Role of angiogenic factors/cell adhesion markers in serum of cirrhotic patients with hepatopulmonary syndrome

Predictive models and clinical manifestations of intrapulmonary vascular dilatation and hepatopulmonary syndrome in patients with cirrhosis: Prospective comparative study

BACKGROUND

Patients with cirrhosis with hepatopulmonary syndrome (HPS) have a poorer prognosis. The disease has a subtle onset, symptoms are easily masked, clinical attention is insufficient, and misdiagnosis rates are high.

AIM

To compare the clinical characteristics of patients with cirrhosis, cirrhosis combined with intrapulmonary vascular dilatation (IPVD), and HPS, and to establish predictive models for IPVD and HPS.

METHODS

Patients with cirrhosis were prospectively screened at a liver-specialized university teaching hospital. Clinical information and blood samples were collected, and biomarker levels in blood samples were measured. Patients with cirrhosis were divided into three groups: Those with pure cirrhosis, those with combined IPVD, and those with HPS based on contrast-enhanced transthoracic echocardiography results and the pulmonary alveolar-arterial oxygen gradient values. Univariate logistic regression and Least Absolute Shrinkage and Selection Operator (LASSO) regression methods were utilized to identify risk factors for IPVD and HPS, and nomograms were constructed to predict IPVD and HPS.

RESULTS

A total of 320 patients were analyzed, with 101 diagnosed with IPVD, of whom 54 were diagnosed with HPS. There were statistically significant differences in clinical parameters among these three groups of patients. Among the tested biomarkers, sphingosine 1 phosphate, angiopoietin-2, and platelet-derived growth factor BB were significantly associated with IPVD and HPS in patients with cirrhosis. Following LASSO logistic regression screening, prediction models for IPVD and HPS were established. The area under the receiver operating characteristic curve for IPVD prediction was 0.792 (95% confidence interval [CI]: 0.737-0.847), and for HPS prediction was 0.891 (95%CI: 0.848-0.934).

CONCLUSION

This study systematically compared the clinical characteristics of patients with cirrhosis, IPVD, and HPS, and constructed predictive models for IPVD and HPS based on clinical parameters and laboratory indicators. These models showed good predictive value for IPVD and HPS in patients with cirrhosis. They can assist clinicians in the early prognosis assessment of patients with cirrhosis, ultimately benefiting the patients.

Hepatopulmonary syndrome in patients with porto-sinusoidal vascular disorder: Characteristics and outcome

Background & Aims

Porto-sinusoidal vascular disorder (PSVD) is a rare cause of portal hypertension. Data on hepatopulmonary syndrome (HPS) in PSVD are limited. This study aimed to determine the associated factors, plasma mediators, and evolution of HPS in patients with PSVD.

Methods

Multicenter observational study of patients with PSVD with signs of portal hypertension in whom contrast-enhanced transthoracic echocardiography (CE-TTE) was performed.

Results

Among 196 patients with PSVD who underwent CE-TTE in 17 centers, 14 (7% [95% confidence interval 3-11%]) had a confirmed diagnosis of HPS. Patients with HPS more frequently had a genetic disorder associated with PSVD (50% vs. 6%, p <0.001), especially telomere biology disorders (p <0.001). Liver function was less preserved in patients with HPS, because they had lower prothrombin index (63% vs. 86%, p = 0.04), higher serum total bilirubin (37 μmol/L vs. 14 μmol/L, p <0.001), and lower serum albumin (32 g/L vs. 38 g/L, p <0.001). HPS tended to be associated with more portal venule obliterations (p = 0.085) and with nodular liver architecture (p = 0.069). Plasma concentrations of Angiopoietin-2, ICAM3, and Tie2 were higher in patients with HPS (p = 0.02, p = 0.04, p = 0.01, respectively). Out of the 14 patients with HPS, five underwent liver transplantation after a median follow-up of 34 months. Overall cumulative incidence of liver-related events and of death was similar between patients with and without HPS, when considering liver transplantation for HPS as a competing risk.

Conclusions

HPS in patients with PSVD was associated with genetic disorders, less preserved liver function, and higher plasma concentrations of angiogenic mediators. When applying HPS model for end-stage liver disease exception policy for liver transplantation, overall survival of patients with PSVD and HPS was similar to that of patients with PSVD without HPS.

Impact and implications

Hepatopulmonary syndrome (HPS) is a rare complication of porto-sinusoidal vascular disorder (PSVD). This multicentric study found that patients with PSVD and HPS had less preserved liver function, and harbored genetic disorders more frequently (especially telomere biology disorders) than patients without HPS. HPS did not negatively impact transplantation-free survival when applying HPS MELD exception policy for liver transplantation through a competitive risk analysis. Our findings suggest that patients with PSVD with respiratory symptoms and/or telomere biology disorders may benefit from systematic screening for HPS.

