- Email: [email protected]
88 EFFECT OF CANNABINOID CB1-RECEPTOR ANTAGONISM ON ASCITIC DECOMPENSATION OF RATS WITH PREASCITIC CIRRHOSIS
S38
Friday, 25 April
86 EFFECTS OF PROPHYLACTIC ANTIBIOTICS ON TOLL-LIKE RECEPTOR (TLR) 2 AND 4 EXPRESSION ON PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) IN PATIENTS WITH DECOMPENSATED CIRRHOSIS A.G. Testro1,2 , K. Visvanathan2 , N.A. Skinner2 , V. Markovska2 , S. Wongseelashote1 , P.W. Angus1 , P.J. Gow1 . 1 Department of Medicine, The University of Melbourne, Melbourne, Victoria, 2 Department of Medicine, Monash University, Victoria, Australia E-mail: [email protected] Background and Aims: TLRs are pivotal in the innate immune recognition of microbial structures, resulting in the production of proinflammatory cytokines, and the priming of an adaptive immune response. TLR4 recognises lipopolysaccharide on gram-negative (G−) bacteria, while TLR2 recognises peptidoglycan on gram-positives (G+). We aimed to determine whether TLR expression is altered in cirrhosis and if this is affected by treatment with antibiotics used to prevent spontaneous bacterial peritonitis (SBP). Methods: 62 patients were included (23 age/sex matched healthy controls and 39 Child-Pugh C cirrhotics). 29 cirrhotics were taking either norfloxacin or trimethoprim-sulfamethoxazole as prophylaxis against SBP and 10 were not receiving prophylaxis. Paired blood samples were taken from a further 7 patients before and after commencing prophylactic antibiotics. 40 mls of blood was taken from each patient. PBMC were extracted using Ficoll-Paque density gradient centrifugation. PBMC expression of TLR2 and 4 was determined using flow cytometry, producing a ratio of the geometric mean of fluorescence intensity to that of a matched isotype control. Results are presented as medians relative to controls (control median = 1.0). Results: There were no differences in Child-Pugh score, age, disease aetiology or sex distribution between patients receiving antibiotics and those who were not. However, cirrhotic patients not taking antibiotics had significantly decreased TLR4 expression compared with both controls (0.74 vs. 1.0, p = 0.01) and patients receiving antibiotics (0.74 vs. 1.125, p = 0.01). There was no difference in TLR4 expression between antibiotic treated patients and controls (p = 0.88). Conversely, antibiotic treated patients expressed lower TLR2 compared to those not on antibiotics (0.909 vs. 1.091, p = 0.04). In the 7 patients with paired samples, TLR4 expression increased significantly from 0.689 to 1.331 (p = 0.002) following commencement of antibiotics, whilst there was a trend towards decreased TLR2 expression from 0.957 to 0.859 (p = 0.28). Conclusions: TLR4 expression is decreased in Child-Pugh C cirrhotics, but is restored by antibiotics targeting enteric G− bacteria. This suggests that the high incidence of G− sepsis in cirrhotics is in part due to downregulation of the host’s TLR4 dependant innate immune response and that this may be mediated by chronic exposure to G− bacterial products. 87 EFFECTS OF THE MULTIKINASE INHIBITOR, SORAFENIB, ON PORTAL PRESSURE, HYPERDYNAMIC CIRCULATION, AORTIC CONTRACTILITY, AND DYSREGULATED RHO-KINASE IN RATS WITH SECONDARY BILIARY CIRRHOSIS M. Hennenberg, C. Stark, J. Trebicka, T. Sauerbruch, J. Heller. Dept. Internal Medicine I, University of Bonn, Bonn, Germany E-mail: [email protected] Background: In cirrhosis, portal hypertension is triggered by splanchnic vasodilation and increased intrahepatic vascular resistance. This results partially from dysregulation of the contraction-mediating Rho-kinase. Whereas Rho-kinase expression and activity is downregulated in preportal vessels (Gastroenterology 2006;130), it is upregulated in the intrahepatic circulation in cirrhotic rats (Gut 2006;55). The signaling module Ras/Rafkinase/MEK/ERK has been shown to regulate Rho-kinase expression.
