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Tangier disease is a rare, autosomal recessive disorder caused by mutations in the ABCA1 gene and is characterized by near absence of plasma high-density lipoprotein cholesterol, accumulation of cholesterol in multiple tissues, peripheral neuropathy, and accelerated atherosclerosis. Here we report three new kindreds with Tangier disease harboring both known and novel mutations in ABCA1. One patient was identified to be homozygous for a nonsense mutation, p.Gln1038*. In a remarkably large Tangier disease pedigree with four affected siblings, we identified compound heterozygosity for previously reported missense variants, p.Arg937Val and p.Thr940Met, and show that both of these mutations result in significantly impaired cholesterol efflux in transfected cells. In a third pedigree, the proband was identified to be compound heterozygous for two novel mutations, a frameshift (p.Ile1200Hisfs*4) and an intronic variant (c.4176-11T>G), that lead to the creation of a cryptic splice site acceptor and premature truncation, p.Ser1392Argfs*6. We demonstrate that this mutation arose de novo, the first demonstration of a pathogenic de novo mutation in ABCA1 associated with Tangier disease. We also report results of glucose tolerance testing in a Tangier disease kindred for the first time, showing a gene-dose relationship between ABCA1 activity and glucose tolerance and suggesting that Tangier disease patients may have substantially impaired islet function. Our findings provide insight into the diverse phenotypic manifestations of this rare disorder, expand the list of pathogenic mutations in ABCA1, and increase our understanding of how specific mutations in this gene lead to abnormal cellular and physiological phenotypes.

The human pathology Wilson disease (WD) is characterized by toxic copper (Cu) accumulation in brain and liver, resulting in, among other indications, mitochondrial dysfunction and apoptosis of hepatocytes. In an effort to identify novel compounds that can alleviate Cu-induced toxicity, we screened the Pharmakon 1600 repositioning library using a Cu-toxicity yeast screen. We identified 2 members of the drug class of Angiotensin II Type 1 receptor blockers (ARBs) that could increase yeast tolerance to Cu, namely Candesartan and Losartan. Subsequently, we show that specific ARBs can increase yeast tolerance to Cu and/or the chemotherapeutic agent cisplatin (Cp). The latter also induces mitochondrial dysfunction and apoptosis in mammalian cells. We further demonstrate that specific ARBs can prevent the prevalence of Cu-induced apoptotic markers in yeast, with Candesartan Cilexetil being the ARB which demonstrated most pronounced reduction of apoptosis-related markers. Next, we tested the sensitivity of a selection of yeast knockout mutants affected in detoxification of reactive oxygen species (ROS) and Cu for Candesartan Cilexetil rescue in presence of Cu. These data indicate that Candesartan Cilexetil increases yeast tolerance to Cu irrespectively of major ROS-detoxifying proteins. Finally, we show that specific ARBs can increase mammalian cell tolerance to Cu, as well as decrease the prevalence of Cu-induced apoptotic markers. All the above point to the potential of ARBs in preventing Cu-induced toxicity in yeast and mammalian cells., Competing Interests: Conflict of interest: The authors declare no conflict of interest.

Background: Most orphan drugs do not meet traditional standards of cost-effectiveness. Yet, most orphan drugs are reimbursed, which implies that other factors are taken into account at the time of reimbursement. To increase accountability of decision-makers, there is a need for more transparency in the factors that play a role in reimbursement decisions of orphan drugs. Therefore, the aim of this study is to use a combination of qualitative research methods to examine which official and non-official factors influence reimbursement decisions for orphan drugs in Belgium., Methods: Six semi-structured interviews with past or present members of the Drug Reimbursement Committee (DRC) were performed with a view to obtaining an overview of the potential factors influencing reimbursement. Additionally, these presence of these factors was assessed in the reimbursement dossiers of all orphan drugs (n = 64) for which an application for reimbursement was submitted to the National Institute for Health and Disability Insurance in Belgium between January 2002 and July 2013., Results: Different official (i.e. therapeutic value, budget impact, price and impact in clinical practice) and non-official factors (i.e. pricing and reimbursement in other countries, interference by patient organisations and experts, arguments related to quality of branded drug versus compounding, media attention, innovative character, economic importance, ethical arguments and the political climate) may have influenced past reimbursement decisions for orphan drugs in Belgium., Discussion: The identification of factors influencing orphan drug reimbursement is a crucial step in the development of a transparent and consistent framework which will guide future decision-making for reimbursement of orphan drugs.

