[The hepato-pulmonary syndrome--where do we stand in the year 2006?]. / Das hepatopulmonale Syndrom -- Wo stehen wir im Jahr 2006?

The hepato-pulmonary syndrome (HPS) is characterized by a combination of liver disease and pulmonary gas exchange abnormalities with arterial hypoxemia, intrapulmonary vasodilatation and arteriovenous shunting in the absence of intrinsic cardiopulmonary disease. The course of the disease is typically progressive. The mortality rate correlates with the pulmonary shunt volume and the degree of hypoxemia at room air. While the patho-physiology of HPS is still not fully understood, a multifactorial etiology is favored. Apart from functional intrapulmonary arteriovenous shunts which appear to represent a major factor in the development of HPS, both ventilation-perfusion mismatch and limited oxygen diffusion contribute to the HPS. Regarding its clinical appearance, pulmonary and hepatic symptoms have to be distinguished. Contrast echocardiography is the primary diagnostic tool. Symptomatically, hypoxemia can be treated with oxygen. So far, the only successful treatment approach which has been tested in larger patient groups, is liver transplantation. Given this background, the aim of this review is to critically discuss current concepts of this serious complication of liver diseases.

Vasodilator mRNA levels are increased in the livers of portal hypertensive NO-synthase 3-deficient mice.

BACKGROUND/AIMS: Nitric oxide synthase (NOS) 3-deficient (NOS-3 KO) mice have an increased systemic arterial pressure but develop portal hypertension to the same extent as wildtype (WT) mice. We hypothesized that other vasodilators in the portal circulation compensate for the lack in NOS-3 activity. We used quantitative PCR as a screening method to identify mediators that possibly compensate for NOS-3 in NOS-3 KO mice. METHODS: Mean arterial pressure (MAP) and portal venous pressure (PVP) were measured in the anaesthetized animal. mRNA levels in whole liver tissue were determined by quantitative RT-PCR. RESULTS: NOS-3 KO mice had a significantly higher mean arterial pressure than WT mice, but portal venous pressure did not differ. Bile duct ligation (BDL) induced a drop in MAP and a rise in PVP in both groups. Bile duct ligation induced a significant increase in mRNA levels of the cannabinoid receptor (CB)-1, adrenomedullin and NOS-2 in the liver of NOS-3 KO and WT mice. Nitric oxide synthase-1 and NOS-3 mRNA levels were elevated in BDL WT mice compared with sham-operated WT mice. Higher mRNA levels of CB-1, NOS-1 and the adrenomedullin receptor were found in sham-operated NOS-3 KO mice compared with sham-operated WT mice. CONCLUSIONS: We used quantitative PCR as a screening method to identify vasodilative mediators that might be involved in the compensation for the lack of NOS-3 activity in NOS-3 KO mice. Elevated mRNA levels in sham-operated NOS-3 KO mice compared with sham-operated WT mice were demonstrated for CB-1, NOS-1 and the adrenomedullin receptor.

[Therapy of viral hepatitis]. / Therapie der viralen Hepatitiden.

Chronic viral hepatitis is a leading cause of chronic hepatitis, liver cirrhosis, hepatic decompensation and hepatocellular carcinoma worldwide. Here, we will briefly review common indications and current therapies for chronic hepatitis B and C and discuss practical aspects of these therapies. Current therapies for hepatitis C aim at viral eradication. With the introduction of pegylated interferon and ribavirin viral eradication is successful in about 55% of treated patients. The goal of therapy of HBe antigen positive chronic hepatitis B is seroconversion to anti-HBe which can be achieved with interferon alpha in 25-45% of patients. A loss of HBs can be achieved in approximately 10%. Responders proceed significantly less to cirrhosis or hepatocellular carcinoma. Anti-HBe positive patients can be treated with interferon alpha or lamivudine. The former requires longer treatment and the results are disappointing. Lamivudine is a promising agent in the treatment of chronic hepatitis B, but the success is hampered by a high relapse rate and the emergence of viral resistance.

