Update on primary sclerosing cholangitis

Primary sclerosing cholangitis: Is qualitative and quantitative 3 T MR imaging useful for the evaluation of disease severity?

Purpose

To analyze the role of qualitative and quantitative 3 T MR imaging assessment as a non-invasive method for the evaluation of disease severity in patients with primary sclerosing cholangitis (PSC).

Methods

A series of 26 patients, with histological diagnosis of PSC undergoing 3 T MRI and hepatological evaluation, was retrospectively enrolled. All MR examinations included diffusion-weighted imaging (DWI), T2-weighted (T2w) and T1-weighted (T1w) sequences, before and after administration of Gd-EOB-DTPA with the acquisition of both dynamic and hepato-biliary phase (HBP). Qualitative analysis was performed by assessment of liver parenchyma and biliary tract changes, also including biliary excretion of gadoxetic acid on HBP. Quantitative evaluation was conducted on liver parenchyma by measurement of apparent diffusion coefficient (ADC) and relative enhancement (RE) on 3-minute delayed phase and on HBP. Results of blood tests (ALT, ALP, GGT, total and direct bilirubin, albumin, and platelets) and transient elastography-derived liver stiffness measurements (TE-LSM) were collected and correlated with qualitative and quantitative MRI findings.

Results

Among qualitative and quantitative findings, fibrosis visual assessment and RE had the best performance in estimating disease severity, showing a statistically significant correlation with both biomarkers of cholestasis and TE-LSM. Statistical analysis also revealed a significant correlation of gadoxetic acid biliary excretion with ALT and direct bilirubin, as well as of ADC with total bilirubin.

Conclusion

Qualitative and quantitative 3 T MR evaluation is a promising non-invasive method for the assessment of disease severity in patients with PSC.

Whole blood RNA sequencing identifies transcriptional differences between primary sclerosing cholangitis and ulcerative colitis

Background & Aims

Genetic and microbiome studies across patients with primary sclerosing cholangitis (PSC) and ulcerative colitis (UC) have indicated that UC in PSC is a separate disease entity to primary UC, but expression studies for PSC are lacking.

Methods

We conducted whole blood RNA sequencing experiments for 495 patients with UC, 220 patients with PSC (including 177 with UC), and 320 healthy controls from Germany and Norway. Differential expression analyses, gene ontology and coexpression analyses and random forest machine learning were performed to identify genes, ontologies and transcriptional features that discriminate diagnoses.

Results

The blood transcriptome in UC and PSC is dominated by neutrophil activation genes (e.g. S100A12). In UC, but not in PSC (neither PSC alone nor patients with an additional diagnosis of UC [PSC/UC]), ribosomal, mitochondrial, and energy metabolism genes are upregulated in conjunction with antibody transcript expression (MZB1, IGJ). In PSC, there is an increase in modules related to apoptosis and expression of genes of interferon-I-related ontologies. Random forest analysis could poorly discriminate PSC alone from PSC/UC (AUROC 0.56), but could discriminate PSC, UC, and controls with high accuracy (AUROC UC vs. controls 0.95, PSC vs. controls 0.88, UC vs. PSC 0.986). The main coexpression modules relevant for distinguishing PSC, UC, and controls are enriched in neutrophil degranulation and antibody production genes.

Conclusions

Supported by machine learning results, PSC and UC appear to be separate entities on a molecular level, while PSC/UC and PSC are indistinguishable.

Impact and implications

Clinical and genetic studies suggest that the colitis-like symptoms in primary sclerosing cholangitis (PSC) represent a different disease entity from primary ulcerative colitis (UC). The present study supports this assumption with transcriptomic data from whole blood and describes notable differences in gene expression between primary UC and PSC, providing insights into the still unclear pathophysiology of both diseases. These findings are of interest to scientists seeking to decipher the molecular pathophysiology of both diseases and provide evidence that a redefinition of the PSC-UC phenotype should be considered. The study practically supports future molecular research by providing a large transcriptomic whole blood reference cohort.

Autoimmune liver disease and multiple sclerosis: state of the art and future perspectives

Clinical observations suggest that the prevalence of autoimmune diseases is changing over time. Both autoimmune liver diseases and multiple sclerosis have shown a significant increase in the last decades. Although the coexistence of autoimmune diseases within individuals and families is a common phenomenon, the extent to which liver disease and multiple sclerosis co-occur is not clear. Case reports and few studies have reported the possible coexistence of multiple sclerosis with thyroid diseases, inflammatory bowel disease, psoriasis, and rheumatoid arthritis. It is unknown whether there is a definite association between multiple sclerosis and autoimmune liver diseases. We reviewed the literature to summarize the available studies on the association between different autoimmune liver diseases (autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis) and treated or untreated multiple sclerosis.

The Role of the Gastrointestinal Microbiome in Liver Disease

Liver disease is a major global health problem leading to approximately two million deaths a year. This is the consequence of a number of aetiologies, including alcohol-related, metabolic-related, viral infection, cholestatic and immune disease, leading to fibrosis and, eventually, cirrhosis. No specific registered antifibrotic therapies exist to reverse liver injury, so current treatment aims at managing the underlying factors to mitigate the development of liver disease. There are bidirectional feedback loops between the liver and the rest of the gastrointestinal tract via the portal venous and biliary systems, which are mediated by microbial metabolites, specifically short-chain fatty acids (SCFAs) and secondary bile acids. The interaction between the liver and the gastrointestinal microbiome has the potential to provide a novel therapeutic modality to mitigate the progression of liver disease and its complications. This review will outline our understanding of hepatic fibrosis, liver disease, and its connection to the microbiome, which may identify potential therapeutic targets or strategies to mitigate liver disease.

Bacteriophage therapy against pathological Klebsiella pneumoniae ameliorates the course of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is characterized by progressive biliary inflammation and fibrosis. Although gut commensals are associated with PSC, their causative roles and therapeutic strategies remain elusive. Here we detect abundant Klebsiella pneumoniae (Kp) and Enterococcus gallinarum in fecal samples from 45 PSC patients, regardless of intestinal complications. Carriers of both pathogens exhibit high disease activity and poor clinical outcomes. Colonization of PSC-derived Kp in specific pathogen-free (SPF) hepatobiliary injury-prone mice enhances hepatic Th17 cell responses and exacerbates liver injury through bacterial translocation to mesenteric lymph nodes. We developed a lytic phage cocktail that targets PSC-derived Kp with a sustained suppressive effect in vitro. Oral administration of the phage cocktail lowers Kp levels in Kp-colonized germ-free mice and SPF mice, without off-target dysbiosis. Furthermore, we demonstrate that oral and intravenous phage administration successfully suppresses Kp levels and attenuates liver inflammation and disease severity in hepatobiliary injury-prone SPF mice. These results collectively suggest that using a lytic phage cocktail shows promise for targeting Kp in PSC.

Inflammatory bowel disease increases the risk of hepatobiliary pancreatic cancer: A two-sample Mendelian randomization analysis of European and East Asian populations

BACKGROUND

Both inflammatory bowel disease (IBD) and hepato-pancreato-biliary cancers (HPBC) have been established to cause a huge socioeconomic burden. Epidemiological studies have revealed a close association between IBD and HPBC.

METHODS

Herein, we utilized inverse-variance weighting to conduct a two-sample Mendelian randomization analysis. We sought to investigate the link between various subtypes of IBD and HPBC. To ensure the accuracy and consistency of our findings, we conducted heterogeneity tests, gene pleiotropy tests, and sensitivity analyses.

RESULTS

Compared to the general population, IBD patients in Europe exhibited a 1.22-fold increased incidence of pancreatic cancer (PC) with a 95% confidence interval (CI) of 1.0022-1.4888 (p = 0.0475). We also found a 1.14-fold increased incidence of PC in Crohn's disease (CD) patients with (95% CI: 1.0017-1.3073, p = 0.0472). In the East Asian population, the incidence of hepatocellular carcinoma (HCC) was 1.28-fold higher (95% CI = 1.0709-1.5244, p = 0.0065) in IBD patients than in the general population. Additionally, ulcerative colitis (UC) patients displayed 1.12-fold (95% CI: 1.1466-1.3334, p < 0.0001) and 1.31-fold (95% CI: 1.0983-1.5641, p = 0.0027) increased incidences of HCC and cholangiocarcinoma (CCA), respectively. Finally, the incidence of PC was 1.19-fold higher in CD patients than in the general population (95% CI = 1.0741-1.3132, p = 0.0008).

CONCLUSION

Our study validated that IBD is a risk factor for HPBC. This causal relationship exhibited significant heterogeneity in different European and East Asian populations.