Background: The pricing mechanism of orphan drugs appears arbitrary and has been referred to as a "black box". Therefore, the aim of this study is to investigate how drug- and disease-specific variables relate to orphan drug prices. Additionally, we aim to explore if certain country-specific pricing and reimbursement policies affect the price level of orphan drugs., Methods: Annual treatment costs per indication per patient were calculated for 59 orphan drugs with a publicly available price in Belgium, the Netherlands, Czech Republic, France, Italy and the United Kingdom. A multiple linear regression model was built with 14 drug- and disease-specific variables. A Mann-Whitney U test was used to explore whether there is a correlation between annual treatment costs of orphan drugs across countries with different pricing and reimbursement policies., Results: Repurposed orphan drugs, orally administered orphan drugs or orphan drugs for which an alternative treatment is available are associated with lower annual treatment costs. Orphan drugs with multiple orphan indications, for chronic treatments or for which an improvement in overall survival or quality-of-life has been demonstrated, are associated with higher annual treatment costs. No association was found between annual treatments cost of orphan drugs across countries and the different pricing and reimbursement systems., Conclusions: This study has shown that prices of orphan drugs are influenced by factors such as the availability of an alternative drug treatment, repurposing, etc. Current debate about the affordability of orphan drugs highlights the need for more transparency in orphan drug price setting.

Congenital disorders of N-glycosylation (CDG) form a rapidly growing group of more than 20 inborn errors of metabolism. Most patients are identified at the pediatric age with multisystem disease. There is no systematic review on the long-term outcome and clinical presentation in adult patients. Here, we review the adult phenotype in 78 CDG patients diagnosed with 18 different forms of N-glycosylation defects. Characteristics include intellectual disability, speech disorder and abnormal gait. After puberty, symptoms might remain non-progressive and patients may lead a socially functional life. Thrombosis and progressive symptoms, such as peripheral neuropathy, scoliosis and visual demise are specifically common in PMM2-CDG. Especially in adult patients, diagnostic glycosylation screening can be mildly abnormal or near-normal, hampering diagnosis. Features of adult CDG patients significantly differ from the pediatric phenotype. Non-syndromal intellectual disability, or congenital malformations in different types of CDG and decreasing sensitivity of screening might be responsible for the CDG cases remaining undiagnosed until adulthood.

Introduction: Individuals with neuropathic pain, angiokeratoma (AK) and/or cornea verticillata (CV) may be tested for Fabry disease (FD). Classical FD is characterised by a specific pattern of these features. When a patient presents with a non-specific pattern, the pathogenicity of a variant in the α-galactosidase A (GLA) gene may be unclear. This uncertainty often leads to considerable distress and inappropriate counselling and treatment. We developed a clinical approach for these individuals with an uncertain diagnosis of FD., Materials and Methods: A document was presented to an FD expert panel with background information based on clinical experience and the literature, followed by an online survey and a written recommendation., Results: The 13 experts agreed that the recommendation is intended for individuals with neuropathic pain, AK and/or CV only, i.e. without kidney, heart or brain disease, with an uncertain diagnosis of FD. Only in the presence of FD-specific neuropathic pain (small fibre neuropathy with FD-specific pattern), AK (FD-specific localisations) or CV (without CV inducing medication), FD is confirmed. When these features have a non-specific pattern, there is insufficient evidence for FD. If no alternative diagnosis is found, follow-up is recommended., Conclusions: In individuals with an uncertain diagnosis of FD, the presence of an FD-specific pattern of CV, AK or neuropathic pain is sufficient to confirm the diagnosis of FD. When these features are non-specific, a definite diagnosis cannot (yet) be established and follow-up is indicated. ERT should be considered only in those patients with a confirmed diagnosis of FD.

