Von Willebrand factor antigen for detection of hepatopulmonary syndrome in patients with cirrhosis

[Liver cirrhosis as a multisystem disease]

In recent years, the pathophysiological concept of decompensated liver cirrhosis has undergone significant changes. Until a few years ago, the focus of pathophysiological considerations was on the hyperdynamic circulation resulting from portal hypertension. In recent years, emerging data suggests that increased bacterial translocation leading to systemic inflammation plays an important role in patients with decompensated liver cirrhosis. This inflammation affects a variety of extrahepatic organs. Nowadays, liver cirrhosis is considered not only a condition confined to the liver but rather an inflammatory-triggered multisystem disease. The existing inflammation serves as the common pathophysiological explanation for the diverse impact of liver cirrhosis on several extrahepatic organs. It plays a significant role in the development of conditions such as hepatorenal syndrome, cirrhotic cardiomyopathy, hepatopulmonary syndrome, hepatic encephalopathy, and even in the emergence of cirrhosis-associated relative adrenal insufficiency. These new pathophysiological insights hold clinical significance as they influence the prophylaxis and treatment of patients with decompensated liver cirrhosis.

Von Willebrand Factor as a Biomarker for Liver Disease - An Update

The von Willebrand factor (vWF) is best known for its role in the hemostatic pathway, aiding platelet adhesion and aggregation, as well as circulating along with coagulation factor VIII, prolonging its half-life. However, vWF is more than a hemostatic protein and is a marker of endothelial dysfunction in patients with cirrhosis. The levels of vWF increase progressively as cirrhosis progresses. Despite its qualitative defects, it can support and carry out its hemostatic role and contribute to a pro-coagulant disbalance. Moreover, it has been shown to be a good noninvasive marker for predicting clinically significant portal hypertension (CSPH). The vWF has been shown to predict decompensation and mortality among cirrhosis patients independently of the stage of liver disease and severity of portal hypertension. Increased vWF levels in the setting of endothelial injury predict bacterial translocation and systemic inflammation. The vWF-to-thrombocyte ratio (VITRO) score adds to the diagnostic ability of vWF alone in detecting CSPH non-invasively. Not only have vWF levels been shown to help predict the risk of hepatocellular carcinoma (HCC) among cirrhosis patients, but they also predict the risk of complications post-resection for HCC and response to systemic therapies. vWF-induced portal microthrombi have been purported to contribute to the pathogenesis of acute liver failure progression as well as non-cirrhotic portal hypertension. The prospect of modulation of vWF levels using drugs such as non-selective beta-blockers, statins, anticoagulants, and non-absorbable antibiotics and its use as a predictive biomarker for the response to these drugs needs to be explored.

Serum Soluble Vascular Endothelial Growth Factor Receptor 1 as a Potential Biomarker of Hepatopulmonary Syndrome

Background and Aims

The results of basic research implicate the vascular endothelial growth factor (VEGF) family as a potential target of hepatopulmonary syndrome (HPS). However, the negative results of anti-angiogenetic therapy in clinical studies have highlighted the need for markers for HPS. Therefore, we aimed to determine whether VEGF family members and their receptors can be potential biomarkers for HPS through clinical and experimental studies.

Methods

Clinically, patients with chronic liver disease from two medical centers were enrolled and examined for HPS. Patients were divided into HPS, intrapulmonary vascular dilation [positive contrast-enhanced echocardiography (CEE) and normal oxygenation] and CEE-negative groups. Baseline information and perioperative clinical data were compared between HPS and non-HPS patients. Serum levels of VEGF family members and their receptors were measured. In parallel, HPS rats were established by common bile duct ligation. Liver, lung and serum samples were collected for the evaluation of pathophysiologic changes, as well as the expression levels of the above factors.

Results

In HPS rats, all VEGF family members and their receptors underwent significant changes; however, only soluble VEGFR1 (sFlt-1) and the sFlt-1/ placental growth factor (PLGF) ratio were changed in almost the same manner as those in HPS patients. Furthermore, through feature selection and internal and external validation, sFlt-1 and the sFlt-1/PLGF ratio were identified as the most important variables to distinguish HPS from non-HPS patients.

Conclusions

Our results from animal and human studies indicate that sFlt-1 and the sFlt-1/PLGF ratio in serum are potential markers for HPS.

Integration of deep learning-based histopathology and transcriptomics reveals key genes associated with fibrogenesis in patients with advanced NASH

Nonalcoholic steatohepatitis (NASH) is the most common chronic liver disease globally and a leading cause for liver transplantation in the US. Its pathogenesis remains imprecisely defined. We combined two high-resolution modalities to tissue samples from NASH clinical trials, machine learning (ML)-based quantification of histological features and transcriptomics, to identify genes that are associated with disease progression and clinical events. A histopathology-driven 5-gene expression signature predicted disease progression and clinical events in patients with NASH with F3 (pre-cirrhotic) and F4 (cirrhotic) fibrosis. Notably, the Notch signaling pathway and genes implicated in liver-related diseases were enriched in this expression signature. In a validation cohort where pharmacologic intervention improved disease histology, multiple Notch signaling components were suppressed.

Hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is a pulmonary vascular complication of liver disease, which adversely affects prognosis. The disease is characterised by intrapulmonary vascular dilatations and shunts, resulting in impaired gas exchange. A complex interaction between the liver, the gut and the lungs, predominately impacting pulmonary endothelial cells, immune cells and respiratory epithelial cells, is responsible for the development of typical pulmonary alterations seen in HPS. Liver transplantation is the only therapeutic option and generally reverses HPS. Since the implementation of the model for end-stage liver disease (MELD) standard exception policy, outcomes in patients with HPS have been significantly better than they were in the pre-MELD era. This review summarises current knowledge and highlights what’s new regarding the diagnosis and management of HPS, and our understanding of pathogenesis based on experimental models and translational studies.

The Role of von Willebrand Factor Antigen in Predicting Survival of Patients with HBV-Related Cirrhosis

OBJECTIVE

The model for end-stage liver disease (MELD) scoring system cannot be used to assess the deterioration of patients with liver cirrhosis caused by infection and portal hypertension. Elevated von Willebrand factor antigen (vWF-Ag) in plasma is associated with portal pressure and complications in patients with liver cirrhosis. We aimed to evaluate whether the addition of vWF-Ag can improve the risk prediction ability of the MELD scoring system.

METHODS

A total of 228 patients with hepatitis B virus (HBV)-related liver cirrhosis were eligible for inclusion in this retrospective study. The vWF-Ag level was assessed by enzyme-linked immunosorbent assay (ELISA). The endpoint of this study was defined as the time to liver transplantation or death. Univariate and multivariate analyses were performed to assess the risk factors associated with transplant-free mortality. Receiver operating characteristic (ROC) curve analysis was used to assess potential discriminatory variables for transplant-free mortality.

RESULTS

During a median follow-up interval of 30.23 months, 124 patients (54.4%) reached the endpoint of this study. Patients who died or underwent liver transplantation had elevated levels of MELD and vWF-Ag. Moreover, vWF-Ag and MELD showed comparable predictive potential for transplant-free survival (area under the curve [AUC], vWF-Ag = 0.71; AUC, MELD = 0.73). Ultimately, vWF-Ag can significantly improve the predictive potential of MELD in determining transplant-free mortality (AUC, MELD-vWF-Ag = 0.79, P = 0.006).

CONCLUSION

An elevated vWF-Ag level was independently associated with transplant-free mortality in patients with liver cirrhosis. The inclusion of vWF-Ag in the MELD scoring system can improve mortality predictions in patients with liver cirrhosis.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Pulmonary Vascular Complications of Liver Disease

Pulmonary vascular disease is a frequent complication of chronic liver disease and portal hypertension, affecting up to 30% of patients. There are two distinct pulmonary vascular complications of liver disease: hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH). HPS affects 25% of patients with chronic liver disease and is characterized by intrapulmonary vasodilatation and abnormal arterial oxygenation. HPS negatively impacts quality of life and is associated with a 2-fold increased risk of death compared to controls with liver disease without HPS. Angiogenesis, endothelin-1 mediated endothelial dysfunction, monocyte influx, and alveolar type 2 cell dysfunction seem to play important roles in disease pathogenesis but there are currently no effective medical therapies. Fortunately, HPS resolves following liver transplant (LT) with improvements in hypoxemia. POPH is a subtype of pulmonary arterial hypertension (PAH) characterized by an elevated mean pulmonary arterial pressure and pulmonary vascular resistance in the setting of normal left-sided filling pressures. POPH affects 5% to 6% of patients with chronic liver disease. Although the pathogenesis has not been fully elucidated, endothelial dysfunction, inflammation, and estrogen signaling have been identified as key pathways involved in disease pathogenesis. POPH is typically treated with PAH targeted therapy and may also improve with liver transplantation in selected patients. This article highlights what is currently known regarding the diagnosis, management, pathobiology, and outcomes of HPS and POPH. Ongoing research is needed to improve understanding of the pathophysiology and outcomes of these distinct and often misunderstood pulmonary vascular complications of liver disease. © 2021 American Physiological Society. Compr Physiol 11:1-22, 2021.

The Addition of C-Reactive Protein and von Willebrand Factor to Model for End-Stage Liver Disease-Sodium Improves Prediction of Waitlist Mortality

BACKGROUND AND AIMS

Patients with cirrhosis on the liver transplant (LT) waiting list may die or be removed because of complications of portal hypertension (PH) or infections. von Willebrand factor antigen (vWF-Ag) and C-reactive protein (CRP) are simple, broadly available markers of these processes.

