Volume 43, Issue 1 (January 2006)
Liver Failure and Liver Disease
Systemic hemodynamics, vasoactive systems, and plasma volume in patients with severe Budd-Chiari syndrome (p 27-33)
Manuel Hernández-Guerra, Eric López, Pablo Bellot, Carlos Piera, Juan Turnes, Juan G. Abraldes, Jaime Bosch, Juan C. García-Pagán
Budd-Chiari syndrome (BCS) causes postsinusoidal portal hypertension, which leads to complications similar to those observed in cirrhosis. However, no studies have investigated whether patients with BCS develop the hyperdynamic circulatory syndrome present in patients with cirrhosis who have portal hypertension. We evaluated systemic and cardiopulmonary hemodynamics, plasma renin activity, aldosterone and norepinephrine levels, and plasma volume in patients with BCS admitted for complications of portal hypertension. BCS patients had mean systemic and cardiopulmonary pressures and cardiac indices that were within the normal range but were significantly different from those of a group of patients with cirrhosis matched by sex, body surface, and liver function (cardiac index 3.1 ± 0.7 vs. 4.9 ± 1.2 L · min-1 · m-2; P < .001; systemic vascular resistance [SVR] index, 2,189 ± 736 vs. 1,377 ± 422 dyne · s · cm-5 · m-2, P < .001). Despite normal systemic vascular resistance, BCS patients had activation of the neurohumoral vasoactive systems, as evidenced by increased plasma renin activity, aldosterone and norepinephrine levels (15.0 ± 21.5 ng/mL · h, 76.7 ± 106.8 ng/dL, 586 ± 868 pg/mL; respectively) and plasma volume expansion. The analysis of individual BCS patients identified that 7 of the 21 patients actually had reduced SVR index. These patients had the greatest plasma volume expansion. A significant inverse correlation between plasma volume and SVR index was observed. In conclusion, patients with BCS had activation of vasoactive neurohumoral systems and expanded plasma volume. This outcome was observed even though most of these patients did not exhibit systemic vasodilation and cardiac output was not increased, in marked contrast with what is observed in patients with cirrhosis.
Influence of beta-2 adrenergic receptor gene polymorphism on the hemodynamic response to propranolol in patients with cirrhosis (p 34-41)
Juan Turnes, Manuel Hernández-Guerra, Juan G. Abraldes, Pau Bellot, Rafael Oliva, Juan Carlos García-Pagán, Jaime Bosch
The beta-2-adrenergic receptor (2--AR) has several single-nucleotide polymorphisms. These influence the functional response to adrenergic stimulation; genotypes homozygous for Gly16-Glu27 or Gly16-Gln27 alleles (Gly16-Glu/Gln27 haplotypes) are associated with enhanced response, whereas genotypes homozygous for Arg16-Gln27 alleles (Arg16-Gln27) show a decreased response. We hypothesized that gene polymorphisms at the 2-AR may influence the hemodynamic response to propranolol in patients with cirrhosis. The 2-AR gene polymorphisms were determined by direct sequencing of the polymerase chain reaction (PCR) products in 48 patients with cirrhosis. All patients also had hepatic and systemic hemodynamic studies before and after propranolol administration. Prevalence of Gly16-Glu/Gln27 haplotypes was 29.1%, Arg16-Gln27 haplotype was 16.7%, and 54.2% were compound heterozygotes. Patients with cirrhosis with Gly16-Glu/Gln27 haplotypes had a greater decrease in heart rate, cardiac index, and hepatic blood flow after propranolol administration than those with Arg16-Gln27 haplotype. However, the HVPG response to propranolol was similar in both groups, whereas estimated hepatic sinusoidal resistance increased significantly in Gly16-Glu/Gln27 haplotypes but not in Arg16-Gln27 (+27.1 ± 17.8% vs -17.9 ± 13.9%, P = .042), suggesting that unopposed vasoconstrictive activity at the intrahepatic circulation hinders the fall in HVPG despite enhanced hemodynamic response to propranolol in Gly16-Glu/Gln27 haplotypes. In conclusion, 2-AR gene polymorphisms influence the response to beta-blockade. However, HVPG reduction cannot be predicted from polymorphism analysis. Patients with the Gly16-Glu/Gln27 haplotypes may benefit from the association of hepatic vasodilators to propranolol therapy.
Brain metabolism of 13N-ammonia during acute hepatic encephalopathy in cirrhosis measured by positron emission tomography (p 42-50)
Susanne Keiding, Michael Sørensen, Dirk Bender, Ole Lajord Munk, Peter Ott, Hendrik Vilstrup
Animal studies and results from 13N-ammonia positron emission tomography (PET) in patients with cirrhosis and minimal hepatic encephalopathy suggest that a disturbed brain ammonia metabolism plays a pivotal role in the pathogenesis of hepatic encephalopathy (HE). We studied brain ammonia kinetics in 8 patients with cirrhosis with an acute episode of clinically overt HE (I-IV), 7 patients with cirrhosis without HE, and 5 healthy subjects, using contemporary dynamic 13N-ammonia PET. Time courses were obtained of 13N-concentrations in cerebral cortex, basal ganglia, and cerebellum (PET-scans) as well as arterial 13N-ammonia, 13N-urea, and 13N-glutamine concentrations (blood samples) after 13N-ammonia injection. Regional 13N-ammonia kinetics was calculated by non-linear fitting of a physiological model of brain ammonia metabolism to the data. Mean permeability-surface area product of 13N-ammonia transfer across blood-brain barrier in cortex, PSBBB, was 0.21 mL blood/min/mL tissue in patients with HE, 0.31 in patients without HE, and 0.34 in healthy controls; similar differences were seen in basal ganglia and cerebellum. Metabolic trapping of blood 13N-ammonia in the brain showed neither regional, nor patient group differences. Mean net metabolic flux of ammonia from blood into intracellular glutamine in the cortex was 13.4 mol/min/L tissue in patients with cirrhosis with HE, 7.4 in patients without HE, and 2.6 in healthy controls, significantly correlated to blood ammonia. In conclusion, increased cerebral trapping of ammonia in patients with cirrhosis with acute HE was primarily attributable to increased blood ammonia and to a minor extent to changed ammonia kinetics in the brain.
Concise Communication
Nasobiliary drainage induces long-lasting remission in benign recurrent intrahepatic cholestasis (p 51-53)
Janneke M. Stapelbroek, Karel J. van Erpecum, Leo W. J. Klomp, Niels G. Venneman, Thijs P. Schwartz, Gerard P. van Berge Henegouwen, John Devlin, Carin M. J. van Nieuwkerk, A. S. Knisely, Roderick H. J. Houwen
Benign recurrent intrahepatic cholestasis (BRIC) is characterized by episodic cholestasis and pruritus without anatomical obstruction. Effective medical treatment is not available. We report complete and long-lasting disappearance of pruritus and normalization of serum bile salt concentrations in cholestatic BRIC patients within 24 hours after endoscopic nasobiliary drainage (NBD). Relative amounts of phospholipids and bile salts in bile collected during NBD appeared to be normal, but phospholipids other than phosphatidylcholine (especially sphingomyelin) were increased. In conclusion, we propose that temporary endoscopic nasobiliary drainage should be considered in cholestatic BRIC patients.
Viral Hepatitis
Limitation of combination therapy of interferon and ribavirin for older patients with chronic hepatitis C (p 54-63)
Yoshiaki Iwasaki, Hiroshi Ikeda, Yasuyuki Araki, Toshiya Osawa, Keiji Kita, Masaharu Ando, Toshinari Shimoe, Kouichi Takaguchi, Noriaki Hashimoto, Toshitsugu Kobatake, Minoru Tomita, Mitsuhiko Kawaguchi, Haruhiko Kobashi, Kohsaku Sakaguchi, Yasushi Shiratori
In contrast to the United States, Japanese patients with chronic hepatitis C currently treated with interferon are generally 10 to 15 years older. Older patients, however, tend to experience more frequent adverse events. This study was conducted to clarify the effect of patient age on the efficacy and safety of combination therapy. We consecutively enrolled 208 patients with naïve chronic hepatitis C. Patients were classified into three groups according to age: younger than 50 years of age (n = 52); 50 to 59 years old (n = 83); and 60 years of age or older (n = 73). Interferon alpha-2b therapy was administered daily for 2 weeks, followed by 3 times per week for 22 weeks, while ribavirin was administered daily. Of the 208 study patients, discontinuation of therapy or dose reduction was required in 116 (56%) and was more frequent in older patient groups: 38%, 48%, and 77% for the <50, 50-59, and 60-year-old patient groups, respectively (P < .001). Multivariate analysis showed patient age to be independently associated with adherence to therapy. A sustained virological response was achieved in 77 (37%) patients, with genotype, viral load, and adherence to therapy associated with this achievement. A tendency toward a lower sustained virological response rate was seen in the older patients. In conclusion, patient age is an important factor contributing to the safety of combination therapy. Thus, treatment schedule should be modified, or other therapeutic modalities should be considered for older patients with chronic hepatitis C.