Objectives: The Z allele (Glu342Lys) in α1-antitrypsin (AAT) deficiency is a combined deficiency and dysfunctional allele. Carrying one Z allele induces a risk of a more aggressive evolution in patients with a chronic liver disease. As most of the carriers of Z allele do not have overt liver disease, it is likely that Z allele-containing livers have been used previously for liver transplantation. We analyzed the incidence, epidemiology, and clinical features of AAT accumulation in the hepatocytes after liver transplantation., Methods: Follow-up biopsies of liver transplant recipients were analyzed with periodic acid Schiff staining until 2006 (n=486); from 2006 on (n=303), all biopsies were stained with a specific monoclonal antibody against mutated AATZ protein. Genotyping of both recipient and donor was performed in the case of positive staining., Results: Of 789 liver transplantation patients, six patients (0.8%) showed mutated AATZ accumulation in the transplanted liver. Mutation analysis confirmed the presence of the Z allele in all donor organs including one transplanted organ with the SZ phenotype. There was a clear concordance between the isoelectrical focusing of the recipient AAT after transplantation and the genotype of the donor., Conclusion: Presumed healthy donor organs containing the Z allele were used for transplantation in 0.8% of cases in our series. As the presence of a Z allele is an independent risk factor of aggravation of chronic liver disease, AATZ accumulation in biopsies after liver transplantation should be actively looked for.

Background: The difficulties associated with organising clinical studies for orphan medicinal products (OMPs) are plentiful. Recent debate on the long-term effectiveness of some OMPs, led us to question whether the initial standards for clinical evidence for OMPs, set by the European Medicines Agency (EMA) at the time of marketing authorization, are too low. Therefore, the aim of this study was to quantitatively evaluate the characteristics and quality of clinical evidence that is presented for OMPs to obtain marketing authorization in Europe, using the new and validated COMPASS tool., Methods: We quantitatively assessed the characteristics and quality of clinical evidence of the pivotal studies of 64 OMPs as described in the European Public Assessment Report and/or the Scientific Discussion document prepared by the Committee for Human Medicinal Products of the EMA., Results: The 64 OMPs were altogether authorized for 78 orphan indications, for which 117 studies were identified as 'pivotal' or 'main' studies. In approximately two thirds of the studies, the allocation was randomized (64.8%) and a control arm was used (68.5%). Half of the studies applied some type of blinding. Only a minority (26.9%) of the studies included a Quality-of-Life (QoL) related endpoint, of which a third claim an improvement in QoL. Upon analyzing the quality of reporting, we found that some aspects (i.e. the endpoints, the sampling criteria, and the interventions) are well described, whereas other items (i.e. a description of the patients and of potential biases) are not reported for all studies., Conclusions: In conclusion, the pivotal studies that are the basis for marketing authorization of OMPs are a cause for concern, as they exhibit methodological flaws i.e. the lack of QoL-related endpoints as outcome, lack of blinding in the study design and the use of surrogate endpoints. Additionally, there are shortcomings in the reporting of those studies that complicate the interpretation. A more demanding regulatory process for OMPs is needed to guide evidence-based clinical decision-making.

Background: Rare diseases are defined as life-threatening or chronically debilitating diseases with a prevalence of 50 out of 100,000 individuals or less. Orphan medicinal products (OMPs) are intended for the treatment of rare diseases. The assessment of quality of evidence in small populations is often complex. Many generic tools are unfit. Therefore, the aim of this study was to develop and validate a new tool to assess the quality of OMPs' clinical evidence (COMPASS)., Methods: Firstly, a draft version of the COMPASS tool, developed by the authors and consisting of three parts, was amended based on suggestions obtained in four rounds of expert consultation. Secondly, the tool was put through three rounds of validation. The data source was information provided on the Orphanet website and in European Public Assessment Report (EPAR) document of the European Medicines Agency., Results: The first pilot round revealed a high (92.2%) inter-rater agreement for part one of the tool. After further improvements, the final inter-rater agreement was 86.4% for part two (on methodological quality) and three (on quality of reporting) of the tool. The COMPASS tool does not attempt to score or rank the quality of clinical evidence, but rather to give an outline of various, key elements with respect to quality of clinical evidence of OMP studies., Conclusions: The COMPASS tool can be applied to assess the quality of evidence of an OMP based on information in the registration dossier, for example by local reimbursement agencies, pharmacists or clinicians. In that way, the tool can contribute to making reimbursement and/or treatment decisions increasingly more founded on the principles of evidence-based decision making.

