José Altamirano

Alcoholic liver disease: Pathogenesis and new targets for therapy

Alcoholic liver disease (ALD) is a major cause of morbidity and mortality worldwide. The spectrum of disease ranges from fatty liver to hepatic inflammation, necrosis, progressive fibrosis and hepatocellular carcinoma. In developed countries, ALD is a major cause of end-stage liver disease that requires transplantation. The most effective therapy for ALD is alcohol abstinence. However, for patients with severe forms of ALD (that is, alcoholic hepatitis) and for those who do not achieve abstinence from alcohol, targeted therapies are urgently needed. The development of new drugs for ALD is hampered by the scarcity of studies and the drawbacks of existing animal models, which do not reflect all the features of the human disease. However, translational research using liver samples from patients with ALD has identified new potential therapeutic targets, such as CXC chemokines, osteopontin and tumor necrosis factor receptor superfamily member 12A. The pathogenetic roles of these targets, however, remain to be confirmed in animal models. This Review summarizes the epidemiology, natural history, risk factors and current knowledge of the pathogenetic mechanisms of ALD. In addition, this article provides a detailed description of the findings of these translational studies and of the animal models used to study ALD.

A Histologic Scoring System for Prognosis of Patients With Alcoholic Hepatitis

BACKGROUND & AIMS There is no histologic classification system to determine prognoses of patients with alcoholic hepatitis (AH). We identified histologic features associated with disease severity and created a histologic scoring system to predict short-term (90-day) mortality. METHODS We analyzed data from 121 patients admitted to the Liver Unit (Hospital Clinic, Barcelona, Spain) from January 2000 to January 2008 with features of AH and developed a histologic scoring system to determine the risk of death using logistic regression. The system was tested and updated in a test set of 96 patients from 5 academic centers in the United States and Europe, and a semiquantitative scoring system called the Alcoholic Hepatitis Histologic Score (AHHS) was developed. The system was validated in an independent set of 109 patients. Interobserver agreement was evaluated by weighted κ statistical analysis. RESULTS The degree of fibrosis, degree of neutrophil infiltration, type of bilirubinostasis, and presence of megamitochondria were independently associated with 90-day mortality. We used these 4 parameters to develop the AHHS to identify patients with a low (0-3 points), moderate (4-5 points), or high (6-9 points) risk of death within 90 days (3%, 19%, and 51%, respectively; P < .0001). The AHHS estimated 90-day mortality in the training and test sets with an area under the receiver operating characteristic value of 0.77 (95% confidence interval, 0.71-0.83). Interrater agreement values were 0.65 for fibrosis, 0.86 for bilirubinostasis, 0.60 for neutrophil infiltration, and 0.46 for megamitochondria. Interestingly, the type of bilirubinostasis predicted the development of bacterial infections. CONCLUSIONS We identified histologic features associated with the severity of AH and developed a patient classification system that might be used in clinical decision making.

Systemic inflammatory response and serum lipopolysaccharide levels predict multiple organ failure and death in alcoholic hepatitis.

Alcoholic hepatitis (AH) frequently progresses to multiple organ failure (MOF) and death. However, the driving factors are largely unknown. At admission, patients with AH often show criteria of systemic inflammatory response syndrome (SIRS) even in the absence of an infection. We hypothesize that the presence of SIRS may predispose to MOF and death. To test this hypothesis, we studied a cohort including 162 patients with biopsy‐proven AH. The presence of SIRS and infections was assessed in all patients, and multivariate analyses identified variables independently associated with MOF and 90‐day mortality. At admission, 32 (19.8%) patients were diagnosed with a bacterial infection, while 75 (46.3%) fulfilled SIRS criteria; 58 patients (35.8%) developed MOF during hospitalization. Short‐term mortality was significantly higher among patients who developed MOF (62.1% versus 3.8%, P < 0.001). The presence of SIRS was a major predictor of MOF (odds ratio = 2.69, P = 0.025) and strongly correlated with mortality. Importantly, the course of patients with SIRS with and without infection was similar in terms of MOF development and short‐term mortality. Finally, we sought to identify serum markers that differentiate SIRS with and without infection. We studied serum levels of high‐sensitivity C‐reactive protein, procalcitonin, and lipopolysaccharide at admission. All of them predicted mortality. Procalcitonin, but not high‐sensitivity C‐reactive protein, serum levels identified those patients with SIRS and infection. Lipopolysaccharide serum levels predicted MOF and the response to prednisolone. Conclusion: In the presence or absence of infections, SIRS is a major determinant of MOF and mortality in AH, and the mechanisms involved in the development of SIRS should be investigated; procalcitonin serum levels can help to identify patients with infection, and lipopolysaccharide levels may help to predict mortality and the response to steroids. (Hepatology 2015;62:762–772)

