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Background: The FIB4 index is clinically useful, but because its formula includes age, the appropriate cutoff point may differ by age group. Here, new FIB4 index cutoff points were validated using cohort data from 14 hepatology centers in Japan., Methods: The FIB4 index was determined in biopsy-confirmed NAFLD patients (n = 1050) who were divided into four groups: ≤ 49, 50-59, 60-69, and ≥ 70 years. ROC analysis predicted advanced fibrosis in each age group; low and high cutoff points were defined by a sensitivity and specificity of 90%. The new and conventional cutoffs were compared for detecting advanced fibrosis., Results: The modified low and high cutoff points were 1.05 and 1.21 in ≤ 49 years, 1.24 and 1.96 in 50-59 years, 1.88 and 3.24 in 60-69 years, and 1.95 and 4.56 in ≥ 70 years. In ≥ 60 years, the false-negative rate was increased using the modified high cutoff point, and the high cutoff point was better with the conventional cutoff point. The new proposed low and high cutoff points are 1.05 and 1.21 in ≤ 49 years, 1.24 and 1.96 in 50-59 years, 1.88 and 2.67 in 60-69 years, and 1.95 and 2.67 in ≥ 70 years; these cutoff points improved the accuracy of advanced fibrosis diagnosis., Conclusions: FIB4 index cutoff points for predicting advanced fibrosis in NAFLD increased with age. Cutoff points modified by age improved the diagnostic accuracy of estimations of advanced liver fibrosis using the FIB4 index.

The coauthor Masashi Yoneda's affiliation has been incorrectly published in the original publication of the article. The correct affiliation is provided in this correction.

Background: In Japan, the prevalence of hepatocellular carcinoma (HCC) associated with nonviral liver disease, especially with nonalcoholic fatty liver disease (NAFLD-HCC) and alcoholic liver disease (ALD-HCC), has been increasing. Clarification of the clinical features of NAFLD-HCC and ALD-HCC is needed. We performed a large retrospective multicenter survey to clarify the clinical course of these two types of HCC., Methods: Clinical characteristics, survival, and recurrence were examined in 532 patients with ALD-HCC and 209 patients with NAFLD-HCC who were diagnosed between January 2000 and December 2013., Results: The ALD-HCC patients were predominantly male and were younger than the patients with NAFLD-HCC. Lifestyle-related diseases were significantly more common in the NAFLD-HCC group, but the prevalence of cirrhosis was significantly higher in the ALD-HCC group. The histological diagnosis of NAFLD-HCC showed a gender difference (F4; 72.7 % in the females vs. 37.6 % in the males). The characteristic features of HCC including histology, survival rate, and recurrence rate were quite similar in the NAFLD-HCC and ALD-HCC groups: 5-year survival rates 49.1 vs. 43.7 %; 5-year recurrence rates 69.6 vs. 65.4 %, respectively. However, the risk factors for recurrence differed between the two groups: des-gamma-carboxy prothrombin was a risk factor in NAFLD-HCC and α-fetoprotein was a risk factor in ALD-HCC., Conclusions: Although the characteristic features underlying these two diseases are different, the two HCC groups showed a similar clinical course. The recurrence rates of the two HCC groups were relatively high. We found that critical tumor markers for recurrence differed between the two diseases.

Background: Fatty liver is an important clinical feature not only in alcoholic and non-alcoholic fatty liver diseases, but in other chronic liver diseases as well. Our aim was to elucidate the effect and relationship between habitual alcohol intake and obesity in the development of fatty liver disease., Methods: We enrolled 8,029 subjects undergoing abdominal ultrasonography with general medical examinations, and analyzed the factors associated with fatty liver based on daily alcohol intake, body mass index (BMI), and waist circumference., Results: For fatty liver, BMI, waist circumference, total cholesterol, triglycerides, and fasting plasma glucose were significant and independent risk factors. Heavy alcohol intake (50 g/day) was a significant risk factor for fatty liver in women (odds ratio [OR], 3.35). Analysis based on the presence or absence of obesity revealed that moderate alcohol intake was a significant negative risk factor for fatty liver in both male and female obese (BMI ≥25 kg/m(2)) subjects (OR, 0.74 for non-obese and 0.39 for obese patients, respectively). Heavy alcohol intake was also a significant negative risk factor in obese males (0.62). In contrast, heavy alcohol intake was a risk factor in non-obese males (OR, 1.29) and in all females (OR, 2.22 for non-obese and 6.6 for obese patients, respectively)., Conclusions: The influence of alcohol intake on fatty liver differed depending on the level of alcohol consumption, gender, and the presence of obesity, and showed biphasic effects.

