Dendritic cell regulation of carbon tetrachloride-induced murine liver fibrosis regression

Although hepatic fibrosis typically follows chronic inflammation, fibrosis will often regress after cessation of liver injury. In this study, we examined whether liver dendritic cells (DCs) play a role in liver fibrosis regression using carbon tetrachloride to induce liver injury. We examined DC dynamics during fibrosis regression and their capacity to modulate liver fibrosis regression upon cessation of injury. We show that conditional DC depletion soon after discontinuation of the liver insult leads to delayed fibrosis regression and reduced clearance of activated hepatic stellate cells, the key fibrogenic cell in the liver. Conversely, DC expansion induced either by Flt3L (fms-like tyrosine kinase-3 ligand) or adoptive transfer of purified DCs accelerates liver fibrosis regression. DC modulation of fibrosis was partially dependent on matrix metalloproteinase (MMP)-9, because MMP-9 inhibition abolished the Flt3L-mediated effect and the ability of transferred DCs to accelerate fibrosis regression. In contrast, transfer of DCs from MMP-9-deficient mice failed to improve fibrosis regression. CONCLUSION: Taken together, these results suggest that DCs increase fibrosis regression and that the effect is correlated with their production of MMP-9. The results also suggest that Flt3L treatment during fibrosis resolution merits evaluation to accelerate regression of advanced liver fibrosis.     

Liver fibrosis markers of nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is one of the major causes of chronic liver injury. NAFLD includes a wide range of clinical conditions from simple steatosis to nonalcoholic steatohepatitis (NASH), advanced fibrosis, and liver cirrhosis. The histological findings of NASH indicate hepatic steatosis and inflammation with characteristic hepatocyte injury (e.g., ballooning degeneration), as is observed in the patients with alcoholic liver disease. NASH is considered to be a potentially health-threatening disease that can progress to cirrhosis. A liver biopsy remains the most reliable diagnostic method to appropriately diagnose NASH, evaluate the severity of liver fibrosis, and determine the prognosis and optimal treatment. However, this invasive technique is associated with several limitations in routine use, and a number of biomarkers have been developed in order to predict the degree of liver fibrosis. In the present article, we review the current status of noninvasive biomarkers available to estimate liver fibrosis in the patients with NASH. We also discuss our recent findings on the use of the glycated albumin-to-glycated hemoglobin ratio, which is a new index that correlates to various chronic liver diseases, including NASH.     

Paediatric cholestatic liver disease: Diagnosis, assessment of disease progression and mechanisms of fibrogenesis

Cholestatic liver disease causes significant morbidity and mortality in children. The diagnosis and management of these diseases can be complicated by an inability to detect early stages of fibrosis and a lack of adequate interventional therapy. There is no single gold standard test that accurately reflects the presence of liver disease, or that can be used to monitor fibrosis progression, particularly in conditions such as cystic fibrosis. This has lead to controversy over how suspected liver disease in children is detected and diagnosed. This review discusses the challenges in using commonly available methods to diagnose hepatic fibrosis and monitor disease progression in children with cholestatic liver disease. In addition, the review examines the mechanisms hypothesised to be involved in the development of hepatic fibrogenesis in paediatric cholestatic liver injury which may ultimately aid in identifying new modalities to assist in both disease detection and therapeutic intervention.     

Association of hepatic iron deposition and serum iron indices with hepatic inflammation and fibrosis stage in nonalcoholic fatty liver disease]

BACKGROUND/AIMS: Nonalcoholic steatohepatitis can develop from nonalcoholic fatty liver and progress to severe liver disease such as cirrhosis. The mechanism determining the progression from fatty liver to steatohepatitis is unknown. Iron is suspected to enhance hepatic damage associated with nonalcoholic fatty liver disease (NAFLD). The aims of this study were to evaluate the relationship of serum iron indices and hepatic iron deposition with hepatic fibrosis or inflammation, and to assess whether the increased hepatic iron deposition is an independent predictor of progression to liver injury. METHODS: The biochemical and histopathological data of thirty-nine patients with NAFLD were analyzed. Liver biopsy findings were graded according to the method described by Brunt, et al. Hepatic iron concentration was available in 29 of 39 patients. RESULTS: The mean hepatic iron concentration and hepatic iron indices were 1,349+/-1,188 microg/g dry weight and 0.9+/-0.7 microg/g/age. Serum ferritin and body mass indices were associated with hepatic inflammation (p=0.001, p=0.006) and fibrosis (p=0.005, p=0.013). Hepatic iron concentration and hepatic iron index were not associated with hepatic inflammation and fibrosis. Multivariate analysis did not identify serum ferritin or body mass index as an independent predictor of liver injury. CONCLUSIONS: Hepatic iron deposition shows no association with the degree of hepatic inflammation or fibrosis. Hepatic iron is not an independent predictor of hepatic injury in patients with NAFLD.     