Background: Statin therapy is recommended for children with familial hypercholesterolemia (FH), but most children do not reach treatment targets., Objective: Here we present the design and results at baseline of the ongoing CHARON study, to evaluate the safety and efficacy of rosuvastatin., Methods: This study comprises an international 2-year open label, titration-to-goal study in 198 children with heterozygous FH aged 6 to 18 years, with rosuvastatin in a maximum dose of 10 mg (<10 years of age) or 20 mg (older children). In addition, 64 unaffected siblings were enrolled as controls. The primary efficacy outcome is the change from baseline in low-density lipoprotein cholesterol, and the secondary outcome is the change in carotid intima-media thickness (c-IMT) in patients with FH compared with their siblings. The primary safety outcomes are growth and sexual maturation; secondary outcomes are the change in other lipoprotein levels and the incidence of adverse events, discontinuation rates, and abnormal laboratory values., Results: At baseline, mean age of patients with FH was 12.1 ± 3.3 years, 44% were boys, and mean low-density lipoprotein cholesterol levels were 6.1 ± 1.3 mmol/L (235.9 ± 48.7 mg/dL). Mean c-IMT was 0.399 mm (95% CI, 0.392-0.406 mm) in children with FH versus 0.377 (95% CI, 0.366-0.388 mm) in unaffected siblings (P = .001)., Conclusions: At baseline, as expected according to on previous observations, children with FH proved to have a greater c-IMT than their healthy siblings. These differences had already occurred at a very young age, which emphasizes the importance of considering early statin initiation in this high-risk population., (Copyright © 2013 National Lipid Association. Published by Elsevier Inc. All rights reserved.)

Aim: Mitochondrial diseases affect about 1/5000-1/10000 in the population. Twenty percent of patients with mitochondrial disease show liver involvement. In contrast to current belief among most internists, these diseases do not only present in childhood., Methods: We present four cases of adults (three with Alpers-Huttenlocher syndrome and one with mitochondrial neurogastrointestinal encephalomyopathy), diagnosed between 2005 and 2010, in our university referral center., Result: We focus on the broad clinical spectrum of liver involvement in mitochondrial diseases and their diagnosis. Biochemical investigations are often found to be inconclusive, and genetic confirmation cannot always be obtained, leaving many patients without a final diagnosis. Evidence-based causal therapy is unavailable for most mitochondrial diseases and liver transplantation for this indication remains a controversial issue., Conclusion: For clinicians, it is important to consider the possibility of an underlying mitochondrial disorder when there is systemic involvement (more than one organ affected), a suggestive family history, or an elevated level of lactic acid in the blood or cerebrospinal fluid.

To encourage the development of orphan drugs, the European Union has implemented specific policies in 2000. However, the political, social, scientific and economic context has changed since the implementation of these policies. For that reason, the aim of this article is to evaluate orphan drug policies in Europe. Firstly, key issues on the orphan drug policy were identified based on desk research. Secondly, a Delphi policy study with 47 European orphan drug experts from different backgrounds was carried out to explore these issues. In the round one of the Delphi, responses were received from 18 experts (38.3%) and from ten (55.5%) in the round two. Experts agree that the orphan drug policies in Europe have not outlived their usefulness. Additionally, the importance of reducing country-dependent inequalities in patient access to orphan drugs has been emphasized. Still, there is room for further refinement of the orphan drug policies. Within that context, we formulated several policy recommendations (e.g. enforcing the policy that is in place to reduce the period of market exclusivity for profitable orphan drugs, stating the level of clinical evidence needed to authorize orphan drugs, etc.) with the overall goal to optimize patient access to orphan drugs., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Heterozygous deletion or mutation in hepatocyte nuclear factor 1 homeobox B/transcription factor 2 (HNF1B/TCF2) causes renal cyst and diabetes syndrome (OMIM #137920). Mice with homozygous liver-specific deletion of Hnf1β revealed that a complete lack of this factor leads to ductopenia and bile duct dysplasia, in addition to mild hepatocyte defects. However, little is known about the hepatic consequences of deficient HNF1B function in humans. Three patients with heterozygous HNF1B deficiency were found to have normal bile duct formation on radiology and routine liver pathology. Electron microscopy revealed a paucity or absence of normal primary cilia. Therefore, heterozygous HNF1B deficiency is associated with ciliary anomalies in cholangiocytes, and this may cause cholestasis., (Copyright © 2012 American Association for the Study of Liver Diseases.)