Transcriptome analysis identifies TNF superfamily receptors as potential therapeutic targets in alcoholic hepatitis

Objective Alcoholic hepatitis (AH) is a severe clinical condition that needs novel therapies. The identification of targets for therapy is hampered by the lack of animal models of advanced AH. The authors performed a translational study through a transcriptome analysis in patients with AH to identify new molecular targets. Design Hepatic gene expression profiling was assessed by DNA microarray in patients with AH (n=15) and normal livers (n=7). Functional analysis was assessed by gene set enrichment analysis. Quantitative PCR was performed in patients with AH (n=40), hepatitis C (n=18), non-alcoholic steatohepatitis (n=20) and in mouse models of acute and chronic liver injury. Protein expression was assessed by immunohistochemistry and western blotting. Results Gene expression analysis showed 207 genes >5-fold differentially expressed in patients with AH and revealed seven pathways differentially regulated including ‘cytokine–cytokine receptor interaction’. Several tumour necrosis factor (TNF) superfamily receptors, but not ligands, were overexpressed in AH. Importantly, Fn14 was the only TNF superfamily receptor exclusively upregulated in AH compared with other liver diseases and correlated with both 90-day mortality and severity of portal hypertension. Fn14 protein expression was detected in areas of fibrogenesis and in a population of hepatocytes. Fn14 expression was increased in experimental models of liver injury and was detected in progenitor cells. Conclusion Translational research revealed that TNF superfamily receptors are overexpressed in AH. Fn14, the receptor for TNF-like weak inducer of apoptosis, is selectively upregulated in patients with AH. TNF superfamily receptors could represent a potential target for therapy.

Predicting Early Mortality After Acute Variceal Hemorrhage Based on Classification and Regression Tree Analysis

BACKGROUND & AIMS Available prognostic models for mortality after an acute variceal hemorrhage have limitations that restrict their clinical value. We assessed the performance of a novel prognostic approach based on classification and regression tree (CART) analysis. METHODS Logistic regression (LR) and CART analyses were performed to identify prognostic models for mortality at 6 weeks in a single-center cohort of 267 consecutive patients with acute variceal bleeding. Receiver operating characteristic (ROC) curves were constructed to assess the performance of the models. Prognostic models were fitted and validated by split-sample technique (training set, 164 patients, 2001-2005; test set, 103 patients, 2006-2008). RESULTS After 6 weeks, 21% of patients experienced rebleeding and 24% died. The best LR model was based on Child-Pugh score, creatinine level, bacterial infection, and hepatocellular carcinoma. CART analysis provided a simple algorithm based on the combined use of just 3 variables (Child-Pugh score, creatinine level, and bacterial infection), allowing accurate early discrimination of 3 distinct prognostic subgroups with 8% (low risk), 17% (intermediate), and 50% to 73% (high) mortality. Its accuracy was similar to the LR model (area under the ROC curves, 0.81 vs 0.84; P = .17) and better than that of Child-Pugh (0.75; P = .05) and model for end-stage liver disease (0.74; P = .05). The prognostic accuracy of both LR and CART models was validated in the test set (area under the ROC curve values, 0.81 and 0.83, respectively). CONCLUSIONS A simple CART algorithm based on Child-Pugh score, creatinine level, and infection allowed an accurate predictive assessment of 6-week mortality after acute variceal bleeding.

Liver progenitor cell markers correlate with liver damage and predict short-term mortality in patients with alcoholic hepatitis.

