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BackgroundPatients with decompensated cirrhosis experience high mortality rates. Current prognostic scores, including the model for end-stage liver disease (MELD), may underperform in settings other than in those they were initially developed. Novel biomarkers have been proposed to improve prognostication accuracy and even to predict development of complications.MethodsWe performed a systematic review and meta-analysis on novel urine and blood biomarkers and their ability to predict 90-day mortality in patients with decompensated cirrhosis. Secondary outcomes included 28-day and 1-year mortality, and development of acute-on-chronic liver failure, acute kidney injury and other complications. To overcome differences in units, temporal changes in assays and reporting heterogeneity, we used the ratio of means (RoM) as measure of association for assessing strength in predicting outcomes. An RoM>1 implies that the mean biomarker level is higher in those that develop the outcome than in those that do not.ResultsOf 6629 unique references, 103 were included, reporting on 29 different biomarkers, with a total of 31 362 biomarker patients. Most studies were prospective cohorts of hospitalised patients (median Child-Pugh-Turcotte score of 9 and MELD score of 18). The pooled 90-day mortality rate was 0.27 (95% CI 0.24 to 0.29). The RoM for predicting 90-day mortality was highest for interleukin 6 (IL-6) (2.56, 95% CI 2.39 to 2.74), followed by urinary neutrophil gelatinase-associated lipocalin (uNGAL) (2.42, 95% CI 2.20 to 2.66) and copeptin (2.33, 95% CI 2.17 to 2.50). These RoMs were all higher than for MELD (1.44, 95% CI 1.42 to 1.46).ConclusionNovel biomarkers, including IL-6, uNGAL and copeptin, can probably improve prognostication of patients with decompensated cirrhosis compared with MELD alone.

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To test the hypothesis that the gut microbiota of individuals with nonalcoholic fatty liver disease (NAFLD) produce enough ethanol to be a driving force in the development and progression of this complex disease, we performed one prospective clinical study and one intervention study. Ethanol was measured while fasting and 120 min after a mixed meal test (MMT) in 146 individuals. In a subset of 37 individuals and in an external validation cohort, ethanol was measured in portal vein blood. In an intervention study, ten individuals with NAFLD and ten overweight but otherwise healthy controls were infused with a selective alcohol dehydrogenase (ADH) inhibitor before an MMT. When compared to fasted peripheral blood, median portal vein ethanol concentrations were 187 (interquartile range (IQR), 17–516) times higher and increased with disease progression from 2.1 mM in individuals without steatosis to 8.0 mM in NAFL 21.0 mM in nonalcoholic steatohepatitis. Inhibition of ADH induced a 15-fold (IQR,1.6- to 20-fold) increase in peripheral blood ethanol concentrations in individuals with NAFLD, although this effect was abolished after antibiotic treatment. Specifically, Lactobacillaceae correlated with postprandial peripheral ethanol concentrations (Spearman’s rho, 0.42; P< 10−5) in the prospective study. Our data show that the first-pass effect obscures the levels of endogenous ethanol production, suggesting that microbial ethanol could be considered in the pathogenesis of this highly prevalent liver disease.

The overall objective of these guidelines is to provide evidence-based recommendations for the diagnosis and management of immunoglobulin G4 (IgG4)-related digestive disease in adults and children. IgG4-related digestive disease can be diagnosed only with a comprehensive work-up that includes histology, organ morphology at imaging, serology, search for other organ involvement, and response to glucocorticoid treatment. Indications for treatment are symptomatic patients with obstructive jaundice, abdominal pain, posterior pancreatic pain, and involvement of extra-pancreatic digestive organs, including IgG4-related cholangitis. Treatment with glucocorticoids should be weight-based and initiated at a dose of 0.6–0.8 mg/kg body weight/day orally (typical starting dose 30-40 mg/day prednisone equivalent) for 1 month to induce remission and then be tapered within two additional months. Response to initial treatment should be assessed at week 2–4 with clinical, biochemical and morphological markers. Maintenance treatment with glucocorticoids should be considered in multi-organ disease or history of relapse. If there is no change in disease activity and burden within 3 months, the diagnosis should be reconsidered. If the disease relapsed during the 3 months of treatment, immunosuppressive drugs should be added.