Longitudinal analysis of transplant candidates with primary sclerosing cholangitis in an Asian liver transplant center

BACKGROUND

Primary sclerosing cholangitis (PSC) is a rare disease in Asia, and few studies have investigated the disease in this ethnicity, particularly in wait-listed patients for liver transplantation (LT). We aimed to investigate the prognostic factors and outcomes of wait-listed patients with PSC in an Asian transplant center.

METHODS

Survival was retrospectively analyzed.

RESULTS

Eighteen (10 male and 8 female) wait-listed patients with PSC, with a median age at diagnosis of 44.5 years, were included. Compared with men, women had significantly higher aspartate aminotransferase to platelet ratio index scores (3.28 vs. 1.13; P  = 0.012) and bilirubin levels (7.68 vs. 4.03 mg/dl; P  = 0.043) and more often presented with decompensating events, including ascites [5 (63%) vs. 1 (10%); P  = 0.043] and splenomegaly [8 (100%) vs. 4 (40%); P  = 0.013]. Compared with the non-LT group, the LT group exhibited a superior survival rate for women ( P  = 0.004) but not for men. In the univariable analysis, significant risk factors associated with overall survival included malignancies with a hazard ratio (95% confidence interval) of 5.53 (1.00-30.51) and esophageal varices (EV) [4.18 (1.05-16.61)], whereas female gender [25.00 (1.49-500.00)], LT [0.09 (0.01-0.80)] and EV [39.03 (2.92-521.96)] were indicated in the multivariable analysis.

CONCLUSIONS

For Asian wait-listed patients with PSC, EV and female gender were the risk factors related to overall survival, and LT was the protective factor. Our experiences suggested that LT brings more benefits in female patients. Strategies are needed to provide equivalent transplant benefits.

PNPLA3 allele frequency has no impact on biliary bile acid composition or disease course in patients with primary sclerosing cholangitis

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease that leads to bile duct strictures, cholestasis, and biliary cirrhosis. PNPLA3 (patatin-like phospholipase domain containing 3), regulates cellular lipid synthesis by converting lysophosphatidic acid into phosphatidic acid. Isoleucine mutation to methionine at position 148 (I148M) causes a loss of this function. Only two studies, with contradictory results, have evaluated the role of PNPLA3 in PSC. The rs738409(G) variant of PNPLA3 has been associated with an increased risk for transplantation in male patients with dominant strictures (DS). The study aimed to evaluate the PNPLA3 allele frequency effect on the clinical outcomes, progression, and prognosis of PSC. Furthermore, we analyzed the impact of PNPLA3 on phospholipid and bile acid composition to evaluate the effect of the PNPLA3 status on UDCA response.

PATIENTS AND METHODS

We recruited 560 patients prospectively and collected clinical and laboratory data as well as liver histology and imaging findings. PNPLA3 (CC, CG, GG) alleles were analyzed with TaqManTM. We also analyzed bile acids (BA), cholesterol and phospholipids and individual BA from a sample aspirated during endoscopic retrograde cholangiography (ERC).

RESULTS

Among the recruited patients, 58.4%, 35.7% and 5.9% had the wild (CC), heterozygous (CG) and homozygous (GG) alleles, respectively. The PNPLA3 haplotype did not impact bile composition or individual BA. In addition, we found no differences in age at diagnosis, disease progression, liver fibrosis or survival between the cohorts.

CONCLUSIONS

The PNPLA3 I148M variant had no significant impact on on bile composition, including UDCA content, clinical outcomes, progression of liver fibrosis, hepatobiliary cancer risk, liver transplantation, or overall survival.

Small bowel obstruction due to Roux-en-Y enterolith 13 years following deceased donor liver transplantation: a case report

Primary sclerosing cholangitis (PSC) is a progressive, cholestatic liver disease, and liver transplantation (LT) is considered the only therapeutic option for patients with end-stage liver disease secondary to PSC. Intestinal obstruction in adults after LT surgery is a rare complication with diverse clinical presentations. The most common etiology is intestinal adhesions, but this can also result from other rare causes such as enterolith. We describe the first case report of small bowel obstruction secondary to biliary stone formation in the common limb of Roux-en-Y hepaticojejunostomy 13 years after the deceased donor LT. The patient failed initial conservative management and developed peritonitis, requiring urgent surgical exploration to remove the enterolith and resect the involved small bowel. In conclusion, small bowel obstructions due to enteroliths are unusual clinical complications following LT, which require a high degree of suspicion in patients who develop a bowel obstruction in the setting of a previous hepaticojejunostomy.

Posttransplant immune-mediated cholangiopathies

PURPOSE OF REVIEW

Liver transplantation (LT) is the treatment of end-stage chronic liver diseases, mainly decompensated cirrhosis and hepatocellular carcinoma. Biliary complications can be schematically classified into macroscopic versus microscopic lesions. Immune-related cholangiopathies include rejection, graft-versus-host disease (GVHD) and recurrence of pre-LT auto-immune biliary diseases, i.e. primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). Here, we review the various types of posttransplant immune-related cholangiopathies, and discuss their clinical implications, especially diagnostic issues.

RECENT FINDINGS

Recurrence of PBC and PSC after LT is increasingly well described in large cohorts and long-term follow-up. In this setting, the preventive effect of ursodeoxycholic acid on PBC recurrence, as well as the deleterious role of tacrolimus are now well documented. In addition, the significant negative impact of recurrent PBC on survival after LT has recently been demonstrated. With respect to rejection-associated biliary injury, a growing body of evidence is emerging on the role of anti-HLA antibody-mediated rejection.

SUMMARY

Immune-mediated cholangiopathies occurring after LT can be divided in two main nosologic groups: biliary lesions due to recurrence of PBC or PSC, or in the context of rejection, either acute or chronic, T-cell- or antibody-mediated. GVHD is very rare. Final diagnosis is strongly based on clinical context (indication for LT, delay since transplantation, biological abnormalities, imaging) but also and to an even greater extent on biopsy of liver graft. Clinico-pathological discussions are recommended, hearing in mind that diseases can be intertwined.

ADAM Metalloproteinase Domain 17 Regulates Cholestasis-Associated Liver Injury and Sickness Behavior Development in Mice

Disintegrin and metalloproteinase domain-containing protein 17 (ADAM17) is a ubiquitously expressed membrane-bound enzyme that mediates shedding of a wide variety of important regulators in inflammation including cytokines and adhesion molecules. Hepatic expression of numerous cytokines and adhesion molecules are increased in cholestatic liver diseases including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), however, the pathophysiological role of ADAM17 in regulating these conditions remains unknown. Therefore, we evaluated the role of ADAM17 in a mouse model of cholestatic liver injury due to bile duct ligation (BDL). We found that BDL enhanced hepatic ADAM17 protein expression, paralleled by increased ADAM17 bioactivity. Moreover, inhibition of ADAM17 bioactivity with the specific inhibitor DPC 333 significantly improved both biochemical and histological evidence of liver damage in BDL mice. Patients with cholestatic liver disease commonly experience adverse behavioral symptoms, termed sickness behaviors. Similarly, BDL in mice induces reproducible sickness behavior development, driven by the upregulated expression of cytokines and adhesion molecules that are in turn regulated by ADAM17 activity. Indeed, inhibition of ADAM17 activity significantly ameliorated BDL-associated sickness behavior development. In translational studies, we evaluated changes in ADAM17 protein expression in liver biopsies obtained from patients with PBC and PSC, compared to normal control livers. PSC and PBC patients demonstrated increased hepatic ADAM17 expression in hepatocytes, cholangiocytes and in association with liver-infiltrating immune cells compared to normal controls. In summary, cholestatic liver injury in mice and humans is associated with increased hepatic ADAM17 expression. Furthermore, inhibition of ADAM17 activity improves both cholestatic liver injury and associated sickness behavior development, suggesting that ADAM17 inhibition may represent a novel therapeutic approach for treating patients with PBC/PSC.

Cross-tissue transcriptome-wide association studies identify susceptibility genes shared between schizophrenia and inflammatory bowel disease

Genetic correlations and an increased incidence of psychiatric disorders in inflammatory-bowel disease have been reported, but shared molecular mechanisms are unknown. We performed cross-tissue and multiple-gene conditioned transcriptome-wide association studies for 23 tissues of the gut-brain-axis using genome-wide association studies data sets (total 180,592 patients) for Crohn’s disease, ulcerative colitis, primary sclerosing cholangitis, schizophrenia, bipolar disorder, major depressive disorder and attention-deficit/hyperactivity disorder. We identified NR5A2, SATB2, and PPP3CA (encoding a target for calcineurin inhibitors in refractory ulcerative colitis) as shared susceptibility genes with transcriptome-wide significance both for Crohn’s disease, ulcerative colitis and schizophrenia, largely explaining fine-mapped association signals at nearby genome-wide association study susceptibility loci. Analysis of bulk and single-cell RNA-sequencing data showed that PPP3CA expression was strongest in neurons and in enteroendocrine and Paneth-like cells of the ileum, colon, and rectum, indicating a possible link to the gut-brain-axis. PPP3CA together with three further suggestive loci can be linked to calcineurin-related signaling pathways such as NFAT activation or Wnt.