移植前终末期肝病模型评分与肝纤维化程度的相关性研究

目的 通过将临床终末期肝病模型(MELD)评分及Ishak病理学肝纤维化分级的相关性进行比较,探讨运用MELD评分评估肝移植患者肝纤维化程度的可行性.方法 采用计算机辅助图像分析法,定量评估华西医院2006年2至9月58例因终末期肝病接受肝移植手术者病肝标本的纤维化程度,同时运用改良Ishak肝纤维化分级法进行病理学诊断;收集入院当天的临床资料,计算MELD评分,利用Spearman等级相关分析法分析图像法、Ishak分级、MELD评分三者间的相关性,利用直线回归分析MELD评分与肝纤维化程度二者之间有无线性依存关系.按其结果 拟定参考标准.结果 图像分析法测定58例患者病肝标本的肝纤维化百分比为23.2%～88.4%,平均56.7%;入院当天的MELD评分为11～38分,平均22.85±9.32;Ishak分级0～6级者分别为0、2、7、12、18、12、7例,随着Ishak级数加大,肝纤维化百分比渐增,MELD评分逐步增高,Spearman等级相关分析表明其相关性有统计学意义(P＜0.01),利用直线回归分析MELD评分与肝纤维化程度二者之间也存在线性依存关系.结论 图像分析法能较准确地评估肝组织纤维化程度,与MELD评分有良好的相关性,运用MELD评分系统能对肝移植患者肝组织纤维化的严重程度进行评估.     

Hepatitis B-associated fibrosis and fibrosis/cirrhosis regression with nucleoside and nucleotide analogs

Hepatitis B virus (HBV) infection currently accounts for approximately 600,000 deaths per year resulting from progression of liver fibrosis to cirrhosis and hepatocellular carcinoma. Treatment of chronic hepatitis B with antiviral agents aims to improve survival through the reduction of HBV DNA to undetectable levels and the resultant prevention of disease progression. In recent years, observations in various disease areas have shown that liver fibrosis can be reversed if the underlying cause of the liver damage is effectively addressed. In line with these observations, there is now considerable evidence to suggest that effective sustained suppression of HBV replication with long-term anti-HBV treatment can result in measurable improvements in liver fibrosis over time, even in patients with advanced cirrhosis. This review article provides an overview of currently available data on regression of fibrosis and cirrhosis in patients with chronic hepatitis B treated with nucleoside and nucleotide analog inhibitors of HBV.     

Magnetic resonance imaging of hepatic fibrosis: emerging clinical applications

Chronic liver disease and cirrhosis remains a major public health problem worldwide. While the majority of complications from chronic liver disease result from progressive hepatic fibrosis, the available diagnostic tests used in clinical practice are not sensitive or specific enough to detect occult liver injury at early or intermediate stages. While liver biopsy can stage the extent of fibrosis at diagnosis, its utility as a tool for longitudinal monitoring will be limited at the population level. To date, a number of methods including serum marker panels and ultrasound-based transient elastrography have been proposed for the non-invasive identification of hepatic fibrosis. Novel techniques including magnetic resonance (MR) spectroscopy, diffusion weighted MR, and MR elastography have also emerged for detecting fibrosis. In contrast to other non-invasive methods, MR imaging holds the promise of providing functional and biological information about hepatic pathophysiology as it relates to the natural history and future treatment of hepatic fibrosis. (HEPATOLOGY 2007.).     

Obesity and fatty liver are 'grease' for the machinery of hepatic fibrosis

Nonalcoholic fatty liver disease (NAFLD) starts with hepatic steatosis, which can progress with inflammation to nonalcoholic steatohepatitis, and a subset of patients develop progressive fibrosis and ultimately cirrhosis. In the majority of cases, NAFLD is associated with (components of) the metabolic syndrome. Obesity, diabetes and hepatic steatosis are also independent risk factors for hepatic fibrosis in different chronic liver diseases. However, the question is whether it is actually nonalcoholic steatohepatitis and not 'simple' steatosis that promotes fibrosis progression based on hepatocellular injury. In this review, the concept will be put forward that (1) hepatic steatosis per se is profibrogenic, and (2) that in NAFLD development and progression of hepatic fibrosis is not simply determined by (the degree of) hepatic inflammation. In addition to the liver, this view is expanded to other organs affected by the metabolic syndrome, which affects hepatic injury and fibrosis also via extrahepatic pathophysiological alterations. In conclusion, fatty liver and the metabolic syndrome, respectively, have to be recognized as significant lubricants of hepatic fibrosis, and simple hepatic steatosis cannot be considered as benign.     