Insulin resistance is associated with steatosis in nondiabetic patients with genotype 1 chronic hepatitis C (p 64-71)
Calogero Cammà, Savino Bruno, Vito Di Marco, Danilo Di Bona, Mariagrazia Rumi, Maria Vinci, Chiara Rebucci, Agostino Cividini, Giuseppe Pizzolanti, Ernesto Minola, Mario U. Mondelli, Massimo Colombo, Giovanbattista Pinzello, Antonio Craxfì
Conflicting data exist regarding the relationship between hepatitis C virus genotype 1 and hepatic steatosis as well as the latter's role in the progression of fibrosis and treatment response. We assessed factors associated with hepatic steatosis in genotype 1 chronic hepatitis C and the impact of hepatic fat on fibrosis development and interferon responsiveness. Two hundred ninety-one non-diabetic patients with genotype 1 chronic hepatitis C were examined for the presence of steatosis and its correlation with clinical, virological, and biochemical data, including insulin resistance (IR), evaluated by the homeostasis model assessment (HOMA) score. Steatosis was graded as mild (1%-20% of hepatocytes involved), moderate (21%-40% of hepatocytes involved), and severe (>40% of hepatocytes involved). Steatosis was mild in 110 of 291 (37.8%) and moderate/severe in 55 of 291 (18.9%) subjects. By logistic regression, moderate/severe steatosis was independently associated with the female sex (odds ratio [OR] 2.74; 95% CI 1.40-5.35), high -glutamyltransferase levels (OR 1.52; 95% CI 1.22-1.91), and HOMA-score (OR 1.076; 95% CI 1.001-1.26). By logistic regression, moderate/severe steatosis (OR 2.78; 95% CI 1.21-6.4), and platelet counts (OR 0.97; 95% CI 0.96-0.98) were independent predictors of advanced fibrosis. Patients with moderate/severe steatosis had an OR of 0.52 (95% CI 0.30-0.90) for sustained virological response compared with patients with mild/absent steatosis. In conclusion, in nondiabetic European patients with genotype 1 hepatitis C at low risk for the metabolic syndrome, the prevalence of steatosis was nearly 60%. IR is a risk factor for moderate/severe steatosis, especially in men. Moderate/severe steatosis has clinical relevance, being associated with advanced fibrosis and hyporesponsiveness to antiviral therapy.
Development and validation of two models for early prediction of response to therapy in genotype 1 chronic hepatitis C (p 72-80)
Eva Martínez-Bauer, Javier Crespo, Manuel Romero-Gómez, Ricardo Moreno-Otero, Ricard Solá, Nancy Tesei, Fernando Pons, Xavier Forns, José M. Sánchez-Tapias
Early prediction of response to therapy in genotype 1 chronic hepatitis C is difficult. Two predictive models, a pretreatment scoring model (PreT-SM) and a fourth week of therapy scoring model (4w-SM) were constructed in a cohort of 104 patients from a single center (estimation cohort) and validated in a cohort of 141 patients from four independent centers (validation cohort). Individual scores were calculated using variables independently associated with sustained virological response (SVR). Baseline viral load, aspartate aminotransferase/alanine aminotransferase ratio, serum cholesterol, and a numerical score for noninvasive estimation of liver fibrosis were included in the PreT-SM; HCV RNA clearance and PreT-SM scores were included in the 4w-SM. Receiver operating characteristic analysis revealed the area under the curve in the estimation cohort and in the validation cohort to be, respectively, 0.856 and 0.847 for the PreT-SM and 0.908 and 0.907 for the 4w-SM. Low scores were associated with SVR, high scores with non-SVR. The best cutoff scores from the PreT-SM (7 and 9.70) identified, respectively, 36% of patients with SVR and 41% of those with non-SVR from the validation cohort, with high accuracy (90% positive predictive value [PPV] and specificity). Similarly, cutoff scores of 3.20 and 5.60 from the 4w-SM identified, respectively, 71% of patients with SVR and 53% of those with non-SVR from the same cohort with high accuracy (PPV and specificity >92%). In conclusion, these models predicted response to therapy before or after 4 weeks of treatment in approximately 60% of genotype 1 patients and may be valuable for the management of this condition.
Mechanistic link between the anti-HCV effect of interferon gamma and control of viral replication by a ras-MAPK signaling cascade (p 81-90)
Ying Huang, Xinyi Cynthia Chen, Madhavi Konduri, Nadejda Fomina, Jin Lu, Ling Jin, Alexander Kolykhalov, Seng-Lai Tan
Interferon-gamma (IFN-) exerts potent antiviral activity in the hepatitis C virus (HCV) replicon systems. However, the mechanisms underlying the direct antiviral effect have not been determined. We found that the type II transcriptional response to IFN- could be suppressed by inhibition of MEK1/2 kinase activity by MEK1/2 inhibitor U0126 in the hepatoma cell line Huh-7. Using a bicistronic HCV replicon system expressing a luciferase reporter gene in Huh-7 cells (RLuc-replicon), we showed that inhibition of MEK1/2 kinase activity is sufficient to counteract the antiviral activity of IFN-. Expression of a constitutive active form of Ras inhibited the luciferase activity of RLuc-replicon, whereas a dominant-negative mutant of Ras enhanced the reporter activity, indicating that the Ras-MAPK pathway has a role in limiting replication of the viral RNA. Consistent with the involvement of the Ras-MAPK pathway, treatment with epidermal growth factor suppressed HCV protein expression in the RLuc-replicon cells, an effect that could be abolished by U0126. Inhibition of MEK1/2 kinase activity correlated with reduced phosphorylation of the HCV NS5A protein and enhanced RLuc-replicon luciferase reporter activity, in line with recent reports that phosphorylation of NS5A negatively modulates HCV RNA replication. Finally, genetic deletion analysis in yeast supported the role of a MEK-like kinase(s) in the regulation of NS5A phosphorylation. In conclusion, the direct anti-HCV effect of IFN- in cell culture is, at least in part, mediated through the Ras-MAPK signaling pathway, which possibly involves a direct or indirect modulation of NS5A protein phosphorylation.
Liver Biology and Pathobiology
Hematopoietic mobilization in mice increases the presence of bone marrow-derived hepatocytes via in vivo cell fusion (p 108-116)
Oscar Quintana-Bustamante, Alberto Alvarez-Barrientos, Alexander V. Kofman, Isabel Fabregat, Juan A. Bueren, Neil D. Theise, José C. Segovia
The mechanisms for in vivo production of bone marrow-derived hepatocytes (BMDHs) remain largely unclear. We investigated whether granulocyte colony-stimulating factor (G-CSF)-mediated mobilization of hematopoietic cells increases the phenomenon. Recurrent liver injury in mice expressing green fluorescent protein (EGFP) in all hematopoietic-derived cells was produced by 3 months of carbon tetrachloride (CCL4) injections. Histologically, there were necrotic foci with histiocyte-rich infiltrates, but little oval cell proliferation. Subsequently, some animals were mobilized with G-CSF for 1, 2, or 3 weeks. Animals were sacrificed 1 month after growth factor treatment. BMDH percentages were lower than previously reported, though G-CSF mobilization significantly augmented BMDH production in injured livers. BMDHs originating from in vivo fusion were evaluated by transplanting female EGFP+ cells into male mice. Binucleated, EGFP+ hepatocytes with one Y chromosome, indicating fusion, were identified. In conclusion, (1) mobilization of hematopoietic cells increases BMDH production and (2) as with the FAH-null model, the first model demonstrating hematopoietic/hepatocyte fusion, recurring CCl4-induced injury has macrophage-rich infiltrates, a blunted oval cell response, and a predominantly in vivo fusion process for circulating cell engraftment into the liver. These findings open the possibility of using hematopoietic growth factors to treat nonhematopoietic degenerative diseases.
