Safety, tolerability, and efficacy of maralixibat in adults with primary sclerosing cholangitis: Open-label pilot study.

BACKGROUND: Primary sclerosing cholangitis (PSC) is frequently associated with pruritus, which significantly impairs quality of life. Maralixibat is a selective ileal bile acid transporter (IBAT) inhibitor that lowers circulating bile acid (BA) levels and reduces pruritus in cholestatic liver diseases. This is the first proof-of-concept study of IBAT inhibition in PSC. METHODS: This open-label study evaluated the safety and tolerability of maralixibat ≤10 mg/d for 14 weeks in adults with PSC. Measures of pruritus, biomarkers of BA synthesis, cholestasis, and liver function were also assessed. RESULTS: Of 27 enrolled participants, 85.2% completed treatment. Gastrointestinal treatment-emergent adverse events (TEAEs) occurred in 81.5%, with diarrhea in 51.9%. TEAEs were mostly mild or moderate (63.0%); 1 serious TEAE (cholangitis) was considered treatment related. Mean serum BA (sBA) levels decreased by 16.7% (-14.84 µmol/L; 95% CI, -27.25 to -2.43; p = 0.0043) by week 14/early termination (ET). In participants with baseline sBA levels above normal (n = 18), mean sBA decreased by 40.0% (-22.3 µmol/L, 95% CI, -40.38 to -4.3; p = 0.004) by week 14/ET. Liver enzyme elevations were not significant; however, increases of unknown clinical significance in conjugated bilirubin levels were observed. ItchRO weekly sum scores decreased from baseline to week 14/ET by 8.4% (p = 0.0495), by 12.6% (p = 0.0275) in 18 participants with pruritus at baseline, and by 70% (p = 0.0078) in 8 participants with ItchRO daily average score ≥3 at baseline. CONCLUSIONS: Maralixibat was associated with reduced sBA levels in adults with PSC. In participants with more severe baseline pruritus, pruritus improved significantly from baseline. TEAEs were mostly gastrointestinal related. These results support further investigation of IBAT inhibitors for adults with PSC-associated pruritus. ClinicalTrials.gov: NCT02061540.

DNA methylation profile of liver tissue in end-stage cholestatic liver disease.

Aims: In this methylome-wide association study of cholestatic liver diseases (primary sclerosing cholangitis and primary biliary cholangitis), the authors aimed to elucidate changes in methylome and pathway enrichment to identify candidate genes. Patients & methods: Reduced representation bisulfite sequencing was performed on liver tissue from 58 patients with primary sclerosing cholangitis (n = 13), primary biliary cholangitis (n = 20), alcoholic liver disease (n = 21) and live liver donors (n = 4). Pathway enrichment and network analysis were used to explore key genes/pathways. Results: Both cholestatic liver diseases were characterized by global hypomethylation, with pathway enrichment demonstrating distinct genes and pathways associated with the methylome. Conclusions: This novel study demonstrated that differential methylation in cholestatic liver disease was associated with unique pathways, suggesting it may drive disease pathogenesis.

While DNA is the permanent code that defines each living being, the epigenome comprises sequences attached to DNA that can change with the environment. This means that abnormal changes to the epigenome may lead to disease and that finding and treating these abnormalities may in turn help treat disease. In this study of liver tissue from individuals with two rare liver diseases, primary sclerosing cholangitis and primary biliary cholangitis, the authors found that the epigenome of these two conditions is distinct, suggesting that the epigenome is linked to the development of these conditions and may be the key to treating them.

Hmgcs2-mediated ketogenesis modulates high-fat diet-induced hepatosteatosis.