Here, we tested the hemodynamic and vascular effects of the multikinase inhibitor, sorafenib, in rats with secondary biliary cirrhosis, which inhibits Raf-kinase among others. Methods: Cirrhosis in rats was induced by bile duct ligation (BDL). One group was treated with sorafenib for one week (60 mg/kg/d, p.o.). Hemodynamic measurements were performed invasively. Contractility of isolated aortic rings was determined by myographic measurements (with the inhibitor of nitric oxide synthases, L-NAME 200 mM). Expression and phosphorylation of proteins was asessed by Western-blot analysis. Rho-kinase activity was evaluated as phosphorylation of the Rho-kinase substrate moesin (thr558). Results: Treatment of BDL rats with sorafenib reduced portal pressure (19±3.3 mmHg in BDL, 11.5±3.4 mmHg in Sorafenib-treated BDL). Contractility (Emax) and sensitivity (EC50) of isolated aortic rings of BDL rats to the a1 adrenergic agonist, methoxamine, were improved by treatment with sorafenib (Emax 0.53±0.04 g in BDL, 0.88±0.12 g in Sorafenibtreated BDL; EC50 4.7 microM in BDL, 2.8 microM in Sorafenib-treated BDL). Treatment of BDL rats with sorafenib caused upregulation of Rhokinase expression and moesin-phosphorylation in aortas from BDL rats, and in parallel downregulation of Rho-kinase expression and moesinphosphorylation in liver homogenates. Conclusions: Sorafenib might correct vascular dysregulation of Rhokinase and shows benefical effects on hyperdynamic circulation in cirrhotic BDL rats. Further investigations are mandatory. 88 EFFECT OF CANNABINOID CB1-RECEPTOR ANTAGONISM ON ASCITIC DECOMPENSATION OF RATS WITH PREASCITIC CIRRHOSIS M. Domenicali, P. Caraceni, A.M. Pertosa, F. Giannone, A. Principe, A. Zambruni, F. Trevisani, M. Bernardi. Department of Medicina Interna, Cardioangiologia, Epatologia and Centro Ricerca Biomedica Applicata (C.R.B.A.), University of Bologna, Bologna, Italy E-mail: [email protected] Background and Aims: Endocannabinoids contribute to the pathogenesis of hemodynamic abnormalities of cirrhosis. Whether this also favours renal sodium retention and ascites formation is unknown. We aimed to determine if endocannabinoid CB1-receptor antagonist Rimonabant (Sanofi-Aventis) prevents sodium retention and ascites formation in cirrhotic rats. Methods: Sodium overload test (SOT) predicts ascites formation within 3−4 weeks in 95% of rats with preascitic cirrhosis once renal sodium excretion declines <60% of the sodium load (J Hepatol, 2005). We weekly performed SOT in rats with CCl4-induced preascitic cirrhosis. Once it decreased <60% for two consecutive weeks, the animals were placed in metabolic cages and randomized to receive either Rimonabant (3 [R3] or 10 [R10] mg/Kg/day) or vehicle (V) for 2 weeks (n = 10 in each group). Renal sodium excretion, diuresis and sodium balance were measured daily. At the end of the protocol, systemic hemodynamics were invasively assessed. After sacrifice, ascites was measured and liver fibrosis assessed by quantitative histologic image analysis. Results: Rimonabant led to a reduction in ascites formation (V: 90%; R3: 54%; R10: 10%) and volume (from 5.5±0.8 ml [V] to 1.6±0.3 ml [R3] and 0.5 ml [R10]) (P < 0.05). During week 1, Rimonabant significantly improved sodium balance, an effect that became even more evident during week 2 (V: 2.23±0.27 mmol; R3: 0.59±0.35 mmol; R10: 0.46±0.29 mmol; P < 0.01). Both treated groups showed lower cardiac output (V: 1.21±0.15 L/min; R3: 0.78±0.17 L/min; R10: 0.41±0.11 L/min) (P < 0.05), and higher mean arterial pressure (MAP) (V: 77.9±2.1 mmHg; R3: 93.0±1.3 mmHg; R10: 97.9±4.1 mmHg) and peripheral vascular resistance (V: 59.0±9.8 dyn x sec/cm5; R3: 94.7±13.1 dyn x sec/cm5; R10: 103.7±10.4 dyn x sec/cm5) (P < 0.05). The liver fibrosis score was reduced by about 30% in the R10 (P < 0.05 vs V) but not in R3. MAP was inversely correlated with sodium balance (R = −0.77; P < 0.001), while no significant correlations were found between fibrosis score and either sodium balance or hemodynamics.