Portal hypertension is associated with increased mRNA levels of vasopressor G-protein-coupled receptors in human hepatic arteries.

BACKGROUND: The contractile response of human splanchnic vessels to different vasoconstrictors is attenuated in cirrhosis. Functional studies indicate a cellular signalling defect upstream of the G-protein level. The aim of the present study was to analyze expression and mRNA levels of the following most relevant vasopressor receptors in the smooth musculature of human hepatic arteries: alpha1 adrenoceptor (AR) subtypes a, b and d, angiotensin II type 1 receptor (AT1), arginine vasopressin receptor type 1a (V1a), endothelin receptor type A (ETA) and B (ETB). MATERIALS AND METHODS: Hepatic arteries were collected from 10 donors (noncirrhotic) and 14 recipients (cirrhotic) at liver transplantations. Real-time-PCR was performed to quantify steady-state levels of receptor mRNAs. RESULTS: alpha 1aAR mRNA levels showed no significant difference between the cirrhotic arteries and the controls while the mRNA levels of the other vasoactive receptors were significantly higher in the cirrhotic hepatic arteries (alpha 1bAR: 4-fold, P = 0.013; AT1: 16-fold, P = 0.024; V1a: 23-fold, P = 0.001; ETA: 4-fold, P = 0.02; ETB: 8-fold, P = 0.008). No mRNA for the alpha 1dAR was detected either in the donor or recipient hepatic arteries. CONCLUSION: We conclude that vascular hyporeactivity to the most relevant endogenous vasoconstrictors of cirrhotic hepatic arteries is not caused by a receptor down-regulation at mRNA levels. In contrast they were up-regulated.

[Gallstones--natural history and conservative management]. / Gallensteine--natürliche Geschichte und konservative Behandlung.

Gallstones have a very high prevalence affecting 9.5 and 19.5% of men and women, respectively. The pathophysiology and risk factors for cholesterol gallstones are considered. Modern imaging techniques, in particular ultrasound, are very sensitive to detect cholecystolithiasis, while ERCP remains the gold standard to detect choledocholithiasis. ERCP could be supplanted soon by endosonography and MRCP. Biliary scintigraphy is useful to detect a 'vésicule exclue' and to document gallbladder/sphincter Oddi dysfunction. The different conservative management strategies including litholytic treatment with ursodeoxycholate and lithotripsy have been largely abandoned in favor of laparoscopic cholecystectomy. Litholytic treatment has still a role to play in the prevention of gallstone formation in patients with rapid weight loss and in the newly detected MDR3 defect associated with sludge formation. Biliary colic is treated with non-steroidal analgesic drugs, analgesics and/or spasmolytic agents.

[Hepatitis B virus infection: diagnosis, clinical sequelae, therapy and prevention]. / Hepatitis B Virusinfektion: Diagnose, klinische Folgen, Therapie und Prophylaxe.

This article gives an overview on the clinical epidemiology of hepatitis B in Switzerland. It considers structure of the hepatitis B virus, serologic diagnosis of hepatitis B and its prevention and treatment. The main conclusions are as follows: 1. Hepatitis B prophylaxis is available. Juveniles should be vaccinated before taking up sexual activity. Pregnant women should be tested and their offspring immunised actively and passively when there is evidence of infection. 2. In cases of acute hepatitis B contact persons should be tested and vaccinated where appropriate. Treatment is not indicated. 3. For the treatment of chronic hepatitis B interferons and lamivudine are currently available. Advantages and shortfalls of the different forms of treatment are discussed.

Peptide vaccines against hepatitis B virus: from animal model to human studies.

