The Art and Science of Diagnosing and Treating Lung and Heart Disease Secondary to Liver Disease

Patients with chronic liver disease are at risk of extrahepatic complications related to cirrhosis and portal hypertension, as well as organ-specific complications of certain liver diseases. These complications can compromise quality of life, while also increasing morbidity and mortality before and after liver transplantation. Patients with chronic liver disease are at risk for pulmonary complications of hepatopulmonary syndrome and portopulmonary syndrome; the cardiac complication fall under the general concept of cirrhotic cardiomyopathy, which can affect systolic and diastolic function, as well as cardiac conduction. In addition, patients with certain diseases are at risk of lung and/or cardiac complications that are specific to the primary disease (ie, emphysema in α-1-antitrypsin deficiency) or occur with increased incidence in certain conditions (ie, ischemic heart disease associated with nonalcoholic steatohepatitis). This article focuses on the epidemiology, clinical presentation, pathogenesis, treatment options, and role of transplantation for lung and heart diseases secondary to liver disease, while also highlighting select liver diseases that directly affect the lungs and heart.

HIV Infection Status as a Predictor of Hepatitis C Virus RNA Testing in Primary Care

INTRODUCTION

Receipt of hepatitis C virus (HCV) RNA testing following a positive HCV antibody (anti-HCV+) test result to establish current infection is a quality indicator for HCV-related care. This study examines HIV infection status as a predictor of HCV RNA test receipt after an anti-HCV+ result in the primary care setting.

METHODS

Electronic medical records of anti-HCV+ patients from a multisite retrospective study of patients aged ≥18 years who utilized one or more primary care outpatient services during 2005-2010 were analyzed in 2014. A multivariable logistic regression model examined the independent relationships between patient characteristics and receipt of HCV RNA testing.

RESULTS

Among 1,115 anti-HCV+ patients, 133 (11.9%) were also HIV-positive. Of these, 77.4% (n=103) underwent HCV RNA testing to determine current infection status. By contrast, 66.7% (n=654/980) of anti-HCV+ patients who were HIV-negative received HCV RNA testing. Following multivariable adjustment, the odds of receiving HCV RNA testing were higher among anti-HCV+ patients who were also HIV-positive (AOR=1.9, 95% CI=1.2, 3.0), compared with their HIV-negative counterparts. Elevated alanine aminotransferase level was also associated with receipt of HCV RNA testing (AOR=1.9, 95% CI=1.4, 2.4). Black race was associated with decreased odds of receiving HCV RNA testing (AOR=0.7, 95% CI=0.5, 1.0).

CONCLUSIONS

HIV infection status is independently associated with the likelihood of receiving HCV RNA testing following an anti-HCV+ result. One quarter of anti-HCV+ patients who were also HIV-positive and one third of their HIV-negative counterparts, respectively, did not receive testing to establish active HCV infection, which is imperative for appropriate care and treatment.

High risk of delisting or death in liver transplant candidates following infections: Results from the North American Consortium for the Study of End-Stage Liver Disease

Because Model for End-Stage Liver Disease (MELD) scores at the time of liver transplantation (LT) increase nationwide, patients are at an increased risk for delisting by becoming too sick or dying while awaiting transplantation. We quantified the risk and defined the predictors of delisting or death in patients with cirrhosis hospitalized with an infection. North American Consortium for the Study of End-Stage Liver Disease (NACSELD) is a 15-center consortium of tertiary-care hepatology centers that prospectively enroll and collect data on infected patients with cirrhosis. Of the 413 patients evaluated, 136 were listed for LT. The listed patients' median age was 55.18 years, 58% were male, and 47% were hepatitis C virus infected, with a mean MELD score of 2303. At 6-month follow-up, 42% (57/136) of patients were delisted/died, 35% (47/136) underwent transplantation, and 24% (32/136) remained listed for transplant. The frequency and types of infection were similar among all 3 groups. MELD scores were highest in those who were delisted/died and were lowest in those remaining listed (25.07, 24.26, 17.59, respectively; P < 0.001). Those who were delisted or died, rather than those who underwent transplantation or were awaiting transplantation, had the highest proportion of 3 or 4 organ failures at hospitalization versus those transplanted or those continuing to await LT (38%, 11%, and 3%, respectively; P = 0.004). For those who were delisted or died, underwent transplantation, or were awaiting transplantation, organ failures were dominated by respiratory (41%, 17%, and 3%, respectively; P < 0.001) and circulatory failures (42%, 16%, and 3%, respectively; P < 0.001). LT-listed patients with end-stage liver disease and infection have a 42% risk of delisting/death within a 6-month period following an admission. The number of organ failures was highly predictive of the risk for delisting/death. Strategies focusing on prevention of infections and extrahepatic organ failure in listed patients with cirrhosis are required.