Parallel Session 10: CIRRHOSIS AND COMPLICATIONS Conclusions: Rimonabant improves sodium balance and delays decompensation in preascitic cirrhosis. This is achieved though and improvement in systemic hemodynamics, although it cannot be excluded that the antifibrotic effect of the drug may play a role. 89 TREATMENT OF ESTABLISHED CIRRHOSIS USING SV40 VECTOR ENCODING INSULIN-LIKE GROWTH FACTOR I L. Sobrevals1 , A. Pa˜neda1 , N. Razquin1 , N. Juanarena1 , I. Monreal1 , G. Gonzalez1 , C. Rodriguez1 , J. Prieto2 , P. Fortes1 . 1 Gene Therapy and Hepatology – CIMA, Pamplona, 2 Gene Therapy And Hepatology – CIMA/University Hospital, Pamplona, Spain E-mail: [email protected] Liver transplantation is the only curative treatment for advanced liver cirrhosis. Therapies aimed at halting the progression of the disease are urgently needed. Previous studies have shown that the administration of recombinant insulin like growth factor-I (IGF-I) induces hepatoprotective effects in experimental cirrhosis. However, the necessity of using high daily doses of the protein for a long period of time makes this therapy very costly hampering their clinical application. As an alternative therapeutic approach, we have evaluated whether sustained IGF-I expression within the liver from viral vectors based on the Simian Virus 40 (rSVIGF-I) could exert therapeutic effects in liver cirrhosis. We have previously shown that intraportal injection of rSVIGF-I in rats prior to the development of liver cirrhosis induces the expression of hepatocyte growth factor (HGF) in the liver and delays the progression of the disease. In the present study we have tested the effect of the vector in rats that had already developed advanced liver cirrhosis. Liver cirrhosis was induced in Sprague-Dawley male rats by intragastric administration of CCl4 for 12 weeks and then a single dose of rSVIGF-I (1011 vp/rat) was administered by different routes. The following administration routes were tested: intraportal (IP), intrahepatic (IH), intraarterial (IA) and intrabiliar (IB). At the end of the study, cirrhotic rats treated with rSVIGF-I showed reduced serum bilirubin, transaminases and liver fibrosis scores as well as increased expression of serum albumin as compared to mock-infected cirrhotic animals. The effects were more prominent in rats treated by IP or IA injection, suggesting that these routes could allow better access of the vector to hepatocytes in fibrotic livers. IGF-I expression correlated with the increase of mRNA levels of IGF-I binding protein 3 (whose synthesis is induced by IGF-I) and with upregulation of HGF, a factor that seems to mediate hepatoprotective effects of IGF-I. These results indicate that established cirrhosis can be reverted by IGF-I and also, that rSVIGF-I are promising vectors for the treatment of this disease. 90 EVIDENCE OF A VASOPRESSIN-INDEPENDENT AQP2 EXPRESSION AND WATER RETENTION IN REFRACTORY ASCITES A. Krag1,2 , S. Moller2 , E.B. Pedersen3 , N.H. Holstein-Rathlou4 , F. Bendtsen1 . 1 Department of Gastroenterology, 2 Department of Clinical Physiology, Hvidovre University Hospital, Copenhagen, 3 Department of Medical Research, Holstebro Hospital, Holestbro, 4 Department of Biomedical Sciences, The Panum Institute, Copenhagen, Denmark E-mail: [email protected] Background and Aim: Development of ascites in patients with cirrhosis is characterized both by sodium retention and avid fluid retention. The mechanisms for transition to refractory ascites are not clear. In this study we hypothesized that: 1 the ability to excrete free-water is progressively impaired in advanced cirrhosis and 2 that this is due to decreased sensitivity to solute free water and increase in non-osmo regulated water retention. Methods: 23 patients with ascites were included, 12 with Child B cirrhosis and 11 with Child C cirrhosis (8 of whom had refractory ascites). Diuretics