The overall objective of these guidelines is to provide evidence-based recommendations for the diagnosis and management of immunoglobulin G4 (IgG4)-related digestive disease in adults and children. IgG4-related digestive disease can be diagnosed only with a comprehensive work-up that includes histology, organ morphology at imaging, serology, search for other organ involvement, and response to glucocorticoid treatment. Indications for treatment are symptomatic patients with obstructive jaundice, abdominal pain, posterior pancreatic pain, and involvement of extra-pancreatic digestive organs, including IgG4-related cholangitis. Treatment with glucocorticoids should be weight-based and initiated at a dose of 0.6–0.8 mg/kg body weight/day orally (typical starting dose 30-40 mg/day prednisone equivalent) for 1 month to induce remission and then be tapered within two additional months. Response to initial treatment should be assessed at week 2–4 with clinical, biochemical and morphological markers. Maintenance treatment with glucocorticoids should be considered in multi-organ disease or history of relapse. If there is no change in disease activity and burden within 3 months, the diagnosis should be reconsidered. If the disease relapsed during the 3 months of treatment, immunosuppressive drugs should be added.

Statins have beneficial effects on intrahepatic circulation and decrease portal hypertension and rifaximin modulates the gut microbiome and might prevent bacterial translocation in patients with cirrhosis. Therefore, this drug combination might be of therapeutic benefit in patients with decompensated cirrhosis. However, there is concern regarding the safety of statins in patients with decompensated cirrhosis. We assessed the safety of two different doses of simvastatin, in combination with rifaximin, in patients with decompensated cirrhosis.

Hepatic encephalopathy (HE) is a frequent complication of cirrhosis and may cause cerebral damage. Neurodegenerative diseases can induce the release of neuroproteins like neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) in body fluids, including blood plasma. We investigated whether NfL and GFAP could serve as potential diagnostic plasma biomarkers for overt HE (oHE).

The principal limitations of the terms NAFLD and NASH are the reliance on exclusionary confounder terms and the use of potentially stigmatising language. This study set out to determine if content experts and patient advocates were in favor of a change in nomenclature and/or definition. A modified Delphi process was led by three large pan-national liver associations. The consensus was defined a priori as a supermajority (67%) vote. An independent committee of experts external to the nomenclature process made the final recommendation on the acronym and its diagnostic criteria. A total of 236 panelists from 56 countries participated in 4 online surveys and 2 hybrid meetings. Response rates across the 4 survey rounds were 87%, 83%, 83%, and 78%, respectively. Seventy-four percent of respondents felt that the current nomenclature was sufficiently flawed to consider a name change. The terms “nonalcoholic” and “fatty” were felt to be stigmatising by 61% and 66% of respondents, respectively. Steatotic liver disease was chosen as an overarching term to encompass the various aetiologies of steatosis. The term steatohepatitis was felt to be an important pathophysiological concept that should be retained. The name chosen to replace NAFLD was metabolic dysfunction–associated steatotic liver disease. There was consensus to change the definition to include the presence of at least 1 of 5 cardiometabolic risk factors. Those with no metabolic parameters and no known cause were deemed to have cryptogenic steatotic liver disease. A new category, outside pure metabolic dysfunction–associated steatotic liver disease, termed metabolic and alcohol related/associated liver disease (MetALD), was selected to describe those with metabolic dysfunction–associated steatotic liver disease, who consume greater amounts of alcohol per week (140–350 g/wk and 210–420 g/wk for females and males, respectively). The new nomenclature and diagnostic criteria are widely supported and nonstigmatising, and can improve awareness and patient identification.

Technetium-99m (99mTc) mebrofenin hepatobiliary scintigraphy (HBS) enables a quantitative assessment of liver function. This is normally performed in a fasting state and might therefore reflect the resting liver function. We evaluated the change in liver function using HBS after stimulation with an oral metabolic challenge. Healthy volunteers aged 50–60 (n=12) or older than or equal to 75 (n=12) years underwent two sequential HBS. The first scan was performed after an overnight fast and the second scan was performed after the administration of chocolate milk. Hepatic 99mTc-mebrofenin uptake rate (cMUR) was calculated and the difference was expressed as percentage. cMUR after fasting was 10.9±2.5%/min/m2(mean±SD) and increased by 20% to 13.0±3.1%/min/m2after stimulation with chocolate milk (P<0.001). cMUR increased markedly after the administration of an oral metabolic challenge in comparison with fasting. This may be a consequence of hepatocyte stimulation, reflecting the hepatic functional reserve capacity.