In recent years, acute-on-chronic liver failure has been recognized as a specific clinical form of liver failure associated with cirrhosis. The syndrome refers to an acute deterioration of liver function and subsequently of other end organs over a period of weeks following a precipitating event in a patient with previously well- or reasonably well-compensated cirrhosis. These precipitating events include either an indirect (e.g., variceal hemorrhage, sepsis) or a direct (e.g., drug-induced) hepatotoxic factor. The short-term mortality for this condition is more than 50%. At present, considerable efforts are ongoing to better characterize the syndrome, to gain further insight into its pathophysiology and to optimize therapy. This article aims to highlight the current concepts of these various aspects.

Here we report a patient with Zellweger syndrome, who presented at the age of 3 months with icterus, dystrophy, axial hypotonia, and hepatomegaly. Abnormal findings of metabolic screening tests included hyperbilirubinaemia, hypoketotic dicarboxylic aciduria, increased C(26:0) and decreased C(22:0) plasma levels, and strongly reduced plasmalogen concentrations. In fibroblasts, both peroxisomal α- and β-oxidation were impaired. Liver histology revealed bile duct paucity, cholestasis, arterial hyperplasia, very small branches of the vena portae, and parenchymatic destruction. Immunocytochemical analysis of cultured fibroblasts demonstrated that the cells contain peroxisomal remnants lacking apparent matrix protein content and PEX14, a central membrane component of the peroxisomal matrix protein import machinery. Transfection of fibroblasts with a plasmid coding for wild-type PEX14 restored peroxisomal matrix protein import. Mutational analysis of this gene revealed a genomic deletion leading to the deletion of exon 3 from the coding DNA (c.85-?&#95;170+?del) and a concomitant change of the reading frame (p.[Ile29&#95;Lys56del;Gly57GlyfsX2]).

Background: Anderson-Fabry disease (AFD) is an X-linked condition originating from a deficiency in alpha-galactosidase, a lysosomal enzyme. Multi-organ involvement ensues in early adulthood and vital organs are affected: the kidneys, brain, heart. Several reports however suggest that AFD is underdiagnosed., Methods: We screened a kidney transplant population using a two-tier approach. The first tier was the determination of alpha-galactosidase A (AGALA) activity using a dried blood spot on filter paper (DBFP); in the second tier, patients with the lowest alpha-galactosidase levels were further subjected to mutation analysis of the GLA gene., Results: From the database of 2328 patients, 1233 subjects met the inclusion criteria. Finally, after informed consent, 673 patients were screened (54.5%-395 women and 278 men). DBFP analysis resulted in a mean AGALA of 2.63 +/- 2.48 micromol/L/h (2.5 and 97.5 percentile were 0.0001 and 5.07 micromol/L/h, respectively). Eleven patients were subjected to further genetic analysis. In a male patient a pathogenic missense mutation p.Ala143Thr (c.427A>G) was identified., Conclusions: Our results show that the proposed approach can detect AFD patients in a until now seldomly screened high-risk group: kidney transplant patients. We conclude that screening for AFD in high-risk populations is a cost-effective, technically feasible and clinically valuable objective.