Placental growth factor modulates endothelial NO production and exacerbates experimental hepatopulmonary syndrome

Background & Aims

Hepatopulmonary syndrome (HPS) results from portal hypertension, with or without cirrhosis, and is marked by pulmonary vascular dilations leading to severe hypoxemia. Although placental growth factor (PlGF) is important for vascular growth and endothelial function, its role in HPS is unclear. This study investigated the involvement of PlGF in experimental models of HPS and in patients.

Methods

Circulating PlGF levels were measured in 64 controls and 137 patients with liver disease, with or without HPS. Two rat models, common bile duct ligation (CBDL) and long-term partial portal vein ligation (PPVL), were used. Plgf-knockout (Plgf -/-) rats were generated using CRISPR-Cas9. Lung RNA-sequencing analysis was performed in the CBDL model. The effects of PlGF on endothelial nitric oxide synthase (eNOS) activity in human pulmonary microvascular endothelial cells were also investigated.

Results

Circulating PlGF levels were significantly higher in patients with cirrhosis compared with healthy controls (29.4 ± 1.2 vs. 20.2 ± 0.8 pg/ml, p <0.0001), but no difference were found between patients with and without HPS. PlGF levels were not elevated in patients with extrahepatic portal hypertension. In Plgf -/- rats, there was a protective effect against CBDL-induced HPS, whereas PPVL-induced HPS severity remained unchanged. RNA sequencing coupled with ingenuity pathway analysis identified significant interactions between PlGF and pulmonary eNOS activity. Following CBDL, Plgf -/- rats showed decreased pulmonary eNOS activity and reduced circulating nitric oxide metabolites. In vitro, PlGF stimulation enhanced eNOS activity in human pulmonary microvascular endothelial cells, whereas PlGF knockdown led to a decrease.

Conclusions

These findings indicate that PlGF aggravates cirrhosis-induced HPS through modulation of pulmonary eNOS activity, and is not involved in HPS from extrahepatic portal hypertension.

Impact and implications

This study identified PlGF as a significant contributor to the exacerbation of HPS associated with cirrhosis, through its regulation of pulmonary nitric oxide production. Our findings demonstrated that PlGF deficiency mitigates the severity of both cirrhosis and HPS in the CBDL model, highlighting its potential as a therapeutic target in cirrhosis-induced HPS. Notably, this protective effect was absent in the PPVL model, which induces HPS associated with portal hypertension without cirrhosis. These results open avenues for novel pharmacological interventions aiming to improve outcomes for patients with cirrhosis-induced HPS.

Pulmonary vascular complications of cirrhosis: hepatopulmonary syndrome and portopulmonary hypertension

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are two distinct pulmonary vascular complications seen in patients with liver disease and/or portal hypertension. HPS is characterized by disturbed gas exchange and hypoxemia because of intrapulmonary vascular dilatations. POPH is defined by pulmonary arterial hypertension, which might lead to right heart failure. HPS affects up to 30% of patients with end-stage liver disease requiring liver transplantation. POPH is rarer and affects 1-5% of this patient population. If not recognized and left untreated, these disorders result in significant mortality. This review provides an update on HPS and POPH and discusses their clinical characteristics, screening and diagnostic modalities, and management, including the place of liver transplantation.

Risk of Cerebral Aneurysm Rupture After Liver Transplantation: Development and Validation of a Hemorrhagic Stroke Scoring Model

BACKGROUND

Liver transplantation (LT) patients appear to be more prone to neurological events compared to individuals undergoing other types of solid-organ transplantation. The aims of the present study were to analyze the prevalence of unruptured intracranial aneurysms (UIAs) in patients undergoing liver transplantation (LT) and to examine the perioperative occurrence of subarachnoid hemorrhage (SAH). Also, it intended to systematically identify the risk factors of SAH and hemorrhagic stroke (HS) within a year after LT and to develop a scoring system which involves distinct clinical features of LT patients.

METHODS

Patients who underwent LT from January 2012 to March 2022 were analyzed. All included patients underwent neurovascular imaging within 6 months before LT. We conducted an analysis of prevalence and radiological features of UIA and SAH. The clinical factors that may have an impact on HS within one year of LT were also reviewed.