An estimated 400 million people are chronically infected with the hepatitis B virus (HBV). Chronic viral hepatitis infection incurs serious sequelae such as liver cirrhosis and hepatocellular carcinoma. Prevention and treatment, thus, represent an important target for public health. Preventive vaccines using HBsAg alone or combined with other antigens allow for the generation of neutralizing antibodies which effectively prevent infection in immunocompetent individuals. Cell-mediated immunological mechanisms are thought to be crucial in determining viral persistence or viral elimination. Therapeutic approaches aiming to shift cellular immunity towards viral elimination have been on the research agenda for many years. This paper summarizes pre-clinical and clinical results obtained with the use of immunogenic peptides formulated as vaccines to selectively boost cellular immune responses. Such vaccines are capable of generating cellular immune responses in animal models as well as in humans and represent an important step towards the development of a therapeutic vaccine against chronic hepatitis.

Perspectives: towards a peptide-based vaccine against hepatitis C virus.

Hepatitis C virus (HCV) is a widespread infectious disease in humans with the negative implication of becoming chronic in most persons. Patients infected with HCV are at risk of liver cirrhosis or hepatocellular carcinoma at later stages. In contrast to hepatitis A and hepatitis B, there is no immunization yet available, neither prophylactic nor therapeutic. Thus, there is an urgent need to develop a safe, protective vaccine against this fatal disease. Developing countries are even more at risk for HCV. There are currently a number of scientific approaches aimed towards solving this problem. Taking both risks and costs of immunization into consideration, a peptide-based vaccine may be a reasonable prophylactic protection. Also, it might be of therapeutic use in already infected patients by increasing a specific CTL response against HCV. In our lab, we are focusing on immunopotentiating reconstituted influenza virosomes (IRIVs) as carriers for immunogenic HLA-A2-restricted core epitopes to induce peptide-specific cytotoxic T lymphocytes (CTLs). The IRIVs are similar to liposomes, but in addition contain influenza-derived hemagglutinin and neuraminidase on their outer surface which makes them fusogenic, thus, permitting antigen delivery to host cells. So far, virosomes have been successfully used for vaccine development and as a result a virosomal vaccine against both influenza virus (Inflexal) BERNA) and hepatitis A virus (HAV) (Epaxal) BERNA) already exist on the market. This paper focuses on the importance of development of a successful vaccine against HCV and, more specifically, we discuss the use, advantages and disadvantages of a peptide-based vaccine. A brief report of our latest findings will be included.

The diagnostic value of liver biopsy.

BACKGROUND: Since the introduction of molecular diagnostic tools such as markers for hepatitis C and different autoimmune diseases, liver biopsy is thought to be useful mainly for staging but not for diagnostic purposes. The aim was to review the liver biopsies for 5 years after introduction of testing for hepatitis C, in order to evaluate what diagnostic insights - if any - remain after serologic testing. METHODS: Retrospective review of all liver biopsies performed between 1.1.1995 and 31.12.1999 at an academic outpatient hepatology department. The diagnoses suspected in the biopsy note were compared with the final diagnosis arrived at during a joint meeting with the responsible clinicians and a hepatopathologist. RESULTS: In 365 patients, 411 diagnoses were carried out before biopsy. 84.4 % were confirmed by biopsy but in 8.8 %, 6.8 % and 10.5 % the diagnosis was specified, changed or a diagnosis added, respectively. Additional diagnoses of clinical relevance were unrecognized biliary obstruction and additional alcoholic liver disease in patients with chronic hepatitis C. Liver biopsy led to change in management for 12.1 % of patients. CONCLUSION: Even in the era of advanced virological, immunological and molecular genetic testing, liver biopsy remains a useful diagnostic tool. The yield is particularly high in marker negative patients but also in patients with a clear-cut prebiopsy diagnosis, liver biopsy can lead to changes in patient management.

Treatment of hepatic hydrothorax and reduction of chest tube output with octreotide.