APPROACH AND RESULTS

We determined whether addition of vWF-Ag and CRP to the Model for End-Stage Liver Disease-Sodium (MELD-Na) score improves risk stratification of patients awaiting LT. CRP and vWF-Ag at LT listing were assessed in two independent cohorts (Medical University of Vienna [exploration cohort] and Mayo Clinic Rochester [validation cohort]). Clinical characteristics, MELD-Na, and mortality on the waiting list were recorded. Prediction of 3-month waiting list mortality was assessed by receiver operating characteristics curve (ROC-AUC). In order to explore potential mechanisms underlying the prognostic utility of vWF-Ag and CRP in this setting, we evaluated their association with PH, bacterial translocation, systemic inflammation, and circulatory dysfunction. In the exploration cohort (n = 269) vWF-Ag and CRP both improved the predictive value of MELD-Na for 3-month waitlist mortality and showed the highest predictive value when combined (AUC: MELD-Na, 0.764; MELD-Na + CRP, 0.790; MELD-Na + vWF, 0.803; MELD-Na + CRP + vWF-Ag, 0.824). Results were confirmed in an independent validation cohort (n = 129; AUC: MELD-Na, 0.677; MELD-Na + CRP + vWF-Ag, 0.882). vWF-Ag was independently associated with PH and inflammatory biomarkers, whereas CRP closely, and MELD independently, correlated with biomarkers of bacterial translocation/inflammation.

CONCLUSIONS

The addition of vWF-Ag and CRP-reflecting central pathophysiological mechanisms of PH, bacterial translocation, and inflammation, that are all drivers of mortality on the waiting list for LT-to the MELD-Na score improves prediction of waitlist mortality. Using the vWFAg-CRP-MELD-Na model for prioritizing organ allocation may improve prediction of waitlist mortality and decrease waitlist mortality.

Targeting von Willebrand factor in liver diseases: A novel therapeutic strategy?

Acute and chronic liver disease are associated with substantial alterations in the hemostatic system. Evidence from both experimental and clinical studies suggests that anticoagulants slow the progression of liver disease. Efficacy of those anticoagulant drugs is, in part, attributed to a reduction of microthrombi formation within the liver. Although anticoagulant drugs show promising results, bleeding risk associated with these drugs is an obvious drawback, particularly in patients with a complex coagulopathy driven by decreased liver function. Identifying therapies that reduce intrahepatic thrombosis with minimal bleeding risk would significantly advance the field. Among the hemostatic alterations observed in patients are substantially increased levels of the platelet-adhesive protein von Willebrand factor (VWF). In contrast, levels of A Disintegrin and Metalloproteinase with Thrombospondin motifs, the enzyme that regulates VWF activity, are significantly reduced in patients with liver disease. Highly elevated VWF levels are proposed to accelerate intrahepatic thrombus formation and thus be a driver of disease progression. Strong clinical evidence suggesting a link between liver disease and changes in VWF is now being matched by emerging mechanistic data showing a detrimental role for VWF in the progression of liver disease. This review focuses on clinical and experimental evidence supporting a connection between VWF function and the progression of acute and chronic liver diseases. Furthermore, with the recent anticipated approval of several novel therapies targeting VWF, we discuss potential strategies and benefits of targeting VWF as an innovative therapy for patients with liver disease.

Von Willebrand Factor, Factor VIII, and Other Acute Phase Reactants as Biomarkers of Inflammation and Endothelial Dysfunction in Chronic Graft-Versus-Host Disease

Chronic graft-versus-host disease (cGvHD) is an immune mediated late complication of allogeneic hematopoietic stem cell transplantation (alloHSCT). Discovery of adequate biomarkers could identify high-risk patients and provide an effective pre-emptive intervention or early modification of therapeutic strategy, thus reducing prevalence and severity of the disease among long-term survivors of alloHSCT. Inflammation, endothelial injury, and endothelial dysfunction are involved in cGvHD development. Altered levels of acute phase reactants have shown a strong correlation with the activity of several immune mediated disorders and are routinely used in clinical practice. Since elevated von Willebrand factor (VWF) and factor VIII (FVIII) levels have been described as acute phase reactants that may indicate endothelial dysfunction and inflammation in different settings, including chronic autoimmune diseases, they could serve as potential candidate biomarkers of cGvHD. In this review we focused on reported data regarding VWF and FVIII as well as other markers of inflammation and endothelial dysfunction, evaluating their potential role in cGvHD.

von Willebrand Factor Antigen Predicts Outcomes in Patients after Liver Resection of Hepatocellular Carcinoma

Background/Aims

von Willebrand factor antigen (vWF-Ag) is a noninvasive predictor of portal hypertension that serves as a negative prognostic marker in various malignancies. Increased portal hypertension is associated with higher postoperative morbidity and decreased survival after hepatectomy. The purpose of this study was to determine the correlation between vWF-Ag, postoperative morbidity and oncological outcome.

Methods

This analysis includes 55 patients who underwent liver resection for hepatocellular carcinoma (HCC) between 2008 and 2015 with available preoperative vWF-Ag levels. The primary endpoints were postoperative complications and long-term outcome, including overall and disease-free survival.