The biliary HCO3−umbrella hypothesis states that human cholangiocytes and hepatocytes create a protective apical alkaline barrier against millimolar concentrations of potentially toxic glycine-conjugated bile salts in bile by secreting HCO3−into the bile duct lumen. This alkaline barrier may retain biliary bile salts in their polar, deprotonated, and membrane-impermeant state to avoid uncontrolled invasion of apolar toxic bile acids, which initiate apoptosis, autophagy and senescence. In primary biliary cholangitis, defects of the biliary HCO3−umbrella, leading to impaired biliary HCO3−secretion have been identified. Current medical therapies stabilize the putatively defective biliary HCO3−umbrella and improve long-term prognosis.

Primary sclerosing cholangitis is a rare, chronic cholestatic liver disease characterised by intrahepatic or extrahepatic stricturing, or both, with bile duct fibrosis. Inflammation and fibrosis of bile ducts and the liver are followed by impaired bile formation or flow and progressive liver dysfunction. Patients might be asymptomatic at presentation or might have pruritus, fatigue, right upper quadrant pain, recurrent cholangitis, or sequelae of portal hypertension. The key diagnostic elements are cholestatic liver biochemistry and bile duct stricturing on cholangiography. Genetic and environmental factors are important in the cause of the disease, with the intestinal microbiome increasingly thought to play a pathogenetic role. Approximately 70% of patients have concurrent inflammatory bowel disease and patients require colonoscopic screening and surveillance. Primary sclerosing cholangitis is associated with increased malignancy risk and surveillance strategies for early cholangiocarcinoma detection are limited. No single drug has been proven to improve transplant-free survival. Liver transplantation is effective for advanced disease but at least 25% of patients develop recurrent disease in the graft.

Proton density fat fraction as measured with MR spectroscopy is superior to the controlled attenuation parameter in detecting biopsy-proven steatosis of at least grade S1 and in grading steatosis.

ObjectiveMost prognostic models for primary sclerosing cholangitis (PSC) are based on patients referred to tertiary care and may not be applicable for the majority of patients with PSC. The aim of this study was to construct and externally validate a novel, broadly applicable prognostic model for transplant-free survival in PSC, based on a large, predominantly population-based cohort using readily available variables.DesignThe derivation cohort consisted of 692 patients with PSC from the Netherlands, the validation cohort of 264 patients with PSC from the UK. Retrospectively, clinical and biochemical variables were collected. We derived the prognostic index from a multivariable Cox regression model in which predictors were selected and parameters were estimated using the least absolute shrinkage and selection operator. The composite end point of PSC-related death and liver transplantation was used. To quantify the models’ predictive value, we calculated the C-statistic as discrimination index and established its calibration accuracy by comparing predicted curves with Kaplan-Meier estimates.ResultsThe final model included the variables: PSC subtype, age at PSC diagnosis, albumin, platelets, aspartate aminotransferase, alkaline phosphatase and bilirubin. The C-statistic was 0.68 (95% CI 0.51 to 0.85). Calibration was satisfactory. The model was robust in the sense that the C-statistic did not change when prediction was based on biochemical variables collected at follow-up.ConclusionThe Amsterdam-Oxford model for PSC showed adequate performance in estimating PSC-related death and/or liver transplant in a predominantly population-based setting. The transplant-free survival probability can be recalculated when updated biochemical values are available.