Vitamin A deficiency in chronic cholestatic liver disease: Is vitamin A therapy beneficial?

Chronic cholestatic diseases are progressive diseases of the biliary tract that cause hepatic fibrosis and ultimately lead to liver failure. Liver transplantation is the sole curative option currently available, and because of high morbidity and mortality rates of these diseases, new therapeutic approaches are needed. Vitamin A is a nutrient essential for health as it regulates many processes, including epithelial growth and immunological processes. Vitamin A is primarily stored in hepatic stellate cells, and during liver injury, through an unknown mechanism, these cells lose vitamin A and convert into collagen‐producing myofibroblasts, which contributes to hepatic fibrosis. Vitamin A deficiencies in chronic cholestatic diseases have been frequently reported, and therefore, retinoid metabolism has attracted a lot of attention. Retinoids have been shown to attenuate or even prevent hepatic fibrosis, and to regulate hepatic immunological response to cholestatic injury in different rodent models of chronic cholestasis. Recently, their potential as therapeutic drugs in primary sclerosing cholangitis patients was analyzed. The aim of this review is to summarize the existing knowledge and hypotheses about vitamin A role and the disease progression in cholestatic liver disease.     

Potential use of metabolic breath tests to assess liver disease and prognosis: has the time arrived for routine use in the clinic?

The progression of liver disease may be unique among organ system diseases in that progressive fibrosis compromises not only the sufficiency of hepatocyte mass but also impairs blood flow to the liver, resulting in porto‐systemic shunting. Although liver biopsy as an assessment of fibrosis has become the key biomarker of and target for new therapies, it is invasive and subject to sampling error, and cannot quantify metabolic function or porto‐systemic shunting. Measurement of the hepatic venous pressure gradient accommodates some of the deficiencies of biopsy but requires expertise not widely available and misses minor changes in hepatocellular mass and thereby information about metabolic function. Thus, an unmet need in clinical hepatology remains unfulfilled: a noninvasive biomarker which quantitates both the hepatocellular insufficiency and porto‐systemic shunting inherent in progressive hepatic fibrosis. Ideally, such a biomarker should correlate with clinical endpoints including liver‐related survival and cirrhotic complications, be performed at the point‐of‐care, and be affordable and easy to use. This review, an expert opinion, summarizes background and recent data suggesting that metabolic breath tests may now meet these requirements and have a valid place in clinical hepatology to supplant the time‐honoured assessment of hepatic fibrosis.     

Peroxisome proliferator-activated receptor alpha protects against alcohol-induced liver damage

The mechanisms underlying alcoholic liver disease are not completely understood, but lipid accumulation seems to be central to the cause of this disease. The peroxisome proliferator-activated receptor alpha (PPARalpha) plays an important role in the control of lipid homeostasis, metabolism of bioactive molecules, and modulation of inflammatory responses. To investigate the roles of PPARalpha in alcoholic liver injury, wild-type and PPARalpha-null mice were continuously fed a diet containing 4% ethanol, and liver injury was analyzed. PPARalpha-null mice fed ethanol exhibited marked hepatomegaly, hepatic inflammation, cell toxicity, fibrosis, apoptosis, and mitochondrial swelling. Some of these hepatic abnormalities were consistent with those of patients with alcoholic liver injury and were not found in wild-type mice. Next, the molecular mechanisms of ethanol-induced liver injury in PPARalpha-null mice were investigated, and changes related to ethanol and acetaldehyde metabolism, oxidative stress, inflammation, hepatocyte proliferation, fibrosis, and mitochondrial permeability transition activation occurred specifically in PPARalpha-null mice as compared with wild-type mice. In conclusion, these studies suggest a protective role for PPARalpha in alcoholic liver disease. Humans may be more susceptible to liver toxicity induced by ethanol as PPARalpha expression in human liver is considerably lower compared to that of rodents.     