NPC2 is expressed in human and murine liver and secreted into bile: Potential implications for body cholesterol homeostasis (p 126-133)
Andrés Klein, Ludwig Amigo, María José Retamal, María Gabriela Morales, Juan Francisco Miquel, Attilio Rigotti, Silvana Zanlungo
The liver plays a critical role in the metabolism of lipoprotein cholesterol and in controlling its elimination through the bile. Niemann-Pick type C 2 (NPC2), a cholesterol-binding protein, is key for normal intracellular trafficking of lipoprotein cholesterol, allowing its exit from the endolysosomal pathway into the metabolically active pool of the cell. In addition, NPC2 is a secretory protein from astrocytes and epididymal cells. Although NPC2 mRNA is detected in the liver, plasma and biliary NPC2 protein levels and function have not been reported. This study demonstrates that NPC2 is present in murine and human plasma and bile. In addition, hepatic NPC2 protein expression was dramatically increased in NPC1-deficient mice but not regulated by cholesterol feeding or pharmacological modulation of various nuclear receptors involved in cholesterol and bile acid metabolism. Interestingly, biliary NPC2 levels were 3-fold increased in gallstone-susceptible C57BL6/J versus gallstone-resistant BALB/c mice. Furthermore, NPC2 was exclusively found in the cholesterol pro-nucleating ConA-binding fraction of human bile. In conclusion, NPC2 is secreted from the liver into bile and plasma, where it may have a functional role in cholesterol transport in normal and disease conditions.
Troglitazone inhibits tumor growth in hepatocellular carcinoma in vitro and in vivo (p 134-143)
Jun Yu, Liang Qiao, Lars Zimmermann, Matthias P. A. Ebert, Hongxia Zhang, Wendy Lin, Christoph Röcken, Peter Malfertheiner, Geoffrey C. Farrell
Peroxisome proliferator-activated receptor (PPAR) has been implicated in the differentiation and growth inhibition of cancer cells. We examined the effects of PPAR activation by troglitazone on hepatocellular carcinoma (HCC) cell growth, proliferation, and apoptosis in vitro and in vivo. We also studied relationships between PPAR activation and cyclooxygenase-2 (COX-2) expression. Human HCC cell lines Huh7 and Hep3B were cultured in the presence or absence of troglitazone. Cell growth was determined via WST-1 assay, proliferation by cell cycle analysis and proliferating cell nuclear antigen (PCNA) Western blotting, and apoptosis by flow cytometry and TUNEL. Tumor growth after subcutaneous implantation of Huh7 cells in nude mice was monitored, and the effects of treatment with troglitazone were determined. In resected HCCs, PPAR expression was less compared with the histologically normal surrounding liver. In cultures of Hep3B and Huh7 cells, basal expression of PPAR was relatively low, but troglitazone caused dose-dependent induction of PPAR expression. Cell cycle analysis revealed a decreased proportion of cells in S phase, with arrest at G0/G1. Concomitant downregulation of PCNA and an increase in TUNEL staining, cells were consistent with decreased proliferation and induction of apoptosis by troglitazaone. Troglitazone-mediated PPAR activation also suppressed COX-2 expression and induced p27 in HCC cells. Administration of troglitazone to Huh7 tumor-bearing mice significantly reduced tumor growth and caused tumor regression. In conclusion, collectively, these results indicate that PPAR could be a regulator of cell survival and growth in HCC. PPAR therefore represents a putative molecular target for chemopreventive therapy or inhibition of liver cancer growth.
Nrf2 is increased by CYP2E1 in rodent liver and HepG2 cells and protects against oxidative stress caused by CYP2E1 (p 144-153)
Pengfei Gong, Arthur I. Cederbaum
Induction of CYP2E1 by ethanol is one pathway through which ethanol generates oxidative stress. Nrf2 is a transcription factor that regulates important antioxidant and phase II detoxification genes. Nrf2 induction by CYP2E1 and its importance in the adaptive response to increased oxidative stress caused by CYP2E1 was studied. Increases in Nrf2 protein and mRNA were observed in livers or hepatocytes of chronic alcohol-fed mice or rats and of pyrazole-treated rats or mice, conditions known to elevate CYP2E1. HepG2 cells expressing CYP2E1 (E47 cells) showed increased Nrf2 mRNA and protein expression compared with control HepG2 C34 cells. Nrf2 is activated in E47 cells as shown by an increase in nuclear Nrf2 levels and Nrf2-antioxidant-responsive element binding activity, and upregulation of Nrf2-regultated genes, glutamate cysteine ligase catalytic subunit (GCLC), and heme oxygenase 1 (HO-1). Increases in Nrf2 protein and mRNA are blocked by inhibitors of CYP2E1 activity and a reactive oxygen species (ROS) scavenger, N-acetylcysteine, which decrease ROS levels as well as Nrf2 mRNA induction. Upregulation of GCLC and HO-1 in E47 cells is dependent on Nrf2 and is prevented by siRNA-Nrf2. Blocking Nrf2 by siRNA-Nrf2 decreases glutathione and increases ROS and lipid peroxidation, resulting in decreased mitochondrial membrane potential and loss of cell viability of E47 cells but not C34 cells. These results suggest that Nrf2 is activated and that levels of protein and mRNA are increased when CYP2E1 is elevated. In conclusion, Nrf2 plays a key role in the adaptive response against increased oxidative stress caused by CYP2E1.
TNF-alpha secreting monocytes are recruited into the brain of cholestatic mice (p 154-162)
Steven M. Kerfoot, Charlotte D'Mello, Henry Nguyen, Maureen N. Ajuebor, Paul Kubes, Tai Le, Mark G. Swain
Signaling occurs between the liver and brain in cholestatic liver disease, giving rise to sickness behaviors such as fatigue. However, the signaling pathways involved are poorly defined. Circulating inflammatory mediator levels are increased in cholestasis, leading to speculation that they may be capable of activating circulating immune cells that subsequently could gain access to the brain. Indeed, we have identified that at day 10 after bile duct resection-induced cholestasis, there is activation of circulating monocytes that express tumor necrosis factor (TNF-alpha) in conjunction with increased expression of adhesion molecules by cerebral endothelium. Moreover, using intravital microscopy, we have identified markedly enhanced leukocytes rolling along cerebral endothelial cells, mediated by P-selectin, in bile duct-resected (BDR) but not control mice. In addition, we have identified increased infiltration of monocytes (but not lymphocytes) into the brains of BDR mice and found that these infiltrating monocytes produce TNF-alpha. Furthermore, infiltration of TNF-alpha secreting monocytes into the brains of cholestatic mice is associated with a broad activation of resident brain macrophages to produce TNF-. In conclusion, cholestasis is associated with an activation of cerebral endothelium that recruits TNF--producing monocytes into the brain. We hypothesize that enhanced TNF- alpha release within the brain may contribute to the development of cholestasis-associated sickness behaviors, including fatigue.
Jnk1 but not jnk2 promotes the development of steatohepatitis in mice (p 163-172)
Jörn M. Schattenberg, Rajat Singh, Yongjun Wang, Jay H. Lefkowitch, Raina M. Rigoli, Philipp E. Scherer, Mark J. Czaja
Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis and varying degrees of necroinflammation. Although chronic oxidative stress, inflammatory cytokines, and insulin resistance have been implicated in the pathogenesis of NAFLD, the mechanisms that underlie the initiation and progression of this disease remain unknown. c-Jun N-terminal kinase (JNK) is activated by oxidants and cytokines and regulates hepatocellular injury and insulin resistance, suggesting that this kinase may mediate the development of steatohepatitis. The presence and function of JNK activation were therefore examined in the murine methionine- and choline-deficient (MCD) diet model of steatohepatitis. Activation of hepatic JNK, c-Jun, and AP-1 signaling occurred in parallel with the development of steatohepatitis in MCD diet-fed mice. Investigations in jnk1 and jnk2 knockout mice demonstrated that jnk1, but not jnk2, was critical for MCD diet-induced JNK activation. JNK promoted the development of steatohepatitis as MCD diet-fed jnk1 null mice had significantly reduced levels of hepatic triglyceride accumulation, inflammation, lipid peroxidation, liver injury, and apoptosis compared with wild-type and jnk2 -/- mice. Ablation of jnk1 led to an increase in serum adiponectin but had no effect on serum levels of tumor necrosis factor-. In conclusion, JNK1 is responsible for JNK activation that promotes the development of steatohepatitis in the MCD diet model. These findings also provide additional support for the critical mechanistic involvement of JNK1 overactivation in conditions associated with insulin resistance and the metabolic syndrome.