ObjectiveImmunoglobulin G4-related disease (IgG4-RD) is a multiorgan immune-mediated disease that predominantly affects the biliary tract (IgG4-associated cholangitis, IAC) and pancreas (autoimmune pancreatitis, AIP). We recently identified highly expanded IgG4+ B-cell receptor clones in blood and affected tissues of patients with IAC/AIP suggestive of specific (auto)antigenic stimuli involved in initiating and/or maintaining the inflammatory response. This study aimed to identify (auto)antigen(s) that are responsible for the clonal expansion of IgG4+ B cells in IgG4-RD.DesignWe screened sera of patients with IAC/AIP (n=50), in comparison to control sera of patients with primary sclerosing cholangitis (PSC) and pancreatobiliary malignancies (n=47), for reactivity against human H69 cholangiocyte lysates on immunoblot. Subsequently, target antigens were immunoprecipitated and analysed by mass spectrometry.ResultsProminent reactivity against a 56 kDa protein was detected in human H69 cholangiocyte lysates exposed to sera of nine patients with IAC/AIP. Affinity purification and mass spectrometry analysis identified annexin A11, a calcium-dependent phospholipid-binding protein. Annexin A11-specific IgG4 and IgG1 antibodies were only detected in serum of patients with IgG4-RD of the biliary tract/pancreas/salivary glands and not in disease mimickers with PSC and pancreatobiliary malignancies. Epitope analysis showed that two annexin A11 epitopes targeted by IgG1 and IgG4 autoantibodies were shared between patients with IAC/AIP and IgG4 antibodies blocked binding of IgG1 antibodies to the shared annexin A11 epitopes.ConclusionOur data suggest that IgG1-mediated pro-inflammatory autoreactivity against annexin A11 in patients with IgG4-RD may be attenuated by formation of annexin A11-specific IgG4 antibodies supporting an anti-inflammatory role of IgG4 in IgG4-RD.

ObjectivePrimary sclerosing cholangitis (PSC) is a genetically complex, inflammatory bile duct disease of largely unknown aetiology often leading to liver transplantation or death. Little is known about the genetic contribution to the severity and progression of PSC. The aim of this study is to identify genetic variants associated with PSC disease progression and development of complications.DesignWe collected standardised PSC subphenotypes in a large cohort of 3402 patients with PSC. After quality control, we combined 130 422 single nucleotide polymorphisms of all patients—obtained using the Illumina immunochip—with their disease subphenotypes. Using logistic regression and Cox proportional hazards models, we identified genetic variants associated with binary and time-to-event PSC subphenotypes.ResultsWe identified genetic variant rs853974 to be associated with liver transplant-free survival (p=6.07×10–9). Kaplan-Meier survival analysis showed a 50.9% (95% CI 41.5% to 59.5%) transplant-free survival for homozygous AA allele carriers of rs853974 compared with 72.8% (95% CI 69.6% to 75.7%) for GG carriers at 10 years after PSC diagnosis. For the candidate gene in the region, RSPO3, we demonstrated expression in key liver-resident effector cells, such as human and murine cholangiocytes and human hepatic stellate cells.ConclusionWe present a large international PSC cohort, and report genetic loci associated with PSC disease progression. For liver transplant-free survival, we identified a genome-wide significant signal and demonstrated expression of the candidate gene RSPO3in key liver-resident effector cells. This warrants further assessments of the role of this potential key PSC modifier gene.

Antiviral treatment is currently not recommended for patients with chronic hepatitis B with a low viral load. However, they might benefit from acquiring a functional cure (hepatitis B surface antigen [HBsAg] loss with or without formation of antibodies against hepatitis B surface antigen [anti-HBs]). We assessed HBsAg loss during peg-interferon-alfa-2a (peg-IFN) and nucleotide analogue combination therapy in patients with chronic hepatitis B with a low viral load.

Up to 70% of patients with primary biliary cholangitis develop pruritus (itch) during the course of their disease. Treatment of pruritus in primary biliary cholangitis is challenging and novel therapies are needed. Ursodeoxycholic acid, the standard first-line treatment for primary biliary cholangitis, is largely ineffective for pruritus. We investigated the efficacy and safety of GSK2330672, a selective inhibitor of human ileal bile acid transporter (IBAT), in patients with primary biliary cholangitis with pruritus.

miR-122 is an important host factor for hepatitis C virus (HCV) replication. The aim of this study was to assess the safety and tolerability, pharmacokinetics, and antiviral effect of a single dose of RG-101, a hepatocyte targeted N-acetylgalactosamine conjugated oligonucleotide that antagonises miR-122, in patients with chronic HCV infection with various genotypes.