Tegafur-uracil-induced rapid development of advanced hepatic fibrosis

Tegafur-uracil has been reported to have only minor adverse effects and is associated with liver injury in 1.79% of Japanese patients. The development of tegafur-uracil-induced hepatic fibrosis with portal hypertension is rare. Here, we report a case of a 74-year-old woman with rapidly developing tegafururacil-induced hepatic fibrosis. The patient had no history of liver disease and had been treated with tegafur-uracil for 8 mo after breast cancer surgery. The patient was admitted to our hospital for abdominal distension and leg edema associated with liver dysfunction. Computed tomography imaging revealed massive ascites and splenomegaly, and a non-invasive assessment of liver fibrosis indicated advanced fibrosis. The histopathological findings revealed periportal fibrosis and bridging fibrosis with septation. The massive ascites resolved after discontinuing tegafururacil. These findings suggest that advanced hepatic fibrosis can develop from a relatively short-term administration of tegafur-uracil and that non-invasive assessment is useful for predicting hepatic fibrosis.     

Long-term histologic follow-up study of alcoholic liver disease.

Forty Japanese patients with alcoholic liver disease (nonspecific change, 9; fatty liver, 5; hepatic fibrosis, 4; chronic hepatitis, 12; alcoholic hepatitis, 5; liver cirrhosis, 5) were followed for 3-17 yr (average 8 yr) with repeated liver biopsies (2-5 times; average 2.5 times) at intervals of more than 3 yr. All of the patients continued to consume alcohol during this observation period. Five out of 12 patients with chronic hepatitis and 2 of 5 patients with alcoholic hepatitis eventually progressed to cirrhosis, while none of the 4 patients with hepatic fibrosis became cirrhotic. Anti-hepatitis C virus antibody was positive in 2 patients with liver cirrhosis among 12 patients whose sera were available. Two patients with cirrhosis died of hepatic failure and one patient died of hepatocellular carcinoma. These data suggest that the long-term prognosis of alcoholic liver disease is not necessarily poor, but patients with chronic hepatitis or alcoholic hepatitis can be at risk of progression to cirrhosis.     

Genetic determinants in hepatic fibrosis: from experimental models to fibrogenic gene signatures in humans

Hepatic fibrosis, or scarring of the liver, is a nonspecific reaction to chronic liver injury. Hepatic fibrosis is commonly caused by exogenous factors such as viral hepatitis or alcohol abuse, but recent studies also indicate a genetic predisposition. Although some patients who have chronic liver diseases show only minor morphologic and functional alterations of the liver and are characterized by slow progression of disease with mild clinical symptoms, others develop pronounced hepatic fibrosis rapidly, culminating in cirrhosis, liver failure, or hepatocellular carcinoma, respectively. These well known differences in progression of hepatic fibrosis persist when controlling for age (at infection), gender, and exogenous factors in multivariate analysis, indicating that genetic factors might play important roles in the modulation of hepatic fibrosis and contribute to the variability in fibrosis progression. This review summarizes genetic determinants in hepatic fibrosis.     

Up-regulated eotaxin plasma levels in chronic liver disease patients indicate hepatic inflammation, advanced fibrosis and adverse clinical course

BACKGROUND AND AIMS: Recent studies highlight the role of chemokines for the attraction of inflammatory cells in liver injury and fibrogenesis. The CC chemokine ligand 11, eotaxin (CCL11), is up-regulated in senescent human hepatic stellate cells and crucial in animal models of T-cell mediated hepatitis. The aim of this study was to analyze the role of eotaxin in chronic liver disease. METHODS: Plasma eotaxin levels of 111 patients with chronic liver disease were correlated with clinical presentation, laboratory parameters, liver histology and clinical course in a 6-year follow-up. RESULTS: Eotaxin concentrations were significantly up-regulated in patients with liver cirrhosis and increased according to Child-Pugh and model of end-stage liver disease (MELD) score. Eotaxin correlated with the hepatic biosynthetic capacity and other inflammatory cytokines. High eotaxin was associated with hepatic necroinflammation and fibrosis in liver histology. In patients with typical clinical complications of cirrhosis, eotaxin was found to be increased. High eotaxin indicated an unfavorable prognosis in 6-year follow-up. CONCLUSIONS: High eotaxin expression may be involved in the pathogenesis of chronic liver diseases. Plasma eotaxin levels correlate with the degree of liver cirrhosis and could serve as an additional biomarker indicating histological hepatic necroinflammation and fibrosis as well as an adverse clinical course.     