Exendin-4, a glucagon-like protein-1 (GLP-1) receptor agonist, reverses hepatic steatosis in ob/ob mice (p 173-181)
Xiaokun Ding, Neeraj K. Saxena, Songbai Lin, Narita Gupta, Frank A. Anania
Nonalcoholic fatty liver disease (NAFLD) represents a burgeoning problem in hepatology, and is associated with insulin resistance. Exendin-4 is a peptide agonist of the glucagon-like peptide (GLP) receptor that promotes insulin secretion. The aim of this study was to determine whether administration of Exendin-4 would reverse hepatic steatosis in ob/ob mice. Ob/ob mice, or their lean littermates, were treated with Exendin-4 [10 g/kg or 20 g/kg] for 60 days. Serum was collected for measurement of insulin, adiponectin, fasting glucose, lipids, and aminotransferase concentrations. Liver tissue was procured for histological examination, real-time RT-PCR analysis and assay for oxidative stress. Rat hepatocytes were isolated and treated with GLP-1. Ob/ob mice sustained a reduction in the net weight gained during Exendin-4 treatment. Serum glucose and hepatic steatosis was significantly reduced in Exendin-4 treated ob/ob mice. Exendin-4 improved insulin sensitivity in ob/ob mice, as calculated by the homeostasis model assessment. The measurement of thiobarbituric reactive substances as a marker of oxidative stress was significantly reduced in ob/ob-treated mice with Exendin-4. Finally, GLP-1-treated hepatocytes resulted in a significant increase in cAMP production as well as reduction in mRNA expression of stearoyl-CoA desaturase 1 and genes associated with fatty acid synthesis; the converse was true for genes associated with fatty acid oxidation. In conclusion, Exendin-4 appears to effectively reverse hepatic steatosis in ob/ob mice by improving insulin sensitivity. Our data suggest that GLP-1 proteins in liver have a novel direct effect on hepatocyte fat metabolism.
LPS inhibits endothelin-1-induced endothelial NOS activation in hepatic sinusoidal cells through a negative feedback involving caveolin-1 (p 182-190)
Walid S. Kamoun, Amel Karaa, Nicole Kresge, Sandra M. Merkel, Katarzyna Korneszczuk, Mark G. Clemens
During endotoxemia, liver microcirculation disruption is characterized by a hypersensitivity to the constrictor effects of endothelin 1 (ET-1). The shift of ET-1-mediated effects toward vasoconstriction may result from depressed ET-1-mediated vasodilation through decreased ET-1-induced nitric oxide (NO) production. We have previously shown that lipopolysaccharide (LPS) pretreatment abrogates ET-1-induced endothelial nitric oxide synthase (eNOS) translocation, but its effects on eNOS activation are yet to be determined. Our aim was to assess the effects of LPS on ET-1-mediated eNOS activation in hepatic sinusoidal endothelial cells (SECs) and to investigate the molecular mechanisms involved. SECs were treated with LPS (100 ng/mL) for 6 hours followed by 30 minutes ET-1 (10 nmol/L) stimulation. LPS significantly inhibited ET-1-mediated eNOS activation. This inhibition was associated with upregulation of Caveolin-1 (CAV-1) and a shift in ET-1-mediated eNOS phosphorylation from an activation (Ser1177) to an inhibition (Thr495). LPS treatment has been shown to induce ET-1 expression and secretion from endothelial cells. We therefore investigated the role of endogenous ET-1 in the inhibition of ET-1 activation of eNOS after LPS. Antagonizing ET-1 effects and blocking its activation in LPS pretreated SECs decreased the LPS-induced overexpression of CAV-1 as well as the inhibition of ET-1-induced NOS activity. Furthermore, 6 hours of ET-1 treatment exerted the same effects on eNOS activity, phosphorylation, and CAV-1 expression as LPS treatment. In conclusion, LPS-induced suppression of ET-1-mediated eNOS activation is ET-1 dependent and suggest a pivotal role of CAV-1 in eNOS induction inhibition under stress.
Copyright © 2006 by the American Association for the Study of Liver Diseases. All rights reserved.
EN attente
Copyright © 2001-2006 by the American Gastroenterological Association. All rights reserved.
Table of Contents for January 2006 (Vol. 44, Issue 1)
Editorial
Treatment of lamivudine-resistant hepatitis B in HIV-infected persons: Is adefovir dipivoxil the answer?, 8 November 2005
Thio CL pages 1-3
Full Text
Treating patients with HCV genotype 1 and low viraemia: More than meets the eye, 8 November 2005
Craxì A, Cammà C pages 4-7
Full Text
Hepatocellular carcinoma in the United States. Lessons from a population-based study in Medicare recipients, 8 November 2005
Varela M, Bruix J pages 8-10
Full Text
Forum on Liver Transplantation
“Will all liver transplantation patients eventually die from cancer?”, 8 November 2005
Sanchez W, Talwalkar JA, Gores GJ pages 13-18
Full Text
Who is at risk for post-transplant lymphoproliferative disorders (PTLD) after liver transplantation?, 8 November 2005
Aucejo F, Rofaiel G, Miller Cpages 19-23
Full Text
What is the current treatment of PTLD after liver transplantation?, 8 November 2005
Dufour JF, Fey MF pages 23-26
Full Text
Skin cancers after liver transplantation: What to do?, 8 November 2005
Euvrard S, Kanitakis Jpages 27-32
Full Text
Should we screen for colorectal cancer in liver transplantation?, 8 November 2005
Delcò F, Müllhaupt B pages 32-38
Full Text
Viral Hepatitis
Transmission of occult hepatitis B virus by transfusion to adult and pediatric recipients in Taiwan, 13 July 2005
Liu CJ, Lo SC, Kao JH, Tseng PT, Lai MY, Ni YH, Yeh SH, Chen PJ, Chen DS
Background/Aims
The infectivity of occult hepatitis B virus (HBV), defined as HBsAg-negative but HBV DNA-positive, after transfusion has been low but not negligible. To address this, we investigated the incidence of post-transfusion HBV infection after receiving screened blood units in Taiwan.
Methods
Consecutive HBV-naïve (anti-HBc-negative) recipients with normal ALT were followed for HBV DNA and serologic markers before and after transfusion. Among 4448 blood recipients, 467 (10.5%) were anti-HBc-negative. Post-transfusion 6-month follow-up was completed for 327. We identified 5 (1.5%) who developed hepatitis B viremia 1 week after transfusion. Three were children who later seroconverted to anti-HBc but with normal ALT indicating subclinical acute infection, despite all had anti-HBs from previous vaccination. One had transient transfusion-transmitted HBV without seroconversion to anti-HBc and one possibly had occult HBV infection. Our findings suggested the possibility that occult HBV infection was transmissible by transfusion. The incidence of post-transfusion acute HBV infection was 0.9% (100 per million units) in naïve recipients in Taiwan, a figure 7?40-fold higher than in developed countries. Moreover, some vaccinated children with anti-HBs were still susceptible.
Conclusions
Therefore, despite active immunization, sensitive screening assays for occult HBV infection such as nucleic acid amplification test could be considered in endemic areas.
Slower fibrosis progression in HIV/HCV-coinfected patients with successful HIV suppression using antiretroviral therapy, 28 July 2005
Bräu N, Salvatore M, Ríos-Bedoya CF, Fernández-Carbia A, Paronetto F, Rodríguez-Orengo JF, Rodríguez-Torres M, for the Puerto Rico-New York Hepatitis Study Group
Background/Aims
HIV/HCV-coinfected patients reportedly have a faster fibrosis progression rate (FPR) than HCV-monoinfected patients. This study examined whether HIV suppression through highly active antiretroviral therapy (HAART) attenuates this accelerated fibrosis progression.
Methods
In two hepatitis C centers, a retrospective analysis identified 656 consecutive treatment-naïve HCV-infected patients who had undergone a liver biopsy, had a presumed date of HCV infection, and had been tested for HIV, 274 of them HIV-positive (95.2% on HAART) and 382 HIV-negative. The primary outcome measure was the FPR, defined as Ishak fibrosis score [0–6] over estimated duration of HCV infection.
Results
Among HIV/HCV-coinfected patients, 51.2% had undetectable HIV RNA (<400copies/mL). There was no difference in FPR between HIV/HCV-coinfected and HCV-monoinfected patients (0.136 vs. 0.128 Ishak fibrosis units/year, P=0.29). However, HIV/HCV-coinfected patients with any detectable HIV viral load >400copies/mL had a faster FPR (0.151) than HCV-monoinfected patients (0.128, P=0.015) and than HIV/HCV-coinfected patients with undetectable plasma HIV RNA (0.122, P=0.013) who in turn had the same FPR as HCV-monoinfected subjects (0.128, P=0.52). An accelerated FPR in HIV viremic patients was seen with CD4+ cells <500/mm3 (0.162 vs. 0.123, undetectable HIV RNA, P=0.005) but not with CD4+ cells >500/mm3 (0.118 vs. 0.121, P=0.89). In multivariable linear regression analysis of HIV/HCV-coinfected patients, log10 HIV RNA level, necroinflammation, and age at HCV infection were independently correlated to FPR, but not alcohol use or CD4+ cell count (r2=0.45 for model).
Conclusions
HIV/HCV-coinfected patients with undetectable HIV RNA through HAART have a slower FPR than those with any HIV RNA level and an FPR similar to HCV-monoinfected individuals.