Florian Uellendahl-Werth et al. conduct cross-tissue transcriptome-wide association studies to explore genetic mechanisms shared across immune-related and psychiatric traits. Their results identify several genes (including PPP3CA) that could mediate the interplay between psychiatric and inflammatory disease.

Liver manifestations and complications in inflammatory bowel disease: A review

Hepatobiliary manifestations are common in inflammatory bowel disease (IBD), with 30% of patients presenting abnormal liver tests and 5% developing chronic liver disease. They range from asymptomatic elevated liver tests to life-threatening disease and usually follow an independent course from IBD. The pathogenesis of liver manifestations or complications and IBD can be closely related by sharing a common auto-immune background (in primary sclerosing cholangitis, IgG4-related cholangitis, and autoimmune hepatitis), intestinal inflammation (in portal vein thrombosis and granulomatous hepatitis), metabolic impairment (in non-alcoholic fatty liver disease or cholelithiasis), or drug toxicity (in drug induced liver injury or hepatitis B virus infection reactivation). Their evaluation should prompt a full diagnostic workup to identify and readily treat all complications, improving management and outcome.

Global incidence, prevalence and features of primary sclerosing cholangitis: A systematic review and meta-analysis

BACKGROUND & AIMS

Primary sclerosing cholangitis (PSC) is an idiopathic, cholestatic liver disease with a diverse range of clinical manifestations. Inter-regional data on PSC are variable, but its global geoepidemiology has not been well-studied. We aimed to examine the worldwide incidence, prevalence and features of PSC and PSC-inflammatory bowel disease (PSC-IBD).

METHODS

A systematic search of multiple databases was conducted to identify all original, full-text studies until December 2020 with data regarding the incidence rate (IR) and/or prevalence of PSC. Outcomes were PSC IR, prevalence, features and IBD concurrence. Additionally, a meta-analysis of PSC IR was performed. The study was registered in PROSPERO (CRD42021224550).

RESULTS

Of the 1003 studies identified, 17 studies spanning three continents were included. PSC IR was 0.60 per 100 000 person-years (PY) (95% confidence interval: 0.37-0.88 per 100 000 PY). In pooled subgroup analysis for studies conducted in Europe and North America, PSC IR was 0.62 and 0.53 per 100 000 PY, respectively. PSC prevalence ranged 0-31.7 per 100 000 persons, with notable inter-regional differences. Mean age at PSC diagnosis was bimodally distributed, with relative peaks at 15 and 35 years. Mean concurrence of IBD with PSC was 50%, with 76% having ulcerative colitis, 17% Crohn's disease and 8% indeterminate/unspecified IBD.

CONCLUSION

While considerable heterogeneity exists in the geoepidemiology of PSC, overall, the classical dogmata of male predilection, bimodal distribution of mean age and high PSC-IBD concurrence appear to hold true. Despite a seemingly stable IR over time, further studies are needed to better understand the geoepidemiology of PSC.

A Fibrosis-Independent Hepatic Transcriptomic Signature Identifies Drivers of Disease Progression in Primary Sclerosing Cholangitis

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is a heterogeneous cholangiopathy characterized by progressive biliary fibrosis. RNA sequencing of liver tissue from patients with PSC (n = 74) enrolled in a 96-week clinical trial was performed to identify associations between biological pathways that were independent of fibrosis and clinical events.

APPROACH AND RESULTS

The effect of fibrosis was subtracted from gene expression using a computational approach. The fibrosis-adjusted gene expression patterns were associated with time to first PSC-related clinical event (e.g., cholangitis, hepatic decompensation), and differential expression based on risk groups and Ingenuity Pathway Analysis were performed. Baseline demographic data were representative of PSC: median age 48 years, 71% male, 49% with inflammatory bowel disease, and 44% with bridging fibrosis or cirrhosis. The first principle component (PC1) of RNA-sequencing data accounted for 18% of variance and correlated with fibrosis stage (ρ = -0.80; P < 0.001). After removing the effect of fibrosis-related genes, the first principle component was not associated with fibrosis (ρ = -0.19; P = 0.11), and a semisupervised clustering approach identified two distinct patient clusters with differential risk of time to first PSC-related event (P < 0.0001). The two groups had similar fibrosis stage, hepatic collagen content, and α-smooth muscle actin expression by morphometry, Enhanced Liver Fibrosis score, and serum liver biochemistry, bile acids, and IL-8 (all P > 0.05). The top pathways identified by Ingenuity Pathway Analysis were eukaryotic translation inhibition factor 2 (eIF2) signaling and regulation of eIF4/p70S6K signaling. Genes involved in the unfolded protein response, activating transcription factor 6 (ATF6) and eIF2, were differentially expressed between the PSC clusters (down-regulated in the high-risk group by log-fold changes of -0.18 [P = 0.02] and -0.16 [P = 0.02], respectively). Clinical events were enriched in the high-risk versus low-risk group (38% [12/32] vs. 2.4% [1/42], P < 0.0001).

CONCLUSIONS

Removing the contribution of fibrosis-related pathways uncovered alterations in the unfolded protein response, which were associated with liver-related complications in PSC.

Intrahepatic cholangiocarcinoma: Morpho-molecular pathology, tumor reactive microenvironment, and malignant progression

Intrahepatic cholangiocarcinoma (iCCA) is a relatively rare, but highly lethal and biologically complex primary biliary epithelial cancer arising within liver. After hepatocellular carcinoma, iCCA is the second most common primary liver cancer, accounting for approximately 10-20% of all primary hepatic malignancies. Over the last 10-20 years, iCCA has become the focus of increasing concern largely due to its rising incidence and high mortality rates in various parts of the world, including the United States. The challenges posed by iCCA are daunting and despite recent progress in the standard of care and management options for iCCA, the prognosis for this cancer continues to be dismal. In an effort to provide a framework for advancing our understanding of iCCA malignant aggressiveness and therapy resistance, this review will highlight key etiological, biological, molecular, and microenvironmental factors hindering more effective management of this hepatobiliary cancer. Particular focus will be on critically reviewing the cell origins and morpho-molecular heterogeneity of iCCAs, providing mechanistic insights into high risk fibroinflammatory cholangiopathies associated with iCCA development, and notably discussing the deleterious role played by the tumor reactive desmoplastic stroma in regulating iCCA malignant progression, lymphangiogenesis, and tumor immunobiology.

Monocytes as Potential Mediators of Pathogen-Induced T-Helper 17 Differentiation in Patients With Primary Sclerosing Cholangitis (PSC)

BACKGROUND AND AIMS

T cells from patients with primary sclerosing cholangitis (PSC) show a prominent interleukin (IL)-17 response upon stimulation with bacteria or fungi, yet the reasons for this dominant T-helper 17 (Th17) response in PSC are not clear. Here, we analyzed the potential role of monocytes in microbial recognition and in skewing the T-cell response toward Th17.

APPROACH AND RESULTS

Monocytes and T cells from blood and livers of PSC patients and controls were analyzed ex vivo and in vitro using transwell experiments with cholangiocytes. Cytokine production was measured using flow cytometry, enzyme-linked immunosorbent assay, RNA in situ hybridization, and quantitative real-time PCR. Genetic polymorphisms were obtained from ImmunoChip analysis. Following ex vivo stimulation with phorbol myristate acetate/ionomycin, PSC patients showed significantly increased numbers of IL-17A-producing peripheral blood CD4⁺ T cells compared to PBC patients and healthy controls, indicating increased Th17 differentiation in vivo. Upon stimulation with microbes, monocytes from PSC patients produced significantly more IL-1β and IL-6, cytokines known to drive Th17 cell differentiation. Moreover, microbe-activated monocytes induced the secretion of Th17 and monocyte-recruiting chemokines chemokine (C-C motif) ligand (CCL)-20 and CCL-2 in human primary cholangiocytes. In livers of patients with PSC cirrhosis, CD14^hiCD16^int and CD14^loCD16^hi monocytes/macrophages were increased compared to alcoholic cirrhosis, and monocytes were found to be located around bile ducts.

CONCLUSIONS

PSC patients show increased Th17 differentiation already in vivo. Microbe-stimulated monocytes drive Th17 differentiation in vitro and induce cholangiocytes to produce chemokines mediating recruitment of Th17 cells and more monocytes into portal tracts. Taken together, these results point to a pathogenic role of monocytes in patients with PSC.