Burden of nonalcoholic fatty liver disease and advanced fibrosis in a Texas Hispanic community cohort

AIM: To investigate the potential burden of nonalcoholic steatohepatitis (NASH) and advanced fibrosis in a hispanic community.

METHODS: Four hundred and forty two participants with available ultrasonography data from the Cameron County Hispanic Cohort were included in this study. Each participant completed a comprehensive questionnaire regarding basic demographic information, medical history, medication use, and social and family history including alcohol use. Values of the nonalcoholic fatty liver disease fibrosis score (NFS), FIB4 index, BARD score, and Aspartate aminotransferase to Platelet Ratio Index (APRI) were computed using the blood samples collected within 6 mo of liver ultrasonography from each participant. Hepatic steatosis was determined by ultrasonography. As part of univariable analysis, for continuous variables, comparisons among groups were performed with student-t test, one way analysis of variance, and Mann-Whitney test. Pearson χ² and the Fisher exact test are used to assess differences in categorical variables. For multivariable analyses, logistic regression analyses were performed to identify characteristics associated with hepatic steatosis. All reported P values are based two-sided tests, and a P value of less than 0.05 was considered to indicate statistical significance.

RESULTS: The mean age and body mass index (BMI) of the study participants were 49.1 years and 31.3 kg/m², respectively. Among them, 65.6% were females, 52% had hepatic steatosis, 49.5% had metabolic syndrome, and 29% had elevated aminotransferases. Based on established cut-offs for diagnostic panels, between 17%-63% of the entire cohort was predicted to have NASH with indeterminate or advanced fibrosis. Participants with hepatic steatosis had significantly higher BMI (32.9 ± 5.6 kg/m²vs 29.6 ± 6.1 kg/m², P < 0.001) and higher prevalence rates of elevation of ALT (42.2% vs 14.6%, P < 0.001), elevation of aspartate aminotransferase (38.7% vs 18.9%, P < 0.001), and metabolic syndrome (64.8% vs 33%, P < 0.001) than those without hepatic steatosis. The NFS scores (P = 0.002) and the APRI scores (P = 0.002) were significantly higher in those with steatosis but the scores of the FIB4 index and BARD were similar between the two groups. After adjusting for age, gender and BMI, elevated transaminases, metabolic syndrome and its components, intermediate NFS and APRI scores were associated hepatic steatosis in multivariable analysis.

CONCLUSION: The burden of NASH and advanced fibrosis in the Hispanic community in South Texas may be more substantial than predicted from referral clinic studies.

Radiofrequency ablation for treatment of refractory gastric antral vascular ectasia (with video)

BACKGROUND AND STUDY AIMS

Gastric antral vascular ectasia (GAVE) is a known cause of gastrointestinal bleeding and chronic iron deficiency anemia. Endoscopic therapy with argon plasma coagulation (APC) is widely used for treatment of GAVE, but most patients continue to require repeated blood transfusions and multiple endoscopic procedures (refractory GAVE). We describe our initial experience regarding safety and efficacy of radiofrequency ablation (RFA) therapy in treating patients with refractory GAVE.

PATIENTS AND METHODS

We prospectively enrolled seven patients with refractory GAVE who had multiple prior treatments with APC. These patients were treated with RFA (HALO90 ULTRA Ablation Catheter System; Covidien, GI Solutions, Sunnyvale, CA) at Ertan Digestive Disease Center at our tertiary University Hospital.