Results

The median plasma level of vWF-Ag was 191% (range, 162.5% to 277%). There was a significant correlation between vWF-Ag levels and tumor size in the resected specimens (p=0.010, r=0.350). Patients who developed any grade of postoperative complication had significantly higher preoperative vWF-Ag levels (216% [range, 178% to 283.25%] vs 176% [range, 148% to 246%], p=0.041). Median overall survival was 39.8 months in patients with high vWF-Ag levels (≥191%) compared with 73.4 months in patients with low levels (<191%, p=0.007). Of note, there was a remarkable disparity in the number of patients who died of HCC with low versus high vWF-Ag levels (14.8% vs 28.6%, p=0.011).

Conclusions

vWF-Ag may serve as a prognostic marker for the outcome of patients undergoing liver resection for HCC that is closely connected to tumor size, postoperative complication rate and long-term outcome.

Recent advances in the approach to hepatopulmonary syndrome and portopulmonary hypertension

Liver disease, cirrhosis and portal hypertension can be complicated by pulmonary vascular disease, which may affect prognosis and influence liver transplantation (LT) candidacy. Pulmonary vascular complications comprise hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH). Although these two conditions develop on a same background and share a common trigger, pulmonary responses are distinct and occur at different anatomical sites of the pulmonary circulation. HPS affects 10-30% of patients referred for LT, and is characterized by gas exchange abnormalities due to pulmonary vasodilation and right-to-left shunting. POPH occurs in 5%, and is defined by pulmonary arterial hypertension due to increased pulmonary vascular resistance, which leads to hemodynamic failure. Even though HPS and POPH may have a substantial negative impact on survival, both entities are clinically underrecognized and frequently misdiagnosed. Without intervention, the 5-year survival rate is 23% in HPS and 14% in POPH. Their presence should be actively sought by organized screening in patients presenting with dyspnea and in all patients on the waitlist for LT, also because clinical symptoms are commonly non-specific or even absent. LT may lead to resolution, however, advanced stages of either HPS or POPH may jeopardize safe and successful LT. This implicates the need of proper identification of HPS and POPH cases, as well as the need to be able to successfully 'bridge' patients to LT by medical intervention. A review article on this topic has been published in this journal in 2007 (1). This updated review focuses on recent advances in the diagnosis and management of these 2 liver-induced pulmonary vascular disorders and incorporates results from our recent work.

Pathophysiological-based treatments of complications of cirrhosis

Detailed knowledge and understanding of the pathophysiological mechanisms and changes in hepatic and splanchnic function leading to the development of haemodynamic changes and portal hypertension in patients with cirrhosis are essential since it guides the search for targets to ameliorate liver-related abnormalities. Recent research has focused on the gut-liver axis, changes in intestinal permeability, translocation of bacterial products, and inflammation as important drivers of haemodynamic alterations and thereby targets for treatment. Additionally, treatment strategies should focus on microbiotic modulation, antiangiogenics, anti-inflammatory strategies, and modulation of bile acid metabolism. This paper aims to review contemporary pathophysiological-based treatment principles of the major complications of cirrhosis and portal hypertension and future targets for treatment.

A Role for Alveolar Exhaled Nitric Oxide Measurement in the Diagnosis of Hepatopulmonary Syndrome

GOALS

The authors sought to characterize predominantly alveolar exhaled nitric oxide (eNO) in hepatopulmonary syndrome (HPS) compared with non-HPS, changes after liver transplantation, and diagnostic properties.

BACKGROUND

HPS is defined by liver disease, intrapulmonary vascular dilatations (IPVDs), and hypoxemia. Rat models and small human studies suggest that NO overproduction may cause IPVDs.

STUDY

A retrospective review of the Canadian HPS Database (2007 to 2017) and prospective eNO measurement (main outcome) in healthy controls (measurement expiratory flow, 200 mL/s). HPS was defined as: (1) liver disease; (2) contrast echocardiography consistent with IPVDs; and (3) partial pressure of arterial oxygen <70 mm Hg with alveolar-arterial gradient >20 mm Hg; subclinical HPS as criteria (1) and (2) only; and no HPS as criterion (1) only. Current smokers and subjects with asthma or pulmonary hypertension were excluded. A linear mixed effects model was used to compare eNO between groups and before and after transplantation.

RESULTS

eNO was 10.4±0.7 ppb in HPS (n=26); 8.3±0.6 ppb in subclinical HPS (n=38); 7.1±1.0 ppb in no HPS (n=15); and 5.6±0.7 ppb in controls (n=30) (P<0.001). eNO decreased from 10.9±0.8 ppb preliver to 6.3±0.8 ppb postliver transplant (n=6 HPS, 6 subclinical HPS) (P<0.001). eNO <6 ppb was 84.4% (73.1% to 92.2%) sensitive and ≥12 ppb was 78.1% (69.4% to 85.3%) specific for HPS (vs. subclinical HPS).

CONCLUSIONS

HPS subjects have higher alveolar eNO than non-HPS subjects, levels normalize with liver transplantation. Applying eNO cutoff values may aid in HPS diagnosis.