De novo and recurrent liver disease

Decompensated cirrhosis due to nonalcoholic steatohepatitis (NASH), and autoimmune liver diseases (AILD) are the most common indications for liver transplantation (LT). AILD include autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC). NASH and AILD share some peculiarities as they can recur in the new graft, compromising the quality of life, and graft and patient survival. De novo NASH or AIH connotes the development of these liver diseases in patients transplanted for other indications. The diagnosis of recurrent or de novo liver disease usually requires a liver biopsy aside from recurrent PSC, which can be diagnosed with compatible imaging studies and exclusion of other causes of biliary strictures. The treatment of recurrent NASH is lifestyle modifications aiming for weight loss. Recurrent and de novo AIH is usually treated with corticosteroids with or without azathioprine. Recurrent PBC should be treated with ursodeoxycholic acid. There are no proven treatment options for recurrent PSC. Patients with graft failure should be considered for repeat LT. Future investigations should use standardized diagnostic criteria for each disease, seek diagnostic biomarkers, and evaluate treatments that improve outcomes.

Antigen-Specific Immunotherapy for Treatment of Autoimmune Liver Diseases

The liver is a critical organ in controlling immune tolerance. In particular, it is now clear that targeting antigens for presentation by antigen presenting cells in the liver can induce immune tolerance to either autoantigens from the liver itself or tissues outside of the liver. Here we review immune mechanisms active within the liver that contribute both to the control of infectious diseases and tolerance to self-antigens. Despite its extraordinary capacity for tolerance induction, the liver remains a target organ for autoimmune diseases. In this review, we compare and contrast known autoimmune diseases of the liver. Currently patients tend to receive strong immunosuppressive treatments and, in many cases, these treatments are associated with deleterious side effects, including a significantly higher risk of infection and associated health complications. We propose that, in future, antigen-specific immunotherapies are adopted for treatment of liver autoimmune diseases in order to avoid such adverse effects. We describe various therapeutic approaches that either are in or close to the clinic, highlight their mechanism of action and assess their suitability for treatment of autoimmune liver diseases.

Glycomic analysis of antibody indicates distinctive glycosylation profile in patients with autoimmune cholangitis

Glycosylation of antibodies, particularly in the Fc domain, critically modulate the ability of antibodies to bind to FcRs, maintaining immune quiescence to achieve a finely orchestrated immune response. The removal of sialic acid and galactose residues dramatically alters the physiological function of IgGs, and alterations of Ig glycosylation have been associated with several autoimmune disorders. However, Ig glycosylation has not been extensively studied in autoimmune cholangitis. We applied triple quadruple mass spectroscopy with subsequent multiple reaction monitoring to elucidate the profile, composition and linkage of sugar residues of antibody glycans in patients with primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and healthy controls (HC). Agalactosylated, HexNAc terminated IgG1 glycoforms were enriched in both PBC and PSC. Levels of IgM glycans at site N439 and fucosylated glycans in J chain, were significantly decreased in PBC compared to PSC and HC. PSC patients had decreased bisecting glycoforms and increased biantennary glycoforms on IgA compared to PBC. Importantly, our data demonstrate the association of distinct branching and composition patterns of Ig glycoforms with disease severity and liver cirrhosis, which highlight the importance of glycan biology as a potential mechanism and/or a disease specific signal of inflammation.

[Systemic manifestations of inflammatory bowel diseases]

The article is devoted to the current data regarding the pathogenesis, classification and frequency of extraintestinal manifestations (EIMs) in inflammatory bowel diseases. We discuss two distinct theories of EIMs pathogenesis. First, EIMs arise from an extension of antigen-specific immune responses from the intestine to non-intestinal sites. Second, EIMs are independent inflammatory events initiated or perpetuated by the presence of IBD or by shared genetic or environmental risk factors in the host. These mechanisms are not mutually exclusive and may contribute to varying degrees in different EIMs. Early diagnosis of EIMs contributes to prevention disability and enhancement of quality of life of IBD patients. It is concluded that treatment of extraintestinal manifestations should be carried out taking into account the course of the IBD and the multidisciplinary approach, which requires close cooperation of doctors of various specialties. Assessment of prognostic markers and predictors for EIM in IBD will be part of a future investigation.

Geoepidemiologic variation in outcomes of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic, progressive, hepatobiliary disease characterized by inflammation and fibrosis of the intra- and extra-hepatic bile ducts. Its natural history is one that generally progresses towards cirrhosis, liver failure, cholangiocarcinoma, and ultimately disease-related death, with a median liver transplantation-free survival time of approximately 15-20 years. However, despite its lethal nature, PSC remains a heterogenous disease with significant variability in outcomes amongst different regions of the world. There are also many regions where the outcomes of PSC have not been studied, limiting the overall understanding of this disease worldwide. In this review, we present the geoepidemiologic variations in outcomes of PSC, with a focus on survival pre- and post-liver transplantation as well as the concurrence of inflammatory bowel disease and hepatobiliary neoplasia.

Expression Analysis of ATP-Binding Cassette Transporters ABCB11 and ABCB4 in Primary Sclerosing Cholangitis and Variety of Pediatric and Adult Cholestatic and Noncholestatic Liver Diseases

ATP-binding cassette (ABC) transporters are the members of the efflux pumps that are responsible for the removal of cytotoxic substances by active transport. ABCB11, the bile salt efflux pump of hepatocytes, coordinates cellular excretion of numerous conjugated bile salts into the bile canaliculi, whereas ABCB4 acts as an ATP-dependent floppase translocating phosphatidylcholine from the inner to the outer leaflet of the bile canalicular membrane. Loss of functional ABCB11 and ABCB4 proteins causes early-onset refractory cholestasis or cholangiopathy. In this study, we investigated the expression and localization pattern of ABCB11 and ABCB4 using immunohistochemistry and RNA profiling in liver samples from patients with different types and stages of chronic cholestatic liver disease, with emphasis on primary sclerosing cholangitis (PSC), compared to a variety of cholestatic and noncholestatic hepatopathies. Therefore, ABCB11 and ABCB4 expressions were investigated on formalin-fixed and paraffin-embedded (FFPE) material in a patient cohort of total 43 patients with or without cholestatic liver diseases, on protein level using immunohistochemistry and on RNA level using nanoString technology. Intriguingly, our results demonstrated increased expression of ABCB11 and ABCB4 on protein as well as RNA level in PSC, and the expression pattern correlated with disease progression. We concluded from our study that patients with PSC demonstrate altered expression levels and pattern of ABCB11 and ABCB4 which correlated with disease progression; thereby, ABCB11 and ABCB4 analysis may be a useful tool for assessment of disease stages in PSC.

Long-term outcomes of pediatric-onset primary sclerosing cholangitis: A single-center experience in Japan

AIM

Primary sclerosing cholangitis (PSC) is very rare in Japan. Although a large-scale cohort study of 781 pediatric-onset PSC patients in Europe and North America showed that the 5-year survival with native liver was 88%, the long-term outcomes of pediatric-onset PSC in Japan are unknown. Here, we evaluated the clinical outcomes of pediatric-onset PSC in Japan.

METHODS

We carried out a retrospective cohort study with a medical records review of pediatric PSC patients diagnosed between 1986 and 2017 at a single center. The PSC diagnoses were based on cholangiography, liver histology, and biochemical findings. The patients' survival was analyzed using the Kaplan-Meier method. Prognostic factors were determined by univariate and multivariate analyses using the Cox proportional hazards regression model.

RESULTS

We identified 39 pediatric-onset PSC patients (22 boys, 17 girls). The median age at diagnosis was 9 years (interquartile range 6.0-13.5 years). The median follow-up period was 5.5 years (interquartile range 3.4-8.7 years). The phenotypes of PSC-autoimmune hepatitis, PSC-inflammatory bowel disease, and small-duct PSC were diagnosed in 13 (33.3%), 36 out of 38 (94.8%), and three (7.7%) patients, respectively. The 5-year liver transplantation-free survival of the whole cohort was 93.5%. Nine patients underwent liver transplantation, and four of these nine cases resulted in death. Both the univariate and multivariate analyses showed that the phenotype of "PSC-autoimmune hepatitis overlap" was an independent poor prognostic factor.

CONCLUSIONS

The overall survival of pediatric-onset PSC in Japan was comparable to those in Western countries. The phenotype of PSC-autoimmune hepatitis was identified as a prognostic factor associated with a poorer long-term outcome.

Primary Sclerosing Cholangitis: A Clinical Update

Primary sclerosing cholangitis (PSC) is a rare cholestatic disorder of the liver, with strictures in the bile ducts leading to cirrhosis of the liver in a proportion of patients. PSC is commonly associated with inflammatory bowel disease and increased risk of cholangiocarcinoma, gall bladder cancer, colorectal cancer, and hepatocellular carcinoma. Medical therapies are primarily aimed at symptom management and disease-modifying therapies are limited. Endoscopic therapies are used in patients with dominant strictures and liver transplantation is a last resort. In this article, the authors aim to comprehensively review the epidemiology, diagnosis, and management of PSC with emphasis on risk of malignancies and management of PSC. The authors also survey the advances in pathogenesis understanding and novel medical therapies for PSC.