S39
were discontinued 48 hours before the study and a 60 meq sodium diet was supplied 4 days before the study. The subjects were studied during 3 × 30 minutes clearance periods on 300-mL/hour oral water load. Plasma vasopressin (AVP), free water clearance (CH2O), urine volume (Vu), cyclic-AMP (cAMP) and aquaporin-2 (AQP2) excretion and plasma- and urine osmolality (Posm, Uosm) was measured. Distal fractional water excretion (DfeH20) was calculated as Vu/lithium clearance. Results: At baseline, Child C ascites patients had a lower glomerular filtration rate (32 vs. 63 mL/min, p < 0.001) and lower Vu (0.86 vs. 1.95 mL/min, p < 0.001) than the Child B ascitic patients, however the CH2O did not differ (−0.60 vs. −0.21 mL/min, P = 0.20). After oral water load both groups decreased AVP significantly, however only the Child B group had a decrease in cAMP and AQP2 (p < 0.05) resulting in increased DfeH20 (13 vs. 23 5%, p = 0.01), Vu (1.95 vs. 3.24 mL/min, p < 0.001) and CH2O (−0.21 vs.1.21 mL/min, p < 0.01) and an ability to decrease Uosm below Posm (356 vs. 212 mosm/kg, p < 0.01). In contrast the Child C patients did not respond to the decrease in AVP by increasing cAMP and AQP2 excretion. The consequence was an inability to increase DfeH20 and to obtain a positive CH2O resulting in water retention. Conclusion: In advanced cirrhosis and ascites there is a vasopressinindependent AQP2 expression and water retention. This escape from normal regulatory mechanisms in the aquaretic system in the setting of low GFR may be a key event in the development of refractory ascites and hyponatremia.
91 MORBIDITY AND MORTALITY FOLLOWING CORONARY ARTERY BYPASS GRAFT (CABG) SURGERY IN PATIENTS WITH CIRRHOSIS: A POPULATION-BASED STUDY A.A. Shaheen1 , G.G. Kaplan2 , R.P. Myers1 . 1 Liver Unit, 2 Gastroenterology Department, University of Calgary, Calgary, Alberta, Canada E-mail: [email protected] Background: Studies describing the outcome of cardiac surgery in patients with cirrhosis have reported heterogeneous outcomes and are limited by small sample sizes and referral bias. Our objective was to describe the outcomes of CABG in a large population of cirrhotics using a nationally representative database. Methods: Patients who underwent CABG (ICD-9-CM codes 36.1−36.3) between 1998 and 2004 were identified using the Nationwide Inpatient Sample, a stratified random sample of 20% of U.S. hospitals. The impact of underlying cirrhosis on in-hospital mortality, post-operative complications, length of stay (LOS), and total hospital charges was assessed. Independent predictors of these outcomes, after adjustment for patient characteristics and hospital volume, were determined using regression models with generalized estimating equations. Results: Of 403,094 patients undergoing CABG, 711 (0.18%) were cirrhotic (~3,531 nationwide). Their median age was 62 years (IQR 54−69), 72% were male, and 36% were decompensated (ascites, encephalopathy, or coagulopathy). CABG indications included chronic ischemic heart disease in 76% and acute myocardial infarction (AMI) in 19%. Compared with non-cirrhotics, patients with cirrhosis were younger (P < 0.0001), but had more comorbidities including diabetes (37% vs. 31%), chronic pulmonary disease (30% vs. 18%), alcohol abuse (21% vs. 2%), and renal failure (7% vs. 3%; P < 0.005 for all). In bivariate analyses, cirrhotics had higher rates of in-hospital mortality (17% vs. 3%; odds ratio [OR] 6.17; 95% CI 5.05−7.53) and post-CABG complications (40% vs. 26%), and greater median LOS (9 vs. 6 days) and hospital charges ($82,411 vs. $59,653); these differences persisted after adjustment for other patient characteristics (P < 0.00005 for all). Among cirrhotic patients, independent predictors of mortality included age >60 years (OR 2.09; 95% CI 1.15−3.79), decompensated features (OR 1.68; 1.06−2.67) and post-operative complications (OR 9.54; 95% CI 5.21−17.5). Post-CABG complications, more common in patients >60 years (OR 2.16; 95% CI 1.31−3.58) and those with