RESULTS

Total of 3,487 patients were enrolled in our study after applying inclusion and exclusion criteria. The prevalence of UIA was 5.4%. The incidence of SAH and HS within one year following LT was 0.5% and 1.6%, respectively. We developed a scoring system based on multivariable analysis to predict the HS within 1-year after LT. The variables were a poor admission mental status, the diagnosis of UIA, serum ammonia levels, and Model for End-stage Liver Disease (MELD) scores. Our model showed good discrimination among the development (C index, 0.727; 95% confidence interval [CI], 0.635-0.820) and validation (C index, 0.719; 95% CI, 0.598-0.801) cohorts.

CONCLUSION

The incidence of UIA and SAH was very low in LT patients. A poor admission mental status, diagnosis of UIA, serum ammonia levels, and MELD scores were significantly associated with the risk of HS within one year after LT. Our scoring system showed a good discrimination to predict the HS in LT patients.

Hepatopulmonary syndrome: diagnosis and treatment

Hepatopulmonary syndrome (HPS) is one of the lung diseases associated with liver cirrhosis and portal hypertension. The diagnosis is based on the triad: liver disease and portal hypertension, evidence of intrapulmonary vascular dilatation and impaired gas exchange. HPS impairs prognosis (23 % survival after 5 years) and patients’ quality of life, so early diagnosis and timely treatment are of great importance. Liver transplantation allows for regression of intrapulmonary vascular dilatation in almost 100 % of cases, normalization of gas exchange and improves a 5-year survival after transplantation from 76 to 87 %. This is the only treatment method indicated for patients with severe HPS, defined by an arterial partial pressure of oxygen (PaO2) below 60 mm Hg. However, in the face of a global shortage of transplants, it is necessary to develop medical therapies to delay or even defer liver transplantation. This goal seems possible due to the growing understanding of the HPS pathophysiology and the development of therapies targeting key mechanisms, mainly inflammatory and angiogenic. This article provides an overview of the clinical manifestations, diagnosis and treatment of HPS based on literature sources from the MEDLINE database on the PubMed platform.

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.

Impact of hepatopulmonary syndrome in liver transplantation candidates and the role of angiogenesis

BACKGROUND

Hepatopulmonary syndrome affects 10-30% of patients with cirrhosis and portal hypertension. We evaluated the serum angiogenic profile of hepatopulmonary syndrome and assessed the clinical impact of hepatopulmonary syndrome in patients evaluated for liver transplantation.

METHODS

The Pulmonary Vascular Complications of Liver Disease 2 study was a multicentre, prospective cohort study of adults undergoing their first liver transplantation evaluation. Hepatopulmonary syndrome was defined as an alveolar-arterial oxygen gradient ≥15 mmHg (≥20 mmHg if age >64 years), positive contrast-enhanced transthoracic echocardiography and absence of lung disease.

RESULTS

We included 85 patients with hepatopulmonary syndrome and 146 patients without hepatopulmonary syndrome. Patients with hepatopulmonary syndrome had more complications of portal hypertension and slightly higher Model for End-Stage Liver Disease-Na score compared to those without hepatopulmonary syndrome (median (interquartile range) 15 (12-19) versus 14 (10-17), p=0.006). Hepatopulmonary syndrome patients had significantly lower 6-min walk distance and worse functional class. Hepatopulmonary syndrome patients had higher circulating angiopoietin 2, Tie2, tenascin C, tyrosine protein kinase Kit (c-Kit), vascular cell adhesion molecule 1 and von Willebrand factor levels, and lower E-selectin levels. Patients with hepatopulmonary syndrome had an increased risk of death (hazard ratio 1.80, 95% CI 1.03-3.16, p=0.04), which persisted despite adjustment for covariates (hazard ratio 1.79, 95% CI 1.02-3.15, p=0.04). This association did not vary based on levels of oxygenation, reflecting the severity of hepatopulmonary syndrome.

CONCLUSION

Hepatopulmonary syndrome was associated with a profile of abnormal systemic angiogenesis, worse exercise and functional capacity, and an overall increased risk of death.

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.

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.

Association between cirrhosis and aneurysmal subarachnoid hemorrhage

Objective

Cirrhosis has been associated with nontraumatic subarachnoid hemorrhage (SAH). We sought to evaluate the specific association between cirrhosis and aneurysmal SAH.

Methods

We performed a retrospective cohort study using a sample of Medicare claims data from 2008 to 2015. Cirrhosis was defined using a validated ICD‐9‐CM diagnosis code algorithm. Nontraumatic SAH was identified using a validated approach requiring an inpatient claim for its ICD‐9‐CM diagnosis code. Additionally, we required the presence of an ICD‐9‐CM procedure code reflecting treatment of a cerebral aneurysm during the same hospitalization to ensure ascertainment of aneurysmal SAH specifically. We used survival statistics to calculate incidence rates and Cox proportional hazards models to evaluate the association between cirrhosis and aneurysmal SAH after adjustment for demographics, stroke risk factors, and comorbidities.