OBJECTIVE: Aberrant ketogenesis is correlated with the degree of steatosis in non-alcoholic fatty liver disease (NAFLD) patients, and an inborn error of ketogenesis (mitochondrial HMG-CoA synthase deficiency) is commonly associated with the development of the fatty liver. Here we aimed to determine the impact of Hmgcs2-mediated ketogenesis and its modulations on the development and treatment of fatty liver disease. METHODS: Loss- and gain-of-ketogenic function models, achieved by Hmgcs2 knockout and overexpression, respectively, were utilized to investigate the role of ketogenesis in the hepatic lipid accumulation during postnatal development and in a high-fat diet-induced NAFLD mouse model. RESULTS: Ketogenic function was decreased in NAFLD mice with a reduction in Hmgcs2 expression. Mice lacking Hmgcs2 developed spontaneous fatty liver phenotype during postnatal development, which was rescued by a shift to a low-fat dietary composition via early weaning. Hmgcs2 heterozygous adult mice, which exhibited lower ketogenic activity, were more susceptible to diet-induced NAFLD development, whereas HMGCS2 overexpression in NAFLD mice improved hepatosteatosis and glucose homeostasis. CONCLUSIONS: Our study adds new knowledge to the field of ketone body metabolism and shows that Hmgcs2-mediated ketogenesis modulates hepatic lipid regulation under a fat-enriched nutritional environment. The regulation of hepatic ketogenesis may be a viable therapeutic strategy in the prevention and treatment of hepatosteatosis.

High-Resolution Exposomics and Metabolomics Reveals Specific Associations in Cholestatic Liver Diseases.

Progress in development of prognostic and therapeutic options for the rare cholestatic liver diseases, primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), is hampered by limited knowledge of their pathogeneses. In particular, the potential role of hepatotoxic and/or metabolism-altering environmental chemicals in the pathogenesis of these diseases remains relatively unstudied. Moreover, the extent to which metabolic pathways are altered due to ongoing cholestasis and subsequent liver damage or possibly influenced by hepatotoxic chemicals is poorly understood. In this study, we applied a comprehensive exposomics-metabolomics approach to uncover potential pathogenic contributors to PSC and PBC. We used untargeted high-resolution mass spectrometry to characterize a wide range of exogenous chemicals and endogenous metabolites in plasma and tested them for association with disease. Exposome-wide association studies (EWAS) identified environmental chemicals, including pesticides, additives and persistent pollutants, that were associated with PSC and/or PBC, suggesting potential roles for these compounds in disease pathogenesis. Metabolome-wide association studies (MWAS) found disease-associated alterations to amino acid, eicosanoid, lipid, co-factor, nucleotide, mitochondrial and microbial metabolic pathways, many of which were shared between PSC and PBC. Notably, this analysis implicates a potential role of the 5-lipoxygenase pathway in the pathogenesis of these diseases. Finally, EWAS × MWAS network analysis uncovered linkages between environmental agents and disrupted metabolic pathways that provide insight into potential mechanisms for PSC and PBC. Conclusion: This study establishes combined exposomics-metabolomics as a generalizable approach to identify potentially pathogenic environmental agents and enumerate metabolic alterations that may impact PSC and PBC, providing a foundation for diagnostic and therapeutic strategies.

Long-term outcomes of liver transplant recipients followed up in non-transplant centres: Care closer to home.

INTRODUCTION: Increasing rates of liver transplantation and improved outcomes have led to greater numbers of transplant recipients followed up in non-transplant centres. Our aim was to document long-term clinical outcomes of liver transplant recipients managed in this 'hub-and-spoke' healthcare model. METHODS: A retrospective analysis of all adult patients who underwent liver transplantation between 1987 and 2016, with post-transplant follow-up in two non-transplant centres in the UK (Nottingham) and Canada (Ottawa), was performed. RESULTS: The 1-, 5-, 10- and 20-year patient survival rates were 98%, 95%, 87% and 62%, and 100%, 96%, 88% and 62% in the Nottingham and Ottawa groups, respectively (p=0.87). There were no significant differences between the two centres in 1-, 5-, 10- and 20-year cumulative incidence of death-censored graft-survival (p=0.10), end-stage renal disease (p=0.29) or de novo cancer (p=0.22). Nottingham had a lower incidence of major cardiovascular events (p=0.008). CONCLUSION: Adopting a new model of healthcare provides a means of delivering post-transplant patient care close to home without compromising patient survival and long-term clinical outcomes.

Effects of Age and Sex of Response to Ursodeoxycholic Acid and Transplant-free Survival in Patients With Primary Biliary Cholangitis.