Friday, 25 April
86 EFFECTS OF PROPHYLACTIC ANTIBIOTICS ON TOLL-LIKE RECEPTOR (TLR) 2 AND 4 EXPRESSION ON PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) IN PATIENTS WITH DECOMPENSATED CIRRHOSIS A.G. Testro1,2 , K. Visvanathan2 , N.A. Skinner2 , V. Markovska2 , S. Wongseelashote1 , P.W. Angus1 , P.J. Gow1 . 1 Department of Medicine, The University of Melbourne, Melbourne, Victoria, 2 Department of Medicine, Monash University, Victoria, Australia E-mail: [email protected] Background and Aims: TLRs are pivotal in the innate immune recognition of microbial structures, resulting in the production of proinflammatory cytokines, and the priming of an adaptive immune response. TLR4 recognises lipopolysaccharide on gram-negative (G−) bacteria, while TLR2 recognises peptidoglycan on gram-positives (G+). We aimed to determine whether TLR expression is altered in cirrhosis and if this is affected by treatment with antibiotics used to prevent spontaneous bacterial peritonitis (SBP). Methods: 62 patients were included (23 age/sex matched healthy controls and 39 Child-Pugh C cirrhotics). 29 cirrhotics were taking either norfloxacin or trimethoprim-sulfamethoxazole as prophylaxis against SBP and 10 were not receiving prophylaxis. Paired blood samples were taken from a further 7 patients before and after commencing prophylactic antibiotics. 40 mls of blood was taken from each patient. PBMC were extracted using Ficoll-Paque density gradient centrifugation. PBMC expression of TLR2 and 4 was determined using flow cytometry, producing a ratio of the geometric mean of fluorescence intensity to that of a matched isotype control. Results are presented as medians relative to controls (control median = 1.0). Results: There were no differences in Child-Pugh score, age, disease aetiology or sex distribution between patients receiving antibiotics and those who were not. However, cirrhotic patients not taking antibiotics had significantly decreased TLR4 expression compared with both controls (0.74 vs. 1.0, p = 0.01) and patients receiving antibiotics (0.74 vs. 1.125, p = 0.01). There was no difference in TLR4 expression between antibiotic treated patients and controls (p = 0.88). Conversely, antibiotic treated patients expressed lower TLR2 compared to those not on antibiotics (0.909 vs. 1.091, p = 0.04). In the 7 patients with paired samples, TLR4 expression increased significantly from 0.689 to 1.331 (p = 0.002) following commencement of antibiotics, whilst there was a trend towards decreased TLR2 expression from 0.957 to 0.859 (p = 0.28). Conclusions: TLR4 expression is decreased in Child-Pugh C cirrhotics, but is restored by antibiotics targeting enteric G− bacteria. This suggests that the high incidence of G− sepsis in cirrhotics is in part due to downregulation of the host’s TLR4 dependant innate immune response and that this may be mediated by chronic exposure to G− bacterial products. 87 EFFECTS OF THE MULTIKINASE INHIBITOR, SORAFENIB, ON PORTAL PRESSURE, HYPERDYNAMIC CIRCULATION, AORTIC CONTRACTILITY, AND DYSREGULATED RHO-KINASE IN RATS WITH SECONDARY BILIARY CIRRHOSIS M. Hennenberg, C. Stark, J. Trebicka, T. Sauerbruch, J. Heller. Dept. Internal Medicine I, University of Bonn, Bonn, Germany E-mail: [email protected] Background: In cirrhosis, portal hypertension is triggered by splanchnic vasodilation and increased intrahepatic vascular resistance. This results partially from dysregulation of the contraction-mediating Rho-kinase. Whereas Rho-kinase expression and activity is downregulated in preportal vessels (Gastroenterology 2006;130), it is upregulated in the intrahepatic circulation in cirrhotic rats (Gut 2006;55). The signaling module Ras/Rafkinase/MEK/ERK has been shown to regulate Rho-kinase expression.
