Amelioration of Ductular Reaction by Stem Cell Derived Extracellular Vesicles in MDR2 Knockout Mice via Lethal-7 microRNA

Cholangiopathies are diseases that affect cholangiocytes, the cells lining the biliary tract. Liver stem cells (LSCs) are able to differentiate into all cells of the liver and possibly influence the surrounding liver tissue by secretion of signaling molecules. One way in which cells can interact is through secretion of extracellular vesicles (EVs), which are small membrane-bound vesicles that contain proteins, microRNAs (miRNAs), and cytokines. We evaluated the contents of liver stem cell-derived EVs (LSCEVs), compared their miRNA contents to those of EVs isolated from hepatocytes, and evaluated the downstream targets of these miRNAs. We finally evaluated the crosstalk among LSCs, cholangiocytes, and human hepatic stellate cells (HSCs). We showed that LSCEVs were able to reduce ductular reaction and biliary fibrosis in multidrug resistance protein 2 (MDR2)-/- mice. Additionally, we showed that cholangiocyte growth was reduced and HSCs were deactivated in LSCEV-treated mice. Evaluation of LSCEV contents compared with EVs derived from hepatocytes showed a large increase in the miRNA, lethal-7 (let-7). Further evaluation of let-7 in MDR2-/- mice and human primary sclerosing cholangitis samples showed reduced levels of let-7 compared with controls. In liver tissues and isolated cholangiocytes, downstream targets of let-7 (identified by ingenuity pathway analysis), Lin28a (Lin28 homolog A), Lin28b (Lin28 homolog B), IL-13 (interleukin 13), NR1H4 (nuclear receptor subfamily 1 group H member 4) and NF-κB (nuclear factor kappa B), are elevated in MDR2-/- mice, but treatment with LSCEVs reduced levels of these mediators of ductular reaction and biliary fibrosis through the inhibition of NF-κB and IL-13 signaling pathways. Evaluation of crosstalk using cholangiocyte supernatants from LSCEV-treated cells on cultured HSCs showed that HSCs had reduced levels of fibrosis and increased senescence. Conclusion: Our studies indicate that LSCEVs could be a possible treatment for cholangiopathies or could be used for target validation for future therapies.

Loss of Wnt Secretion by Macrophages Promotes Hepatobiliary Injury after Administration of 3,5-Diethoxycarbonyl-1, 4-Dihydrocollidine Diet

Exposure of mice to a diet containing 3,5-diethoxycarbonyl-1, 4-dihydrocollidine (DDC) induces porphyrin accumulation, cholestasis, immune response, and hepatobiliary damage mimicking hepatic porphyria and sclerosing cholangitis. Although β-catenin signaling promotes hepatocyte proliferation, and macrophages are a source of Wnts, the role of macrophage-derived Wnts in modulating hepatobiliary injury/repair remains unresolved. We investigated the effect of macrophage-specific deletion of Wntless, a cargo protein critical for cellular Wnt secretion, by feeding macrophage-Wntless-knockout (Mac-KO) and wild-type littermates a DDC diet for 14 days. DDC exposure induced Wnt11 up-regulation in macrophages. Mac-KO mice on DDC showed increased serum alkaline phosphatase, aspartate aminotransferase, direct bilirubin, and histologic evidence of more cell death, inflammation, and ductular reaction. There was impaired hepatocyte proliferation evidenced by Ki-67 immunostaining, which was associated with decreased hepatocyte β-catenin activation and cyclin-D1 in Mac-KO. Mac-KO also showed increased CD45, F4/80, and neutrophil infiltration after DDC diet, along with increased expression of several proinflammatory cytokines and chemokines. Gene expression analyses of bone marrow-derived macrophages from Mac-KO mice and F4/80+ macrophages isolated from DDC-fed Mac-KO livers showed proinflammatory M1 polarization. In conclusion, this study shows that a lack of macrophage Wnt secretion leads to more DDC-induced hepatic injury due to impaired hepatocyte proliferation and increased M1 macrophages, which promotes immune-mediated cell injury.

Patient-Derived Organoids from Human Bile: An In Vitro Method to Study Cholangiopathies

Cholangiopathies, including primary sclerosing cholangitis, are a group of heterogeneous diseases characterized by inflammation and fibrosis of the intrahepatic and extrahepatic bile duct epithelium. Studies, especially of primary sclerosing cholangitis, have been hampered by the difficulty in accessing the cholangiocyte, instability of in vitro culture systems, and reliance on (limited) samples from end-stage disease. Here we describe a novel method of culturing biliary cells from bile of primary sclerosing cholangitis patients undergoing endoscopic retrograde cholangiopancreatography for clinical indications. These 3D organoid cultures demonstrate a biliary phenotype, can be maintained in vitro, and biobanked for future analyses. Given the need for diagnostic and therapeutic endoscopic retrograde cholangiopancreatography throughout the disease in many primary sclerosing cholangitis patients, this method can provide longitudinal studies in individual patients, allowing for a correlation of gene expression with disease status. These organoids can react to inflammatory stimuli, resulting in the secretion of chemo/cytokines indicative of the reactive immune phenotype characteristic of primary sclerosing cholangitis. Therefore, bile-derived organoids provide a model to study the pathogenesis and pharmacotherapeutic treatment of cholangiopathies.