Results

We identified 10,658 (0.6%) patients with cirrhosis from among the 1,778,604 beneficiaries in our sample. The mean age of patients with cirrhosis was 73.5 (±7.8) years, and 48% were female. Over a mean of 4.7 (±2.1) years of follow‐up, 4,272 patients were hospitalized with aneurysmal SAH. The annual incidence of aneurysmal SAH in patients with cirrhosis was 0.12% (95% confidence interval [CI], 0.08–0.17%) compared to 0.05% (95% CI, 0.05–0.05%) in patients without cirrhosis. In the adjusted model, cirrhosis was independently associated with aneurysmal SAH (hazard ratio, 2.2; 95% confidence interval, 1.5–3.4).

Interpretation

Cirrhosis was independently associated with an increased risk of aneurysmal SAH among older individuals. Confirmation of these findings may yield opportunities for risk stratification and prevention.

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).

MIR196A2 rs11614913 C > T polymorphism correlates with an increased risk of hepatopulmonary syndrome in liver cirrhosis: a case-control study in China

OBJECTIVE

This case-control study is designed to explore the relationship between microRNA-196a2 (MIR196A2) rs11614913 C > T polymorphism and the risk of hepatopulmonary syndrome (HPS) in liver cirrhosis.

METHODS

From January 2013 to January 2015, 163 liver cirrhosis patients with HPS (case group), 264 liver cirrhosis patients without HPS (control group), and 195 healthy people (normal group) were selected. A DNA extraction kit was used to extract plasma DNA from peripheral blood. Polymerase chain reaction-restriction fragment length polymorphism was used to detect the allele and genotype frequencies of MIR196A2 C > T polymorphism. Real-time quantitative polymerase chain reaction was adopted to detect the relative expression of MIR196A.

RESULTS

The frequencies of C allele in the case group were higher than those in the control and normal groups (all P < 0.05), whereas no significant difference was found between the control and normal groups, which indicated that MIR196A2 C > T polymorphism was closely associated with an increased risk of HPS in patients with liver cirrhosis. Compared with the normal group, the relative expression of MIR196A in the case group was significantly increased (P < 0.05), but there was no significant difference in the control group (P > 0.05). In the case group, compared with patients carrying the TT genotype, the relative expression of MIR196A of patients carrying the C allele (CT + CC) evidently increased (P < 0.05).

CONCLUSIONS

The MIR196A2 rs11614913 C > T polymorphism may contribute to an increased risk of HPS in liver cirrhosis patients.

Circulating bile acids predict outcome in critically ill patients

Background

Jaundice and cholestatic hepatic dysfunction are frequent findings in critically ill patients associated with increased mortality. Cholestasis in critically ill patients is closely associated with stimulation of pro-inflammatory cytokines resulting in impaired bile secretion and subsequent accumulation of bile acids.

Aim of this study was to evaluate the clinical role of circulating bile acids in critically ill patients.

Methods

Total and individual serum bile acids were assessed via high-performance liquid chromatography in 320 critically ill patients and 19 controls.

Results

Total serum bile acids were threefold higher in septic than cardiogenic shock patients and sixfold higher than in post-surgical patients or controls (p < 0.001). Elevated bile acid levels correlated with severity of illness, renal dysfunction and inflammation (p < 0.05). Total bile acids predicted 28-day mortality independently of sex, age, serum bilirubin and severity of illness (HR 1.041, 95% CI 1.013–1.071, p < 0.005). Best prediction of mortality of total bile acids was seen in patients suffering from septic shock.

Conclusions

Individual and total BAs are elevated by various degrees in different shock conditions. BAs represent an early predictor of short-term survival in a mixed cohort of ICU patients and may serve as marker for early risk stratification in critically ill patients. Future studies should elucidate whether modulation of BA metabolism and signalling influences the clinical course and outcome in critically ill patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0272-7) contains supplementary material, which is available to authorized users.

Serum vascular cell adhesion molecule-1 predicts significant liver fibrosis in non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and is strongly associated with obesity, dyslipidemia and insulin resistance. NAFLD often presents as simple steatosis (NAFL) but can progress to non-alcoholic steatohepatitis (NASH) and fibrosis. Current non-invasive biomarkers are not tailored to identify significant (⩾F2) fibrosis, although recent guidelines recommend a stringent follow-up of this patient population. We and others have reported on the role of pathological angiogenesis in the pathogenesis of NAFLD, highlighting pro-angiogenic factors as potential diagnostic markers.