Here, we tested the hemodynamic and vascular effects of the multikinase inhibitor, sorafenib, in rats with secondary biliary cirrhosis, which inhibits Raf-kinase among others. Methods: Cirrhosis in rats was induced by bile duct ligation (BDL). One group was treated with sorafenib for one week (60 mg/kg/d, p.o.). Hemodynamic measurements were performed invasively. Contractility of isolated aortic rings was determined by myographic measurements (with the inhibitor of nitric oxide synthases, L-NAME 200 mM). Expression and phosphorylation of proteins was asessed by Western-blot analysis. Rho-kinase activity was evaluated as phosphorylation of the Rho-kinase substrate moesin (thr558). Results: Treatment of BDL rats with sorafenib reduced portal pressure (19±3.3 mmHg in BDL, 11.5±3.4 mmHg in Sorafenib-treated BDL). Contractility (Emax) and sensitivity (EC50) of isolated aortic rings of BDL rats to the a1 adrenergic agonist, methoxamine, were improved by treatment with sorafenib (Emax 0.53±0.04 g in BDL, 0.88±0.12 g in Sorafenibtreated BDL; EC50 4.7 microM in BDL, 2.8 microM in Sorafenib-treated BDL). Treatment of BDL rats with sorafenib caused upregulation of Rhokinase expression and moesin-phosphorylation in aortas from BDL rats, and in parallel downregulation of Rho-kinase expression and moesinphosphorylation in liver homogenates. Conclusions: Sorafenib might correct vascular dysregulation of Rhokinase and shows benefical effects on hyperdynamic circulation in cirrhotic BDL rats. Further investigations are mandatory. 88 EFFECT OF CANNABINOID CB1-RECEPTOR ANTAGONISM ON ASCITIC DECOMPENSATION OF RATS WITH PREASCITIC CIRRHOSIS M. Domenicali, P. Caraceni, A.M. Pertosa, F. Giannone, A. Principe, A. Zambruni, F. Trevisani, M. Bernardi. Department of Medicina Interna, Cardioangiologia, Epatologia and Centro Ricerca Biomedica Applicata (C.R.B.A.), University of Bologna, Bologna, Italy E-mail: [email protected] Background and Aims: Endocannabinoids contribute to the pathogenesis of hemodynamic abnormalities of cirrhosis. Whether this also favours renal sodium retention and ascites formation is unknown. We aimed to determine if endocannabinoid CB1-receptor antagonist Rimonabant (Sanofi-Aventis) prevents sodium retention and ascites formation in cirrhotic rats. Methods: Sodium overload test (SOT) predicts ascites formation within 3−4 weeks in 95% of rats with preascitic cirrhosis once renal sodium excretion declines <60% of the sodium load (J Hepatol, 2005). We weekly performed SOT in rats with CCl4-induced preascitic cirrhosis. Once it decreased <60% for two consecutive weeks, the animals were placed in metabolic cages and randomized to receive either Rimonabant (3 [R3] or 10 [R10] mg/Kg/day) or vehicle (V) for 2 weeks (n = 10 in each group). Renal sodium excretion, diuresis and sodium balance were measured daily. At the end of the protocol, systemic hemodynamics were invasively assessed. After sacrifice, ascites was measured and liver fibrosis assessed by quantitative histologic image analysis. Results: Rimonabant led to a reduction in ascites formation (V: 90%; R3: 54%; R10: 10%) and volume (from 5.5±0.8 ml [V] to 1.6±0.3 ml [R3] and 0.5 ml [R10]) (P < 0.05). During week 1, Rimonabant significantly improved sodium balance, an effect that became even more evident during week 2 (V: 2.23±0.27 mmol; R3: 0.59±0.35 mmol; R10: 0.46±0.29 mmol; P < 0.01). Both treated groups showed lower cardiac output (V: 1.21±0.15 L/min; R3: 0.78±0.17 L/min; R10: 0.41±0.11 L/min) (P < 0.05), and higher mean arterial pressure (MAP) (V: 77.9±2.1 mmHg; R3: 93.0±1.3 mmHg; R10: 97.9±4.1 mmHg) and peripheral vascular resistance (V: 59.0±9.8 dyn x sec/cm5; R3: 94.7±13.1 dyn x sec/cm5; R10: 103.7±10.4 dyn x sec/cm5) (P < 0.05). The liver fibrosis score was reduced by about 30% in the R10 (P < 0.05 vs V) but not in R3. MAP was inversely correlated with sodium balance (R = −0.77; P < 0.001), while no significant correlations were found between fibrosis score and either sodium balance or hemodynamics.