Nonalcoholic fatty liver disease (NAFLD) is currently the most common cause of chronic liver disease in industrialized countries worldwide, and has become a serious public health issue not only in Western countries but also in many Asian countries including Japan. Within the wide spectrum of NAFLD, nonalcoholic steatohepatitis (NASH) is a progressive form of disease, which often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma. In turn, a large proportion of NAFLD/NASH is the liver manifestation of metabolic syndrome, suggesting that NAFLD/NASH plays a key role in the pathogenesis of systemic atherosclerotic diseases. Currently, a definite diagnosis of NASH requires liver biopsy, though various noninvasive measures are under development. The mainstays of prevention and treatment of NAFLD/NASH include dietary restriction and exercise; however, pharmacological approaches are often necessary. Currently, vitamin E and thiazolidinedione derivatives are the most evidence-based therapeutic options, although the clinical evidence for long-term efficacy and safety is limited. This practice guideline for NAFLD/NASH, established by the Japanese Society of Gastroenterology in cooperation with The Japan Society of Hepatology, covers lines of clinical evidence reported internationally in the period starting from 1983 to January 2012, and each clinical question was evaluated using the GRADE system. Based on the primary release of the full version in Japanese, this English summary provides the core essentials of this clinical practice guideline comprising the definition, diagnosis, and current therapeutic recommendations for NAFLD/NASH in Japan.

Background: The prevalence of nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome have been increasing worldwide. The associations between metabolic factors and the histologic severity of NAFLD have not yet been clarified. Therefore, we studied the relationships between relevant metabolic factors and the histological severity of NAFLD., Methods: In a cross-sectional multicenter study conducted in Japan, we examined 1,365 biopsy-proven NAFLD patients. The frequencies of underlying lifestyle-related diseases and their relationships to the NAFLD histology were investigated., Results: The hepatic fibrosis stages (Stage 0/1/2/3/4) were 22.6/34.1/26.7/14.5/2.1 (%) in the male patients, and 16.2/31.7/23.9/21.6/6.6 (%) in the female patients. Dyslipidemia was present in 65.7% (hypertriglyceridemia, 45.3%; increased low-density lipoprotein cholesterol, 37.5%; decreased high density lipoprotein cholesterol, 19.5%) of patients. Hypertension was present in 30.2%, and diabetes mellitus (DM) in 47.3%. The fibrosis stage increased with age, especially in postmenopausal females. The body mass index was positively correlated with the fibrosis stage. Deterioration of glucose control was positively correlated with the fibrosis stage, this correlation being more prominent in females. Multivariate analysis identified age and DM as significant risk factors for advanced fibrosis. No significant correlation of the fibrosis stage was observed with hypertension. There was a negative correlation between the serum triglyceride levels and the fibrosis stage., Conclusions: DM appeared to be a significant risk factor for advanced fibrosis in patients with NAFLD, and would therefore need to be properly managed to prevent the progression of NAFLD.