Paroxysmal exercise-induced dyskinesia (PED) can occur in isolation or in association with epilepsy, but the genetic causes and pathophysiological mechanisms are still poorly understood. We performed a clinical evaluation and genetic analysis in a five-generation family with co-occurrence of PED and epilepsy (n = 39), suggesting that this combination represents a clinical entity. Based on a whole genome linkage analysis we screened SLC2A1, encoding the glucose transporter of the blood-brain-barrier, GLUT1 and identified heterozygous missense and frameshift mutations segregating in this and three other nuclear families with a similar phenotype. PED was characterized by choreoathetosis, dystonia or both, affecting mainly the legs. Predominant epileptic seizure types were primary generalized. A median CSF/blood glucose ratio of 0.52 (normal >0.60) in the patients and a reduced glucose uptake by mutated transporters compared with the wild-type as determined in Xenopus oocytes confirmed a pathogenic role of these mutations. Functional imaging studies implicated alterations in glucose metabolism in the corticostriate pathways in the pathophysiology of PED and in the frontal lobe cortex in the pathophysiology of epileptic seizures. Three patients were successfully treated with a ketogenic diet. In conclusion, co-occurring PED and epilepsy can be due to autosomal dominant heterozygous SLC2A1 mutations, expanding the phenotypic spectrum associated with GLUT1 deficiency and providing a potential new treatment option for this clinical syndrome.

Background/aims: Sporadic Porphyria Cutanea Tarda (sPCT) is associated with liver disease, e.g. HCV infection, haemochromatosis and especially alcoholic liver disease. We conducted a retrospective analysis on the prevalence of liver disorders in association with Porphyria Cutanea Tarda (PCT), in a university referral centre., Methods: The PCT cases were retrieved from computerized databases. Patient files lacking information on the presence of concomitant liver disease were excluded from further analysis., Results: 29 PCT patients were retrieved from our databases, of which 17 patients with sPCT were retained for further analysis. Patients were middle aged (mean age: 43 +/- 3) and there was no gender difference (10 males vs. 7 females). Almost all patients had iron overload (14/17). 5 patients had chronic HCV, with type 1b in 3 of them, 7 abused alcohol, 4 patients had hereditary haemochromatosis (3 homozygous C282Y--1 heterozygous H63D/C282Y). In 3 patients sPCT was associated with medication intake and one patient had chronic hepatitis B (HBV). 13 patients were treated with phlebotomies, with success in 11/13. 4 patients were treated with chloroquine, 3 of which also underwent phlebotomies. Of the 5 patients with HCV, 3 were successfully treated with combined antiviral therapy; one of them is planned to be treated; one patient never received therapy and was lost from follow-up. One patient developed hepatocellular carcinoma (HCC) during a median follow-up of 24 years., Conclusions: We found a significant association between sPCT and liver disorders, such as chronic HCV infection, alcohol abuse, iron overload and hereditary haemochromatosis. Therefore, patients presenting with PCT should be screened for concomitant liver disease. Iron overload is present in a majority of patients, the majority of patients can be successfully treated with phlebotomies. The risk of developing HCC in our sPCT patients and in literature is low.

Background: We recently showed that human hepatic progenitor cells (HPCs) express muscarinic acetylcholine (Ach) receptor subtype 3 and that--following liver transplantation--HPC numbers are significantly reduced. To further elaborate on this, we examined whether HPC also express receptors for vasoactive intestinal peptide (VIP), which, besides Ach, also is an important parasympathetic neurotransmitter. VIP expressing nerves are known to be present in the liver., Methods: We performed immunohistochemistry for VIP receptor subtypes 1 and 2 (VIPR1 and 2), on sections of normal and diseased human liver (n=17), and double staining for VIPR2 and known HPC markers. We performed RT-PCR for VIPR1 and 2 on total RNA from purified rat HPC. To document the probability of direct interaction, we also performed double immunostaining for nerve markers and HPC markers on human liver sections., Results: VIPR2 immunostaining was clearly positive in HPC and reactive bile ductules on paraffin-embedded and frozen tissue sections. We could not demonstrate VIPR1 protein expression in the liver, with either of two VIPR1 antibodies tested. The presence of VIPR2 mRNA in HPC was confirmed by RT-PCR. Nerve endings were shown to abut on reactive bile ductules., Conclusion: We show here for the first time that HPC express VIPR2 and receive nerve endings. These features, and the fact that HPC numbers are influenced by the presence or absence of the autonomic innervation of the liver, suggest a direct interaction.