Diosmin enhances the anti-angiogenic activity of sildenafil and pentoxifylline against hepatopulmonary syndrome via regulation of TNF-α/VEGF, IGF-1/PI3K/AKT, and FGF-1/ANG-2 signaling pathways

Hepatopulmonary syndrome (HPS) is a severe complication of hepatic cirrhosis, which is characterized by hypoxia, intrapulmonary vasodilation, inflammation, and angiogenesis. In this study, we aimed to investigate the regulatory effects of diosmin (DS) on selected phosphodiesterase inhibitors against chronic bile duct ligation (CBDL)-induced HPS. Experimentally, Wistar Albino rats were used and HPS was induced by CBDL for 28 days. DS (100 mg/kg, daily, P.O.), sildenafil (Sild; 10 mg/kg, twice daily, P.O.), and pentoxifylline (PTX; 50 mg/kg, daily, P.O.) were evaluated either alone or in combinations for their anti-angiogenic activity. CBDL significantly altered oxidative stress biomarkers and up-regulated pulmonary mRNA expressions of VEGF, IGF-1, ET-1, iNOS, eNOS, and ANG-2 as well as the protein expressions of vWF, FGF-1, PI3K, AKT, p-AKT, TGF-β, HYP, MPO activity and circulating TNF-α. Treatment with DS, Sild, PTX, and their combinations significantly attenuated molecular and cellular changes due to CBDL. Improvement of histopathological changes was also observed after drug treatment which further supported our results. Furthermore, DS combination with Sild or PTX exhibited an improvement in HPS in comparison to each drug alone. Collectively, DS can augment the anti-angiogenic activity of Sild and PTX during HPS through regulation of TNF-α/VEGF, IGF-1/PI3K/AKT, and FGF-1/ANG-2 signaling pathways.

von Willebrand factor as a biomarker of clinically significant portal hypertension and severe portal hypertension: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis was performed to investigate the correlation between von Willebrand factor (vWF) antigen and hepatic venous pressure gradient (HVPG) and to evaluate the diagnostic performance of vWF to detect clinically significant portal hypertension (CSPH) and severe portal hypertension (SPH).

DESIGN

Systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE, Web of Science and the Cochrane Library were screened up to 5 April 2018. Studies related to the diagnostic performance of vWF to detect CSPH and/or SPH with HVPG as the reference standard were included. Study quality was assessed by using the Quality Assessment of Diagnostic Accuracy Studies scale. Two authors independently used a standardised form to extract data.

OUTCOMES

The primary outcome was the correlation coefficient between vWF and HVPG. The secondary outcome was the diagnostic performance of vWF to detect CSPH or SPH.

RESULTS

A total of six articles involving 994 patients were included in this study. Five of the included articles were used to stratify the results for the correlation coefficient, three for the diagnostic performance of CSPH and two for SPH. The pooled correlation coefficient based on the random effects model was 0.54 (95% CI 0.35 to 0.69), thus suggesting a moderate correlation between vWF and HVPG. The pooled sensitivity, specificity and area under the curve of vWF for CSPH detection were 82% (95% CI 78 to 86), 76% (95% CI 68 to 83) and 0.87 (95% CI 0.80 to 0.94), respectively. Regarding the ability of vWF to detect SPH, the pooled sensitivity and specificity were 86% (95% CI 80 to 90) and 75% (95% CI 66 to 83), respectively. These results supported the satisfactory diagnostic performance of vWF for CSPH and SPH detection.

CONCLUSIONS

vWF, as a novel biomarker, has a moderate correlation with HVPG and shows a satisfactory performance for the diagnosis of CSPH and SPH in patients with cirrhosis.

Potential Clinical Targets in Hepatopulmonary Syndrome: Lessons From Experimental Models

Hepatopulmonary syndrome (HPS) is a relatively common and potentially severe pulmonary complication of cirrhosis with increased risk of mortality. In experimental models, a complex interaction between pulmonary endothelial cells, monocytes, and the respiratory epithelium, which produces chemokines, cytokines, and angiogenic growth factors, causes alterations in the alveolar microvasculature, resulting in impaired oxygenation. Model systems are critical for evaluating mechanisms and for preclinical testing in HPS, due to the challenges of evaluating the lung in the setting of advanced liver disease in humans. This review provides an overview of current knowledge and recent findings in the rodent common bile duct ligation model of HPS, which recapitulates many features of human disease. We focus on the concepts of endothelial derangement, monocyte infiltration, angiogenesis, and alveolar type II cell dysfunction as main contributors and potential targets for therapy.

