for mechanisms that hinder the PH-regression warrants further study.

Angiogenesis in the progression from liver fibrosis to cirrhosis and hepatocelluar carcinoma

Introduction: Persistent inflammation and hypoxia are strong stimulus for pathological angiogenesis and vascular remodeling, and are also the most important elements resulting in liver fibrosis. Sustained inflammatory process stimulates fibrosis to the end-point of cirrhosis and sinusoidal portal hypertension is an important feature of cirrhosis. Neovascularization plays a pivotal role in collateral circulation formation of portal vein, mesenteric congestion, and high perfusion. Imbalance of hepatic artery and portal vein blood flow leads to the increase of hepatic artery inflow, which is beneficial to the formation of nodules. Angiogenesis contributes to progression from liver fibrosis to cirrhosis and hepatocellular carcinoma (HCC) and anti-angiogenesis therapy can improve liver fibrosis, reduce portal pressure, and prolong overall survival of patients with HCC. Areas covers: This paper will try to address the difference of the morphological characteristics and mechanisms of neovascularization in the process from liver fibrosis to cirrhosis and HCC and further compare the different efficacy of anti-angiogenesis therapy in these three stages. Expert opinion: More in-depth understanding of the role of angiogenesis factors and the relationship between angiogenesis and other aspects of the pathogenesis and transformation may be the key to enabling future progress in the treatment of patients with liver fibrosis, cirrhosis, and HCC.

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.