BACKGROUND & AIMS: Primary biliary cholangitis (PBC) predominantly affects middle-aged women; there are few data on disease phenotypes and outcomes of PBC in men and younger patients. We investigated whether differences in sex and/or age at the start of ursodeoxycholic acid (UDCA) treatment are associated with response to therapy, based on biochemical markers, or differences in transplant-free survival. METHODS: We performed a longitudinal retrospective study of 4355 adults in the Global PBC Study cohort, collected from 17 centers across Europe and North America. Patients received a diagnosis of PBC from 1961 through 2014. We evaluated the effects of sex and age on response to UDCA treatment (based on GLOBE score) and transplant-free survival using logistic regression and Cox regression analyses, respectively. RESULTS: Male patients were older at the start of treatment (58.3±12.1 years vs 54.3±11.6 years for women; P<.0001) and had higher levels of bilirubin and lower circulating platelet counts (P<.0001). Younger patients (45 years or younger) had increased serum levels of transaminases than older patients (older than 45 years). Patients older than 45 years at time of treatment initiation had increased odds of a biochemical response to UDCA therapy, based on GLOBE score, compared to younger patients. The greatest odds of response to UDCA were observed in patients older than 65 years (odds ratio compared to younger patients 45 years or younger, 5.48; 95% CI, 3.92-7.67; P<.0001). Risk of liver transplant or death (compared to a general population matched for age, sex, and birth year) decreased significantly with advancing age: hazard ratio for patients 35 years or younger, 14.59 (95% CI, 9.66-22.02) vs hazard ratio for patients older than 65 years, 1.39 (95% CI, 1.23-1.57) (P<.0001). On multivariable analysis, sex was not independently associated with response or transplant-free survival. CONCLUSION: In longitudinal analysis of 4355 adults in the Global PBC Study, we associated patient age, but not sex, with response to UDCA treatment and transplant-free survival. Younger age at time of treatment initiation is associated with increased risk of treatment failure, liver transplant, and death.

The development and validation of magnetic resonance elastography for fibrosis staging in primary sclerosing cholangitis.

OBJECTIVES: To develop and internally validate MR elastography (MRE) quantified liver stiffness (LS) cut-off values for distinguishing early/moderate fibrosis from cirrhosis in primary sclerosing cholangitis (PSC) against non-invasive fibrosis test of vibration-controlled transient elastography (VCTE). METHODS: Sixty-seven patients were enrolled prospectively at a tertiary care centre to undergo MRE and VCTE. MRE-quantified LS was calculated using three region-of-interest (ROI) methods: Trace, Average and Maximum. Each ROI method was compared with the reference standard of VCTE. Internal validation was performed with bootstrapping. Univariable and multivariable linear regression determined independent predictors for MRE-quantified LS and final Mayo Risk Score (MRS). RESULTS: MRE-quantified LS by Trace ROI method had the highest sensitivity [87.5%; 95% confidence interval (CI), 66.0-96.8] and specificity (96.1%; 95%CI, 89.6-99.0) for distinguishing cirrhosis; and was the strongest predictor of final MRS (ß, 0.44; 95% CI, 0.27-0.61). Alkaline phosphatase twice the normal upper limit (ß, 1.55; 95% CI, 0.95-2.17), abnormal bilirubin (ß, 1.27; 95% CI, 0.41-2.14) and thrombocytopaenia (ß, 0.79; 95% CI, 0.12-1.46) were independent predictors of LS. CONCLUSIONS: MRE has a higher correlation with MRS than VCTE; and though MRE is possibly influenced by severe cholestasis and portal hypertension, MRE-quantified LS is an independent predictor of worse MRS. KEY POINTS: • MRE is valid and reliable in assessing cirrhosis in PSC, and MRE-quantified Liver stiffness (LS) score was the strongest predictor of final Mayo Risk Score (MRS). • Trace ROI performs best for distinguishing moderate fibrosis from cirrhosis and has the highest correlation with Mayo Risk Score (MRS). • Cholestasis, hyperbilirubinaemia and portal hypertension may influence MRE LS score.

External validation of the United Kingdom-primary biliary cholangitis risk scores of patients with primary biliary cholangitis treated with ursodeoxycholic acid.