Hepatic hydrothorax is a dreaded complication in patients with liver cirrhosis. Placement of chest tubes can alleviate respiratory distress, but patients often succumb due to excessive fluid and protein loss via the open drain. Our case illustrates that high-dose octreotide can strongly reduce hepatic hydrothorax drainage volume. This allows removal of the chest tube, which would otherwise not have been possible.

Alterations in hemodynamics and hepatic and splanchnic circulation during laparoscopy in rats.

BACKGROUND: There is growing evidence that a pneumoperitoneum with increased intraabdominal pressure exerts adverse cardiovascular and splanchnic circulatory effects, whereby portal blood flow, in particular, is disturbed. METHODS: Cardiovascular hemodynamics and the blood flow of hollow viscus and solid organs were evaluated in rats undergoing laparotomy, followed by diagnostic carbon dioxide (CO2) laparoscopy with an intraabdominal pressure of either 4 or 10 mmHg and rapid desufflation of the abdominal cavity. The method we employed used g-labeled microspheres and conventional hemodynamic measurements. RESULTS: During CO2 laparoscopy, cardiac output and mean arterial pressure were significantly reduced to between 20.5% and 25% and 14.8% and 18% respectively. After rapid desufflation, cardiovascular hemodynamics normalized to baseline values. During laparoscopy, blood flow in the hollow viscus organs was less disturbed than that in the solid organs. Although small and large bowel blood flow was reduced significantly (26.6% and 23.9%, respectively), gastric blood flow remained unchanged. The decreases in the liver, spleen, pancreas, and kidney circulation were 29-37.2%, 37.6-64.6%, 51.2-57.5%, and 34.8-40.6%, respectively. Total hepatic blood flow was influenced predominantly by portal blood flow, which was particularly decreased; hepatic arterial flow remained stable. CONCLUSIONS: Severe alterations in cardiovascular hemodynamics, and to hepatic and splanchnic circulation occur rapidly during CO2 laparoscopy. It can be presumed that both increased intraabdominal pressure and hypercapnia are the main factors underlying these disturbances.

Characterisation of portal hypertension models by microspheres in anaesthetised rats: a comparison of liver flow.

Several portal hypertensive animal models are available and frequently used for haemodynamic studies. The portal venous inflows, measured with microspheres in pentobarbital anaesthetised rats, are compared here. The partial portal vein ligation model is characterised by a high portal venous inflow, together with extensive portal systemic shunting, at the cost of portal sinusoidal flow. In carbon tetrachloride-induced micronodular cirrhosis, portal sinusoidal flow, which reaches liver parenchyma, is high, and this is more pronounced in the presence of ascites. In bile duct ligation and excision-induced cirrhosis, an increase in liver weight was not equally followed by an increase in portal sinusoidal flow, pointing to a relatively underperfused liver.

Efficacy and safety of an intravenous monoclonal anti-HBs in chronic hepatitis B patients.

BACKGROUND/AIMS: In this study the safety and efficacy of a monoclonal anti-HBs, Tuvirumab (Mab), were investigated. Tuvirumab is a human monoclonal antibody recognizing the stable 'a'-determinant of the HBsAg. METHODS: We included ten chronic hepatitis B patients: four received monotherapy, and six combination therapy with interferon alpha 2b. RESULTS: Because the development of insoluble [HBsAg-HBsAb] complexes led to adverse events, the Mab dose had to be reduced in seven patients. In nine patients treatment was stopped prematurely because of lack of efficacy, i.e. neutralization of HBsAg in serum. However, temporary HBsAg levels were reduced by at least 50% in all patients; in three patients receiving combination therapy, background levels of HBsAg in serum were reached. A loss of serum HBV-DNA was seen in three patients in the combination group, followed by HBeAg seroconversion in two patients. CONCLUSIONS: We conclude that Mab was not effective in achieving primary efficacy as assessed by neutralization of circulating HBsAg. Whether a combination of Mab with an antiviral agent that reduces the HBsAg load--and therefore minimizes the risk of adverse events--may result in clinical efficacy should be investigated.