RESULTS

Seven patients underwent a total of 12 RFA procedures for treatment of refractory GAVE. The median number of RFA procedures was 2 (Range, 1 - 3). Average pre- and post-procedural hemoglobin were 9.3 g/dL and 10.16 g/dL, respectively. Five of seven patients (71 %) were transfusion-free after the RFA treatments while two patients continued to require blood transfusions. There were no complications in this series.

CONCLUSION

RFA can be an effective alternative to APC for treatment of GAVE refractory to previous endoscopic therapy. Additional studies are needed to identify which subset of patients will benefit the most with RFA treatment.

Long-term use of antibiotics and proton pump inhibitors predict development of infections in patients with cirrhosis

BACKGROUND & AIMS

Bacterial infections, particularly repeated infections, are significant causes of morbidity and mortality among patients with cirrhosis. We investigated and characterized risk factors for repeat infections in these patients.

METHODS

In a prospective study, we collected data from 188 patients hospitalized with cirrhosis and infections and enrolled in the North American Consortium for the Study of End-Stage Liver Disease (12 centers). Patients were followed up for 6 months after hospital discharge and data were analyzed on type of infections and factors associated with subsequent infections.

RESULTS

Six months after hospital discharge, 14% of subjects had received liver transplants, 27% died, and 59% were alive without liver transplantation. After discharge, 45% had subsequent infections, but only 26% of the subsequent infections occurred at the same site. Compared with patients not re-infected, patients with repeat infections were older and a higher proportion used proton pump inhibitors (PPIs) (P = .006), rifaximin (P < .001), or prophylactic therapy for spontaneous bacterial peritonitis (SBP) (P < .001). Logistic regression showed that SBP prophylaxis (odds ratio [OR], 3.44; 95% confidence interval [CI], 1.56-7.63), PPI use (OR, 2.94; 95% CI, 1.39-6.20), SBP at hospital admission (OR, 0.37; 95% CI, 0.15-0.91), and age (OR, 1.06; 95% CI, 1.02-1.11) were independent predictors of subsequent infections.

CONCLUSIONS

Patients hospitalized with cirrhosis and infections are at high risk for subsequent infections, mostly at different sites, within 6 months of index infection resolution. Those at highest risk include previously infected older patients receiving PPIs and/or SBP prophylaxis, although these associations do not prove that these factors cause the infections. New strategies are needed to prevent infections in patients with cirrhosis.

Hepatitis C virus antibody positivity and predictors among previously undiagnosed adult primary care outpatients: cross-sectional analysis of a multisite retrospective cohort study

BACKGROUND

Hepatitis C virus (HCV) testing guidance issued by the Centers for Disease Control and Prevention in 1998 recommends HCV antibody (anti-HCV) testing for persons with specified risk factors. The purpose of this study was to determine the prevalence and predictors of anti-HCV positivity among primary care outpatients and estimate the proportion of unidentified anti-HCV-positive (anti-HCV+) persons using risk-based testing.

METHODS

We analyzed electronic medical record data from a 4-site retrospective study. Patients were aged ≥18 years, utilized ≥1 outpatient primary care service(s) between 2005 and 2010, and had no documented evidence of prior HCV diagnosis. Among persons tested for anti-HCV, we fit a multilevel logistic regression model to identify patient-level independent predictors of anti-HCV positivity. We estimated the proportion of unidentified anti-HCV+ persons by using multiple imputation to assign anti-HCV results to untested patients.

RESULTS

We observed 209 076 patients for a median of 5 months (interquartile range, 1-23 months). Among 17 464 (8.4%) patients who were tested for anti-HCV, 6.4% (n=1115) were positive. We identified history of injection drug use (adjusted odds ratio [95% confidence interval], 6.3 [5.2-7.6]), 1945-1965 birth cohort (4.4 [3.8-5.1]), and elevated alanine aminotransferase levels (4.8 [4.2-5.6]) as independently associated with anti-HCV positivity. We estimated that 81.5% (n=4890/6005) of anti-HCV+ patients were unidentified using risk-based testing.