In chronic liver injury, hepatic stellate cells (HSCs) have been implicated as regulators of sinusoidal vascular tone. We studied the relative role of Ca(2+)-dependent and Ca(2+)-independent contraction pathways in rat HSCs and correlated these findings to in situ perfused cirrhotic rat livers. Contraction of primary rat HSCs was studied by a stress-relaxed collagen lattice model. Dose-response curves to the Ca(2+) ionophore A-23187 and to the calmodulin/myosin light chain kinase inhibitor W-7 served to study Ca(2+)-dependent pathways. Y-27632, staurosporin, and calyculin (inhibitors of Rho kinase, protein kinase C, and myosin light chain phosphatase, respectively) were used to investigate Ca(2+)-independent pathways. The actomyosin interaction, the common end target, was inhibited by 2,3-butanedione monoxime. Additionally, the effects of W-7, Y-27632, and staurosporin on intrahepatic vascular resistance were evaluated by in situ perfusion of normal and thioacetamide-treated cirrhotic rat livers stimulated with methoxamine (n = 25 each). In vitro, HSC contraction was shown to be actomyosin based with a regulating role for both Ca(2+)-dependent and -independent pathways. Although the former seem important, an important auxiliary role for the latter was illustrated through their involvement in the phenomenon of "Ca(2+) sensitization." In vivo, preincubation of cirrhotic livers with Y-27632 (10(-4) M) and staurosporin (25 nM), more than with W-7 (10(-4) M), significantly reduced the hyperresponsiveness to methoxamine (10(-4) M) by -66.8 +/- 1.3%, -52.4 +/- 2.7%, and -28.7 +/- 2.8%, respectively, whereas in normal livers this was significantly less: -43.1 +/- 4.2%, -40.2 +/- 4.2%, and -3.8 +/- 6.3%, respectively. Taken together, these results suggest that HSC contraction is based on both Ca(2+)-dependent and -independent pathways, which were shown to be upregulated in the perfused cirrhotic liver, with a predominance of Ca(2+)-independent pathways.

Obesity is a frequent complication following liver transplantation and is insufficiently responsive to dietary and life style advice. We studied the safety of orlistat treatment in obese and overweight liver transplant recipients (n = 15) on a stable tacrolimus-based immunosuppressive regimen. For safety reasons, the treatment period was restricted (6 months 120 mg t.i.d., 3 months 120 mg daily). Three patients dropped out, tacrolimus dose was adjusted in six of 12 remaining patients (dose reduction in 4, increase in 2, P = N.S.). All dose adjustments occurred during the 6 months of orlistat 120 mg t.i.d. therapy. No drug intolerance, adverse events or episodes of rejection occurred during the study. Efficacy of orlistat treatment in this population could not be shown, because a formal control population was not included in this safety trial. Moreover, only a significant decrease of waist circumference (P < 0.01 versus start of the study), but not of weight or body mass index, was achieved in the treated group. Orlistat treatment is well tolerated in liver transplant recipients and can be started safely, provided immunosuppressive drug levels and dietary adherence are closely monitored.

Objectives: Focal nodular hyperplasia-like nodules (FNH-like nodules) are focal lesions occurring in liver cirrhosis and are morphologically very similar to classical FNH in an otherwise normal liver. They are sometimes misdiagnosed as hepatocellular carcinoma (HCC) on imaging because both types of lesions show arterial-phase enhancement. Although the morphological, immunohistochemical, and imaging features of FNH-like nodules are well-known, their pathogenesis and role in hepatocarcinogenesis have not been studied in detail. Therefore, we performed a detailed pathological evaluation of 130 cirrhotic explant livers and correlated these data with the clinical features of the patients., Methods: All cirrhotic explant livers were uniformly sliced at 5-mm intervals and all detected focal lesions were microscopically classified according to internationally accepted criteria. The obtained data regarding FNH-like nodules were then correlated with other pathological findings and with clinical data obtained during pretransplant evaluation and recorded in a database., Results: FNH-like nodules were present in 15% of patients and their small size (75% of cases < 1 cm) appears to preclude detection by imaging in almost all cases. The presence of esophageal varices and pretransplant treatment with chemoembolization were independently and significantly associated with the presence of FNH-like nodules. There were no associations between FNH-like nodules on the one hand and low-grade dysplastic nodules, high-grade dysplastic nodules, and HCCs on the other hand., Conclusions: The clinicopathological features of FNH-like nodules support the hypothesis that vascular alterations in liver cirrhosis play an important role in their pathogenesis and that FNH-like nodules do not have an increased risk of malignant transformation.