Alcoholic hepatitis (AH) is a severe condition developed in patients with underlying alcoholic liver disease. Ductular reaction has been associated with chronic alcohol consumption but there is no information regarding the extent of liver progenitor cell (LPC) proliferation in AH. The aim of this study was to investigate LPC markers in AH and its correlation with disease severity. Fifty‐nine patients with clinical and histological diagnosis of AH were included in the study. LPC markers were assessed by real‐time polymerase chain reaction (PCR) and immunohistochemistry. Standard logistic regression analysis and classification and regression trees (CART) analysis were used for statistical analysis. A microarray analysis showed an up‐regulation of LPC markers in patients with AH. Real‐time PCR demonstrated that epithelial cell adhesion molecule (EpCAM), Prominin‐1, and Keratin7 were significantly increased in patients with AH compared with normal livers (P ≤ 0.01), chronic hepatitis C (P ≤ 0.01), and HCV‐induced cirrhosis (P ≤ 0.01). Immunohistochemistry scores generated for Keratin7 and EpCAM demonstrated a good correlation with gene expression. Keratin7 gene expression correlated with liver failure as assessed by model for endstage liver disease score (r = 0.41, P = 0.006) and Maddreys discriminant function (r = 0.43, P = 0.004). Moreover, Keratin7 (OR1.14, P = 0.004) and Prominin‐1 (OR1.14, P = 0.002), but not EpCAM (OR1.16, P = 0.06), were identified as independent predictors of 90‐day mortality. CART analysis generated an algorithm based on the combination of Keratin7 and EpCAM gene expression that stratified three groups of patients with high, intermediate, and low short‐term mortality (89%, 33%, and 6%, respectively; area under the receiver operating curve 0.73, 95% confidence interval 0.60‐0.87). Keratin7 expression provided additional discrimination potential to the age, bilirubin, international normalization ratio, creatinine (ABIC) score. Conclusion: LPC markers correlate positively with severity of liver disease and short‐term mortality in AH patients. This study suggests that LPC proliferation may be an important feature of AH pathophysiology. (HEPATOLOGY 2012;55:1931–1941)

Acute Kidney Injury Is an Early Predictor of Mortality for Patients With Alcoholic Hepatitis

BACKGROUND & AIMS Alcoholic hepatitis (AH) is a severe condition with high mortality. To improve therapeutic strategies, it is important to identify factors that affect survival times. The age, bilirubin, international normalized ratio, and creatinine scoring system (also known as the ABIC scoring system) was developed previously to determine the prognosis of patients with AH. We studied effects of acute kidney injury (AKI) on survival of patients with AH. METHODS We retrospectively analyzed data from 103 patients with biopsy-proven AH. AKI was defined as an abrupt reduction (within 48 h) in kidney function that resulted in an absolute increase of at least 0.3 mg/dL (or a 50% increase) in serum levels of creatinine from baseline (the AKI network [AKIN] criteria). RESULTS Twenty-nine patients (28%) developed AKI during hospitalization, with a median time to diagnosis of 3 days. Overall 90-day mortality was 23%, which was significantly higher among patients with AKI than those without (65% vs 7%; P < .0001). The age, bilirubin, international normalized ratio, and creatinine score (P < .0001) and development of AKI (P < .0001) were the most accurate independent predictors of 90-day mortality. The presence of systemic inflammatory response syndrome (P < .0001), serum bilirubin (P = .01), and international normalized ratio at admission (P = .03) were the most accurate predictors of AKI. Importantly, the AKIN criteria were more accurate than traditional criteria for renal failure (serum creatinine >1.5 mg/dL) in predicting 90-day mortality (area under the receiver operating characteristic, 0.83 vs 0.70, respectively; P = .02). CONCLUSIONS Development of AKI reduces survival of patients with AH, in the short term. The AKIN criteria are useful and more accurate than traditional criteria in predicting mortality. Strategies to prevent AKI therefore should be considered in the management of patients with AH.

Effectiveness of Combined Pharmacologic and Ligation Therapy in High-Risk Patients With Acute Esophageal Variceal Bleeding