Cholangiocarcinoma is associated with a raised enhanced liver fibrosis score independent of primary sclerosing cholangitis

BACKGROUND

Cholangiocarcinoma (CCA) complicates primary sclerosing cholangitis (PSC) in 10%-20% of cases, but current tools for prediction of a CCA diagnosis are inadequate. Recently, we demonstrated the utility of the enhanced liver fibrosis (ELF) test to stratify prognosis in PSC. We observed that patients with PSC + CCA had significantly higher ELF score than those with PSC alone. In this study, we aimed to investigate further this association in a larger cohort of PSC patients with CCA compared with patients with PSC or CCA alone.

MATERIALS AND METHODS

Stored sera from patients with PSC (n = 119), CCA without known chronic liver disease (n = 36) and PSC + CCA (n = 32) were tested for ELF. ELF score, gender, age, age at disease diagnosis, inflammatory bowel disease, PSC duration and severity, and CCA features were compared amongst the three cohorts. Factors related to an elevated ELF score were investigated.

RESULTS

Enhanced liver fibrosis score was significantly higher in patients with CCA without underlying chronic liver disease and in patients with PSC + CCA compared to those with PSC alone (P < 0.001). In multivariate analysis, elevated ELF score was associated with the diagnosis of CCA independently of age and PSC status (P < 0.001).

CONCLUSIONS

Enhanced liver fibrosis score was elevated in patients with CCA irrespective of the presence of PSC, and independently of liver disease stage. Our results indicate that the association between high ELF score and CCA may be related to the tumour's desmoplastic nature, independent of background liver fibrosis, suggesting that ELF score could be used to risk stratify for CCA in PSC.

A Review of Extraintestinal Manifestations and Complications of Inflammatory Bowel Disease

Extraintestinal manifestations (EIMs) are common in inflammatory bowel disease (IBD), in both Crohn's disease and ulcerative colitis. Almost any organ system can be affected, including the musculoskeletal, dermatologic, renal, hepatopancreatobiliary, pulmonary and ocular systems. However, the musculoskeletal and dermatologic systems are the most commonly involved sites of manifestations. While some manifestations such as peripheral arthritis and erythema nodosum have an association with IBD activity, others such as axial arthropathy, pyoderma gangrenosum and primary sclerosing cholangitis have an independent disease course. This review provides a summary of the most common EIMs in IBD and their prevalence and management.

Extraintestinal manifestations in inflammatory bowel disease - epidemiology, genetics, and pathogenesis

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder, primarily of, but not restricted to the gut. Extraintestinal manifestations (EIMs) are frequently observed and involve the joints, eyes, hepatobiliary tract, and skin. Areas covered: In this review, we discuss classical EIM focusing on epidemiology, genetics, and pathogenesis, highlighting recent advances in the understanding of EIM. We further discuss treatment-induced immunological phenomena, which are increasingly recognized and might challenge IBD-treating physicians in the era of biological treatment. Expert opinion: EIM considerably contributes to morbidity and mortality. Genetic studies have revealed a common genetic background between EIM and IBD and among specific EIM. Identified protein interactions have been shown to cluster in shared biological pathways. However - despite these recent advances - pathogenesis of EIM is at best partially understood. Several pathogenic mechanisms have been proposed such as upregulation of tumor necrosis factor, aberrant lymphocyte homing, and cross-reactive antigen presentation. It still remains unclear whether EIM is a direct result of the inflammatory process in the gut or rather a consequence of a shared genetic background leading to dysfunctional immune responses to environmental stimuli. Exploration and understanding of EIM genetics and pathophysiology will pave the road for better and more efficacious treatment options in the future.

Molecular Pathogenesis of Cholangiocarcinoma

BACKGROUND

Cholangiocarcinomas are a heterogeneous group of malignancies arising from a number of cells of origin along the biliary tree. Although most cases in Western countries are sporadic, large population-based studies have identified a number of risk factors. This review summarises the evidence behind reported risk factors and current understanding of the molecular pathogenesis of cholangiocarcinoma, with a focus on inflammation and cholestasis as the driving forces in cholangiocarcinoma development.

RISK FACTORS FOR CHOLANGIOCARCINOGENESIS

Cholestatic liver diseases (e.g. primary sclerosing cholangitis and fibropolycystic liver diseases), liver cirrhosis, and biliary stone disease all increase the risk of cholangiocarcinoma. Certain bacterial, viral or parasitic infections such as hepatitis B and C and liver flukes also increase cholangiocarcinoma risk. Other risk factors include inflammatory disorders (such as inflammatory bowel disease and chronic pancreatitis), toxins (e.g. alcohol and tobacco), metabolic conditions (diabetes, obesity and non-alcoholic fatty liver disease) and a number of genetic disorders.

MOLECULAR PATHOGENESIS OF CHOLANGIOCARCINOMA

Regardless of aetiology, most risk factors cause chronic inflammation or cholestasis. Chronic inflammation leads to increased exposure of cholangiocytes to the inflammatory mediators interleukin-6, Tumour Necrosis Factor-ɑ, Cyclo-oxygenase-2 and Wnt, resulting in progressive mutations in tumour suppressor genes, proto-oncogenes and DNA mismatch-repair genes. Accumulating bile acids from cholestasis lead to reduced pH, increased apoptosis and activation of ERK1/2, Akt and NF-κB pathways that encourage cell proliferation, migration and survival. Other mediators upregulated in cholangiocarcinoma include Transforming Growth Factor-β, Vascular Endothelial Growth Factor, Hepatocyte Growth Factor and several microRNAs. Increased expression of the cell surface receptor c-Met, the glucose transporter GLUT-1 and the sodium iodide symporter lead to tumour growth, angiogenesis and cell migration. Stromal changes are also observed, resulting in alterations to the extracellular matrix composition and recruitment of fibroblasts and macrophages that create a microenvironment promoting cell survival, invasion and metastasis.

CONCLUSION

Regardless of aetiology, most risk factors for cholangiocarcinoma cause chronic inflammation and/or cholestasis, leading to the activation of common intracellular pathways that result in reactive cell proliferation, genetic/epigenetic mutations and cholangiocarcinogenesis. An understanding of the molecular pathogenesis of cholangiocarcinoma is vital when developing new diagnostic biomarkers and targeted therapies for this disease.

Gut pathobionts underlie intestinal barrier dysfunction and liver T helper 17 cell immune response in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic inflammatory liver disease and its frequent complication with ulcerative colitis highlights the pathogenic role of epithelial barrier dysfunction. Intestinal barrier dysfunction has been implicated in the pathogenesis of PSC, yet its underlying mechanism remains unknown. Here, we identify Klebsiella pneumonia in the microbiota of patients with PSC and demonstrate that K. pneumoniae disrupts the epithelial barrier to initiate bacterial translocation and liver inflammatory responses. Gnotobiotic mice inoculated with PSC-derived microbiota exhibited T helper 17 (T_H17) cell responses in the liver and increased susceptibility to hepatobiliary injuries. Bacterial culture of mesenteric lymph nodes in these mice isolated K. pneumoniae, Proteus mirabilis and Enterococcus gallinarum, which were prevalently detected in patients with PSC. A bacterial-organoid co-culture system visualized the epithelial-damaging effect of PSC-derived K. pneumoniae that was associated with bacterial translocation and susceptibility to T_H17-mediated hepatobiliary injuries. We also show that antibiotic treatment ameliorated the T_H17 immune response induced by PSC-derived microbiota. These results highlight the role of pathobionts in intestinal barrier dysfunction and liver inflammation, providing insights into therapeutic strategies for PSC.

Cholangiocarcinoma: a guide for the nonspecialist

Cholangiocarcinoma (CCA) is a tumor with increasing prevalence around the world. The prevalence of CCA is highest in East Asia and most significantly in the countries through which the Mekong River flows, owing to the presence of liver flukes, which are consumed in raw fish dishes. Outside Asia, the causes of bile duct cancers for the most part are unknown. In this review, we assess the current state of knowledge in both fluke-associated and sporadic CCA, from etiological, diagnostic, and treatment perspectives.

A novel prognostic model for transplant-free survival in primary sclerosing cholangitis

OBJECTIVE

Most 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.

DESIGN

The 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.

RESULTS

The 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.

CONCLUSION

The 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.