Pathophysiological similarities and synergisms in alcoholic and non-alcoholic steatohepatitis

Chronic alcohol consumption is one of the main etiological factors for liver disease worldwide, however only a fraction of drinkers develop significant hepatic inflammation (alcoholic steatohepatitis), and even less progress to significant hepatic fibrosis and cirrhosis. The pathophysiological significance of hepatic lipid accumulation in the absence of significant alcohol consumption is also increasingly recognized. Non-alcoholic fatty liver disease (NAFLD) is regarded as the hepatic manifestation of the metabolic syndrome, and it is the most common cause of liver enzyme elevations in Western countries. Similarly to alcoholic liver disease, NAFLD encompasses mild hepatic steatosis to non-alcoholic steatohepatitis with significant necroinflammation and progressive fibrosis. Several clinical studies suggest a strong causative link between the consumption of alcohol and progressive liver disease in individuals with high fat intake and/or diabetes. However, it is incompletely understood how alcohol and obesity interact and whether the combined effects on the progression of liver injury are additive or synergistic. This review describes single as well as combined effects of alcohol and (components of) the metabolic syndrome on hepatic steatosis, inflammation and fibrosis. In addition to direct effects on the liver, the view is expanded to other organs affected by chronic alcohol consumption or the metabolic syndrome, to understand also extrahepatic pathophysiological mechanisms involved in hepatocellular injury. Undoubtedly, alcohol and the metabolic syndrome appear as a dangerous mix, and there are important synergistic effects of either condition with regard to crucial triggers of liver injury.     

Clinicopathological Study of Alcoholic Fibrosis

Among 112 patients with alcoholic liver injury, 45 had alcoholic fibrosis. The incidence of alcoholic fibrosis was 40.2% which was the highest among various types of alcoholic liver injury (fatty liver: 3.6%, alcoholic hepatitis; 2.7% and liver cirrhosis: 31.3%). Clinical features of alcoholic fibrosis were milder than those of liver cirrhosis and more severe than those of fatty liver. The mean laboratory values in alcoholic fibrosis were significantly different from those in fatty liver and liver cirrhosis. The laboratory data were well correlated with the presence of pericellular fibrosis and thickening of the terminal hepatic venule, but only partially with hepatic cell necrosis and not with fatty metamorphosis. Two patients with alcoholic fibrosis who developed cirrhosis without any clinical and histological features of hepatitis were observed during 5-yr follow-up. These results indicate that alcoholic fibrosis is the most common type of alcoholic liver injury in Japan and is an independent clinicopathological entity distinct from the classical types of alcoholic liver injury. Pericellular fibrosis and thickening of the terminal hepatic venule which are the main histological features of alcoholic fibrosis may play an important role in its transition to liver cirrhosis.     

The role of hypercoagulability in liver fibrogenesis

The development of hepatic fibrosis on a background of chronic liver injury represents a complex disease trait modulated through the interaction of host genetic factors and environmental influences. Early observations that hepatic inflammation and cirrhosis are associated with the presence of microthrombi within the hepatic vasculature and fibrin/fibrinogen deposition were followed by epidemiological studies showing that carriage of the Factor V Leiden (FvL) mutation, protein C deficiency and increased expression of factor VIII are associated with accelerated progression to cirrhosis in a chronic hepatitis C infection. Additional data suggest that these factors may influence fibrogenesis in many forms of chronic liver disease and extra-hepatic fibrotic processes. Drawing evidence both from liver research and studies of fibrogenesis in other organ systems, two hypotheses may explain how activity of the coagulation cascade influences the rate of hepatic fibrogenesis: tissue ischaemia and parenchymal extinction and direct thrombin mediated stellate cell activation via PAR-1 cleavage. Drawing on preclinical and clinical studies we discuss the evidence for a role for coagulation cascade activity in hepatic fibrogenesis and explore the proposed pathogenic mechanisms that lead to stellate cell activation. The corollary of an association between hypercoagulation and increased fibrosis is that interference with the coagulation cascade may reduce hepatic fibrosis. We conclude this article by examining the implications for future therapeutic intervention.     

Hepatitis C virus infection in children in the era of directacting antiviral

Hepatitis C virus(HCV) infection remains an important global health problem with chronic infection affecting approximately 11 million children worldwide. The emergence of direct-acting antiviral(DAA) therapies and the development of non-invasive methods for the determination of liver fibrosis will significantly improve the management of paediatric patients with chronic HCV infection in subsequent years. For paediatric patients, a new era of highly effective DAA agents is beginning, and the first results of available clinical trials are very promising. In this era, the identification and monitoring of patients continues to be an important issue. The availability of non-invasive serological and imaging methods to measure hepatic fibrosis enables the identification of patients with significant or advanced liver fibrosis stages. This article summarizes the current data on the epidemiology and progress of research aimed to evaluate the new therapies and non-invasive methods for liver injury in paediatric patients with chronic hepatitis C.