CONCLUSIONS

In these outpatient primary care settings, risk-based testing may have missed 4 of 5 newly enrolled patients who are anti-HCV+. Without knowing their status, unidentified anti-HCV+ persons cannot receive further clinical evaluation or antiviral treatment, and are unlikely to benefit from secondary prevention recommendations to limit disease progression and mortality.

Alveolar type II epithelial cell dysfunction in rat experimental hepatopulmonary syndrome (HPS)

The hepatopulmonary syndrome (HPS) develops when pulmonary vasodilatation leads to abnormal gas exchange. However, in human HPS, restrictive ventilatory defects are also observed supporting that the alveolar epithelial compartment may also be affected. Alveolar type II epithelial cells (AT2) play a critical role in maintaining the alveolar compartment by producing four surfactant proteins (SPs, SP-A, SP-B, SP-C and SP-D) which also facilitate alveolar repair following injury. However, no studies have evaluated the alveolar epithelial compartment in experimental HPS. In this study, we evaluated the alveolar epithelial compartment and particularly AT2 cells in experimental HPS induced by common bile duct ligation (CBDL). We found a significant reduction in pulmonary SP production associated with increased apoptosis in AT2 cells after CBDL relative to controls. Lung morphology showed decreased mean alveolar chord length and lung volumes in CBDL animals that were not seen in control models supporting a selective reduction of alveolar airspace. Furthermore, we found that administration of TNF-α, the bile acid, chenodeoxycholic acid, and FXR nuclear receptor activation (GW4064) induced apoptosis and impaired SP-B and SP-C production in alveolar epithelial cells in vitro. These results imply that AT2 cell dysfunction occurs in experimental HPS and is associated with alterations in the alveolar epithelial compartment. Our findings support a novel contributing mechanism in experimental HPS that may be relevant to humans and a potential therapeutic target.

Inflammation and portal hypertension - the undiscovered country

Portal hypertension has traditionally been viewed as a progressive process, involving ultrastructural changes including fibrosis, nodule formation, and vascular thrombosis, leading to increased intrahepatic resistance to flow. However, it is increasingly recognized that a significant component of this vascular resistance results from a dynamic process, regulated by complex interactions between the injured hepatocyte, the sinusoidal endothelial cell, the Kupffer cell and the hepatic stellate cell, which impact on sinusoidal calibre. Recent findings suggest these haemodynamic findings are most marked in patients with superimposed inflammation. The precise mechanisms for vascular dysfunction in cirrhosis with superimposed inflammation remain to be fully elucidated but several studies over the past decade have started to generate the hypothesis that inflammation may be a key mediator of the pathogenesis and severity of portal hypertension in this context. This review provides a comprehensive overview of the biological mechanisms for inflammation playing a key role in the severity of portal hypertension, and illustrates potential novel therapies that act by modifying these processes.

Survival in infection-related acute-on-chronic liver failure is defined by extrahepatic organ failures

Infections worsen survival in cirrhosis; however, simple predictors of survival in infection-related acute-on-chronic liver failure (I-ACLF) derived from multicenter studies are required in order to improve prognostication and resource allocation. Using the North American Consortium for Study of End-stage Liver Disease (NACSELD) database, data from 18 centers were collected for survival analysis of prospectively enrolled cirrhosis patients hospitalized with an infection. We defined organ failures as 1) shock, 2) grade III/IV hepatic encephalopathy (HE), 3) need for dialysis and mechanical ventilation. Determinants of survival with these organ failures were analyzed. In all, 507 patients were included (55 years, 52% hepatitis C virus [HCV], 15.8% nosocomial infection, 96% Child score ≥ 7) and 30-day evaluations were available in 453 patients. Urinary tract infection (UTI) (28.5%), and spontaneous bacterial peritonitis (SBP) (22.5%) were the most prevalent infections. During hospitalization, 55.7% developed HE, 17.6% shock, 15.1% required renal replacement, and 15.8% needed ventilation; 23% died within 30 days and 21.6% developed second infections. Admitted patients developed none (38.4%), one (37.3%), two (10.4%), three (10%), or four (4%) organ failures. The 30-day survival worsened with a higher number of extrahepatic organ failures, none (92%), one (72.6%), two (51.3%), three (36%), and all four (23%). I-ACLF was defined as ≥ 2 organ failures given the significant change in survival probability associated at this cutoff. Baseline independent predictors for development of ACLF were nosocomial infections, Model for Endstage Liver Disease (MELD) score, low mean arterial pressure (MAP), and non-SBP infections. Independent predictors of poor 30-day survival were I-ACLF, second infections, and admission values of high MELD, low MAP, high white blood count, and low albumin.