Placental growth factor inhibition targets pulmonary angiogenesis and represents a therapy for hepatopulmonary syndrome in mice

Hepatopulmonary syndrome (HPS) is a severe complication of cirrhosis with increased risk of mortality. Pulmonary microvascular alterations are key features of HPS; but underlying mechanisms are incompletely understood, and studies on HPS are limited to rats. Placental growth factor (PlGF), a proangiogenic molecule that is selectively involved in pathological angiogenesis, may play an important role in HPS development; however, its role has never been investigated. In this study, we validated an HPS model by common bile duct ligation (CBDL) in mice, investigated the kinetic changes in pulmonary angiogenesis and inflammation during HPS development, and provide evidence for a novel therapeutic strategy by targeting pathological angiogenesis. Mice with CBDL developed hypoxemia and intrapulmonary shunting on a background of liver fibrosis. Pulmonary alterations included increased levels of proangiogenic and inflammatory markers, which was confirmed in serum of human HPS patients. Increased PlGF production in HPS mice originated from alveolar type II cells and lung macrophages, as demonstrated by immunofluorescent staining. Dysfunctional vessel formation in CBDL mice was visualized by microscopy on vascular corrosion casts. Both prophylactic and therapeutic anti-PlGF (αPlGF) antibody treatment impeded HPS development, as demonstrated by significantly less intrapulmonary shunting and improved gas exchange. αPlGF treatment decreased endothelial cell dysfunction in vivo and in vitro and was accompanied by reduced pulmonary inflammation. Importantly, αPlGF therapy did not affect liver alterations, supporting αPlGF's ability to directly target the pulmonary compartment.

CONCLUSION

CBDL in mice induces HPS, which is mediated by PlGF production; αPlGF treatment improves experimental HPS by counteracting pulmonary angiogenesis and might be an attractive therapeutic strategy for human HPS. (Hepatology 2017).

Differential diagnosis of hepatopulmonary syndrome (HPS): Portopulmonary hypertension (PPH) and hereditary hemorrhagic telangiectasia (HHT)

Hepatopulmonary syndrome (HPS) is a severe complication of advanced liver disease associated with an extremely poor prognosis. HPS is diagnosed in 4-47% of patients with cirrhosis and in 15-20% of candidates for liver transplantation. In addition, severe hypoxia is associated with a high risk of complications of liver transplantation (a 30% chance during the first 90 days) and increases the gap between transplantation and improving arterial oxygenation. The pathogenesis of HPS is not fully understood, and no effective pharmacological treatment has been developed yet. Currently, the treatment of choice for HPS is orthotopic liver transplantation. Non-specific clinical criteria and the lack of standardized diagnostic criteria for determining HPS can lead to diagnostic errors. Portopulmonary hypertension and hereditary hemorrhagic telangiectasia, also known as Osler-Weber-Rendu syndrome, are pulmonary complications of liver disease which should be differentially diagnosed from HPS.

Hepatopulmonary syndrome is associated with the presence of hepatocellular carcinoma in patients with decompensated cirrhosis

Background

Hepatopulmonary syndrome (HPS) is a relatively common complication in patients with decompensated cirrhosis. Our aim was to evaluate the prevalence of HPS, its clinical impact, and the possible association between HPS and characteristics of patients with decompensated cirrhosis.

Methods

Patients with stable decompensated cirrhosis admitted to our department and assessed for HPS were included. For each patient, several clinical, laboratory and echocardiographic parameters as well as renal function were recorded. The severity of liver disease was evaluated according to the Model for End-stage Liver Disease and Child-Pugh scores, and renal function was assessed using ⁵¹chromium complexed with ethylene diamine tetracetic acid. In addition, the short synacthen test was performed in each patient to evaluate the adrenal function.

Results

Sixty-three patients were enrolled, 26 (41.3%) of whom diagnosed with HPS. In multivariate analysis, the presence of hepatocellular carcinoma [odds ratio (OR) 8.1, 95% confidence interval (CI) 5.3-27.9, P=0.045] and salivary cortisol at T60 (60 min after the intravenous injection of 250 μg corticotropin) (OR 0.88, 95%CI 0.71-0.98, P=0.045) were the factors independently associated with HPS. T60 salivary cortisol had relatively good discriminative ability for the presence of HPS (area under the curve=0.73). The presence of HPS was not associated with the outcome (P=0.22).

Conclusion

In our cohort of patients with decompensated cirrhosis, the presence of hepatocellular carcinoma and T60 salivary cortisol were the only factors independently associated with HPS.

von Willebrand factor antigen (vWF-Ag): A non-invasive predictor of treatment response and serious adverse events in HCV patients with interferon triple therapy

BACKGROUND

Treatment of chronic hepatitis C virus (HCV) infection was revolutionized within the last years. Interferon free antiviral regimens are not accessible without limitations. Combination of peginterferon/ribavirin with first generation direct acting antivirals is less effective and associated with serious adverse events.

AIM

We have shown that vWF-Ag is associated with portal hypertension and treatment response to PEG/RBV and we evaluated if vWF-Ag is a predictive marker for treatment response and safety in patients with triple therapy.