The United Kingdom-Primary Biliary Cholangitis (UK-PBC) risk scores are a set of prognostic models that estimate the risk of end-stage liver disease in patients with PBC at 5-, 10- and 15-year intervals. They have not been externally validated outside the United Kingdom. In this retrospective, external validation study, data were abstracted from outpatient charts and discrimination and calibration of the UK-PBC risk scores were assessed. A total of 464 patients with PBC treated with ursodeoxycholic acid were included. The median diagnosis age was 52.4 years, and 88% were female patients. The cumulative incidence of events was 6%, 9%, and 15% at 5, 10, and 15 years, respectively. Concordance (c-statistic) was 0.88, 0.85, and 0.84 using the 5-, 10- and 15-year risk scores, respectively, which was slightly lower than values observed in the United Kingdom validation cohort. Using the 5-year risk score, more events were observed than predicted (25 versus 16.8; P = 0.046); using the 10-year risk score, there was no difference between the observed and predicted number of events (35 versus 44.9; P = 0.14); conversely, using the 15-year risk score, fewer events were observed than predicted (46 versus 67.5; P = 0.009). Limiting evaluation by the 15-year UK-PBC risk score to those with >10 years of follow-up demonstrated no difference between observed and predicted events. Using the 5-year risk score, patients within the highest quartile had statistically significant worse event-free survival compared to the rest of the cohort: 82% versus 98% at 5 years, 73% versus 97% at 10 years, and 58% versus 93% at 15 years. Conclusion: In patients assessed at a North American tertiary medical center, the UK-PBC risk score had excellent discrimination and was reasonably calibrated both in the short and long term. (Hepatology Communications 2018;2:676-682).

Pathobiology of biliary epithelia.

Cholangiocytes are epithelial cells that line the intra- and extrahepatic biliary tree. They serve predominantly to mediate the content of luminal biliary fluid, which is controlled via numerous signaling pathways influenced by endogenous (e.g., bile acids, nucleotides, hormones, neurotransmitters) and exogenous (e.g., microbes/microbial products, drugs etc.) molecules. When injured, cholangiocytes undergo apoptosis/lysis, repair and proliferation. They also become senescent, a form of cell cycle arrest, which may prevent propagation of injury and/or malignant transformation. Senescent cholangiocytes can undergo further transformation to a senescence-associated secretory phenotype (SASP), where they begin secreting pro-inflammatory and pro-fibrotic signals that may contribute to disease initiation and progression. These and other concepts related to cholangiocyte pathobiology will be reviewed herein. This article is part of a Special Issue entitled: Cholangiocytes in Health and Disease edited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

First-year medical students use of ultrasound or physical examination to diagnose hepatomegaly and ascites: a randomized controlled trial.

PURPOSE: To compare point-of-care ultrasound and physical examination (PEx), each performed by first-year medical students after brief teaching, for assessing ascites and hepatomegaly. Ultrasound and PEx were compared on: (1) reliability, validity and performance, (2) diagnostic confidence, ease of use, utility, and applicability. METHODS: A single-center, randomized controlled trial was performed at a tertiary centre. First-year medical students were randomized to use ultrasound or PEx to assess for ascites and hepatomegaly. Cohen's kappa and interclass coefficient (ICC) were used to measure interrater reliability between trainee assessments and the reference standard (a same day ultrasound by a radiologist). Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were compared. A ten-point Likert scale was used to assess trainee diagnostic confidence and perceptions of utility. RESULTS: There were no significant differences in interobserver reliability, sensitivity, specificity, accuracy, PPV, or NPV between the ultrasound and PEx groups. However, students in the ultrasound group provided higher scores for perceived utility (ascites 8.38 ± 1.35 vs 7.08 ± 1.86, p = 0.008; hepatomegaly 7.68 ± 1.52 vs 5.36 ± 2.48, p < 0.001) and likelihood of adoption (ascites 8.67 ± 1.61 vs 7.46 ± 1.79, p = 0.02; hepatomegaly 8.12 ± 1.90 vs 5.92 ± 2.32, p = 0.001). CONCLUSIONS: When performed by first-year medical students, the validity and reliability of ultrasound is comparable to PEx, but with greater perceived utility and likelihood of adoption. With similarly brief instruction, point-of-care ultrasonography can be as effectively learned and performed as PEx, with a high degree of interest from trainees.

Emerging pharmacologic therapies for primary sclerosing cholangitis.