CONCLUSION

Using multicenter study data in hospitalized decompensated infected cirrhosis patients, I-ACLF defined by the presence of two or more organ failures using simple definitions is predictive of poor survival.

The impact of left ventricular hypertrophy on survival in candidates for liver transplantation

Left ventricular hypertrophy (LVH) occurs in 12% to 30% of patients with cirrhosis; however, its prognostic significance is not well studied. We assessed the association of LVH with survival in patients undergoing a liver transplantation (LT) evaluation. We performed a multicenter cohort study of patients undergoing an evaluation for LT. LVH was defined with transthoracic echocardiography. The outcome of interest was all-cause mortality. LVH was present in 138 of 485 patients (28%). Patients with LVH were older, more likely to be male and African American, and were more likely to have hypertension. Three hundred forty-five patients did not undergo transplantation (212 declined, and 133 were waiting): 36 of 110 patients with LVH (33%) died, whereas 57 of 235 patients without LVH (24%) died (P = 0.23). After LT, 8 of 28 patients with LVH (29%) died over the course of 3 years, whereas 9 of 112 patients without LVH (8%) died (P = 0.007). This finding was independent of conventional risk factors for LVH, and all deaths for patients with LVH occurred within 9 months of LT. No clinical or demographic characteristics were associated with mortality among LVH patients. In conclusion, the presence of LVH is associated with an early increase in mortality after LT, and this is independent of conventional risk factors for LVH. Further studies are needed to confirm these findings and identify factors associated with mortality after transplantation to improve outcomes.

Gender and racial differences in nonalcoholic fatty liver disease

Due to the worldwide epidemic of obesity, nonalcoholic fatty liver disease (NAFLD) has become the most common cause of elevated liver enzymes. NAFLD represents a spectrum of liver injury ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) which may progress to advanced fibrosis and cirrhosis. Individuals with NAFLD, especially those with metabolic syndrome, have higher overall mortality, cardiovascular mortality, and liver-related mortality compared with the general population. According to the population-based studies, NAFLD and NASH are more prevalent in males and in Hispanics. Both the gender and racial ethnic differences in NAFLD and NASH are likely attributed to interaction between environmental, behavioral, and genetic factors. Using genome-wide association studies, several genetic variants have been identified to be associated with NAFLD/NASH. However, these variants account for only a small amount of variation in hepatic steatosis among ethnic groups and may serve as modifiers of the natural history of NAFLD. Alternatively, these variants may not be the causative variants but simply markers representing a larger body of genetic variations. In this article, we provide a concise review of the gender and racial differences in the prevalence of NAFLD and NASH in adults. We also discuss the possible mechanisms for these disparities.

Impact of the hepatopulmonary syndrome MELD exception policy on outcomes of patients after liver transplantation: an analysis of the UNOS database

BACKGROUND & AIMS

Patients with hepatopulmonary syndrome (HPS) are prioritized for liver transplantation (given exception points) due to their high pre- and post-transplantation mortality. However, few studies have evaluated the outcomes of these patients.

METHODS

We performed a retrospective cohort study using data submitted to the United Network for Organ Sharing in a study of the effects of room-air oxygenation on pre- and post-transplantation outcomes of patients with HPS. We identified thresholds associated with post-transplantation survival using cubic spline analysis and compared overall survival times of patients with and without HPS.