METHODS

222 HCV-GT 1 patients and DAA based triple therapy were included in this retrospective, multicenter study.

RESULTS

Median vWF-Ag levels were 167.0% [IQR: 124.0-210.0%]. Significantly higher levels were seen in patients without SVR; median 190% [IQR: 146.0-259.5%] versus SVR: 142.5% [IQR: 114.3-196.8%], p<0.001. Furthermore levels of vWF-Ag were identified as independent predictor of non SVR; (OR: 1.009; 95%CI: 1.016-1.3, p=0.005). In patients with cirrhosis elevated vWF-Ag levels were associated with increased incidence of SAEs (OR: 1.016; 95%CI: 1.004-1.028; p=0.007). Best cut off for prediction of SAEs was vWF-Ag>281.5% with a sensitivity of 78% and a specificity of 90%.

CONCLUSION

Baseline vWF-Ag levels predict outcome of DAA based treatment in HCV-1 patients and identify patients with a risk of SAEs. Therefore vWF-Ag may be an additional marker for selecting patients for interferon free therapeutic regimens.

Inhibition of autophagy ameliorates pulmonary microvascular dilation and PMVECs excessive proliferation in rat experimental hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is a defective liver-induced pulmonary vascular disorder with massive pulmonary microvascular dilation and excessive proliferation of pulmonary microvascular endothelial cells (PMVECs). Growing evidence suggests that autophagy is involved in pulmonary diseases, protectively or detrimentally. Thus, it is interesting and important to explore whether autophagy might be involved in and critical in HPS. In the present study, we report that autophagy was activated in common bile duct ligation (CBDL) rats and cultured pulmonary PMVECs induced by CBDL rat serum, two accepted in vivo and in vitro experimental models of HPS. Furthermore, pharmacological inhibition of autophagy with 3-methyladenine (3-MA) significantly alleviated pathological alterations and typical symptom of HPS in CBDL rats in vivo, and consistently 3-MA significantly attenuated the CBDL rat serum-induced excessive proliferation of PMVECs in vitro. All these changes mediated by 3-MA might explain the observed prominent improvement of pulmonary appearance, edema, microvascular dilatation and arterial oxygenation in vivo. Collectively, these results suggest that autophagy activation may play a critical role in the pathogenesis of HPS, and autophagy inhibition may have a therapeutic potential for this disease.

Coagulation parameters and major bleeding in critically ill patients with cirrhosis

Disturbances of coagulation and hemostasis are common in patients with liver cirrhosis. The typical laboratory pattern mimics disseminated intravascular coagulation (DIC). The aim of this study was to assess the impact of routine coagulation parameters in critically ill cirrhosis patients with regard to new onset of major bleeding and outcome. A total of 1,493 critically ill patients were studied prospectively. Routine coagulation parameters were assessed, and the DIC score was calculated based on platelets, fibrinogen, d-dimer, and prothrombin index. New onset of major bleeding during the stay at the intensive care unit and mortality were assessed. Patients were followed for 1 year. Two hundred eleven patients of the cohort had liver cirrhosis. Platelets, fibrinogen, prothrombin index, activated partial thromboplastin time, and d-dimer as well as the DIC score differed significantly between patients with and without cirrhosis (P < 0.001 for all). Moreover, fibrinogen, platelets, and activated partial thromboplastin time (but not prothrombin index) differed significantly between cirrhosis patients with and without major bleeding (P < 0.01 for all). Bleeding on admission, platelet count <30 < 10(9) /L, fibrinogen level <60 mg/dL, and activated partial thromboplastin time values >100 seconds were the strongest independent predictors for new onset of major bleeding in multivariate regression analysis. One-year mortality in cirrhosis patients with and without major bleeding was 89% and 68%, respectively (P < 0.05 between groups).

CONCLUSION

Abnormal coagulation parameters and high DIC scores (primarily due to fibrinogen and platelets) correspond to increased bleeding risk in patients with liver cirrhosis in the intensive care unit, and fibrinogen and platelet count were identified as the best routine coagulation parameters for prediction of new onset of major bleeding; however, further studies are required to evaluate the potential therapeutic implications of these findings. (Hepatology 2016;64:556-568).

Hepatopulmonary syndrome: What we know and what we would like to know

Hepatopulmonary syndrome (HPS) is characterized by abnormalities in blood oxygenation caused by the presence of intrapulmonary vascular dilations (IPVD) in the context of liver disease, generally at a cirrhotic stage. Knowledge about the subject is still only partial. The majority of the information about the etiopathogenesis of HPS has been obtained through experiments on animals. Reported prevalence in patients who are candidates for a liver transplantation (LT) varies between 4% and 32%, with a predominance of mild or moderate cases. Although it is generally asymptomatic it does have an impact on their quality of life and survival. The diagnosis requires taking an arterial blood gas sample of a seated patient with alveolar-arterial oxygen gradient (AaO₂) ≥ 15 mm Hg, or ≥ 20 mm Hg in those over 64 years of age. The IPVD are identified through a transthoracic contrast echocardiography or a macroaggregated albumin lung perfusion scan (^99mTc-MAA). There is currently no effective medical treatment. LT has been shown to reverse the syndrome and improve survival rates, even in severe cases. Therefore the policy of prioritizing LT would appear to increase survival rates. This paper takes a critical and clinical look at the current understanding of HPS, as well as the controversies surrounding it and possible future research.