Primary sclerosing cholangitis (PSC) is a rare progressive disorder leading to bile duct destruction; ∼75% of patients have comorbid inflammatory bowel disease (IBD). We undertook the largest genome-wide association study of PSC (4,796 cases and 19,955 population controls) and identified four new genome-wide significant loci. The most associated SNP at one locus affects splicing and expression of UBASH3A, with the protective allele (C) predicted to cause nonstop-mediated mRNA decay and lower expression of UBASH3A. Further analyses based on common variants suggested that the genome-wide genetic correlation (rG) between PSC and ulcerative colitis (UC) (rG= 0.29) was significantly greater than that between PSC and Crohn's disease (CD) (rG= 0.04) (P = 2.55 × 10−15). UC and CD were genetically more similar to each other (rG= 0.56) than either was to PSC (P < 1.0 × 10−15). Our study represents a substantial advance in understanding of the genetics of PSC.

Pruritus is a common symptom of cholestatic liver disorders. The present study aimed at evaluating autotaxin (ATX), a lysophospholipase recently identified as potential cause for cholestatic pruritus, in pediatric cholestatic diseases presenting with or without itching. A cohort of 45 children consisting of 14 patients experiencing itching (Alagille syndrome [n?=?10], complete extrahepatic biliary atresia [n?=?2], neonatal sclerosing cholangitis (n?=?1), progressive familial intrahepatic cholestasis type 2 [n?=?1]), 9 patients with bile acid synthesis defects (3ß-hydroxy-C27-steroid-oxidoreductase [n?=?7] and ?4–3-oxosteroid-5ß-reductase deficiency [n?=?2]), and 22 healthy children were studied. Serum ATX activity and total serum bile salt were determined enzymatically, ATX protein content was semiquantified by Western blotting. Using real-time polymerase chain reaction, ATX mRNA expression was studied in HepG2 cells treated with farnesoid-X-receptor agonists or vehicle. Serum ATX activity was increased in pruritic children with Alagille and other cholestatic syndromes (mean?±?standard deviation: 16.1?±?4.3 nmol?·?mL-1?·?min-1) compared with children with nonpruritic cholestatic diseases with bile acid synthesis defects (10.4?±?4.7 nmol?·?mL-1?·?min-1; P?

We conclude that hepatic ultrasmall superparamagnetic iron oxide particle–enhanced MR imaging is feasible, has high intra- and interreader agreement in nonalcoholic fatty liver disease, and performs well in the differentiation of nonalcoholic steatohepatitis and simple steatosis.

Primary biliary cirrhosis (PBC) is a chronic immune-mediated liver disease characterized by progressive cholestasis, biliary fibrosis and eventually cirrhosis. It results in characteristic symptoms with marked effects on life quality. The advent of large patient cohorts has challenged the view of PBC as a benign condition treated effectively by the single licensed therapy—ursodeoxycholic acid (UDCA). UDCA nonresponse or under-response has a major bearing on outcome, substantially increasing the likelihood that liver transplantation will be required or that patients will die of the disease. In patients with high-risk, treatment-unresponsive or highly symptomatic disease the need for new treatment approaches is clear. Evolution in our understanding of disease mechanisms is rapidly leading to the advent of new and re-purposed therapeutic agents targeting key processes. Notable opportunities are offered by targeting what could be considered as the 'upstream' immune response, 'midstream' biliary injury and 'downstream' fibrotic processes. Combination therapy targeting several pathways or the development of novel agents addressing multiple components of the disease pathway might be required. Ultimately, PBC therapeutics will require a stratified approach to be adopted in practice. This Review provides a current perspective on potential approaches to PBC treatment, and highlights the challenges faced in evaluating and implementing those treatments.

Several diagnostic scoring systems for autoimmune pancreatitis (AIP) have been proposed including the Asian, HISORt (Histology, Imaging, Serology, Other organ involvement and Response to therapy), and International Consensus Diagnostic Criteria (ICDC), which have been compared by a few studies. We evaluated the diagnostic performance of these criteria in patients diagnosed with AIP between May 1992 and August 2011.

The objective of this study was to compare efficacy of high versus low doses of prednisone for induction of remission in autoimmune pancreatitis (AIP).