Background: It is suggested that nonalcoholic fatty liver disease (NAFLD), including nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH), can be associated with insomnia and gastro-esophageal reflux disease (GERD). The relationship between GERD and insomnia in subjects with biopsy-proven NAFLD was investigated., Methods: This study enrolled 123 patients with biopsy-proven NAFLD. Insomnia was assessed by the Athens Insomnia Scale (AIS), a self-assessment psychometric instrument designed to quantify sleep difficulty based on ICD-10 criteria; AIS scores ≥ 6 were considered positive for insomnia. GERD symptoms were evaluated using a frequency scale for the symptoms of GERD (FSSG); FSSG scores ≥ 8 were considered positive. Logistic regression models were used to evaluate the association of insomnia with GERD, after adjusting for potential confounders. Thirteen patients with GERD were treated with the proton pump inhibitor rabeprazole (RPZ; 10 mg/day), for 12 weeks., Results: Of the 123 patients, 76 (62%) were female and 87 (71%) were obese, with 34 (28%) having AIS scores ≥ 6 and 31 (25%) having FSSG scores ≥ 8. Liver biopsy revealed that 40 patients (33%) had NAFL and 83 (67%) had NASH. FSSG and AIS scores were similar in the two groups. HOMA-IR, FSSG scores and γGT (GGT) concentrations were significantly higher in insomniacs than in non-insomniacs. Logistic regression analysis demonstrated that FSSG score and GGT concentration were independently associated with insomnia. RPZ treatment resulted in significantly reductions in both AIS and FSSG scores., Conclusions: Nearly 30% of patients with biopsy-proven NAFLD had insomnia, which was related to GGT and GERD and could be relieved by RPZ treatment.

Background: Obesity-induced liver disease (nonalcoholic fatty liver disease, NAFLD) is now the commonest cause of chronic liver disease in affluent nations. There are presently no proven treatments for NAFLD or its more severe stage, nonalcoholic steatohepatitis (NASH). Bofutsushosan (BTS), a Japanese herbal (Kampo) medicine, long used as an anti-obesity medicine in Japan and other Asian countries, has been shown to reduce body weight and improve insulin resistance (IR) and hepatic steatosis. The precise mechanism of action of BTS, however, remains unclear. To evaluate the ability of BTS to prevent the development of NASH, and determine the mediators and pathways involved., Methods: C57BL/6 mice were injected intra-peritoneally with gold-thioglucose and fed a high-fat diet (HF) or HF diet admixed with either 2 or 5 % BTS for 12 weeks. The effectiveness of BTS in attenuating features of NASH and the mechanisms through which BTS attenuated NASH were then assayed through an assessment of the anthropometric, radiological, biochemical and histological parameters., Results: BTS attenuated the progression of NASH through induction of adiponectin and its receptors along with an induction of PPAR-α and PPAR-γ, decreased expression of SREBP-1c, increased hepatic fatty acid oxidation and increased hepatic export of triglycerides. BTS moreover, reduced IR through phosphorylation of the protein kinase, Akt., Conclusions: BTS through induction of adiponectin signaling and Akt attenuated development of NASH. Identification of the active entity in BTS should allow development of novel treatments for NASH.

Background: The severity of liver fibrosis must be estimated to determine the prognosis, for surveillance, and for optimal treatment of nonalcoholic fatty liver disease (NAFLD). However, the severity of hepatic fibrosis tends to be underestimated in patients with normal ALT., Methods: We investigated histological data and scoring systems (FIB-4 index, NAFLD fibrosis score, BARD score, and AST/ALT ratio) of 1,102 liver-biopsy-confirmed NAFLD patients., Results: A total of 235 NAFLD patients with normal ALT were estimated to exist. The ratio of advanced fibrosis (stage 3-4) was seen in 16.1 % of subjects with normal ALT. Scoring systems, especially the FIB-4 index and NAFLD fibrosis score, were clinically very useful (AUROC >0.8), even in patients with normal ALT. Furthermore, with resetting of the cutoff values, the FIB-4 index (>1.659) and NAFLD fibrosis score (>0.735) were found to have a higher sensitivity and higher specificity for the prediction of advanced fibrosis, and all of these scoring systems (FIB-4 index, NAFLD fibrosis score, BARD score, and AST/ALT ratio) had higher negative predictive values (>90.3 %). By using the resetting cutoff value, liver biopsy could have been avoided in 60.4 % (FIB-4), 66.4 % (NAFLD fibrosis score), 51.9 % (BARD score), and 62.1 % (AST/ALT ratio)., Conclusions: We reset the cutoff values of numerous non-invasive scoring systems to improve their clinical usefulness in the prediction of liver fibrosis in NAFLD patients with normal ALT, and these non-invasive scoring systems with the reset cutoff values could be of substantial benefit to reduce the number of liver biopsies performed.