Parallel Session 10: CIRRHOSIS AND COMPLICATIONS Conclusions: Rimonabant improves sodium balance and delays decompensation in preascitic cirrhosis. This is achieved though and improvement in systemic hemodynamics, although it cannot be excluded that the antifibrotic effect of the drug may play a role. 89 TREATMENT OF ESTABLISHED CIRRHOSIS USING SV40 VECTOR ENCODING INSULIN-LIKE GROWTH FACTOR I L. Sobrevals1 , A. Pa˜neda1 , N. Razquin1 , N. Juanarena1 , I. Monreal1 , G. Gonzalez1 , C. Rodriguez1 , J. Prieto2 , P. Fortes1 . 1 Gene Therapy and Hepatology – CIMA, Pamplona, 2 Gene Therapy And Hepatology – CIMA/University Hospital, Pamplona, Spain E-mail: [email protected] Liver transplantation is the only curative treatment for advanced liver cirrhosis. Therapies aimed at halting the progression of the disease are urgently needed. Previous studies have shown that the administration of recombinant insulin like growth factor-I (IGF-I) induces hepatoprotective effects in experimental cirrhosis. However, the necessity of using high daily doses of the protein for a long period of time makes this therapy very costly hampering their clinical application. As an alternative therapeutic approach, we have evaluated whether sustained IGF-I expression within the liver from viral vectors based on the Simian Virus 40 (rSVIGF-I) could exert therapeutic effects in liver cirrhosis. We have previously shown that intraportal injection of rSVIGF-I in rats prior to the development of liver cirrhosis induces the expression of hepatocyte growth factor (HGF) in the liver and delays the progression of the disease. In the present study we have tested the effect of the vector in rats that had already developed advanced liver cirrhosis. Liver cirrhosis was induced in Sprague-Dawley male rats by intragastric administration of CCl4 for 12 weeks and then a single dose of rSVIGF-I (1011 vp/rat) was administered by different routes. The following administration routes were tested: intraportal (IP), intrahepatic (IH), intraarterial (IA) and intrabiliar (IB). At the end of the study, cirrhotic rats treated with rSVIGF-I showed reduced serum bilirubin, transaminases and liver fibrosis scores as well as increased expression of serum albumin as compared to mock-infected cirrhotic animals. The effects were more prominent in rats treated by IP or IA injection, suggesting that these routes could allow better access of the vector to hepatocytes in fibrotic livers. IGF-I expression correlated with the increase of mRNA levels of IGF-I binding protein 3 (whose synthesis is induced by IGF-I) and with upregulation of HGF, a factor that seems to mediate hepatoprotective effects of IGF-I. These results indicate that established cirrhosis can be reverted by IGF-I and also, that rSVIGF-I are promising vectors for the treatment of this disease. 90 EVIDENCE OF A VASOPRESSIN-INDEPENDENT AQP2 EXPRESSION AND WATER RETENTION IN REFRACTORY ASCITES A. Krag1,2 , S. Moller2 , E.B. Pedersen3 , N.H. Holstein-Rathlou4 , F. Bendtsen1 . 1 Department of Gastroenterology, 2 Department of Clinical Physiology, Hvidovre University Hospital, Copenhagen, 3 Department of Medical Research, Holstebro Hospital, Holestbro, 4 Department of Biomedical Sciences, The Panum Institute, Copenhagen, Denmark E-mail: [email protected] Background and Aim: Development of ascites in patients with cirrhosis is characterized both by sodium retention and avid fluid retention. The mechanisms for transition to refractory ascites are not clear. In this study we hypothesized that: 1 the ability to excrete free-water is progressively impaired in advanced cirrhosis and 2 that this is due to decreased sensitivity to solute free water and increase in non-osmo regulated water retention. Methods: 23 patients with ascites were included, 12 with Child B cirrhosis and 11 with Child C cirrhosis (8 of whom had refractory ascites). Diuretics
S39