OBJECTIVES:After an acute variceal bleeding, early decision for aggressive management of patients with worse prognosis may improve outcomes. The effectiveness of currently recommended standard therapy (drugs plus endoscopic ligation) for different risk subgroups and the validity of available risk criteria in clinical practice are unknown.METHODS:We analyzed data of 301 consecutive cirrhotic patients admitted with esophageal variceal bleeding. All patients received antibiotics, somatostatin, and in 263 early endoscopic therapy. A stratified 6-week mortality assessment according to risk (low-risk: Child-Pugh B without active bleeding or Child-Pugh A; high-risk: Child-Pugh B with active bleeding or Child-Pugh C) was performed. A multivariate analysis was conducted to elaborate a new risk classification rule.RESULTS:Among the 162 patients receiving emergency ligation, 14% rebled and 16% died. Standard therapy was very effective in all risk strata, even in high-risk patients, specially if eligible for therapeutic trials (child <14, age ≤75 years, creatinine ≤3.0 mg/dl, no hepatocellular carcinoma, or portal thrombosis), showing this stratum a 10% mortality. In patients receiving ligation, Child-Pugh C patients with baseline creatinine <1.0 mg/dl showed similar mortality to Child-Pugh A or B patients (8% vs. 7%, respectively). Only Child-Pugh C patients with creatinine ≥1.0 were at a significant higher risk (Child-Pugh C: 46% mortality if creatinine ≥1.0 vs. 8% if creatinine <1.0, P=0.006).CONCLUSIONS:The combination of somatostatin, antibiotics, and endoscopic ligation after an acute variceal bleeding in a real-life situation is associated with very low mortality. Child-Pugh C patients with baseline creatinine ≥1.0 mg/dl should be considered high-risk patients in this setting.

CCL20 mediates lipopolysaccharide induced liver injury and is a potential driver of inflammation and fibrosis in alcoholic hepatitis

Objective Chemokines are known to play an important role in the pathophysiology of alcoholic hepatitis (AH), a form of acute-on-chronic liver injury frequently mediated by gut derived lipopolysaccharide (LPS). In our study, we hypothesise that chemokine CCL20, one of the most upregulated chemokines in patients with AH, is implicated in the pathogenesis of AH by mediating LPS induced liver injury. Design CCL20 gene expression and serum levels and their correlation with disease severity were assessed in patients with AH. Cellular sources of CCL20 and its biological effects were evaluated in vitro and in vivo in chronic, acute and acute-on-chronic experimental models of carbon tetrachloride and LPS induced liver injury. RNA interference technology was used to knockdown CCL20 in vivo. Results CCL20 hepatic and serum levels were increased in patients with AH and correlated with the degree of fibrosis, portal hypertension, endotoxaemia, disease severity scores and short term mortality. Moreover, CCL20 expression was increased in animal models of liver injury and particularly under acute-on-chronic conditions. Macrophages and hepatic stellate cells (HSCs) were identified as the main CCL20 producing cell types. Silencing CCL20 in vivo reduced LPS induced aspartate aminotransferase and lactate dehydrogenase serum levels and hepatic proinflammatory and profibrogenic genes. CCL20 induced proinflammatory and profibrogenic effects in cultured primary HSCs. Conclusions Our results suggest that CCL20 upregulation is strongly associated with LPS and may not only represent a new potential biomarker to predict outcome in patients with AH but also an important mediator linking hepatic inflammation, injury and fibrosis in AH.

Inhibition of Placental Growth Factor Activity Reduces the Severity of Fibrosis, Inflammation, and Portal Hypertension in Cirrhotic Mice

Placental growth factor (PlGF) is associated selectively with pathological angiogenesis, and PlGF blockade does not affect the healthy vasculature. Anti‐PlGF is therefore currently being clinically evaluated for the treatment of cancer patients. In cirrhosis, hepatic fibrogenesis is accompanied by extensive angiogenesis. In this paper, we evaluated the pathophysiological role of PlGF and the therapeutic potential of anti‐PlGF in liver cirrhosis. PlGF was significantly up‐regulated in the CCl4‐induced rodent model of liver cirrhosis as well as in cirrhotic patients. Compared with wild‐type animals, cirrhotic PlGF−/− mice showed a significant reduction in angiogenesis, arteriogenesis, inflammation, fibrosis, and portal hypertension. Importantly, pharmacological inhibition with anti‐PlGF antibodies yielded similar results as genetic loss of PlGF. Notably, PlGF treatment of activated hepatic stellate cells induced sustained extracellular signal‐regulated kinase 1/2 phosphorylation, as well as chemotaxis and proliferation, indicating a previously unrecognized profibrogenic role of PlGF. Conclusion: PlGF is a disease‐candidate gene in liver cirrhosis, and inhibition of PlGF offers a therapeutic alternative with an attractive safety profile. (HEPATOLOGY 2011;)