RESULTS

From 2002 through 2012, nine hundred and seventy-three patients on the liver transplant waitlist received HPS exception points. There was no association between oxygenation and waitlist mortality among patients with HPS exception points. Transplant recipients with more severe hypoxemia had increased risk of death after liver transplantation. Rates of 3-year unadjusted post-transplantation survival were 84% for patients with PaO2 of 44.1-54.0 mm Hg vs 68% for those with PaO2 ≤ 44.0 mm Hg. In multivariable Cox models, transplant recipients with an initial room-air PaO2 ≤ 44.0 mm Hg had significant increases in post-transplantation mortality (hazard ratio = 1.58; 95% confidence interval [CI]: 1.15-2.18) compared with those with a PaO2 of 44.1-54.0 mm Hg. Overall mortality was significantly lower among waitlist candidates with HPS exception points than those without (hazard ratio = 0.82; 95% CI: 0.70-0.96), possibly because patients with HPS have a reduced risk of pre-transplantation mortality and similar rate of post-transplantation survival.

CONCLUSIONS

Although there was no association between pre-transplantation oxygenation and waitlist survival in patients with HPS Model for End-Stage Liver Disease exception points, a pre-transplantation room-air PaO2 ≤ 44.0 mm Hg was associated with increased post-transplantation mortality. HPS Model for End-Stage Liver Disease exception patients had lower overall mortality compared with others awaiting liver transplantation, suggesting that the appropriateness of the HPS exception policy should be reassessed.

Endothelin-1 activation of the endothelin B receptor modulates pulmonary endothelial CX3CL1 and contributes to pulmonary angiogenesis in experimental hepatopulmonary syndrome

Hepatic production and release of endothelin-1 (ET-1) binding to endothelin B (ETB) receptors, overexpressed in the lung microvasculature, is associated with accumulation of pro-angiogenic monocytes and vascular remodeling in experimental hepatopulmonary syndrome (HPS) after common bile duct ligation (CBDL). We have recently found that lung vascular monocyte adhesion and angiogenesis in HPS involve interaction of endothelial C-X3-C motif ligand 1 (CX3CL1) with monocyte CX3C chemokine receptor 1 (CX3CR1), although whether ET-1/ETB receptor activation influences these events is unknown. Our aim was to define if ET-1/ETB receptor activation modulates CX3CL1/CX3CR1 signaling and lung angiogenesis in experimental HPS. A selective ETB receptor antagonist, BQ788, was given for 2 weeks to 1-week CBDL rats. ET-1 (±BQ788) was given to cultured rat pulmonary microvascular endothelial cells overexpressing ETB receptors. BQ788 treatment significantly decreased lung angiogenesis, monocyte accumulation, and CX3CL1 levels after CBDL. ET-1 treatment significantly induced CX3CL1 production in lung microvascular endothelial cells, which was blocked by inhibitors of Ca(2+) and mitogen-activated protein kinase (MEK)/ERK pathways. ET-1-induced ERK activation was Ca(2+) independent. ET-1 administration also increased endothelial tube formation in vitro, which was inhibited by BQ788 or by blocking Ca(2+) and MEK/ERK activation. CX3CR1 neutralizing antibody partially inhibited ET-1 effects on tube formation. These findings identify a novel mechanistic interaction between the ET-1/ETB receptor axis and CX3CL1/CX3CR1 in mediating pulmonary angiogenesis and vascular monocyte accumulation in experimental HPS.

Pulmonary complications in chronic liver disease

The association of chronic liver disease with respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease have been characterized: hepatopulmonary syndrome (HPS), portopulmonary hypertension (POPH), and hepatic hydrothorax (HH). The development of portal hypertension is fundamental in the pathogenesis of each of these disorders. HPS is the most common condition, found in 5%-30% of cirrhosis patients, manifested by abnormal oxygenation due to the development of intrapulmonary vascular dilatations. The presence of HPS increases mortality and impairs quality of life, but is reversible with liver transplantation (LT). POPH is characterized by development of pulmonary arterial hypertension in the setting of portal hypertension, and is present in 5%-10% of cirrhosis patients evaluated for LT. Screening for POPH in cirrhosis patients eligible for LT is critical since severe POPH is a relative contraindication for LT. Patients with moderate POPH, who respond adequately to medical therapy, may benefit from LT, although sufficient controlled data are lacking. HH is a transudative pleural effusion seen in 5%-10% of cirrhosis patients, in the absence of cardiopulmonary disease. Diagnosis of HH should prompt consideration for LT, which is the ultimate treatment for HH. Conservative management includes salt restriction and diuretics, with thoracentesis and transjugular intrahepatic portosystemic shunt (TIPS) as second-line therapeutic options.