Is high prevalence of Echinococcus multilocularis in wild and domestic animals associated with disease incidence in humans?

We investigated a focus of highly endemic Echinococcus multilocularis infection to assess persistence of high endemicity in rural rodents, explore potential for parasite transmission to domestic carnivores, and assess (serologically) putative exposure versus infection frequency in inhabitants of the region. From spring 1993 to spring 1998, the prevalence of E. multilocularis in rodents was 9% to 39% for Arvicola terrestris and 10% to 21% for Microtus arvalis. From June 1996 to October 1997, 6 (7%) of 86 feral dogs and 1 of 33 cats living close to the region tested positive for intestinal E. multilocularis infection. Testing included egg detection by coproscopy, antigen detection by enzyme-linked immunosorbent assay (ELISA), and specific parasite DNA amplification by polymerase chain reaction. Thus, the presence of infected domestic carnivores can increase E. multilocularis exposure risk in humans. A seroepidemiologic survey of 2,943 blood donors in the area used specific Em2-ELISA. Comparative statistical analyses of seroprevalence and clinical incidence showed an increase in Em2-seroprevalence from 1986 and 1996-97 but no increase in clinical incidence of alveolar hydatid disease.

Veno-occlusive disease, nodular regenerative hyperplasia and hepatocellular carcinoma after azathioprine treatment in a patient with ulcerative colitis.

We report the case of a 66-year-old male with ulcerative colitis diagnosed in 1987, who had been treated with azathioprine (AZA) for the past two years (average dose about 1.6 mg/kg/day). In May 1999 he presented with painless jaundice, fatigue and recent weight loss. Cholestatic enzymes were elevated, alpha-fetoprotein was normal and hepatitis B/C serology negative. After diagnosis of veno-occlusive disease (VOD) and hepatocellular carcinoma (HCC) via biopsy, tumour resection was performed. The histology was typical for a well-differentiated HCC with trabecular and pseudoglandular structures. Neighbouring liver tissue was atrophic, with nodular regenerative hyperplasia (NRH), peliosis-like sinusoidal ectasias and intra-sinusoidal accumulation of blood, associated with peri-sinusoidal fibrosis. Although none of the well-established risk factors for HCC such as cirrhosis, hepatitis B/C, metabolic liver disease or toxins were present, this patient developed HCC. This and previous reports suggest that NRH and/or VOD associated with AZA represent a risk factor for HCC. AZA should therefore not only be stopped in patients with NRH/VOD but patients should also be screened for HCC.

The endothelin antagonist bosentan inhibits the canalicular bile salt export pump: a potential mechanism for hepatic adverse reactions.

BACKGROUND: During clinical trials bosentan, the first orally active endothelin receptor antagonist, caused asymptomatic transaminase elevations in some patients. In this study we investigated whether inhibition of the hepatocanalicular bile salt export pump (rodents, Bsep; humans, BSEP ABCB11) could account for bosentan-induced liver injury. METHODS: We reanalyzed the safety database of the bosentan trials for cholestatic liver injury, determined the cholestatic potency of bosentan in the rat, and studied the effects of bosentan and its metabolites on Bsep-mediated taurocholate transport in vitro. RESULTS: Bosentan caused dose-dependent and reversible liver injury in 2% to 18% of patients and caused a significant increase of serum bile salt levels (P <.01). Concomitant administration of glyburide (INN, glibenclamide) enhanced the cholestatic potency of bosentan. Similar effects were seen in rats, in which serum bile salt levels were increased by glyburide less than by bosentan, which increased the levels less than a combination of bosentan and glyburide. In vitro, Bsep-mediated taurocholate transport was inhibited by bosentan (inhibition constant, approximately 12 micromol/L) and metabolites (inhibition constant, approximately 8.5 micromol/L for metabolite Ro 47-8634). CONCLUSIONS: These results indicate that bosentan-induced liver injury is mediated, at least in part, by inhibition of Bsep/BSEP-causing intracellular accumulation of cytotoxic bile salts and bile salt induced liver cell damage. The data further emphasize the pathophysiologic importance of drug-Bsep interactions in acquired forms of cholestatic liver injury.