Comprehensive Review of Molecular Mechanisms during Cholestatic Liver Injury and Cholangiocarcinoma

Cholestatic liver injury is characterized by damage induced on the biliary tree and cholangiocytes, the cells lining the biliary tree, thus they are termed "cholangiopathies". Cholangiopathies include diseases such as Primary Biliary Cholangitis, Primary Sclerosing Cholangitis, Biliary Atresia and Cholangiocarcinoma. These pathologies lack viable therapies and most patients are diagnosed during late stage disease progression (with the exception of Biliary Atresia, which is found shortly after birth). The lack of therapies for these diseases has put a significant burden on the need for liver transplantation as this is the only indicative "cure" for cholangiopathies. The molecular mechanisms for cholangiopathies have been extensively studied; however, and unfortunately, the lack of effective biomarkers and therapeutics remains. In this review article we highlight the latest studies to investigate the molecular mechanisms regulating cholangiopathies and the potential therapeutics that might be discovered.

Blocking H1/H2 histamine receptors inhibits damage/fibrosis in Mdr2-/- mice and human cholangiocarcinoma tumorigenesis

Primary sclerosing cholangitis (PSC) patients are at risk of developing cholangiocarcinoma (CCA). We have shown that (1) histamine increases biliary hyperplasia through H1/H2 histamine receptors (HRs) and (2) histamine levels increase and mast cells (MCs) infiltrate during PSC and CCA. We examined the effects of chronic treatment with H1/H2HR antagonists on PSC and CCA. Wild-type and multidrug-resistant knockout (Mdr2-/- ) mice were treated by osmotic minipumps with saline, mepyramine, or ranitidine (10 mg/kg body weight/day) or a combination of mepyramine/ranitidine for 4 weeks. Liver damage was assessed by hematoxylin and eosin. We evaluated (1) H1/H2HR expression, (2) MC presence, (3) L-histidine decarboxylase/histamine axis, (4) cholangiocyte proliferation/bile duct mass, and (5) fibrosis/hepatic stellate cell activation. Nu/nu mice were implanted with Mz-ChA-1 cells into the hind flanks and treated with saline, mepyramine, or ranitidine. Tumor growth was measured, and (1) H1/H2HR expression, (2) proliferation, (3) MC activation, (4) angiogenesis, and (5) epithelial-mesenchymal transition (EMT) were evaluated. In vitro, human hepatic stellate cells were evaluated for H1HR and H2HR expression. Cultured cholangiocytes and CCA lines were treated with saline, mepyramine, or ranitidine (25 μM) before evaluating proliferation, angiogenesis, EMT, and potential signaling mechanisms. H1/H2HR and MC presence increased in human PSC and CCA. In H1/H2HR antagonist (alone or in combination)-treated Mdr2-/- mice, liver and biliary damage and fibrosis decreased compared to saline treatment. H1/H2HR antagonists decreased tumor growth, serum histamine, angiogenesis, and EMT. In vitro, H1/H2HR blockers reduced biliary proliferation, and CCA cells had decreased proliferation, angiogenesis, EMT, and migration. Conclusion: Inhibition of H1/H2HR reverses PSC-associated damage and decreases CCA growth, angiogenesis, and EMT; because PSC patients are at risk of developing CCA, using HR blockers may be therapeutic for these diseases. (Hepatology 2018).

Animal models of cholestasis: An update on inflammatory cholangiopathies

Cholestasis is a frequent clinical condition initiating or complicating chronic liver diseases, particularly cholangiopathies, where the biliary epithelium is the primary target of the pathogenetic sequence. Until a few decades ago, understanding of cholestasis relied mostly on the experimental model of bile duct ligation in rodents. However, a simple model of biliary obstruction cannot reproduce the complex mechanisms and networks leading to cholestasis in cholangiopathies. These networks are underpinned by an intricate dysregulation of pro-inflammatory and pro-fibrotic signals involving besides cholangiocytes, multiple cell elements of both innate and adaptive immunity. Therefore, in the last years, a wide range of animal models of biliary injury have been developed, mostly in mice, following three main approaches, chemical induction, immunization and genetic manipulation. In this review, we will give an update of the animal models of the two main cholangiopathies, primary sclerosing cholangitis and primary biliary cholangitis, which have provided us with the most relevant insights into the pathogenesis of these still controversial diseases.

Effectiveness and safety of anti-TNF therapy for inflammatory bowel disease in liver transplant recipients for primary sclerosing cholangitis: A nationwide case series

BACKGROUND

There is a lack of consensus regarding the treatment of inflammatory bowel disease (IBD) after liver transplantation (LT) forprimary sclerosing cholangitis (PSC).

AIM

To investigate the safety and effectiveness of anti-TNF therapy in patients with IBD after a LT for PSC.

METHODS

We reviewed the medical files of all of the IBD patients who underwent a LT for PSC and who were treated with anti-TNF therapy at 23 French liver transplantation centers between 1989 and 2012.

RESULTS

Eighteen patients (12 with ulcerative colitis and 6 who had Crohn's disease) were recruited at 9 LT centers. All of these patients received infliximab or adalimumab following their LT, and the median duration of their anti-TNF treatment was 10.4 months. The most frequent concomitant immunosuppressive treatment comprised a combination of tacrolimus and corticosteroids. Following anti-TNF therapy induction, a clinical response was seen in 16/18 patients (89%) and clinical remission in 10 (56%). At the end of the anti-TNF treatment or at the last follow-up examination (the median follow-up was 20.9 months), a clinical response was achieved in 12 patients (67%) and clinical remission in 7 (39%). A significant endoscopic improvement was observed in 9 out of 14 patients and a complete mucosal healing in 3 out of 14 patients (21%). Six patients experienced a severe infection. These were due to cholangitis, cytomegalovirus (CMV) infection, Clostridium difficile, cryptosporidiosis, or Enterococcus faecalis. Three patients developed colorectal cancer after LT, and two patients died during the follow-up period.

CONCLUSIONS

Anti-TNF therapy proved to be effective for treating IBD after LT for PSC. However, as 17% of the patients developed colorectal cancer during the follow-up, colonoscopic annual surveillance is recommended after LT, as specified in the current guidelines.

Inflammatory bowel disease with primary sclerosing cholangitis: A Danish population-based cohort study 1977-2011

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) may be complicated by primary sclerosing cholangitis (PSC). We aimed to assess the characteristics of Danish PSC-IBD patients and to compare their prognosis with IBD patients without PSC.

METHODS

A retrospective nationwide population-based cohort of 257 PSC-IBD patients was assessed through Danish national registries and manual scrutiny of patient files.

RESULTS

For all PSC-IBD patients diagnosed after 1976 (n = 222) and 8231 IBD controls (ie, without PSC), the cumulative probability of resective surgery, liver transplantation, cancer, and survival from 1977 through 2011 was estimated and compared by log-rank test and Cox regression. PSC-IBD patients primarily had ulcerative colitis (UC) (72%), were diagnosed in young adulthood (median age at IBD diagnosis, 23 years), and 9% were smokers. Among PSC-UC patients 78% had pancolitis at diagnosis. Among patients with PSC and Crohn's disease (CD) 91% had colonic involvement. The PSC-IBD patients had a significantly higher probability of receiving resective surgery (HR; 2.13, 95% CI: 1.50-3.03); of developing colorectal cancer (CRC) (HR; 21.4, 95% CI: 9.6-47.6), of cholangiocarcinoma (HR; 190, 95% CI: 54.8-660), and of dying (HR; 4.39, 95% CI: 3.22-6.00) as compared to non-PSC-IBD controls. The 25-year cumulative risk of liver transplantation was high (53%).

CONCLUSIONS

This unselected population-based study shows that PSC-IBD patients not only have an extensive phenotype of IBD, they are also treated more intensively than other patients with IBD. However, the prognosis remains poor and without any apparent improvement over calendar time.

Cholangitis: Diagnosis, Treatment and Prognosis

Cholangitis is a serious life-threatening situation affecting the hepatobiliary system. This review provides an update regarding the clinical and pathological features of various forms of cholangitis. A comprehensive search was performed in the PubMed, Scopus, and Web of Knowledge databases. It was found that the etiology and pathogenesis of cholangitis are heterogeneous. Cholangitis can be categorized as primary sclerosing (PSC), secondary (acute) cholangitis, and a recently characterized form, known as IgG4-associated cholangitis (IAC). Roles of genetic and acquired factors have been noted in development of various forms of cholangitis. PSC commonly follows a chronic and progressive course that may terminate in hepatobiliary neoplasms. In particular, PSC commonly has been associated with inflammatory bowel disease. Bacterial infections are known as the most common cause for AC. On the other hand, IAC has been commonly encountered along with pancreatitis. Imaging evaluation of the hepatobiliary system has emerged as a crucial tool in the management of cholangitis. Endoscopic retrograde cholangiography, magnetic resonance cholangiopancreatography and endoscopic ultrasonography comprise three of the modalities that are frequently exploited as both diagnostic and therapeutic tools. Biliary drainage procedures using these methods is necessary for controlling the progression of cholangitis. Promising results have been reported for the role of antibiotic treatment in management of AC and PSC; however, immunosuppressive drugs have also rendered clinical responses in IAC. With respect to the high rate of complications, surgical interventions in patients with cholangitis are generally restricted to those patients in whom other therapeutic approaches have failed.