The role of receptor tyrosine kinase activation in cholangiocytes and pulmonary vascular endothelium in experimental hepatopulmonary syndrome

Pulmonary vascular dilation and angiogenesis underlie experimental hepatopulmonary syndrome (HPS) induced by common bile duct ligation (CBDL) and may respond to receptor tyrosine kinase (RTK) inhibition. Vascular endothelial growth factor-A (VEGF-A) expression occurs in proliferating cholangiocytes and pulmonary intravascular monocytes after CBDL, the latter contributing to angiogenesis. CBDL cholangiocytes also produce endothelin-1 (ET-1), which triggers lung vascular endothelin B receptor-mediated endothelial nitric oxide synthase (eNOS) activation and pulmonary intravascular monocyte accumulation. However, whether RTK pathway activation directly regulates cholangiocyte and pulmonary microvascular alterations in experimental HPS is not defined. We assessed RTK pathway activation in cholangiocytes and lung after CBDL and the effects of the type II RTK inhibitor sorafenib in experimental HPS. Cholangiocyte VEGF-A expression and ERK activation accompanied proliferation and increased hepatic and circulating ET-1 levels after CBDL. Sorafenib decreased each of these events and led to a reduction in lung eNOS activation and intravascular monocyte accumulation. Lung monocyte VEGF-A expression and microvascular Akt and ERK activation were also found in vivo after CBDL, and VEGF-A activated Akt and ERK and angiogenesis in rat pulmonary microvascular endothelial cells in vitro. Sorafenib inhibited VEGF-A-mediated signaling and angiogenesis in vivo and in vitro and improved arterial gas exchange and intrapulmonary shunting. RTK activation in experimental HPS upregulates cholangiocyte proliferation and ET-1 production, leading to pulmonary microvascular eNOS activation, intravascular monocyte accumulation, and VEGF-A-mediated angiogenic signaling pathways. These findings identify a novel mechanism in cholangiocytes through which RTK inhibition ameliorates experimental HPS.

New consensus definition of acute kidney injury accurately predicts 30-day mortality in patients with cirrhosis and infection

BACKGROUND & AIMS

Participants at a consensus conference proposed defining cirrhosis-associated acute kidney injury (AKI) based on a >50% increase in serum creatinine level from the stable baseline value in <6 months or an increase of ≥ 0.3 mg/dL in <48 hours. We performed a prospective study to evaluate the ability of these criteria to predict mortality within 30 days of hospitalization among patients with cirrhosis and infection.

METHODS

We followed up 337 patients with cirrhosis who were admitted to the hospital with an infection or developed an infection during hospitalization (56% men; 56 ± 10 years of age; Model for End-Stage Liver Disease [MELD] score, 20 ± 8) at 12 centers in North America. We compared data on 30-day mortality, length of stay in the hospital, and organ failure between patients with and without AKI.

RESULTS

In total, based on the consensus criteria, 166 patients (49%) developed AKI during hospitalization. Patients who developed AKI were admitted with higher Child-Pugh scores than those who did not develop AKI (11.0 ± 2.1 vs 9.6 ± 2.1; P < .0001) as well as higher MELD scores (23 ± 8 vs 17 ± 7; P < .0001) and lower mean arterial pressure (81 ± 16 vs 85 ± 15 mm Hg; P < .01). Higher percentages of patients with AKI died within 30 days of hospitalization (34% vs 7%), were transferred to the intensive care unit (46% vs 20%), required ventilation (27% vs 6%), or went into shock (31% vs 8%); patients with AKI also had longer stays in the hospital (17.8 ± 19.8 vs 13.3 ± 31.8 days) (all P < .001). Of the AKI episodes, 56% were transient, 28% were persistent, and 16% resulted in dialysis. Mortality was higher among those without renal recovery (80%) compared with partial (40%) or complete recovery (15%) or those who did not develop AKI (7%; P < .0001).