Ectopic relapse of IgG4-related disease presenting as IgG4-related sclerosing cholecystitis: A case report and review of literature

RATIONALE

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a chronic inflammatory disorder characterized by high levels of serum IgG4, swollen organs with fibrosis and abundant infiltration of IgG4-positive plasmacytes.

PATIENT CONCERNS

An 82-year-old male visited our hospital for an evaluation of a pancreatic enlargement and a bilateral submandibular adenopathy. Further investigation revealed elevation of serum IgG4 and bilateral lacrimal submandibular adenopathy. We diagnosed him with IgG4-related disease (IgG4-RD) and started administration of corticosteroid (CS) therapy. Both pancreatic enlargement and adenopathy rapidly improved; however, there was a new occurrence of diffuse wall thickening of the gallbladder during CS treatment.

DIAGNOSIS

Radiological examination revealed diffuse wall thickening of the gallbladder, and its inner layer was smooth and homogenous. These findings suggested an inflammatory change, but the possibility of malignancy could not be excluded.

INTERVENTIONS

The patient underwent laparoscopic cholecystectomy for a pathological diagnosis.

OUTCOMES

Histological examination revealed a transmural infiltration of IgG4 positive plasma cells and dense fibrosis. The patient was pathologically diagnosed with IgG4 related cholecystitis presenting as an ectopic relapse.

LESSONS

There are 2 major types of IgG4-related cholecystitis, a diffuse wall thickening type and a mass formation type. It is sometimes difficult to differentiate IgG4-related cholecystitis with gallbladder cancer.Corticosteroid (CS) is effective for induction of remission; however, we sometimes encounter disease relapse after reduction of CS dose. We should be mindful that some patients may relapse with new organ involvements even if the primary site and serum IgG4 level are well controlled.

MR elastography in primary sclerosing cholangitis: correlating liver stiffness with bile duct strictures and parenchymal changes

AIM

To determine correlation of liver stiffness measured by MR Elastography (MRE) with biliary abnormalities on MR Cholangiopancreatography (MRCP) and MRI parenchymal features in patients with primary sclerosing cholangitis (PSC).

METHODS

Fifty-five patients with PSC who underwent MRI of the liver with MRCP and MRE were retrospectively evaluated. Two board-certified abdominal radiologists in agreement reviewed the MRI, MRCP, and MRE images. The biliary tree was evaluated for stricture, dilatation, wall enhancement, and thickening at segmental duct, right main duct, left main duct, and common bile duct levels. Liver parenchyma features including signal intensity on T2W and DWI, and hyperenhancement in arterial, portal venous, and delayed phase were evaluated in nine Couinaud liver segments. Atrophy or hypertrophy of segments, cirrhotic morphology, varices, and splenomegaly were scored as present or absent. Regions of interest were placed in each of the nine segments on stiffness maps wherever available and liver stiffness (LS) was recorded. Mean segmental LS, right lobar (V-VIII), left lobar (I-III, and IVA, IVB), and global LS (average of all segments) were calculated. Spearman rank correlation analysis was performed for significant correlation. Features with significant correlation were then analyzed for significant differences in mean LS. Multiple regression analysis of MRI and MRCP features was performed for significant correlation with elevated LS.

RESULTS

A total of 439/495 segments were evaluated and 56 segments not included in MRE slices were excluded for correlation analysis. Mean segmental LS correlated with the presence of strictures (r = 0.18, p < 0.001), T2W hyperintensity (r = 0.38, p < 0.001), DWI hyperintensity (r = 0.30, p < 0.001), and hyperenhancement of segment in all three phases. Mean LS of atrophic and hypertrophic segments were significantly higher than normal segments (7.07 ± 3.6 and 6.67 ± 3.26 vs. 5.1 ± 3.6 kPa, p < 0.001). In multiple regression analysis, only the presence of segmental strictures (p < 0.001), T2W hyperintensity (p = 0.01), and segmental hypertrophy (p < 0.001) were significantly associated with elevated segmental LS. Only left ductal stricture correlated with left lobe LS (r = 0.41, p = 0.018). Global LS correlated significantly with CBD stricture (r = 0.31, p = 0.02), number of segmental strictures (r = 0.28, p = 0.04), splenomegaly (r = 0.56, p < 0.001), and varices (r = 0.58, p < 0.001).

CONCLUSION

In PSC, there is low but positive correlation between segmental LS and segmental duct strictures. Segments with increased LS show T2 hyperintensity, DWI hyperintensity, and post-contrast hyperenhancement. Global liver stiffness shows a moderate correlation with number of segmental strictures and significantly correlates with spleen stiffness, splenomegaly, and varices.

Risk of recurrence of primary sclerosing cholangitis after liver transplantation is associated with de novo inflammatory bowel disease

AIM

To evaluate risk factors for primary sclerosing cholangitis (PSC) recurrence (rPSC) after orthotopic liver transplantation (OLT) in patients with well-preserved colons.