Ophthalmologic side effects during alpha-interferon therapy for viral hepatitis, 22 August 2005
d'Alteroche L, Majzoub S, Lecuyer AI, Delplace MP, Bacq Y
Background/Aims
Ophthalmologic side effects have been reported during interferon therapy, particularly retinal lesions and neurovisual impairment. The aim of this prospective study was to assess the nature and the frequency of such lesions during alpha-interferon therapy for viral hepatitis.
Methods
Between 1995 and 2003, 156 patients treated with standard or pegylated alpha-interferon, with or without ribavirin, had a regular ophthalmologic examination before and during treatment. No patient had signs of retinopathy before treatment. Cotton-wool spots were found in 31 patients and retinal hemorrhage in nine patients during treatment (24% of patients). These lesions remained asymptomatic and disappeared in all patients. A previous history of arterial hypertension (RR 4.60, 95% CI 1.95–10.85), age above 45 years (RR 2.80, 95% CI 1.36–5.85), and use of pegylated alpha-interferon (RR 2.75, 95% CI 1.41–5.38) were significantly associated with retinopathy. Neurovisual impairment was present in 31 patients (20%) before treatment and in 74 patients (47%) during treatment.
Conclusions
In conclusion, this study showed that signs of retinopathy and neurovisual impairment were common in patients receiving alpha-interferon therapy but were rarely symptomatic. It suggests that alpha-interferon may usually be continued in asymptomatic patients as long as there is careful fundoscopic examination.
Safety and efficacy of adefovir dipivoxil in patients infected with lamivudine-resistant hepatitis B and HIV-1, 26 September 2005
Benhamou Y, Thibault V, Vig P, Calvez V, Marcelin AG, Fievet MH, Currie G, Chang CG, Biao L, Xiong S, Brosgart C, Poynard T
Background/Aims
Adefovir dipivoxil (10mg once-daily) was added to antiretroviral therapy including lamivudine in 35 HIV/HBV co-infected patients.
Methods
Parameters evaluated included alanine aminotransferase (ALT), HBV DNA and serological markers, HIV-1 RNA, and CD4+ cell count.
Results
Twenty-nine patients (83%) completed 144 weeks. Serum HBV DNA declined from a baseline 9.76log10 copies/mL (median) to 4.68, 5.24, and 5.90log10 copies/mL at weeks 48, 96, and 144, respectively (P<0.0001 at all time points). Seven patients (25%) achieved HBV DNA<2.3log10 copies/mL. No adefovir-associated resistance mutations in HBV DNA polymerase or HIV-1 reverse transcriptase were detected. ALT declined from 81 IU/L (median) at baseline by ?16.0, ?44.5, and ?46.0 IU/L at week 48, 96 and 144, respectively (P=<0.05, respectively), and normalized in 71% of patients (20 of 28) by week 144. Two patients developed antibodies against HB ‘e’ antigen by week 48. No serious adverse events related to adefovir dipivoxil occurred during the study, and HIV-1 RNA and CD4+ cell counts were stable.
Conclusions
Treatment with adefovir dipivoxil for 144 weeks was well tolerated and resulted in significant and sustained reductions in HBV DNA and ALT in HIV/HBV co-infected patients. Efficacy increased with treatment duration, with no loss of viral suppression.
A pilot approach for quantitative assessment of liver fibrosis using ultrasound: preliminary results in 79 cases, 26 September 2005
Yamada H, Ebara M, Yamaguchi T, Okabe S, Fukuda H, Yoshikawa M, Kishimoto T, Matsubara H, Hachiya H, Ishikura H, Saisho H
Background/Aims
Ultrasound is noninvasive and useful to evaluate liver disease despite its operator dependency. This pilot study was conducted to quantitatively assess liver fibrosis using ultrasound.
Methods
Fibrosis extraction ratios (FER) (fiber volume/total volume) of ultrasound and histological images of 8 autopsy specimens were compared. We also compared FER of ultrasound images from clinical patients (n=79) with histological fibrosis stages.
Results
In the autopsy study, FER correlation coefficient between histological images and ultrasound images was 0.992. Regarding clinical patients, there was sufficient evidence to indicate differences in the distributions of FER for each fibrosis stage (Kruskal–Wallis test P<0.0001). With FER cut-off to distinguish ≥F2 from F0 and F1 defined as mean plus standard deviation of F0 and F1, sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio were 62, 75, 78, 57%, and 2.47, respectively. Regarding HCV cohort (n=44), they were 55, 87, 89, 50%, and 4.14, respectively. Areas under receiver operating characteristic curves were 0.78, 0.79, 0.83 and 0.83 for ≥F1, ≥F2, ≥F3 and =F4, respectively. Regarding HCV cohort, they were 0.74, 0.71, 0.79 for ≥F2, ≥3 and =4, respectively.
Conclusions
The FER method has great potential for diagnosing liver fibrosis using ultrasound.
Comparison of sequence changes of precore and core promoter regions in HBeAg-positive chronic hepatitis B patients with and without HBeAg clearance in lamivudine therapy, 26 September 2005
Chen CH, Lee CM, Lu SN, Changchien CS, Wang JC, Wang JH, Hung CH, Hu TH
Background/Aims
The aim of this study was to compare the serial sequence changes of precore and core promoter regions in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) patients with and without HBeAg clearance in lamivudine treatment.
Methods
Precore and core promoter genes of the hepatitis B virus (HBV) were sequenced from five serial serum samples of 74 HBeAg-positive CHB patients received lamivudine for 9–12 months (34 complete responders and 40 non-responders).
Results
Before lamivudine therapy, stepwise logistic regression analysis disclosed that ALT level≥300 U/L, A1896 mutant, and log HBV DNA levels were the major determinants for complete response. In addition, Cox regression showed that age<35 years and G1752 mutant were independent factors for sustained response. Compared with complete responders, a higher frequency of mutation in nucleotides 1773, 1802, 1803, 1845, 1850, and 1858 was found in the non-responders during therapy. Lamivudine therapy resulted in a further increase in T1762/1764 mutants and a further decrease in A1896 mutant during treatment and after HBeAg clearance in complete responders.
Conclusions
T1762/A1764 mutation (not A1896) played an important role in lamivudine-induced HBeAg clearance. Moreover, T1773, C1802, G1803, T1846, A1850, and C1858 mutations might have significant correlation with HBeAg nonseroconversion.
Hepatitis C minimal residual viremia (MRV) detected by TMA at the end of Peg-IFN plus ribavirin therapy predicts post-treatment relapse, 26 September 2005
Gerotto M, Dal Pero F, Bortoletto G, Ferrari A, Pistis R, Sebastiani G, Fagiuoli S, Realdon S, Alberti A
Background/Aims
Around 15–25% of chronic hepatitis C patients treated with Peg-IFN plus ribavirin become HCV-RNA negative by PCR during therapy but relapse after its withdrawal. We investigated whether minimal residual viremia (MRV) might be detected in these cases by Transcription-Mediated Amplification (TMA).
Methods
Two hundred and ninety-two consecutive patients (143 HCV-1, 82 HCV-2, 56 HCV-3 and 11 HCV-4) were prospectively treated with a standard schedule of Peg-IFN? 2b plus ribavirin combination and end-of-therapy response was assessed by conventional PCR using 2 protocol serum samples obtained 6–8h before the last two scheduled weekly injections of Peg-IFN. PCR negative samples were re-tested by TMA and the results were then correlated with the virological outcome after therapy withdrawal.
Results
Among 208 patients who were repeatedly HCV-RNA negative by PCR at the end-of-therapy, 26 (12.5%) were found HCV-RNA positive by TMA. Twenty-two of them, (96%) were PCR-relapsers after therapy withdrawal, compared to only 14% of the 182 TMA negative patients (P<0.0001). This virological profile was more frequent in HCV-1 and HCV-3 infected patients and correlated with a slower virological response during therapy.
Conclusions
At the end of Peg-IFN plus ribavirin therapy, TMA is superior to PCR in identifying patients with sustained HCV-RNA clearance.
A phase I trial of an antisense inhibitor of hepatitis C virus (ISIS 14803), administered to chronic hepatitis C patients, 25 October 2005
McHutchison JG, Patel K, Pockros P, Nyberg L, Pianko S, Yu RZ, Andrew Dorr F, Kwoh T J
Background/Aims
ISIS 14803 is a 20-unit antisense phosphorothioate oligodeoxynucleotide that binds to hepatitis C virus (HCV) RNA at the translation initiation region of the internal ribosome entry site (IRES) and inhibits protein expression in cell culture and mouse models. This Phase I, open-label, dose-escalation trial of ISIS 14803 was performed in chronic HCV patients.
Methods
At least 7 days after receiving an initial single dose, twenty-eight patients received 0.5–3mg/kg ISIS 14803 thrice weekly for 4 weeks by intravenous infusion or subcutaneous injection.