Breast cancer resistance protein (BCRP/ABCG2) is an ATP-binding cassette transport protein that is expressed in several organs including the liver. Previous studies have shown that ABC transport proteins play an important pathophysiological role in several liver diseases. However, to date, expression pattern and possible role of BCRP in human liver diseases and animal models have not been studied in detail. Here we investigated the expression pattern of BCRP in normal liver, chronic parenchymal and biliary human liver diseases, and parallel in different rat models of liver diseases. Expression was studied by immunohistochemistry and additionally by RT-PCR analysis in Thy-1-positive rat oval cells. Bile ducts, hepatic progenitor cells, reactive bile ductules, and blood vessel endothelium were immunoreactive for BCRP in normal liver and all types of human liver diseases and in rat models. BCRP was expressed by the canalicular membrane of hepatocytes in normal and diseased human liver, but never in rat liver. Remarkably, there was also expression of BCRP at the basolateral pole of human hepatocytes, and this was most pronounced in chronic biliary diseases. In conclusion, BCRP positivity in the progenitor cells/reactive ductules could contribute to the resistance of these cells to cytotoxic agents and xenotoxins. Basolateral hepatocytic expression in chronic biliary diseases may be an adaptive mechanism to pump bile constituents back into the sinusoidal blood. Strong differences between human and rat liver must be taken into account in future studies with animal models.

Alagille syndrome (AGS) is a developmental, multiorgan disease caused by mutations of the Jagged1 gene. The liver is one of the major organs affected in AGS, and the hallmark of liver pathology in AGS is an age-related increase in the proportion of portal tracts that have no bile duct, but without evidence of prominent bile duct damage. The pathogenesis of this bile duct paucity is currently not well understood. (Immuno)histochemical and molecular analyses were performed on several liver biopsies that were taken during macroscopic examination of the explant liver of a 17-year-old AGS patient. The liver periphery was macroscopically pale and was microscopically characterized by complete absence of bile ducts and presence of severe cholestasis, but there was no ductular reaction. Conversely, the central, hilar portion contained normally developed bile ducts showing no or minimal damage and cholestasis. A missense mutation in the Jagged1 gene was present in both parts of the liver, indicating that mosaicism did not cause this peculiar picture. There was also a hypertrophy of the hepatic arterial branches in the liver periphery. Together with previous indirect findings, the current study of the explant liver of an AGS patient strongly suggests that a lack of branching and elongation of bile ducts during postnatal liver growth is the mechanism by which peripheral bile duct paucity and cholestasis develops in AGS. Our findings also suggest that anomalies of the intrahepatic arterial branches may be part of AGS in some patients.

Background/aims: The development of the intrahepatic bile ducts most likely requires interactions between epithelial and mesenchymal cells. In view of the epithelial-mesenchymal interactions between portal myofibroblasts (pMFs) and biliary epithelial cells in adult diseases of the bile ducts, we investigated the presence and function of pMFs during the development of intrahepatic bile ducts, as well as the development of intrahepatic branches of the hepatic artery., Methods: We performed haematoxylin-eosin-stainings and immunohistochemistry for alpha-smooth-muscle actin, cytokeratin 19 and vimentin on serial sections of 45 fetal and postnatal liver biopsies., Results: The mesenchyme of portal tracts in the ductal plate stage devoid of a hepatic artery branch, contained numerous and diffusely scattered pMFs. Portal tracts with a hepatic artery branch were always larger than those without and showed a decreasing number of pMFs. In the remodeling stage, all portal tracts contained a hepatic artery branch, and pMFs were restricted to the periductal mesenchyme. These periductal pMFs disappeared after full incorporation of the bile duct., Conclusion: Our findings strongly suggest interactions between pMFs and epithelial cells of the developing bile ducts. The development of the intrahepatic arterial branches always precedes the incorporation of the tubular segments of the ductal plate.