Background: The prevalence of nonalcoholic fatty liver disease (NAFLD) has been increasing. This study aimed to assess the recent prevalence of NAFLD and to predict the prevalence of nonalcoholic steatohepatitis (NASH) with liver fibrosis using established scoring systems in the general population., Methods: A cross-sectional study was conducted among 8352 subjects who received health checkups from 2009 to 2010 in three health centers in Japan. Subjects with an intake over 20 g of alcohol/day or with other chronic liver diseases were excluded. Fatty liver was detected by ultrasonography. The probability of NASH with advanced fibrosis was calculated according to the body mass index, age, ALT, and triglyceride (BAAT) and FIB-4 (based on age, aspartate aminotransferase and alanine aminotransferase levels, and platelet counts) indices., Results: A total of 5075 subjects were enrolled. The overall prevalence of NAFLD was 29.7%. There was a significant threefold difference in the mean prevalence between males (41.0%) and females (17.7%). This prevalence showed a linear increase with body mass index, triglycerides, and low-density lipoprotein cholesterol regardless of threshold values, even without obesity. The estimated prevalence of NASH according to the BAAT index ≥3 was 2.7%, and according to the FIB-4 index it was 1.9%., Conclusions: The prevalence of NAFLD has increased in the general population, especially in males. There is a linear relationship between the prevalence of NAFLD and various metabolic parameters, even in nonobese subjects. The prevalence of NASH with advanced fibrosis is estimated to be considerably high in subjects with NAFLD.

Background: The severity of liver fibrosis is known to be a good indicator for surveillance, and for determining the prognosis and optimal treatment of nonalcoholic fatty liver disease (NAFLD). However, it is virtually impossible to carry out liver biopsies in all NAFLD patients. The purpose of this study was to investigate the clinical usefulness of measuring the platelet count for predicting the severity of liver fibrosis in a large retrospective cohort of Japanese patients with NAFLD., Methods: A total of 1,048 patients with liver-biopsy-confirmed NAFLD seen between 2002 and 2008 were enrolled from nine hepatology centers in Japan. Laboratory evaluations were performed for all patients., Results: A linear decrease of the platelet count with increasing histological severity of hepatic fibrosis was revealed. The area under the receiver operating characteristic curve estimating the diagnostic performance of the platelet count for hepatic fibrosis Stage 3 was 0.774 (optimal cutoff value, 19.2 × 10(4)/μl; sensitivity, 62.7%; specificity, 76.3%), and that for Stage 4 was 0.918 (optimal cutoff value, 15.3 × 10(4)/μl; sensitivity, 80.5%; specificity, 88.8%)., Conclusions: The platelet count may be an ideal biomarker of the severity of fibrosis in NAFLD patients, because it is simple, easy to measure and handle, cost-effective, and accurate for predicting the severity of fibrosis. Furthermore, by using the platelet count cutoff value validated in our multiple large trials, efficient recruitment of NAFLD patients may be facilitated.

Background: Liver histology is the gold standard for the diagnosis of nonalcoholic steatohepatitis (NASH). Noninvasive, simple, reproducible, and reliable biomarkers are greatly needed to differentiate NASH from nonalcoholic fatty liver disease (NAFLD)., Methods: To construct a scoring system for predicting NASH, 177 Japanese patients with biopsy-proven NAFLD were enrolled. To validate the scoring system, 442 biopsy-proven NAFLD patients from eight hepatology centers in Japan were also enrolled., Results: In the estimation group, 98 (55%) patients had NASH. Serum ferritin [≥200 ng/ml (female) or ≥300 ng/ml (male)], fasting insulin (≥10 μU/ml), and type IV collagen 7S (≥5.0 ng/ml) were selected as independent variables associated with NASH, by multilogistic regression analysis. These three variables were combined in a weighted sum [serum ferritin ≥200 ng/ml (female) or ≥300 ng/ml (male) = 1 point, fasting insulin ≥10 μU/ml = 1 point, and type IV collagen 7S ≥5.0 ng/ml = 2 points] to form an easily calculated composite score for predicting NASH, called the NAFIC score. The area under the receiver operating characteristic (AUROC) curve for predicting NASH was 0.851 in the estimation group and 0.782 in the validation group. The NAFIC AUROC was the greatest among several previously established scoring systems for detecting NASH, but also for predicting severe fibrosis., Conclusions: NAFIC score can predict NASH in Japanese NAFLD patients with sufficient accuracy and simplicity to be considered for clinical use.