PURPOSE OF REVIEW: The only currently approved treatment for primary sclerosing cholangitis (PSC) is liver transplantation, with a median time to transplant of 12-18 years after diagnosis. There are a number of emerging drugs that have the potential to meet this critically unmet need that will be summarized and discussed herein. RECENT FINDINGS: Although the cause of PSC is unknown, there are a number of novel therapeutics under development. These drugs target presumed pathogenic mechanisms largely extrapolated from ex-vivo and in-vivo preclinical models, as well as translational observations. SUMMARY: Future therapeutic strategies for PSC may include a multitude of complex pathogenic mechanisms encompassing pathways of immunomodulation, the microbiome and inflammation-related fibrosis.

Factors that Influence Health-Related Quality of Life in Patients with Primary Sclerosing Cholangitis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is an incurable, cholestatic liver disease often coincident with inflammatory bowel disease (IBD). AIMS: To evaluate the impact of liver disease and IBD on health-related quality of life (HRQoL) in PSC. METHODS: A mixed-methods, cross-sectional study was performed at a tertiary center. Short Form-36 (SF-36) scores were compared between PSC, Canadian normative data, and disease controls. Disease-specific instruments scores [PBC-40, Short IBD questionnaire, Liver Disease Quality of Life Questionnaire (LDQOL)] were compared between PSC and disease controls. Multivariable regression identified factors independently associated with final SF-36 component scores. Qualitative evaluation of patient questionnaires was performed using a content analysis framework. RESULTS: One hundred and sixty-two surveys were completed (99 PSC, 26 primary biliary cirrhosis, 16 non-autoimmune cholestatic liver disease, and 21 IBD). PSC patients had significantly lower SF-36 scores than Canadian controls, but similar scores to disease controls. LDQOL most accurately predicted HRQoL. Factors negatively associated with physical HRQoL included shorter IBD duration, liver disease symptoms, and decompensated cirrhosis. Mental HRQoL was influenced by liver disease and IBD symptoms, pruritus, social isolation, and depression. Nearly 75 % expressed existential anxiety regarding disease progression and diminished life expectancy, with 25 % disclosing social isolation. CONCLUSIONS: Patients with PSC have significantly lower HRQoL than healthy controls. Both symptoms of IBD and chronic liver disease impact HRQoL in patients with PSC, which lead to significant psychologic burden that is expressed by existential anxieties and social isolation. A PSC-specific HRQoL tool is critical to adequately quantify the distinct impact of IBD and cholestatic liver disease.

Anti-kelch-like 12 and anti-hexokinase 1: novel autoantibodies in primary biliary cirrhosis.

BACKGROUND & AIMS: Using high-density human recombinant protein microarrays, we identified two potential biomarkers, kelch-like 12 (KLHL12) and hexokinase-1 (HK1), in primary biliary cirrhosis (PBC). The objective of this study was to determine the diagnostic value of anti-KLHL12/HK1 autoantibodies in PBC. Initial discovery used sera from 22 patients with PBC and 62 non-PBC controls. KLHL12 and HK1 proteins were then analysed for immunoglobulin reactivity by immunoblot and enzyme-linked immunosorbent assay (ELISA) in two independent cohorts of PBC and disease/healthy control patients. METHODS: Serum samples from 100 patients with PBC and 165 non-PBC disease controls were analysed by immunoblot and samples from 366 patients with PBC, 174 disease controls, and 80 healthy donors were tested by ELISA. RESULTS: Anti-KLHL12 and anti-HK1 antibodies were each detected more frequently in PBC compared with non-PBC disease controls (P < 0.001). Not only are both markers highly specific for PBC (≥95%) but they also yielded higher sensitivity than anti-gp210 and anti-sp100 antibodies. Combining anti-HK1 and anti-KLHL12 with available markers (MIT3, gp210 and sp100), increased the diagnostic sensitivity for PBC. Most importantly, anti-KLHL12 and anti-HK1 antibodies were present in 10-35% of anti-mitochondrial antibody (AMA)-negative PBC patients and adding these two biomarkers to conventional PBC assays dramatically improved the serological sensitivity in AMA-negative PBC from 55% to 75% in immunoblot and 48.3% to 68.5% in ELISA. CONCLUSIONS: The addition of tests for highly specific anti-KLHL12 and anti-HK1 antibodies to AMA and ANA serological assays significantly improves efficacy in the clinical detection and diagnosis of PBC, especially for AMA-negative subjects.