OBJECTIVE

To investigate the applicability of angiogenic and endothelial dysfunction markers as non-invasive diagnostic tools for NASH or NASH-associated fibrosis in obese patients.

METHODS

In a prospective cross-sectional study, male patients undergoing bariatric surgery (n=61) and control patients (n=35) were recruited. Serum protein levels and visceral adipose tissue gene expression of endothelial dysfunction and angiogenic markers were analyzed by multiplex bead-based assay and quantitative RT-PCR, respectively. For validation, we recruited a second cohort of patients undergoing bariatric surgery (n=40) and a cohort of NAFLD patients from our outpatient clinic (n=30).

RESULTS

We identified serum vascular cell adhesion molecule-1 (VCAM-1) as an independent predictor for ⩾F2 fibrosis (median 14.0 vs 8.7 ng ml^-1 in patients with and without significant fibrosis; P<0.0001) with an area under the receiver-operating characteristics (AUROC) curve of 0.80. The cutoff point of 13.2 ng ml^-1 showed a sensitivity of 80% and specificity of 83%. In line with these results, VCAM-1 visceral adipose tissue gene expression was also elevated in patients with fibrosis (P=0.030). In the bariatric surgery and clinical validation cohorts, VCAM-1 displayed similar AUROCs of 0.89 and 0.85, respectively.

CONCLUSIONS

VCAM-1 levels are able to accurately predict significant (⩾F2) fibrosis in NAFLD patients.

Prevalence and impact on survival of hepatopulmonary syndrome and cirrhotic cardiomyopathy in a cohort of cirrhotic patients

BACKGROUND & AIMS

Extrahepatic complications of cirrhosis increase the risk for decompensation of the liver disease and death. Previous studies show common pathogenetic mechanisms involved in the development of hepatopulmonary syndrome and cirrhotic cardiomyopathy. We aimed to assess the link between these entities and their effect on disease-related patient morbidity and mortality.

METHODS

Seventy-four consecutive cirrhotic patients without prior history of cardiovascular and pulmonary disease were included in a prospective observational study. Routine blood work, arterial blood gas analysis, pulse oximetry measurements, N-terminal pro-brain natriuretic peptide levels and contrast enhanced echocardiography examination with tissue Doppler imaging were performed in all patients. Patients were followed up for a median of 6 months and disease-related adverse events and death were the main outcomes tested. Statistical analysis was conducted according to the presence of hepatopulmonary syndrome or cirrhotic cardiomyopathy.

RESULTS

Hepatopulmonary syndrome was diagnosed in 17 patients (23%) and cirrhotic cardiomyopathy in 30 patients (40.5%). There was no association between the presence of cirrhotic cardiomyopathy and the existence of mild or moderate hepatopulmonary syndrome. No echocardiographic parameters were useful in predicting the presence of hepatopulmonary syndrome. N-terminal pro-brain natriuretic peptide levels and length of QT interval did not aid in diagnosis of cirrhotic cardiomyopathy. Neither entity had significant influence on disease-related outcomes in the follow-up period.

CONCLUSIONS

Hepatopulmonary syndrome and cirrhotic cardiomyopathy are independent complications arising in cirrhosis and have a limited influence on morbidity and mortality on a pre-liver transplantation population.

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.

Angiogenesis and liver fibrosis

Recent data indicate that hepatic angiogenesis, regardless of the etiology, takes place in chronic liver diseases (CLDs) that are characterized by inflammation and progressive fibrosis. Because anti-angiogenic therapy has been found to be efficient in the prevention of fibrosis in experimental models of CLDs, it is suggested that blocking angiogenesis could be a promising therapeutic option in patients with advanced fibrosis. Consequently, efforts are being directed to revealing the mechanisms involved in angiogenesis during the progression of liver fibrosis. Literature evidences indicate that hepatic angiogenesis and fibrosis are closely related in both clinical and experimental conditions. Hypoxia is a major inducer of angiogenesis together with inflammation and hepatic stellate cells. These profibrogenic cells stand at the intersection between inflammation, angiogenesis and fibrosis and play also a pivotal role in angiogenesis. This review mainly focuses to give a clear view on the relevant features that communicate angiogenesis with progression of fibrosis in CLDs towards the-end point of cirrhosis that may be translated into future therapies. The pathogenesis of hepatic angiogenesis associated with portal hypertension, viral hepatitis, non-alcoholic fatty liver disease and alcoholic liver disease are also discussed to emphasize the various mechanisms involved in angiogenesis during liver fibrogenesis.