Development of hepatocellular carcinoma in a murine model of nonalcoholic steatohepatitis induced by use of a high-fat/fructose diet and sedentary lifestyle.

Obesity is increasingly prevalent, strongly associated with nonalcoholic liver disease, and a risk factor for numerous cancers. Here, we describe the liver-related consequences of long-term diet-induced obesity. Mice were exposed to an extended obesity model comprising a diet high in trans-fats and fructose corn syrup concurrent with a sedentary lifestyle. Livers were assessed histologically using the nonalcoholic fatty liver disease (NAFLD) activity score (Kleiner system). Mice in the American Lifestyle-Induced Obesity Syndrome (ALIOS) model developed features of early nonalcoholic steatohepatitis at 6 months (mean NAFLD activity score = 2.4) and features of more advanced nonalcoholic steatohepatitis at 12 months, including liver inflammation and bridging fibrosis (mean NAFLD activity score = 5.0). Hepatic expression of lipid metabolism and insulin signaling genes were increased in ALIOS mice compared with normal chow-fed mice. Progressive activation of the mouse hepatic stem cell niche in response to ALIOS correlated with steatosis, fibrosis, and inflammation. Hepatocellular neoplasms were observed in 6 of 10 ALIOS mice after 12 months. Tumors displayed cytological atypia, absence of biliary epithelia, loss of reticulin, alteration of normal perivenular glutamine synthetase staining (absent or diffuse), and variable α-fetoprotein expression. Notably, perivascular tumor cells expressed hepatic stem cell markers. These studies indicate an adipogenic lifestyle alone is sufficient for the development of nonalcoholic steatohepatitis, hepatic stem cell activation, and hepatocarcinogenesis in wild-type mice.

Porto-pulmonary hypertension exacerbated by platelet transfusion in a patient with ADAMTS13 deficiency.

We propose that porto-pulmonary hypertension (PPH) may arise as a consequence of deficiency of ADAMTS13 (a plasma metalloprotease that regulates von Willebrand factor size and reduces its platelet adhesive activity) and provide a clinical case history to support our hypothesis. A patient with non-cirrhotic intrahepatic portal hypertension (NCIPH), ulcerative colitis and celiac disease developed symptoms of PPH, which had advanced beyond levels which would have made her an eligible candidate for liver transplantation (mean pulmonary artery pressure (PAP) 49 mm Hg). She was known to have severe ADAMTS13 deficiency, which we considered to be causative of, or contributory to her NCIPH. We postulated that increasing porto-systemic shunting associated with advancing portal hypertension would make the next encountered vascular bed, the lung, susceptible to the pathogenic process that was previously confined to the portal system, with pulmonary hypertension as its consequence. Her pulmonary artery pressures fell significantly during the next year on weekly replacement of plasma ADAMTS13 by infusions of fresh frozen plasma and conventional drug treatment of her pulmonary hypertension. Her pulmonary artery pressures had fallen to acceptable levels when, in response to platelet infusion, it rose precipitously and dangerously. The sequence strongly supports our hypothesis that PPH is a consequence of ADAMTS13 deficiency and is caused by platelet deposition in afferent pulmonary vessels.

Presence and severity of non-alcoholic fatty liver disease in a large prospective primary care cohort.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) is a common cause of abnormal LFTs in primary care, but there are no data defining its contribution nor reporting the range of NAFLD severity in this setting. This study seeks to calculate the range of disease severity of NAFLD in a primary care setting. METHODS: Adult patients with incidental abnormal LFTs, in the absence of a previous history, or current symptoms/signs of liver disease were prospectively recruited from eight primary care practices in Birmingham. NAFLD was diagnosed as fatty liver on ultrasound, negative serological liver aetiology screen, and alcohol consumption ≤30 and ≤20 g/day in males and females, respectively. The NAFLD Fibrosis Score (NFS) was calculated to determine the presence or absence of advanced liver fibrosis in subjects identified with NAFLD. RESULTS: Data from 1118 adult patients were analysed. The cause of abnormal LFTs was identified in 55% (614/1118) of subjects, with NAFLD (26.4%; 295/1118) and alcohol excess (25.3%; 282/1118) accounting for the majority. A high NFS (>0.676) suggesting the presence of advanced liver fibrosis was found in 7.6% of NAFLD subjects, whereas 57.2% of NAFLD patients had a low NFS (<-1.455) allowing advanced fibrosis to be confidently excluded. CONCLUSIONS: NAFLD is the commonest cause of incidental LFT abnormalities in primary care (26.4%), of whom 7.6% have advanced fibrosis as calculated by the NFS. This study is the first of its kind to highlight the burden of NAFLD in primary care and provide data on disease severity in this setting.