Metabolic syndrome, that is, obesity, hypertension, hyperlipidemia, and insulin resistance with hyperinsulinemia, is a new disease entity prevailing worldwide, and nonalcoholic steatohepatitis (NASH) is believed to be a hepatic expression of this syndrome. NASH is characterized by zone 3-dominant hepatic steatosis with ballooned hepatocytes and Mallory bodies, zone 3 pericellular and perivenular fibrosis with or without bridging fibrosis, and lobular inflammatory cell infiltration. Indeed, 90% of NASH has been revealed to be complicated by visceral obesity, and two-thirds of NASH patients fulfill the criteria of metabolic syndrome. Therefore, a variety of lifestyle-related diseases such as obesity, hypertension, hyperlipidemia, and diabetes mellitus may share the same background. NASH is most prevalent and well characterized in Caucasians; however, little is known about its occurrence in Asia-Oceania, because obesity has not been frequent in countries in these areas. Obesity is expected to become a serious social problem in Asia-Oceania in the next two decades, so we need to prevent a corresponding increase of NASH. For that purpose, we need to know much about not only NASH but also ourselves. To elucidate the status of NASH in Japan, recent progress in the study of NASH in Japan is reviewed in this article.

In liver injuries, the quiescent hepatic stellate cells (HSCs) promptly change to activated HSCs, which are easily identified by the intense immunoreactivity for alpha-smooth muscle actin. However, reproducible markers for quiescent HSCs in formalin-fixed, paraffin-embedded liver tissue sections have not yet been reported. We immunohistochemically examined the expression of vinculin, one major protein of dense plaques, on cultured LI90 cells and on HSCs in normal and diseased human and rat livers. In cultured LI90 cells, vinculin appeared as small linear patches. Although vinculin was consistently negative in the routine liver tissue sections, an antigen retrieval technique using microwave oven heating yielded excellent effects. Using this technique, the formalin-fixed, paraffin-embedded human and rat normal liver tissue sections showed the vinculin immunoreactivity along the sinusoidal wall. Immunoelectron microscopic observation of hepatic parenchyma demonstrated that the vinculin was exclusively expressed in quiescent HSCs. In fetal rat livers, vinculin-positive quiescent HSCs gradually increased in number with gestation. In diseased livers the activated HSCs showed more intense immunoreaction for vinculin. These results indicate that, using microwave pretreatment, vinculin is expressed in quiescent and activated HSCs in routinely processed liver tissue sections. It could allow us to evaluate the development and distribution of quiescent HSCs and to examine the relationship between quiescent and activated HSCs.

We examined regeneration and fibrosis in the necrotic areas of hepatic stellate cells (HSCs). Acute hepatic injury was induced in rats by administration of an intraperitoneal injection of high-dose dimethylnitrosamine (50 mg/kg body weight). Liver samples were obtained from rats 6, 12, 24, 36 h and 2, 3, 5, 7, 10, and 14 days after the injection. They were examined by light and electron microscopy and by immunohistochemical methods. Hemorrhagic necrosis became most prominent 36 h after treatment and extended into zones 3 and 2. In the submassive necrotic areas the sinusoidal structure was destroyed. No HSCs positive for alpha-smooth muscle actin or desmin were present. On day 5, when necrotic tissues were almost removed by infiltrating macrophages, HSCs strongly positive for alpha-smooth muscle actin and desmin appeared along the surface of the preserved parenchyma and migrated into the necrotic areas along the residual reticulin fibers. By day 14 most of the necrotic areas were almost completely replaced by the regeneration of hepatocytes and central to central (C-C) bridging fibrosis. Our results indicate that following submassive complete necrosis, HSCs in the preserved liver parenchyma have roles in the formation of sinusoidal wall for remodeling in necrotic areas via their activation, proliferation, and migration into the necrotic areas.