Results
In most patients, the 4-week treatment did not reduce plasma HCV RNA. However, 3 patients receiving ≥2mg/kg had transient HCV reductions of 1.2–1.7log10 that persisted ≤32 days. These reductions were accompanied by asymptomatic, self-resolving elevations in serum alanine transaminase (ALT) levels to >10? the upper limit of normal. Two other patients had ALT flares without plasma HCV reduction. No clinical signs, symptoms of hepatic dysfunction, or laboratory changes in albumin or prothrombin time accompanied ALT elevations.
Conclusions
ISIS 14803 treatment was associated with HCV reductions in only 3/28 patients. ALT flares in 5 patients also occurred. Further studies to evaluate ISIS 14803 treatment and the mechanisms of the ALT flares are now required.
Efficacy of 24 weeks treatment with peginterferon alfa-2b plus ribavirin in patients with chronic hepatitis C infected with genotype 1 and low pretreatment viremia, 8 November 2005
Zeuzem S, Buti M, Ferenci P, Sperl J, Horsmans Y, Cianciara J, Ibranyi E, Weiland O, Noviello S, Brass C, Albrecht J
Background/Aims
Previous studies using standard interferon and ribavirin combination therapy suggested that patients infected with HCV-1 and a low pretreatment HCV-RNA level can be treated for 24 weeks without compromising sustained virologic response rates. The aim of the present study was to investigate this schedule in the era of pegylated interferon-? plus ribavirin.
Methods
Patients chronically infected with HCV-1 (n=235) and a screening viremia ≤600,000IU/mL (real-time PCR) were treated with peginterferon alfa-2b 1.5?g/kg subcutaneously once weekly plus ribavirin 800–1400mg/day based on body weight for 24 weeks.
Results
End-of-treatment and sustained virologic response rates were 80 and 50%, respectively. The 48-week historical control (Manns et al., Lancet 2001;358:958–65) had similar end-of-treatment (74%) but higher sustained virologic response rates (71%). This difference was due to a high virologic relapse rate after 24 weeks of therapy (37%) compared with the historical control (4%). A subset of patients who had undetectable serum HCV-RNA at treatment week 4, however, achieved similar sustained virologic response rate (89%) as in the control group (85%).
Conclusions
HCV-1 infected patients with a low baseline HCV-RNA concentration who become HCV-RNA negative at week 4 may be treated for 24 weeks without compromising sustained virologic response rates.
Cirrhosis and its Complications
Neuropsychological abnormalities in cirrhosis include learning impairment, 11 July 2005
Ortiz M, Córdoba J, Jacas C, Flavià M, Esteban R, Guardia J
Background/Aims
Minimal hepatic encephalopathy is a neurocognitive disorder secondary to liver failure that is characterized by a pattern of subcortical impairment. The most conspicuous neuropsychological abnormalities are on attention and psychomotor tests; memory has been inconsistently implicated. We designed a study to assess the presence of memory abnormalities in cirrhotic patients and the effects of liver transplantation.
Methods
Ninety-seven cirrhotics without overt hepatic encephalopathy underwent neuropsychological assessment, including the Auditory Verbal Learning Memory Test. The results were compared to those of healthy controls (n=75) and the assessment was repeated at one year of follow-up (n=33) or after liver transplantation (n=23).
Results
Cirrhotic patients exhibited multiple neuropsychological abnormalities, including several disturbances of the Auditory Verbal Learning memory test: learning, long-term memory and recognition. Abnormalities of long-term memory and recognition were corrected after adjusting for learning impairment. Memory abnormalities correlated to attention impairment and to parameters of liver function. Neuropsychological indexes following liver transplantation did not differ from controls. Repeated testing did not have a major effect on neuropsychological tests in healthy subjects and in non-transplanted cirrhotics.
Conclusions
Learning impairment is present in cirrhotic patients with neuropsychological abnormalities. This abnormality is consistent with attention deficit secondary to minimal hepatic encephalopathy.
Histological-hemodynamic correlation in cirrhosis—a histological classification of the severity of cirrhosis, 26 September 2005
Nagula S, Jain D, Groszmann RJ, Garcia-Tsao G
Background/Aims
While the definitive diagnosis of cirrhosis is histological, it is the degree of portal hypertension, as determined by the hepatic venous pressure gradient (HVPG), that is an important determinant of the severity of cirrhosis. An HVPG ≥10mmHg (termed clinically significant portal hypertension or CSPH) is predictive of the development of complications of cirrhosis, including death. This study aimed to determine the relationship between specific histological parameters and HVPG in cirrhosis.
Methods
Forty-three patients with biopsy-proven cirrhosis and HVPG measurements within 6 months of the biopsy were included in the study. The following parameters were scored semiquantitatively and without knowledge of HVPG results: sinusoidal fibrosis, septal thickness, loss of portal tracts and central veins, nodule size, inflammation, steatosis, and iron.
Results
Septal thickness (p=0.03), small nodularity (p=0.003), loss of portal tracts (p=0.01), inflammation (p=0.04) and alcoholic etiology (p=0.01) correlated with the presence of CSPH. However, small nodularity and septal thickness were the only parameters independently predictive of CSPH (r=0.658, p<0.05).
Conclusions
We describe a subclassification of histological cirrhosis based on the severity of portal hypertension that consists of a combination of nodule size and septal thickness, with small nodularity and thick septa being independent predictors of the presence of CSPH.
Transplantation
Cadaveric full-size liver transplantation and the graft alternatives in adults: A comparative study from a single centre, 25 August 2005
Sebagh M, Yilmaz F, Karam V, Falissard B, Ichaï P, Roche B, Castaing D, Guettier C, Samuel D, Azoulay D
Background/Aims
This study aims to compare the results of living donor (LDLT), cadaveric split (SLT) and domino (DO) liver transplantation which are currently available alternatives to the conventional cadaveric full-size liver transplantation (CAD).
Methods
Immunologic, vascular and biliary complications (BC) were evaluated in 38 LDLT, 20 SLT, 17 DO and 38 CAD recipients.
Results
The incidence of acute rejection (AR) was similar between groups, and between blood-related and blood-unrelated patients. AR was more severe in the SLT group according to the Banff scores (P=0.03, P<0.001, P<0.001). The evolution of AR was similar between the groups, in terms of development of chronic rejection. No venous complications occurred in the overall population. The rate of arterial thrombosis (10.5, 10, 0 and 3%, respectively) was statistically similar between groups. The rate of BC (26, 40, 12, and 8%, respectively) was higher in the partial grafts than in the whole grafts (P=0.006), but was not significantly different within each group. There was an association between the severity of preservation injury and occurrence of AR (P=0.01) and arterial thrombosis (P=0.016), but not BC. One- and 2-year graft and patient survival rates were similar between groups.
Conclusions
None of the graft types seemed to confer immunological advantage. BC remained problematic in the partial grafts, independently from ischemia time.
Liver Failure, Growth and Cancer
Selection of tumour specific promoters for adenoviral gene therapy of cholangiocarcinoma, 11 July 2005
Lie-A-Ling M, Bakker CT, Deurholt T, Hoekstra R, Wesseling JG, Afford SC, Bosma PJ
Background/Aims
The majority of cholangiocarcinoma patients present with advanced incurable disease. Therefore development of new therapeutic modalities including adenoviral gene therapy is of paramount importance. We set out to identify tumour specific promoters which have low activity in human liver cells and retain their specificity in an adenoviral vector.
Methods
mRNA levels of cyclo-oxygenase-2, cytokeratin-19, mucin-1, midkine and telomerase reverse transcriptase (TERT) were determined in human liver, cholangiocarcinoma (resection specimens and cell lines), primary human hepatocytes, cholangiocytes and endothelial cells by Reverse Transcriptase-quantitatve PCR. The activity of candidate promoters in adenoviral vectors was then determined in cholangiocarcinoma cell lines, primary human hepatocytes and cholangiocytes.
Results
mRNA levels of all tested tumour markers were significantly higher in cholangiocarcinoma than in normal liver. Based on low expression in hepatocytes, either in combination with low expression in primary cholangiocytes or endothelial cells, the cytokeratin-19, mucin-1 and TERT promoters were selected for further analyses. In an adenoviral vector, the activity of the TERT or cytokeratin-19 promoters were low in normal human hepatocytes and cholangiocytes, and high in cholangiocarcinoma cell lines.
Conclusions
The TERT and Cytokeratin-19 promoters are highly expressed in cholangiocarcinoma and seem suitable to restrict adenoviral gene therapy to these intra-hepatic tumours.