Distinct roles for CCR4 and CXCR3 in the recruitment and positioning of regulatory T cells in the inflamed human liver.

Regulatory T cells (T(regs)) are found at sites of chronic inflammation where they mediate bystander and Ag-specific suppression of local immune responses. However, little is known about the molecular control of T(reg) recruitment into inflamed human tissues. We report that up to 18% of T cells in areas of inflammation in human liver disease are forkhead family transcriptional regulator box P3 (FoxP3)(+) T(regs). We isolated CD4(+)CD25(+)CD127(low)FoxP3(+) T(regs) from chronically inflamed human liver removed at transplantation; compared with blood-derived T(regs), liver-derived T(regs) express high levels of the chemokine receptors CXCR3 and CCR4. In flow-based adhesion assays using human hepatic sinusoidal endothelium, T(regs) used CXCR3 and alpha4beta1 to bind and transmigrate, whereas CCR4 played no role. The CCR4 ligands CCL17 and CCL22 were absent from healthy liver, but they were detected in chronically inflamed liver where their expression was restricted to dendritic cells (DCs) within inflammatory infiltrates. These DCs were closely associated with CD8 T cells and CCR4(+) T(regs) in the parenchyma and septal areas. Ex vivo, liver-derived T(regs) migrated to CCR4 ligands secreted by intrahepatic DCs. We propose that CXCR3 mediates the recruitment of T(regs) via hepatic sinusoidal endothelium and that CCR4 ligands secreted by DCs recruit T(regs) to sites of inflammation in patients with chronic hepatitis. Thus, different chemokine receptors play distinct roles in the recruitment and positioning of T(regs) at sites of hepatitis in chronic liver disease.

Idiopathic noncirrhotic intrahepatic portal hypertension is associated with sustained ADAMTS13 Deficiency.

BACKGROUND: ADAMTS13 deficiency leading to excess ultralarge von Willebrand factor (VWF) multimers and platelet clumping is typically found in thrombotic thrombocytopenic purpura (a type of thrombotic microangiopathy). Idiopathic noncirrhotic intrahepatic portal hypertension (NCIPH) is a microangiopathy of portal venules associated with significant thrombocytopenia and predisposing gut disorders. AIM: To determine whether the portal microangiopathy in NCIPH is associated with ADAMTS13 deficiency. METHODS: Plasma levels of ADAMTS13, anti-ADAMTS13 antibodies, and VWF were compared between cases (NCIPH patients) and controls (with chronic liver diseases of other etiology) matched for severity of liver dysfunction. Eighteen NCIPH patients [median (range) MELD score 12 (7-25)] and 25 controls [MELD score 11 (4-26)] were studied. RESULTS: ADAMTS13 activity was reduced in all 18 NCIPH patients and significantly lower than controls (median, IQR: 12.5%, 5-25% and 59.0%, 44-84%, respectively, P<0.0001) [normal range for plasma ADAMTS13 activity (55-160%)]. ADAMTS13 activity was <5% in 5/18 NCIPH patients (28%) and 0/25 controls (P=0.009). ADAMTS13 antigen levels were also decreased. Sustained low ADAMTS13 levels were seen in four NCIPH patients over 6 weeks to 11 months (highest ADAMTS13 level in each patient: <5%, 6%, 6%, and 25%), despite two patients having MELD score 12. Although nine cases had low titer anti-ADAMTS13 antibodies, there was no significant difference between cases and controls. Abnormally large VWF multimers were observed in 4/11 NCIPH patients (36%) and in 0/22 controls (P=0.008). CONCLUSIONS: Sustained deficiency of ADAMTS13 appears characteristic of NCIPH, irrespective of severity of liver disease.