To examine the relationship of Ito cells to postnecrotic liver fibrosis, liver specimens, obtained at autopsy from 17 patients with acute massive necrosis (AMN) and acute submassive hepatic necrosis (ASMN), were examined immunohistochemically. In normal adult livers, Ito cells positive for alpha-smooth muscle actin isoform (ASMA) were rarely seen, scattered along hepatic sinusoids. In contrast, in AMN the Ito cells in necrotic areas became strongly positive for ASMA. They were swollen with elongated cytoplasmic processes along collapsed sinusoidal walls. Around these ASMA-positive Ito cells, there were numerous infiltrated macrophages and lymphocytes present. There was no significant alteration of fibroblasts in the portal tracts. In the middle and late stages of ASMN, the spindle-shaped ASMA-positive Ito cells formed a continuous cellular network. New fibre formation was predominantly around them. In this immediate postnecrotic fibrosis, ASMA-positive stromal cells of Ito cell origin were distributed irregularly and were closely associated with reticulin and newly-formed collagen fibres. Regenerative nodules were surrounded by dense layers of ASMA-positive stromal cells. Throughout the stages of ASMN, portal fibroblasts remained negative for ASMA. We believe that Ito cells in necrotic areas show myofibroblastic transformation and play a central role in the postnecrotic liver fibrosis. Portal fibroblasts play no significant part in this type of fibrosis.

To identify Ito cells in normal and pathological adult human livers, immunohistochemical studies were performed by the avidin-biotin-peroxidase complex method using monoclonal antibodies for alpha-smooth muscle actin (ASMA), desmin, and vimentin. Fifty one needle biopsies, 7 surgically resected specimens, and 5 autopsy specimens were studied. In the normal adult liver vascular smooth muscle cells and pericytes, together with perisinusoidal cells with thin cytoplasmic processes were positive for ASMA. These latter cells formed a loose and discontinuous layer along the sinusoidal walls. Immunoelectron microscopy showed that the ASMA-positive perisinusoidal cells were Ito cells containing fat droplets. The other sinusoidal lining cells were negative for ASMA. In chronic liver disease, ASMA-positive Ito cells showed an increase in number, size, and the intensity of immunostaining in areas of piece-meal necrosis), and formed a continuous cellular network. These cells were dendritic in shape with irregularly elongated cytoplasmic processes and contained an increased amount of microfilaments, in association with loss of the characteristic fat droplets. Thus, their ultrastructural features corresponded to those of myofibroblastic cells. Ito cells showed no staining for desmin in both normal and pathological livers. These results indicate that immunohistochemistry using an anti-ASMA antibody is a sensitive and reliable method for the identification of both normal and transformed Ito cells in adult human livers.

We investigated the liver biopsies of 78 patients with hepatitis virus-related chronic liver diseases (B type; 14 patients, C type; 64 patients) by immunoelectron microscopy with the Leu-7 monoclonal antibody in order to determine the association of NK/K cells in virus-related chronic liver diseases. Most Leu-7 positive cells in the liver had the Pit cell morphology but a few Pit cells were Leu-7 negative. A few Leu-7 positive cells had neither Pit cell nor typical T cell morphology. No ultrastructural difference was observed in Leu-7 positive cells between hepatitis B virus- and hepatitis C virus-related chronic liver diseases. Regardless of virus type and hepatitis activity, the fine morphology of extravascular Leu-7 positive cells differed considerably from intravascular cells. Leu-7 positive cells were regularly seen in the cellular infiltrates but the ratio of Leu-7 positive cells/whole infiltrates was low. There was no correlation between the inflammatory activity of the disease and the level of Leu-7 positive cell infiltration. A virus aetiology (hepatitis-C or hepatitis-B) did not affect Leu-7 positive cell infiltration. We conclude that NK cells play only a small role in the pathogenesis of hepatitis B virus or hepatitis C virus-related hepatocytolysis, during the chronic stage.