Characterization of acute liver failure and development of a continuous risk of death staging system in children, 18 July 2005
Liu E, MacKenzie T, Dobyns EL, Parikh CR, Karrer FM, Narkewicz MR, Sokol RJ
ackground/Aims
Acute liver failure (ALF) in children has been associated with an overall mortality of approximately 70% in the pretransplant era and 50–80% survival in those undergoing orthotopic liver transplantation. There is currently no system for staging severity of ALF in children. The aim of this study was to characterize pediatric ALF in a tertiary hospital and to derive a scoring system to stratify severity of ALF based on predicted mortality.
Methods
Prospective data collection of 81 children from December 1993–2003 who presented with ALF. Data recorded included peak laboratory values, clinical characteristics, and survival.
Results
Transplant-free survival was 56% with overall survival including those undergoing OLT of 72%. Transplantation rate was 22% with transplant survival of 72%. Of the peak laboratory values analyzed, total bilirubin, prothrombin time/INR, and ammonia were the most predictive of death or a need for liver transplant. A simple risk staging system was developed based on the ability of these three laboratory measurements to predict mortality.
Conclusions
The survival in pediatric ALF has improved in recent years. Risk staging for ALF could potentially be used in clinical research for risk-adjusted outcomes analysis and to help stratify patients for clinical studies according to mortality risk.
Pamidronate induced anti-proliferative, apoptotic, and anti-migratory effects in hepatocellular carcinoma, 10 November 2005
Wada A, Fukui K, Sawai Y, Imanaka K, Kiso S, Tamura S, Shimomura I, Hayashi N
Background/Aims
The small GTPase of Ras and Rho families are widely involved in human tumorgenesis and metastasis. It has recently been reported that pamidronate inhibits the mevalonate pathway, which is required for the prenylation of the small GTPase. We demonstrated a possible beneficial use of pamidronate in the treatment of hepatocellular carcinoma (HCC).
Methods
The effect of pamidronate on cell proliferation was analyzed with five hepatoma cell lines using MTT assay. Apoptosis was evaluated by staining with DAPI and a histon ELISA assay. A cell migration assay was performed using the Modified Boyden Chamber. To analyze anti-proliferation effect of pamidronate in vivo, tumor volumes were monitored with the intraperitoneal injection of pamidronate after subcutaneous inoculation of PLC/PRF/5 cells into nude mice.
Results
Pamidronate inhibited cell growth for all hepatoma cell lines. The amount of membrane associated Ras and phosphorylated extracellular signal-regulated kinase 2 (ERK 2) were reduced after pamidronate treatment. Pamidronate increased apoptosis and cleavage of Caspase-3, and -9. Pamidronate suppressed membrane associated RhoA and cell motility. In vivo, tumor volumes were significantly suppressed by pamidronate at three weeks (P<0.03).
Conclusions
We conclude that pamidronate has therapeutic potential in inducing anti-proliferative, apoptotic, and anti-migratory effects in HCC.
Mcl-1 overexpression in hepatocellular carcinoma: A potential target for antisense therapy, 25 October 2005
Sieghart W, Losert D, Strommer S, Cejka D, Schmid K, Rasoul-Rockenschaub S, Bodingbauer M, Crevenna R, Monia BP, Peck-Radosavljevic M, Wacheck V
Background/Aims
Recently, the anti-apoptotic Mcl-1 protein has been reported as a resistance factor in various types of cancer. Here we investigated the presence of Mcl-1 protein in hepatocellular carcinoma (HCC) tissues and its potential role as a molecular drug target for HCC therapy.
Methods
HCC specimens of 149 patients were examined by immunohistochemistry for Mcl-1 expression. Antisense oligonucleotides (ASO) targeting Mcl-1 were evaluated as monotherapy and in combination with cisplatin in the HCC cell lines HepG2 and Snu398. Protein regulation, cell viability, and apoptosis were assessed by western blotting, cell counting, and FACS analysis.
Results
Mcl-1 protein is overexpressed in 51% of all cases irrespective of underlying disease. Targeting Mcl-1 by ASO specifically downregulated Mcl-1 protein expression and led to significant dose and time dependent single agent activity in HCC cells characterized by increased apoptosis and decreased cell viability. No significant target regulation or cell death was observed for control oligonucleotide treatment. Upon combination with cisplatin, Mcl-1 ASO revealed a significant chemosensitizing effect.
Conclusions
Mcl-1 is overexpressed in half of HCC-tissues. ASO targeting Mcl-1 revealed a prominent single agent and chemosensitizing activity against HCC in vitro. Targeting Mcl-1 might qualify as a promising novel approach in HCC therapy.
Treatment and outcomes of treating of hepatocellular carcinoma among Medicare recipients in the United States: A population-based study, 31 October 2005
El-Serag HB, Siegel AB, Davila JA, Shaib YH, Cayton-Woody M, McBride R, McGlynn KA
Background/Aims
There are several treatment alternatives available for patients diagnosed with hepatocellular carcinoma (HCC). Yet, neither the extent to which potentially curative or palliative therapy is used to treat HCC, nor the determinants of using such therapies are known. Further, it is unclear how effective different modalities are for treating HCC.
Methods
We used the linked SEER-Medicare dataset to identify patients diagnosed with HCC between 1992 and 1999.We identified 2963 patients with continuous Medicare enrollment who were not enrolled in a Medicare-HMO. HCC treatments were categorized as potentially curative therapy (resection, transplant, local ablation), or palliative (trans-arterial chemoembolization (TACE), chemotherapy), and no therapy. Demographic (age, sex, race, geographic region), clinical (comorbidity, risk factors and severity of liver disease) and tumor factors (tumor size, extent of disease) were examined as potential determinants of therapy, as well as survival in univariate and multivariable analyses. Survival curves were also generated and compared among the different treatment modalities.
Results
The median age at diagnosis was 74 years (range: 32–105), and most patients (91%) were older than 65 years. Approximately 68% were White, 10% Black, 4% Hispanic, 8% Asian, and 9% were of other race. Thirteen percent of the patients received potentially curative therapy (transplant 0.9%, resection 8.2%, local ablation 4.1%), 4% received TACE, 57% received other palliative therapy, and 26% received no specific therapy. Only 34% of 513 patients with single lesions, and 34% of 143 patients with lesions <3.0cm received potentially curative therapy. However, 19.2% of patients with unfavorable tumor features (lesion >10.0cm) received such therapy. Among patients who received potentially curative therapy (n=392), resection was the most common procedure (n=243, 62%) followed by local ablation (n=122, 31%) and finally transplantation (n=27, 7%). In regression analyses, geographic variations in the extent and type of curative therapy persisted after adjusting for demographic, clinical, and tumor features. Median overall survival was 104 days following HCC diagnosis with the longest survival in the transplant group (852 days) and the shortest survival in the group with no treatment (58 days). In the survival analysis, transplantation led to the longest survival, followed by resection. Neither ablation nor TACE yielded prolonged survival (3 year survival was less than 10%).
Conclusions
In this predominantly 65 years and older Medicare population, there are marked geographic variations in the management of HCC that seem to be at least as important as clinical and tumor-related features in determining the extent and type of HCC therapy. There is underutilization of potentially curative therapy, even among those with favorable tumor features.
Molecular and Cell Biology
Oral imatinib treatment reduces early fibrogenesis but does not prevent progression in the long term, 13 July 2005
Neef M, Ledermann M, Saegesser H, Schneider V, Widmer N, Decosterd LA, Rochat B, Reichen J
Background/Aims
Transactivated hepatic stellate cells (HSCs) represent the key source of extra cellular matrix (ECM) in fibrotic liver. Imatinib, a potent inhibitor of the PDGF receptor tyrosine kinase, reduces HSC proliferation and fibrogenesis when treatment is initiated before fibrosis has developed. We tested the antifibrotic potential of imatinib in ongoing liver injury and in established fibrosis.
Methods
BDL-rats were gavage fed with 20mg/kg/d imatinib either early (days 0–21) or late (days 22–35) after BDL. Untreated BDL-rats served as controls. ECM and activated HSCs were quantified by morphometry. Tissue activity of MMP-2 was determined by gelatin zymography. mRNA expression of TIMP-1 and procollagen ?1(I) were measured by RT-PCR. Liver tissue concentration of imatinib was measured by tandem mass spectrometry.
Results
Early imatinib reduced ECM formation by 30% (P=0.0455) but left numbers of activated HSCs and procollagen I expression unchanged. MMP-2 activity and TIMP-1 expression were reduced by 50%. Late imatinib treatment did not alter histological or molecular markers of fibrogenesis despite high imatinib tissue levels.
Conclusions
The antifibrotic effectiveness of imatinib is limited to the early phase of fibrogenesis. In ongoing liver injury other mediators most likely compensate for the inhibited PDGF effect.