CONCLUSIONS

Among patients with cirrhosis, 30-day mortality is 10-fold higher among those with irreversible AKI than those without AKI. The consensus definition of AKI accurately predicts 30-day mortality, length of hospital stay, and organ failure.

Muscle cramps in liver disease

Muscle cramps are common in patients with liver disease and adversely influence quality of life. The exact mechanisms by which they occur remain unclear, although a number of pathophysiological events unique to liver disease may contribute. Clinical studies have identified alterations in 3 areas: nerve function, energy metabolism, and plasma volume/electrolytes. Treatments have focused on these particular areas with varied results. This review will focus on the clinical features of muscle cramps in patients with liver disease and review potential mechanisms and current therapies.

Endoscopic retrograde cholangiopancreatography for suspected choledocholithiasis: testing the current guidelines

BACKGROUND

Current guidelines include an algorithm for predicting choledocholithiasis. Presence of any very strong predictor or both strong predictors confers a high (>50%) probability of choledocholithiasis. Absence of predictors confers low risk (<10%) of choledocholithiasis. Other combinations have an intermediate risk of choledocholithiasis.

AIM

Determine accuracy of the proposed algorithm in predicting choledocholithiasis.

METHODS

Retrospective analysis of all endoscopic retrograde cholangiopancreatographies performed for suspected choledocholithiasis in 3 years in a Tertiary care hospital and a community hospital serviced by The University of Texas Health Science Center at Houston Division of Gastroenterology. Application of the guidelines, and comparing results to endoscopic retrograde cholangiopancreatography findings.

RESULTS

A total of 1080 endoscopic retrograde cholangiopancreatographies were performed; 521 for choledocholithiasis. Most patients were Hispanic and female. Univariate analysis: presence of any very strong predictor and both strong predictors had an OR for choledocholithiasis of 3.30 and 2.36 respectively. Multivariate analysis: odds of choledocholithiasis with any very strong predictor was 2.87, and both strong predictors 3.24. Choledocholithiasis was present in 71.5%, and 41% of patients with high, and intermediate risk respectively.

CONCLUSION

This study confirms the utility of clinical predictors for the diagnosis of choledocholithiasis. All of the very strong predictors and one of the strong predictors increased the odds of choledocholithiasis. Patients with high risk for choledocholithiasis had a probability of 79% of choledocholithiasis. Sensitivity and specificity of current predictors are too low to obviate the possible need of non-invasive tests to confirm or exclude choledocholithiasis in all risk groups.

The lung in liver disease: old problem, new concepts

Liver dysfunction has been recognized to influence the lung in many different clinical situations, although the mechanisms for these effects are not well understood. One increasingly recognized interaction, the hepatopulmonary syndrome (HPS) occurs in the context of cirrhosis and results when alveolar microvascular dilation causes arterial gas exchange abnormalities and hypoxemia. HPS occurs in up to 30% of patients with cirrhosis and significantly increases mortality in affected patients. Currently, liver transplantation is the only curative therapy. Experimental biliary cirrhosis induced by common bile duct ligation (CBDL) in the rat reproduces the pulmonary vascular and gas exchange abnormalities of human HPS and has been contrasted with other experimental models of cirrhosis in which HPS does not develop. Microvascular dilation, intravascular monocyte infiltration, and angiogenesis in the lung have been identified as pathologic features that drive gas exchange abnormalities in experimental HPS. Our recent studies have identified biliary epithelium and activation and interaction between the endothelin-1 (ET-1)/endothelial endothelin B (ETB) receptor and CX3CL1/CX3CR1 pathways as important mechanisms for the observed pathologic events. These studies define novel interactions between the lung and liver in cirrhosis and may lead to effective medical therapies.