The role of natural killer T cells in a mouse model with spontaneous bile duct inflammation

Natural killer T (NKT) cells are activated by lipid antigens presented by CD1d molecules and represent a major lymphocyte subset of the liver. NODc3c4 mice spontaneously develop biliary inflammation in extra- and intrahepatic bile ducts. We demonstrated by flow cytometry that invariant NKT (iNKT) cells were more abundant in the thymus, spleen, and liver of NODc3c4 mice compared to NOD mice. iNKT cells in NODc3c4 mice displayed an activated phenotype. Further, NOD and NODCd1d^-/- mice were irradiated and injected with NODc3c4 bone marrow, and injection of NODc3c4 bone marrow resulted in biliary infiltrates independently of CD1d expression in recipient mice. Activation or blocking of NKT cells with α-galactosylceramide or anti-CD1d antibody injections did not affect the biliary phenotype of NODc3c4 mice. NODc3c4.Cd1d^-/- mice were generated by crossing NODCd1d^-/- mice onto a NODc3c4 background. NODc3c4.Cd1d^-/- and NODc3c4 mice developed the same extent of biliary disease. This study demonstrates that iNKT cells are more abundant and activated in the NODc3c4 model. The portal inflammation of NODc3c4 mice can be transferred to irradiated recipients, which suggests an immune-driven disease. Our findings imply that NKT cells can potentially participate in the biliary inflammation, but are not the primary drivers of disease in NODc3c4 mice.

Long-term Prognosis and Recurrence of Primary Sclerosing Cholangitis After Liver Transplantation: A Single-Center Experience

Background

Primary sclerosing cholangitis (PSC) is a progressive cholestatic liver disease, with liver transplantation being the sole life-saving treatment for end-stage PSC-related liver disease. However, recurrence of PSC after liver transplantation is a common complication, with the risk factors for recurrence being controversial.

Methods

We conducted a retrospective chart review of 45 patients who had undergone liver transplantation for PSC at our institute. The risk factors for PSC recurrence and graft failure after liver transplantation were analyzed.

Results

The graft survival rates were 55.4% at 5 years and 32.8% at 10 years after liver transplantation for PSC. PSC recurrence was diagnosed in 16 (40%) of 40 patients, at a median 30 months (range, 9-70 months) after liver transplantation. The cumulative incidence rate of PSC recurrence was 24.5% at 3 years, 39.3% at 5 years, and 45.8% at 6 years. Among the 16 patients diagnosed with PSC recurrence, the graft survival rate was 56.3% at 5 years, and 21.9% at 10 years after the recurrence. Active inflammatory bowel disease after liver transplantation was identified as an independent risk factor for PSC recurrence. Age younger than 30 years at the time of PSC diagnosis and bacteremia were factors significantly associated with graft failure after liver transplantation on multivariate analysis.

Conclusions

PSC frequently recurred and progressed to graft failure after liver transplantation for PSC. Maintaining an inactive status of inflammatory bowel disease might offer protection against PSC recurrence.

Serum extracellular vesicles contain protein biomarkers for primary sclerosing cholangitis and cholangiocarcinoma

Cholangiocarcinoma (CCA) includes a heterogeneous group of biliary cancers with poor prognosis. Several conditions, such as primary sclerosing cholangitis (PSC), are risk factors. Noninvasive differential diagnosis between intrahepatic CCA and hepatocellular carcinoma (HCC) is sometimes difficult. Accurate noninvasive biomarkers for PSC, CCA, and HCC are not available. In the search for novel biomarkers, serum extracellular vesicles (EV) were isolated from CCA (n = 43), PSC (n = 30), or HCC (n = 29) patients and healthy individuals (control, n = 32); and their protein content was characterized. By using nanoparticle tracking analysis, serum EV concentration was found to be higher in HCC than in all the other groups. Round morphology (by transmission electron microscopy), size (∼180 nm diameter by nanoparticle tracking analysis), and markers (clusters of differentiation 9, 63, and 81 by immunoblot) indicated that most serum EV were exosomes. Proteome profiles (by mass spectrometry) revealed multiple differentially expressed proteins among groups. Several of these proteins showed high diagnostic values with maximum area under the receiver operating characteristic curve of 0.878 for CCA versus control, 0.905 for CCA stage I-II versus control, 0.789 for PSC versus control, 0.806 for noncirhottic PSC versus control, 0.796 for CCA versus PSC, 0.956 for CCA stage I-II versus PSC, 0.904 for HCC versus control, and 0.894 for intrahepatic CCA versus HCC. Proteomic analysis of EV derived from CCA human cells in vitro revealed higher abundance of oncogenic proteins compared to EV released by normal human cholangiocytes. Orthotopic implant of CCA human cells in the liver of immunodeficient mice resulted in the release to serum of EV containing some similar human oncogenic proteins.

CONCLUSION

Proteomic signatures found in serum EV of CCA, PSC, and HCC patients show potential usefulness as diagnostic tools. (Hepatology 2017;66:1125-1143).

Patients with inflammatory bowel disease have increased risk of autoimmune and inflammatory diseases

AIM

To investigate whether immune mediated diseases (IMD) are more frequent in patients with inflammatory bowel disease (IBD).

METHODS

In this population based registry study, a total of 47325 patients with IBD were alive and registered in the Danish National Patient Registry on December 16, 2013. Controls were randomly selected from the Danish Civil Registration System (CRS) and matched for sex, age, and municipality. We used ICD 10 codes to identify the diagnoses of the included patients. The IBD population was divided into three subgroups: Ulcerative colitis (UC), Crohn’s disease (CD) and Both the latter referring to those registered with both diagnoses. Subsequently, odds-ratios (OR) and 95%CI were obtained separately for each group and their respective controls. The use of Bonferoni post-test correction adjusted the significance level to P < 0.00125. P-values were estimated using Fisher’s exact test.

RESULTS

There were significantly more women than men in the registry, and a greater percentage of comorbidity in the IBD groups (P < 0.05). Twenty different IMDs were all significantly more frequent in the IBD group. Sixteen were associated with UC versus twelve with CD. In both UC and CD ORs were significantly increased (P < 0.00125) for primary sclerosing cholangitis (PSC), celiac disease, type 1 diabetes (T1D), sarcoidosis, asthma, iridocyclitis, psoriasis, pyoderma gangrenosum, rheumatoid arthritis, and ankylosing spondylitis. Restricted to UC (P < 0.00125) were autoimmune hepatitis, primary biliary cholangitis, Grave’s disease, polymyalgia rheumatica, temporal arteritis , and atrophic gastritis. Restricted to CD (P < 0.00125) were psoriatic arthritis and episcleritis. Restricted to women with UC (P < 0.00125) were atrophic gastritis, rheumatoid arthritis, temporal arteritis, and polymyalgia rheumatica. Restricted to women with CD were episcleritis, rheumatoid arthritis, and psoriatic arthritis. The only disease restricted to men (P < 0.00125) was sarcoidosis.

CONCLUSION

Immune mediated diseases were significantly more frequent in patients with IBD. Our results strengthen the hypothesis that some IMDs and IBD may have overlapping pathogenic pathways.

Bile microbiota in primary sclerosing cholangitis: Impact on disease progression and development of biliary dysplasia

Objective

The etiopathogenesis and risk for development of biliary neoplasia in primary sclerosing cholangitis (PSC) are largely unknown. Microbes or their metabolites have been suggested to play a role. To explore this potential microbial involvement, we evaluated the differences in biliary microbiota in PSC patients at an early disease stage without previous endoscopic retrograde cholangiography (ERC) examinations, advanced disease stage, and with biliary dysplasia or cholangiocarcinoma.

Design

Bile samples from the common bile duct were collected from 46 controls and 80 patients with PSC during ERC (37 with early disease, 32 with advanced disease, and 11 with biliary dysplasia). DNA isolation, amplification, and Illumina MiSeq sequencing were performed for the V1-V3 regions of the bacterial 16S rRNA gene.

Results

The most common phyla found were Bacteroidetes, Firmicutes, Proteobacteria, Fusobacteria, and Actinobacteria. The most common families were Prevotellaceae, Streptococcaceae, Veillonellaceae, Fusobacteriaceae, and Pasteurellaceae, and the most common genera were Prevotella, Streptococcus, Veillonella, Fusobacterium, and Haemophilus. The bacterial communities of non-PSC subjects and early stage PSC patients were similar. Alpha diversity was lower in patients with biliary dysplasia/cholangiocarcinoma than in other groups. An increase in Streptococcus abundance was positively correlated with the number of ERC examinations. Streptococcus abundance was also positively correlated with an increase in disease severity, even after controlling for the number of ERC examinations.