Limited iron export by hepatocytes contributes to hepatic iron-loading in the Hfe knockout mouse, 26 September 2005
Chua ACG, Drake SF, Herbison CE, Olynyk JK, Leedman PJ, Trinder D
Background/Aims
In hereditary hemochromatosis, iron-loading of hepatocytes is associated with increased iron uptake while little is known about iron release. This study aims to characterise iron release and ferroportin expression by Hfe knockout hepatocytes to determine if they contribute to iron overload in haemochromatosis.
Methods
Iron release by hepatocytes from Hfe knockout, non-iron-loaded and iron-loaded wild-type mice was measured after incubation with nontransferrin-bound iron as iron-citrate.
Results
Iron release and ferroportin expression by hepatocytes from Hfe knockout, non-iron-loaded and in vivo iron-loaded wild-type mice were similar although, nontransferrin-bound iron uptake was significantly increased in Hfe knockout hepatocytes and decreased in iron-loaded wild-type hepatocytes compared with non-iron-loaded wild-type cells. When expressed as a percentage of total iron uptake, iron release was decreased in Hfe knockout hepatocytes (4.6±0.7 versus 13.7±1.2%, P<0.0001) and increased in iron-loaded wild-type hepatocytes (29.5±0.5 versus 13.5±0.7%; P<0.0001) compared with wild-type hepatocytes. In contrast, in vitro iron-loading increased iron release and ferroportin expression by both Hfe knockout and wild-type hepatocytes.
Conclusions
Hfe knockout hepatocytes accumulate iron as a result of limited iron export and enhanced iron uptake. The correlation between iron release and ferroportin expression suggests that iron export in hepatocytes is mediated by ferroportin.
Genetic and Metabolic Liver Disease
Anti-phospholipid antibodies associated with alcoholic liver disease target oxidized phosphatidylserine on apoptotic cell plasma membranes, 11 July 2005
Vay D, Rigamonti C, Vidali M, Mottaran E, Alchera E, Occhino G, Sartori M, Albano E
Background/Aims
Circulating anti-phospholipid antibodies (aPL) are often present in patients with alcoholic liver disease (ALD). The observations that defects in the disposal of apoptotic corpses leads to the development of aPL prompted us to investigate whether ALD-associated aPL might recognize antigens in apoptotic cells.
Methods
Apoptosis was induced in HuT-78 human T-lymphoma and HepG2 hepatoma cells by, respectively, FAS ligation with CH11 monoclonal antibodies or the incubation with ethanol (400mmol/L).
Results
Flow cytometry revealed that IgG from ALD patients with high aPL titers selectively bind to the surface of apoptotic, but not to viable cells. No binding was instead evident using either control or aPL-negative ALD sera. ELISA assays using different oxidized phospholipids as antigens showed that anti-phospholipid reactivity of ALD sera was mainly directed towards oxidized cardiolipin and phosphatidylserine. The pre-adsorption of aPL-positive sera with oxidized phosphatidylserine, but not with oxidized cardiolipin, lowered aPL binding to apoptotic HuT-78 cells by about 50%. No effect was instead observed by pre-adsorption with oxidation-protected phospholipids or with human serum albumin adducted with different lipid peroxidation products.
Conclusions
aPL associated with ALD target apoptotic cells by specifically recognizing oxidized phosphatidylserine, suggesting a possible link between hepatocyte apoptosis and anti-phospholipid auto-reactivity in ALD.
Hepatic steatosis and insulin resistance: Does etiology make a difference?, 13 July 2005
Lonardo A, Lombardini S, Scaglioni F, Carulli L, Ricchi M, Ganazzi D, Adinolfi LE, Ruggiero G, Carulli N, Loria P
Background/Aims
To ascertain whether the etiology of hepatic steatosis modulates insulin resistance (IR) and to determine the predictors of IR.
Methods
We studied IR through HOMA IR in 146 subjects, 99 of whom had ultrasonographic and/or histologic steatosis. Twenty-two had familial heterozygous hypobetalipoproteinemia (FHBL), 48 had non-alcoholic fatty liver disease (NAFLD), 34 HCV infection (17 with HCV1b, 17 with HCV3a) and 42 were healthy controls without steatosis.
Results
Steatosis was present in 77.3% of FHBL and, by enrolment criteria, in all NAFLD and HCV cases. Overall HOMA-IR correlated with BMI and GGT (P<0.01). FHBL and healthy groups had similar HOMA-IR and GGT values, whereas higher levels were observed in HCV and NAFLD. HCV3a and FHBL patients were hypolipidemic. HOMA-IR was similar in FHBL patients and controls and lower than in HCV and NAFLD. FHBL patients had a high extent of steatosis, similar to that observed in HCV3a, but lower grading and staging than NAFLD and HCV. At multivariate analysis, steatosis and GGT predicted HOMA-IR.
Conclusions
Data suggest that not all hepatic fat associates with IR. FHBL patients, for some aspects, resemble HCV3a infection, possibly suggesting a shared steatogenic mechanism. Among steatotic patients serum GGT levels is the independent predictor of IR.
Special article
Non-alcoholic steatohepatitis: From cell biology to clinical practice, 6 October 2005
Cortez-Pinto H, de Moura MC, Day CP pages 197-208
Full Text
Review
Nitric oxide and portal hypertension: Interface of vasoreactivity and angiogenesis, 4 November 2005
Langer DA, Shah VH pages 209-216
Full Text
Natural history and prognostic indicators of survival in cirrhosis: A systematic review of 118 studies, 10 November 2005
D'Amico G, Garcia-Tsao G, Pagliaro L pages 217-231
Full Text
Copyright © 2001-2006 European Association for the Study of the Liver. All rights reserved.
Copyright © 2005 BMJ Publishing Group Ltd
Volume 354 - January 5, 2006 - Number 1
Safety and Efficacy of an Attenuated Vaccine against Severe Rotavirus Gastroenteritis
G. M. Ruiz-Palacios and Others
Background The safety and efficacy of an attenuated G1P[8] human rotavirus (HRV) vaccine were tested in a randomized, double-blind, phase 3 trial.
Methods We studied 63,225 healthy infants from 11 Latin American countries and Finland who received two oral doses of either the HRV vaccine (31,673 infants) or placebo (31,552 infants) at approximately two months and four months of age. Severe gastroenteritis episodes were identified by active surveillance. The severity of disease was graded with the use of the 20-point Vesikari scale. Vaccine efficacy was evaluated in a subgroup of 20,169 infants (10,159 vaccinees and 10,010 placebo recipients).
Results The efficacy of the vaccine against severe rotavirus gastroenteritis and against rotavirus-associated hospitalization was 85 percent (P<0.001 for the comparison with placebo) and reached 100 percent against more severe rotavirus gastroenteritis. Hospitalization for diarrhea of any cause was reduced by 42 percent (95 percent confidence interval, 29 to 53 percent; P<0.001). During the 31-day window after each dose, six vaccine recipients and seven placebo recipients had definite intussusception (difference in risk, –0.32 per 10,000 infants; 95 percent confidence interval, –2.91 to 2.18; P=0.78).
Conclusions Two oral doses of the live attenuated G1P[8] HRV vaccine were highly efficacious in protecting infants against severe rotavirus gastroenteritis, significantly reduced the rate of severe gastroenteritis from any cause, and were not associated with an increased risk of intussusception.
The New England Journal of Medicine is owned, published, and copyrighted © 2005 Massachusetts Medical Society. All rights reserved.
Volume 367, Number 9504, 7 January 2006
Liver cirrhosis mortality rates in Britain from 1950 to 2002: an analysis of routine data
The Lancet 2006; 367:52-56
David A Leon and Jim McCambridge
Background
Rates of mortality due to cirrhosis of the liver are an important indicator of population levels of alcohol harm. Total recorded alcohol consumption in Britain doubled between 1960 and 2002, giving rise to a need to examine and assess cirrhosis mortality trends.
Methods
Mortality rates were calculated for all ages and for specific age-groups (15–44 years and 45–64 years) for cirrhosis of the liver. Rates were directly age-standardised to the European standard population and compared with rates from 12 western European countries for the period 1955–2001.
Findings
Cirrhosis mortality rates increased steeply in Britain during the 1990s. Between the periods 1987–1991, and 1997–2001, cirrhosis mortality in men in Scotland more than doubled (104% increase) and in England and Wales rose by over two-thirds (69%). Mortality in women increased by almost half (46% in Scotland and 44% in England and Wales). These relative increases are the steepest in western Europe, and contrast with the declines apparent in most other countries examined, particularly those of southern Europe. Cirrhosis mortality rates in Scotland are now one of the highest in western Europe, in 2002 being 45·2 per 100?000 in men and 19·9 in women.
Interpretation
Current alcohol policies in Britain should be assessed by the extent to which they can successfully halt the adverse trends in liver cirrhosis mortality. The situation in Scotland warrants particular attention.
The Lancet, published, and copyrighted © 2006. All rights reserved.