Dilatation of the common bile duct (CBD) can be an ominous sign for malignancy of the pancreatobiliary tract; however, it has also been described as a presumably harmless side effect of opioid use. We investigated the prevalence and determinants of CBD dilatation among drug users receiving methadone maintenance therapy in the Netherlands.

Mipomersen has been approved by the US Food and Drug Administration as an orphan drug for patients with homozygous familial hypercholesterolemia (HoFH). In contrast, the European Medicines Agency advised negatively on the use of mipomersen. In this review, we discuss the efficacy and safety considerations for this discrepancy.

The pathogenesis of itch during cholestasis is largely unknown and treatment options are limited. Lysophosphatidate, female steroid hormones, and endogenous opioids are among the agents discussed as potential pruritogens in cholestasis. The itch-alleviating action of guideline-based therapeutic interventions with anion exchanger resins, rifampicin, opioid antagonists, and serotonin reuptake inhibitors are studied to unravel the molecular pathogenesis of itch. Still, a considerable part of the patients is in need of alternative experimental therapeutic approaches (eg, UV-B phototherapy, extracorporeal albumin dialysis, nasobiliary drainage), providing additional information about the enigmatic pathophysiology of cholestatic pruritus.

Diagnosis of focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) using conventional imaging techniques can be difficult; however, it is important to differentiate between them as these benign liver tumors require different therapeutic strategies. The aim of our study was to prospectively evaluate the use of PETcomputed tomography (CT) with 18F-fluoromethylcholine (18F-FCH) as a novel diagnostic approach in the differentiation between HCA and FNH.

Introduction: Multidrug resistance 3 (MDR3) P-glycoprotein is a lipid floppase that is encoded by the ATP-binding cassette sub-family B member 4 (ABCB4) gene and plays a crucial role in proper bile formation by transporting phosphatidylcholine across the canalicular plasma membrane of the hepatocyte into bile. The relevance of this function is underscored by the severe pathology that develops in patients with ABCB4 deficiency. This deficiency leads to the destruction of hepatocytes and cholangiocytes by bile salts, because their cytolytic action is not reduced by formation of mixed micelles with phospholipid.Areas covered: Evidence that phospholipid secretion into bile is also essential for biliary cholesterol secretion as cholesterol dissolves much better in mixed micelles of bile salts and phospholipid than in pure bile salt micelles. As a consequence, net biliary cholesterol secretion depends on the amount of phospholipid secreted and hence, the expression of ABCB4 indirectly determines biliary cholesterol output.Expert opinion: It can be argued that upregulation of the ABCB4 gene expression may not only be beneficial for liver pathology in patients with partial ABCB4 deficiency, but also for the prevention of gallstone formation and optimal cholesterol disposition in a much larger population.

Bile formation is a key function of the liver and is driven by active secretion of bile salts and other organic compounds into the biliary tree. Bile salts represent the major organic constituent of bile. They are released with bile into the small intestine, where they are almost quantitatively reabsorbed and transported via the portal circulation back to the liver. In the liver, they are taken up into hepatocytes and secreted into bile. This cycling between the liver and the small intestine is called enterohepatic circulation of bile salts. Bile salts are secreted from hepatocytes into the bile by the bile salt export pump BSEP. This step constitutes the rate-limiting step of handling of bile salts in the liver and is the major driving force of the enterohepatic circulation of bile salts. Improper functioning of BSEP leads to an accumulation of bile salts within hepatocytes, where bile salts become cytotoxic. If persistent, accumulation of bile salts in hepatocytes will lead to liver disease. This review summarizes the essential concepts of bile formation and the current knowledge of mechanisms known to impair BSEP function. Finally, it sets the current therapeutic approaches for cholestatic liver disease into perspective to the pathophysiologic mechanisms of impaired BSEP function.

Pruritus is a frequent symptom in patients with cholestatic liver diseases. Itching may be excruciating, may seriously impair quality of life and even induce suicidal ideation in the most severe cases.

To evaluate the function of coagulation and fibrinolysis in cholestatic patients before and after preoperative biliary drainage (PBD).