Conclusions

Our findings suggest that the aetiology of PSC is not associated with changes in bile microbial communities, but the genus Streptococcus may play a pathogenic role in the progression of the disease.

Knockout of the primary sclerosing cholangitis-risk gene Fut2 causes liver disease in mice

The etiopathogenesis of primary sclerosing cholangitis is unknown. Genetic variants of fucosyltransferase 2 (FUT2) have been identified in genome-wide association studies as risk factors for primary sclerosing cholangitis. We investigated the role of Fut2 in murine liver pathophysiology by studying Fut2-/- mice. Fut2-/- mice were viable and fertile, had lower body weight than wild-type (wt) littermates and gray fur. Half of the Fut2-/- mice showed serum bile salt levels 40 times higher than wt (Fut2-/-high ), whereas the remainder were normocholanemic (Fut2-/-low ). Fut2-/- mice showed normal serum liver tests, bile flow, biliary bile salt secretion, fecal bile salt loss, and expression of major hepatocellular bile salt transporters and cytochrome P450 7a1, the key regulator of bile salt synthesis, indicating that elevated serum bile salts in Fut2-/-high mice were not explained by cholestasis. Fut2-/-high mice, but not Fut2-/-low mice, were sensitive to hydrophobic bile salt feeding (0.3% glycochenodeoxycholate); they rapidly lost weight and showed elevation of serum liver tests (alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase) and areas of liver parenchymal necrosis. Histomorphological evaluation revealed the presence of paraportal shunting vessels, increased numbers of portal vascular structures, wall thickening of some portal arteries, and periductal fibrosis in Fut2-/-high mice more than Fut2-/-low mice and not wt mice. Unconjugated bilirubin and ammonia were or tended to be elevated in Fut2-/-high mice only. Portosystemic shunting was demonstrated by portal angiography, which disclosed virtually complete portosystemic shunting in Fut2-/-high mice, discrete portosystemic shunting in Fut2-/-low mice, and no shunting in wt littermates.

CONCLUSION

Liver pathology in Fut2-/- mice is dominated by consequences of portosystemic shunting resulting in microcirculatory disturbances, mild (secondary) periductal fibrosis, and sensitivity toward human bile salt toxicity. (Hepatology 2017;66:542-554).

Pathophysiologic implications of innate immunity and autoinflammation in the biliary epithelium

The most studied physiological function of biliary epithelial cells (cholangiocytes) is to regulate bile flow and composition, in particular the hydration and alkalinity of the primary bile secreted by hepatocytes. After almost three decades of studies it is now become clear that cholangiocytes are also involved in epithelial innate immunity, in inflammation, and in the reparative processes in response to liver damage. An increasing number of evidence highlights the ability of cholangiocyte to undergo changes in phenotype and function in response to liver damage. By participating actively to the immune and inflammatory responses, cholangiocytes represent a first defense line against liver injury from different causes. Indeed, cholangiocytes express a number of receptors able to recognize pathogen- or damage-associated molecular patterns (PAMPs/DAMPs), such as Toll-like receptors (TLR), which modulate their pro-inflammatory behavior. Cholangiocytes can be both the targets and the initiators of the inflammatory process. Derangements of the signals controlling these mechanisms are at the basis of the pathogenesis of different cholangiopathies, both hereditary and acquired, such as cystic fibrosis-related liver disease and sclerosing cholangitis. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

Are Dominant Strictures in Primary Sclerosing Cholangitis a Risk Factor for Cholangiocarcinoma?

PURPOSE OF REVIEW

Cholangiocarcinoma is a devastating, unpredictable complication of large duct primary sclerosing cholangitis (PSC), which occurs in 5-15% of patients. The aim of this review is to discuss whether dominant strictures (DS) occurring in the larger bile ducts in PSC are a risk factor for the development of cholangiocarcinoma.

RECENT FINDINGS

The development of DS is related to specific genetic polymorphisms affecting the innate immune system and the microbiome. In a recent study, the mean survival of PSC patients with DS was much worse (13.7 years) than for those without a DS (23 years). Survival difference was related to a 26% risk of cholangiocarcinoma, which developed only in those with DS. Half of the patients with cholangiocarcinoma presented within 4 months of the diagnosis of PSC. In another study, the risk of developing cholangiocarcinoma was directly related to the presence of underlying IBD, although this remains controversial. Efforts are being made towards surveying for cholangiocarcinoma including magnetic resonance imaging, endoscopic surveillance and serum tumour markers, but so far, an effective surveillance strategy has not been identified. DS should be treated endoscopically in the setting of symptoms, and there is limited evidence to suggest this may impact protectively on progression to cholangiocarcinoma.

SUMMARY

It is established that the presence of symptomatic DS occurring in the larger bile ducts in PSC can be the first presentation of cholangiocarcinoma. There is an increasing body of evidence that even when proven to be benign, dominant biliary strictures predispose to the future development of cholangiocarcinoma. Regular surveillance should be targeted at this selected high-risk group of PSC patients.

Recurrence of primary sclerosing cholangitis, primary biliary cholangitis and auto-immune hepatitis after liver transplantation

Liver transplantation is a well-accepted treatment for decompensated chronic liver disease due to primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC) and auto-immune hepatitis (AIH). Survival after liver transplantation is generally good with 1 and 5-year survival rates around 90% and 70-85%. After transplantation, however, these diseases recur in 8.6-27% (rPSC), 10.9-42.3% (rPBC) and 7-42% (rAIH), and this poses significant challenges in terms of management and graft outcome in these patients. In this review we discuss the incidence, clinical presentation, challenges in diagnosis, reported risk factors and impact on post-transplant outcomes of recurrence of PSC, PBC and AIH after liver transplantation. We also discuss some of the limitations of current investigations and formulate idea's for future research objectives.

Patients with primary sclerosing cholangitis require more sedation during endoscopic retrograde cholangiography

Background and study aims Patients with primary sclerosing cholangitis (PSC) require repeated endoscopic retrograde cholangiography (ERC). Our aim was to evaluate whether patients with PSC require higher doses of sedation during ERC. Patients and methods We retrospectively analyzed all patients undergoing ERC from 2006 to 2013 who received conscious sedation with propofol and midazolam. The duration of the intervention and a potential progression of propofol consumption or intervention time by visit number were analyzed. Univariable and multivariable analyses were performed to identify independent factors which influence propofol consumption. Results A total of 2962 ERC procedures were performed in 1211 patients. Patients with PSC (n = 157) underwent 461 ERC procedures whereas patients without PSC (n = 1054) had 2501 ERC examinations. The total median propofol dose was 450 mg (290 - 630 mg) for patients with PSC and 300 mg (200 - 450 mg) for the non-PSC group (P < 0.05). The propofol consumption in patients with PSC was increased by a factor of 1.24 (P = 0.0071) independent of intervention time. Younger age (< 60.8 years) and duration of the intervention were associated with a higher need for sedation by factors of 1.21 and 1.71, respectively (P < 0.0001). The robustness of the results was tested in a sensitivity analysis which confirmed the results (P < 0.0001). Conclusions Patients with PSC may require higher doses of sedation for ERC compared to other patient groups independent of age and duration of ERC. The higher dosage of sedation has to be taken into account when using ERC to treat a patient with PSC.

Development of a scoring system for differentiating IgG4-related sclerosing cholangitis from primary sclerosing cholangitis

BACKGROUND

Recent research has shown that a substantial number of patients with primary sclerosing cholangitis (PSC) can also have elevated serum/tissue IgG4. The aim of our study was to develop a simple scoring system for the discrimination of IgG4-related sclerosing cholangits (IgG4-SC) from PSC.

METHODS

Patients with IgG4-SC (n = 39) and PSC (n = 76) who had intrahepatic/hilar strictures were included. Candidate-differentiating variables included patient age, other organ involvement (OOI), inflammatory bowel disease, serum IgG4, and cholangiographic features. A scoring system was developed on the basis of these variables, and its performance was internally validated using a bootstrapping-based method.

RESULTS

The scoring system in the final model included age (<30 years, 0 points; 30-39 years, 1 point; 40-49 years, 2 points; 50-59 years, 3 points; ≥60 years, 4 points), OOI (no, 0 points; yes, 3 points), and beaded appearance (yes, 0 points; no, 2 points). The patients were classified according to their total score into three categories: 0-4 points, probable PSC; 5-6 points, indicating diagnostic steroid trial; 7-9 points, probable IgG4-SC. The discrimination between IgG4-SC and PSC using the scoring system was excellent (area under the receiver operating characteristic curve, 0.986).

CONCLUSIONS

A reliable differentiation of IgG4-SC from PSC can be made using the scoring system presented here. We suggest the diagnosis of IgG4-SC at a cutoff of 7 points or higher and the indication of diagnostic steroid trial at 5 or 6 points. External validation of our scoring system is warranted.