Apoptosis of hepatic stellate cells: involvement in resolution of biliary fibrosis and regulation by soluble growth factors.

BACKGROUND: Activated hepatic stellate cells (HSC) are central to the pathogenesis of liver fibrosis, both as a source of fibrillar collagens that characterise fibrosis and matrix degrading metalloproteinases and their tissue inhibitors, the TIMPs. AIMS: To test the hypothesis that HSC apoptosis is critical to recovery from biliary fibrosis and that soluble growth factors may regulate HSC survival and apoptosis. METHODS: Rats (n=15) were subjected to bile duct ligation for 21 days, after which biliodigestive anastomosis was undertaken (n=13). Livers were harvested at fixed time points of recovery for periods of up to 42 days. Numbers of activated HSCs were quantified after alpha smooth muscle actin staining and HSC apoptosis was detected by terminal UDP-nick end labelling (TUNEL) staining and quantified at each time point. HSC apoptosis was quantified in vitro in the presence or absence of insulin-like growth factor (IGF)-1, IGF-2, platelet derived growth factor (PDGF), and transforming growth factor beta1 (TGF-beta1). RESULTS: Following biliodigestive anastomosis after 21 days of bile duct ligation, rat liver demonstrated a progressive resolution of biliary fibrosis over 42 days, associated with a fivefold decrease in activated HSC determined by alpha smooth muscle actin staining. TUNEL staining indicated that loss of activated HSC resulted from an increase in the rate of apoptosis during the first two days post biliodigestive anastomosis. Serum deprivation and culture in the presence of 50 microM cycloheximide was associated with an increase in HSC apoptosis which was significantly inhibited by addition of 10 ng/ml and 100 ng/ml IGF-1, respectively (0.05>p, n=5). In contrast, 1 and 10 ng/ml of TGF-beta1 caused a significant increase in HSC apoptosis compared with serum free controls (p<0.05, n=4). PDGF and IGF-2 were neutral with respect to their effect on HSC apoptosis. CONCLUSION: HSC apoptosis plays a critical role in the spontaneous recovery from biliary fibrosis. Both survival and apoptosis of HSC are regulated by growth factors expressed during fibrotic liver injury.

Overexpression of endothelin-1 in bile duct ligated rats: correlation with activation of hepatic stellate cells and portal pressure.

BACKGROUND/AIMS: Hepatic stellate cells (HSC) are involved in the pathogenesis of liver fibrosis; although ET-1 is increased in cirrhosis, its pathophysiological role in fibrogenesis and portal hypertension remains controversial. The aim of this study was to investigate splanchnic hemodynamics and to correlate them with changes in ET-1 expression and HSC activation in bile duct ligated (BDL) rats. METHODS/RESULTS: Expression of the ET-1 gene was increased early as measured by quantitative reverse transcriptase-polymerase chain reaction (6-fold 3 days after BDL) whereas ET-1 peptide measured by RIA increased significantly only in the late phase (30-fold at 28 days). There was a linear correlation between portal pressure and the amount of ET-1 in the portal vein (r = 0.66; P = 0.003), as well as between ET-1 and the volume fraction of myofibroblasts (r = 0.80, P < 10(-7)) as assessed by morphometry and immunohistochemical staining using alpha-smooth muscle actin. CONCLUSIONS: During chronic liver injury activation of HSCs and of preproET-1 mRNA is accentuated in the early phase after BDL. The late increase in ET-1 peptide may indicate that this peptide is only secondarily involved in HSC activation. The correlation between ET-1 in portal vein and portal pressure suggests that ET-1 may play an important role in the development of portal hypertension.