Acute-on-chronic liver failure (ACLF) is accompanied by marked intrahepatic cholestasis leading to accumulation of cytotoxic bile acids. Extracorporeal liver support systems efficiently remove bile acids, but their effect on bile acid composition in ACLF is unknown. The aim of the present study was to compare elimination of individual plasma bile acids by albumin dialysis (Molecular Adsorbents Recirculating System, MARS) and fractionated plasma separation (Prometheus). Eight consecutive patients with ACLF underwent alternating 6-hour sessions with MARS or Prometheus in a randomized, cross-over design. Serum samples were obtained before, during, and after each treatment, and individual bile acids including cholic acid and chenodeoxycholic acid (CDCA) were measured by gas chromatography. MARS and Prometheus removed total bile acids to a similar extent (reduction ratio, 45% and 46%, respectively). Both devices cleared cholic acid more efficiently than did CDCA. The molar fraction of CDCA (fCDCA) was elevated at baseline and correlated with the degree of liver dysfunction. Prometheus but not MARS treatments further increased fCDCA. Although both devices eliminate total bile acids to a similar extent, clearance of individual bile acids is different, leading to a slight change of the bile acid profile toward hydrophobic bile acids during Prometheus treatments.

Increasing evidence suggests that a genetically determined functional impairment of the hepatocellular efflux transporters bile salt export pump (BSEP, ABCB11) and multidrug resistance protein 3 (MDR3, ABCB4) play a pathophysiological role in the development of drug-induced liver injury. The aim of this study was therefore to describe the extent of genetic variability in ABCB11and ABCB4in patients with drug-induced liver injury and to in vitrofunctionally characterize newly detected ABCB11mutations and polymorphisms.

Ursodeoxycholic acid (UDCA) exerts anticholestatic effects in various cholestatic disorders. Several potential mechanisms and sites of action of UDCA have been unraveled in clinical and experimental studies, which could explain its beneficial effects. The relative contribution of these mechanisms to the anticholestatic action of UDCA depends on the type and stage of the cholestatic injury. In early-stage primary biliary cirrhosis and primary sclerosing cholangitis, protection of injured cholangiocytes against the toxic effects of bile acids might prevail. Stimulation of impaired hepatocellular secretion by mainly post-transcriptional mechanisms, including stimulation of synthesis, targeting and apical membrane insertion of key transporters, seems to be relevant in more advanced cholestasis. In intrahepatic cholestasis of pregnancy, stimulation of impaired hepatocellular secretion could be crucial for rapid relief of pruritus and improvement of serum liver tests, as it is in some forms of drug-induced cholestasis. In cystic fibrosis, stimulation of cholangiocellular calcium-dependent secretion of chloride and bicarbonate ions could have a major impact. Inhibition of bile-acid-induced hepatocyte apoptosis can have a role in all states of cholestasis that are characterized by hepatocellular bile-acid retention. Different mechanisms of action could, therefore, contribute to the beneficial effect of UDCA under various cholestatic conditions.

Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder associated with increased risk of intrauterine fetal death and prematurity. There is increasing evidence that genetically determined dysfunction in the canalicular ABC transporters bile salt export pump (BSEP, ABCB11) and multidrug resistance protein 3 (MDR3, ABCB4) might be risk factors for ICP development. This study aimed to (i) describe the extent of genetic variability in BSEPand MDR3in ICP and (ii) identify new disease-causing mutations. Twenty-one women with ICP and 40 women with uneventful pregnancies were recruited between April 2001 and April 2003. Sequencing of BSEPand MDR3spanned 8–10 kb per gene and comprised the promoter region and 100–350 bp of the flanking intronic region around each exon. DNA sequencing of polymerase chain reaction fragments was performed on an ABI3700 capillary sequencer. MDR3promoter activity of promoter constructs carrying different ICP-specific mutations was studied using reporter assays. A total of 37 and 51 variant sites were detected in BSEPand MDR3, respectively. Three non-synonymous sites in codons for evolutionarily conserved amino acids were specific for the ICP collective (BSEP, N591S; MDR3, S320F and G762E). Furthermore, four ICP-specific splicing mutations were detected in MDR3[intron 21, G(+1)A; intron 25, G(+5)C and C(–3)G; and intron 26, T(+2)A]. Activity of the mutated MDR3promoter was similar to that observed for the wild-type promoter. Our data further support an involvement of MDR3genetic variation in the pathogenesis of ICP, whereas analysis of BSEPsequence variation indicates that this gene is probably less important for the development of pregnancy-associated cholestasis.

