Decreased phagocytic activity of Kupffer cells in a rat nonalcoholic steatohepatitis model

AIM: To investigate Kupffer cell dynamics and phagocytic activity,using a rat nonalcoholic steatohepatitis (NASH) model. METHODS: Male F344 rats were fed either a control diet or a choline-deficient L-amino acid-defined (CDAA) diet,followed by contrast enhanced ultrasonography (CEUS) using Levovist. The uptake of latex beads by the Kupffer cells was determined by fluorescent microscopy. The status of the Kupffer cells was compared between the two groups,using the immunohistochemical staining technique. RESULTS: After 4 or more wk of the CDAA diet,CEUS examination revealed a decrease in the signal intensity,20 min after intravenous Levovist. Fluorescent microscopic examination showed that the uptake of latex beads by the Kupffer cells was reduced at week 1 and 2 in the study group,compared with the controls,with no further reduction after 3 wk. Immunohistochemical staining revealed no significant difference in the Kupffer cell counts between the control group and the CDAA group. CONCLUSION: CEUS examination using Levovist demonstrated reduced contrast effect and phagocytic activity in the liver parenchymal phase,although the Kupffer cell numbers were unchanged,indicating reduced phagocytic function of the Kupffer cells in the rat NASH model. We believe that CEUS examination using Levovist is a useful screening modality,which can detect NASH in fatty liver patients.

Non invasive evaluation of liver fibrosis in paediatric patients with nonalcoholic steatohepatitis

AIM: To identify the independent predictors of hepatic fibrosis in 69 children with nonalcoholic steatohepatitis (NASH) due to nonalcoholic fatty liver disease (NAFLD). METHODS: All patients with clinically suspected NASH underwent liver biopsy as a confirmatory test. The following clinical and biochemical variables at baseline were examined as likely predictors of fibrosis at histology: age, body mass index (BMI), systolic blood pressure (SBP), dyastolic blood pressure (DBP), fasting glucose, fasting insulin, homeostatic model assessment for insulin resistence (HOMA-IR), cholesterol, tryglicerides, alanine aminotransferase (ALT), aspartate aminotransferase (AST), AST/ALT ratio, gamma glutamil transferase (GT), platelet count, prothrombin time (PT). RESULTS: At histology 28 (40.6%) patients had no fibrosis and 41 (59.4%) had mild to bridging fibrosis. At multivariate analysis, BMI > 26.3 was the only independent predictor of fibrosis (OR = 5.85, 95% CI = 1.6-21). CONCLUSION: BMI helps identify children with NASH who might have fibrotic deposition in the liver.

Cryptogenic cirrhosis in the region where obesity is not prevalent

AIM： Recent studies have demonstrated that obesity is the common feature of cryptogenic cirrhosis （CC） and non-alcoholic steatohepatitis. However, there is little information on CC in the region where obesity is not prevalent, METHODS： The clinical features, and the liver-related morbidity and mortality of CC were analyzed in Japan where the prevalence of obesity is low. Among 652 cirrhotic patients, we identified 29 patients （4.4%） with CC. Of these, 24 CC patients who were followed up for more than 6 months were compared in a case-control study with age-, sex-, and Child-Pugh score-matched controls having cirrhosis of viral etiology. RESULTS： Obesity （BMI≥25 kg/m^2）, diabetes mellitus, and hypertriglyceridemia were more frequent, and the visceral fat area was larger in the CC patients than in the controls. The indices of insulin resistance were higher and the serum aminotransferase levels were lower in the CC patients than in the controls. Logistic regression analysis identified the elevated hemoglobin A1c, BMI ≥ 25 kg/m^2, and normal aminotransferase levels as independent predictors of CC. Kaplan-Meier analysis demonstrated lower occurrence of hepatocellular carcinoma and higher survival rate in the CC than in the controls in contrast to the similar cumulatlve probability of liverrelated morbidity between those groups.CONCLUSION： CC more frequently presents with the clinical features suggestive of non-alcoholic steatohepatitis compared with controls even in the region where obesity is not prevalent. The lower occurrence of hepatocellular carcinoma and higher survival rate may indicate an indolent clinical course in CC as compared with viral cirrhosis.

Association between thrombotic risk factors and extent of fibrosis in patients with non-alcoholic fatty liver diseases

AIM: To evaluate the prevalence of genetic and acquired prothrombotic risk factors and their association with the extent of fibrosis and fatty infiltration in patients with non-alcoholic fatty liver disease (NAFLD).METHODS: Forty-four patients with chronic hepatitis (28 men and 16 women, with mean age of 45±11 and 49±12 years, respectively) constituted the patient population of this study. The groups were divided as follows: 15 patients with fatty liver (FL); 15 with non-alcoholic steatohepatitis (NASH); 14 with chronic viral hepatitis (CH) diagnosed by histology and liver technetium scan or ultrasound; and 10 healthy individuals. Thrombophilic, coagulation factors and genetic mutations were diagnosed by standard hemostatic and molecular coagulation assays.RESULTS: Activated protein C (APC) resistance and protein S were the most prevalent thrombotic risk factors (6% and 10% in NAFLD vs 21% and 14% in CH; P＜0.01 and P＜0.05, respectively). One thrombotic risk factor was identified in 41% of patients (23% mild fibrosis, 18% severe fibrosis) and two thrombotic risk factors in 6% of patients with NAFLD and severe fibrosis. While no differences in APC ratio, lupus anticoagulant, fibrinogen, factor V Leiden,prothrombin, and MTHFR mutation were found. Protein S levels were significantly lower in NASH patients than in patients with FL alone (92±19 vs106±2, P＜0.01). Protein C levels were markedly higher in patients with NAFLD and mild or severe fibrosis as compared to the patients with CH, respectively (128±40 vs96±14, P＜0.001 or 129±36 vs 88±13, P＜0.01).CONCLUSION: Up to 46% of patients with NAFLD may have thrombotic risk factors, and the presence of thrombotic risk factors is correlated with the extent of hepatic fibrosis,suggesting a crucial role of the coagulation system in the pathogenesis of hepatic fibrosis.

Acute esophageal necrosis caused by alcohol abuse

Acute esophageal necrosis (AEN) is extremely rare and the pathogenesis of this is still unknown. We report a case of AEN caused by alcohol abuse. In our case, the main pathogenesis could be accounted for low systemic perfusion caused by severe alcoholic lactic acidosis. After the healing of AEN, balloon dilatation was effective to manage the stricture.

Controversies in and challenges to our understanding of hepatitis C

Discovered in 1989, the hepatitis C virus (HCV) continues to cause signifi cant morbidity and mortality world-wide despite a huge research commitment to defining and understanding the virus and the disease it causes. This paper discusses a number of areas where progress in the management of the HCV have not kept pace with the scientifi c understanding of the HCV. It is suggested that in the fi elds of HCV prevention and providing access to treatment, practice falls short of what could be achieved. The role of alcohol in the pathogenesis of HCV liver injury is discussed. Discrimination against those with HCV infection and particularly those in prison settings fails to match good clinical practice. The complicated processes of sharing information between specialty groups is also discussed in an attempt to optimise knowledge dissemination in this field.