Hepatopulmonary Syndrome and Liver Transplantation: A Recent Review of the Literature

A severe and common pulmonary vascular complication of liver disease is hepatopulmonary syndrome (HPS). It is a triad of liver dysfunction and/or portal hypertension, intrapulmonary vascular dilatations, and increased alveolar-arterial oxygen gradient. Prevalence varies according to various study groups from 4%-47%. While the most common presenting symptom of HPS is dyspnea, it is usually asymptomatic, and thus all liver transplant candidates should be screened for its presence. Pulse oximetry is a useful screening method, but arterial blood gas examination is the gold standard. If there is an abnormal P (A-a)O2 gradient, microbubble transthoracic echocardiography should be done for diagnosis. Outcome is unpredictable, and there is currently no effective medical therapy. The only effective therapy is considered to be liver transplantation. Complete resolution of HPS after liver transplantation is seen within a year in most HPS patients.

Hepatopulmonary Syndrome

Hepatopulmonary syndrome (HPS) is a pulmonary complication observed in patients with chronic liver disease and/or portal hypertension, attributable to an intrapulmonary vascular dilatation that may induce severe hypoxemia. Microvascular dilation and angiogenesis in the lung have been identified as pathologic features that drive gas exchange abnormalities in experimental HPS. Pulse oximetry is a useful screening test for HPS, which can guide subsequent use of arterial blood gases. Contrast-enhanced echocardiography, perfusion lung scanning, and pulmonary arteriography are three currently used diagnostic imaging modalities that identify the presence of intrapulmonary vascular abnormalities. The presence of HPS increases mortality and impairs quality of life, but is reversible with liver transplantation. No medical therapy is established as effective for HPS. At the present time, liver transplantation is the only available treatment for HPS.

Hepatopulmonary syndrome and portopulmonary hypertension: recent knowledge in pathogenesis and overview of clinical assessment

Hepatopulmonary syndrome and portopulmonary hypertension are cardiopulmonary complications, which are not infrequently seen in patients with liver disease and/or portal hypertension. These entities are both clinically and pathophysiologically different: the hepatopulmonary syndrome is characterized by abnormal pulmonary vasodilation and right-to-left shunting resulting in gas exchange abnormalities, whereas portopulmonary hypertension is caused by pulmonary artery vasoconstriction leading to hemodynamic failure. As both hepatopulmonary syndrome and portopulmonary hypertension are associated with significantly increased morbidity and mortality, and as these patients are commonly asymptomatic, all liver transplantation candidates should be actively screened for the presence of these two complications. The aim of is this review is to provide an overview on the hepatopulmonary syndrome and portopulmonary hypertension with primary focus on diagnosis and recent knowledge regarding pathogenesis and therapeutic targets.

Effects of increased von Willebrand factor levels on primary hemostasis in thrombocytopenic patients with liver cirrhosis

In patients with liver cirrhosis procoagulant and anticoagulant changes occur simultaneously. During primary hemostasis, platelets adhere to subendothelial structures, via von Willebrand factor (vWF). We aimed to investigate the influence of vWF on primary hemostasis in patients with liver cirrhosis. Therefore we assessed in-vitro bleeding time as marker of primary hemostasis in cirrhotic patients, measuring the Platelet Function Analyzer (PFA-100) closure times with collagen and epinephrine (Col-Epi, upper limit of normal ≤ 165 s) or collagen and ADP (Col-ADP, upper limit of normal ≤ 118 s). If Col-Epi and Col-ADP were prolonged, the PFA-100 was considered to be pathological. Effects of vWF on primary hemostasis in thrombocytopenic patients were analyzed and plasma vWF levels were modified by adding recombinant vWF or anti-vWF antibody. Of the 72 included cirrhotic patients, 32 (44.4%) showed a pathological result for the PFA-100. They had mean closure times (± SD) of 180 ± 62 s with Col-Epi and 160 ± 70 s with Col-ADP. Multivariate analysis revealed that hematocrit (P = 0.027) and vWF-antigen levels (P = 0.010) are the predictors of a pathological PFA-100 test in cirrhotic patients. In 21.4% of cirrhotic patients with platelet count ≥ 150/nL and hematocrit ≥ 27.0%, pathological PFA-100 results were found. In thrombocytopenic (< 150/nL) patients with cirrhosis, normal PFA-100 results were associated with higher vWF-antigen levels (462.3 ± 235.9% vs. 338.7 ± 151.6%, P = 0.021). These results were confirmed by multivariate analysis in these patients as well as by adding recombinant vWF or polyclonal anti-vWF antibody that significantly shortened or prolonged closure times, respectively. In conclusion, primary hemostasis is impaired in cirrhotic patients. The effect of reduced platelet count in cirrhotic patients can at least be partly compensated by increased vWF levels. Recombinant vWF could be an alternative to platelet transfusions in the future.