were discontinued 48 hours before the study and a 60 meq sodium diet was supplied 4 days before the study. The subjects were studied during 3 × 30 minutes clearance periods on 300-mL/hour oral water load. Plasma vasopressin (AVP), free water clearance (CH2O), urine volume (Vu), cyclic-AMP (cAMP) and aquaporin-2 (AQP2) excretion and plasma- and urine osmolality (Posm, Uosm) was measured. Distal fractional water excretion (DfeH20) was calculated as Vu/lithium clearance. Results: At baseline, Child C ascites patients had a lower glomerular filtration rate (32 vs. 63 mL/min, p < 0.001) and lower Vu (0.86 vs. 1.95 mL/min, p < 0.001) than the Child B ascitic patients, however the CH2O did not differ (−0.60 vs. −0.21 mL/min, P = 0.20). After oral water load both groups decreased AVP significantly, however only the Child B group had a decrease in cAMP and AQP2 (p < 0.05) resulting in increased DfeH20 (13 vs. 23 5%, p = 0.01), Vu (1.95 vs. 3.24 mL/min, p < 0.001) and CH2O (−0.21 vs.1.21 mL/min, p < 0.01) and an ability to decrease Uosm below Posm (356 vs. 212 mosm/kg, p < 0.01). In contrast the Child C patients did not respond to the decrease in AVP by increasing cAMP and AQP2 excretion. The consequence was an inability to increase DfeH20 and to obtain a positive CH2O resulting in water retention. Conclusion: In advanced cirrhosis and ascites there is a vasopressinindependent AQP2 expression and water retention. This escape from normal regulatory mechanisms in the aquaretic system in the setting of low GFR may be a key event in the development of refractory ascites and hyponatremia.
91 MORBIDITY AND MORTALITY FOLLOWING CORONARY ARTERY BYPASS GRAFT (CABG) SURGERY IN PATIENTS WITH CIRRHOSIS: A POPULATION-BASED STUDY A.A. Shaheen1 , G.G. Kaplan2 , R.P. Myers1 . 1 Liver Unit, 2 Gastroenterology Department, University of Calgary, Calgary, Alberta, Canada E-mail: [email protected] Background: Studies describing the outcome of cardiac surgery in patients with cirrhosis have reported heterogeneous outcomes and are limited by small sample sizes and referral bias. Our objective was to describe the outcomes of CABG in a large population of cirrhotics using a nationally representative database. Methods: Patients who underwent CABG (ICD-9-CM codes 36.1−36.3) between 1998 and 2004 were identified using the Nationwide Inpatient Sample, a stratified random sample of 20% of U.S. hospitals. The impact of underlying cirrhosis on in-hospital mortality, post-operative complications, length of stay (LOS), and total hospital charges was assessed. Independent predictors of these outcomes, after adjustment for patient characteristics and hospital volume, were determined using regression models with generalized estimating equations. Results: Of 403,094 patients undergoing CABG, 711 (0.18%) were cirrhotic (~3,531 nationwide). Their median age was 62 years (IQR 54−69), 72% were male, and 36% were decompensated (ascites, encephalopathy, or coagulopathy). CABG indications included chronic ischemic heart disease in 76% and acute myocardial infarction (AMI) in 19%. Compared with non-cirrhotics, patients with cirrhosis were younger (P < 0.0001), but had more comorbidities including diabetes (37% vs. 31%), chronic pulmonary disease (30% vs. 18%), alcohol abuse (21% vs. 2%), and renal failure (7% vs. 3%; P < 0.005 for all). In bivariate analyses, cirrhotics had higher rates of in-hospital mortality (17% vs. 3%; odds ratio [OR] 6.17; 95% CI 5.05−7.53) and post-CABG complications (40% vs. 26%), and greater median LOS (9 vs. 6 days) and hospital charges ($82,411 vs. $59,653); these differences persisted after adjustment for other patient characteristics (P < 0.00005 for all). Among cirrhotic patients, independent predictors of mortality included age >60 years (OR 2.09; 95% CI 1.15−3.79), decompensated features (OR 1.68; 1.06−2.67) and post-operative complications (OR 9.54; 95% CI 5.21−17.5). Post-CABG complications, more common in patients >60 years (OR 2.16; 95% CI 1.31−3.58) and those with