Sodium-dependent uptake of bile acids from blood is aliver-specific function which is mediated by theNa+-taurocholate cotransporting polypeptide(Ntcp). We report the stable expression of aNa+-taurocholate cotransporting green fluorescentfusion protein in the human hepatoblastoma cell lineHepG2, normally lacking Ntcp expression. Ntcp-EGFPassociated green fluorescence colocalized with Ntcpimmunofluorescence in the plasma membrane. Intransfected HepG2 cells, the fusion protein mediatedthe sodium-dependent uptake of the bile acidtaurocholate (Km: 24.6 μmol/l) and of the anionicsteroids estrone-3-sulfate and dehydroepiandrosteronesulfate. We conclude that the Ntcp-EGFP fusion proteinfollows the sorting route of Ntcp, is functionallyidentical to Ntcp and could be used to monitor proteintrafficking in living HepG2 cells.

Background:Tauroursodeoxycholic acid (TUDCA) is of potential benefit in cholestatic disorders. However, the effects of TUDCA on cytosolic free calcium [(Ca2+)i], which regulates hepatocyte secretion, are unknown. Methods:The effect of TUDCA on (Ca2+)iwas investigated in groups of isolated rat hepatocytes by microspectrofluorometry and in single cells by confocal line scanning microscopy. Results:Administration of TUDCA (5–50 μmol/L) induced a nearly fourfold increase of basal levels of (Ca2+)i. After a 15 minute treatment period, the TUDCA (10 μmol/L)-induced change in (Ca2+)iwas higher than that of other monodi-, and trihydroxy bile acids at equimolar concentrations. Pretreatment with TUDCA (10 μmol/L) markedly reduced or abolished increases in (Ca2+)iinduced by phenylephrine (1 μmol/L), the microsomal Ca2+translocase inhibitor 2,5-di-(tert-butyl)-1,4-benzohydroquinone (25 μmol/L), or taurolithocholic acid (10–25 μmol/L). In Ca2+-free medium, TUDCA caused only a reduced and transient increase in (Ca2+)i. TUDCA (10 μmol/L) induced Ca2+oscillations in all single cells that responded. However, levels of inositol-1,4,5-trisphosphate (IP3) in hepatocytes were not increased by treatment with TUDCA (10 μmol/L). Conclusions:TUDCA at physiological concentrations potently modulates (Ca2+)isignals in hepatocytes by (1) mobilizing microsomal IP3-sensitive Ca2+stores by an IP3-independent mechanism, (2) initiating Ca2+oscillations, and (3) inducing influx of extracellular Ca2+.

Dehydroepiandrosterone sulfate (DHEAS) is the major circulating steroid in man. Pharmacologically, it exerts marked neuropsychiatric effects. Since no target receptor has been identified, we investigated whether the organic anion transporting polypeptide (OATP), a multispecific steroid carrier, transports DHEAS. Expression of the human liver OATP in Xenopus laevisoocytes resulted in high-affinity, partially Na +-dependent uptake of [ 3H]DHEAS ( Km: 6.6 μmol/l). DHEAS transport was inhibited by bromosulfophthalein, bile acids, sulfated estrogens and dexamethasone. Northern blot analysis showed widespread expression of OATP in human brain. These data identify OATP as the first known target protein of DHEAS in human liver and brain.

Dehydroepiandrosterone sulfate (DHEAS) is the major circulating steroid in man. Pharmacologically, it exerts marked neuropsychiatric effects. Since no target receptor has been identified, we investigated whether the organic anion transporting polypeptide (OATP), a multispecific steroid carrier, transports DHEAS. Expression of the human liver OATP in Xenopus laevisoocytes resulted in high‐affinity, partially Na+‐dependent uptake of [3H]DHEAS (Km: 6.6 μmol/l). DHEAS transport was inhibited by bromosulfophthalein, bile acids, sulfated estrogens and dexamethasone. Northern blot analysis showed widespread expression of OATP in human brain. These data identify OATP as the first known target protein of DHEAS in human liver and brain.