METHODS

We retrospectively evaluated the medical records of all patients transplanted for PSC in our center between July 1994 and May 2015 and selected 47 with follow-up of at least 60 mo for further analysis based on strict inclusion and exclusion criteria. rPSC was confirmed by magnetic resonance or endoscopic retrograde cholangiopancreatography and liver biopsy. All patients were evaluated by protocolary pre-OLT colonoscopy with randomized mucosal biopsies. Colonoscopy was repeated annually after OLT. Both organ donors and recipients were human leukocyte antigen (HLA) typed by serological and/or DNA methods. All input data were thoroughly analyzed employing relevant statistical methods.

RESULTS

Altogether, 31 men and 16 women with a median (range) age of 36 (15-68) years at the time of OLT and a median follow-up of 122 (60-249) mo were included. rPSC was confirmed in 21/47 (44.7%) of patients, a median 63 (12-180) mo after transplantation. De novo colitis [rPSC in 11/12, P ≤ 0.05, hazard ratio (HR): 4.02, 95% confidence interval (CI): 1.58-10.98] and history of acute cellular rejection (rPSC in 14/25, P ≤ 0.05; HR: 2.66, 95%CI: 1.03-7.86) showed strong positive associations with rPSC. According to the univariate analysis, overlapping features of autoimmune hepatitis (rPSC in 5/5, P ≤ 0.05) and HLA-DRB1*07 in the donor (rPSC in 10/15, P ≤ 0.05) represent other potential risk factors for rPSC, while the HLA-DRB1*04 (rPSC in 0/6, P ≤ 0.05), HLA-DQB1*03 (rPSC in 1/11, P ≤ 0.05), and HLA-DQB1*07 (rPSC in 0/7, P ≤ 0.05) recipient alleles may have protective roles.

CONCLUSION

De novo colitis and acute cellular rejection are clinical conditions significantly predisposed towards recurrence of PSC after liver transplantation.

Macrophages contribute to the pathogenesis of sclerosing cholangitis in mice

BACKGROUND & AIMS

Macrophages contribute to liver disease, but their role in cholestatic liver injury, including primary sclerosing cholangitis (PSC), is unclear. We tested the hypothesis that macrophages contribute to the pathogenesis of, and are therapeutic targets for, PSC.

METHODS

Immune cell profile, hepatic macrophage number, localization and polarization, fibrosis, and serum markers of liver injury and cholestasis were measured in an acute (intrabiliary injection of the inhibitor of apoptosis antagonist BV6) and chronic (Mdr2^-/- mice) mouse model of sclerosing cholangitis (SC). Selected observations were confirmed in liver specimens from patients with PSC. Because of the known role of the CCR2/CCL2 axis in monocyte/macrophage chemotaxis, therapeutic effects of the CCR2/5 antagonist cenicriviroc (CVC), or genetic deletion of CCR2 (Ccr2^-/- mice) were determined in BV6-injected mice.

RESULTS

We found increased peribiliary pro-inflammatory (M1-like) and alternatively-activated (M2-like) monocyte-derived macrophages in PSC compared to normal livers. In both SC models, genetic profiling of liver immune cells identified a predominance of monocytes/macrophages; immunohistochemistry confirmed peribiliary monocyte-derived macrophage recruitment (M1>M2-polarized), which paralleled injury onset and was reversed upon resolution in acute SC mice. PSC, senescent and BV6-treated human cholangiocytes released monocyte chemoattractants (CCL2, IL-8) and macrophage-activating factors in vitro. Pharmacological inhibition of monocyte recruitment by CVC treatment or CCR2 genetic deletion attenuated macrophage accumulation, liver injury and fibrosis in acute SC.

CONCLUSIONS

Peribiliary recruited macrophages are a feature of both PSC and acute and chronic murine SC models. Pharmacologic and genetic inhibition of peribiliary macrophage recruitment decreases liver injury and fibrosis in mouse SC. These observations suggest monocyte-derived macrophages contribute to the development of SC in mice and in PSC pathogenesis, and support their potential as a therapeutic target.

LAY SUMMARY

Primary sclerosing cholangitis (PSC) is an inflammatory liver disease which often progresses to liver failure. The cause of the disease is unclear and therapeutic options are limited. Therefore, we explored the role of white blood cells termed macrophages in PSC given their frequent contribution to other human inflammatory diseases. Our results implicate macrophages in PSC and PSC-like diseases in mice. More importantly, we found that pharmacologic inhibition of macrophage recruitment to the liver reduces PSC-like liver injury in the mouse. These exciting observations highlight potential new strategies to treat PSC.

Mucosal Autoimmunity to Cell-Bound GP2 Isoforms Is a Sensitive Marker in PSC and Associated With the Clinical Phenotype

Introduction: Zymogen granule glycoprotein 2 (GP2) was demonstrated as first autoimmune mucosal target in primary sclerosing cholangitis (PSC) associated with disease severity. Autoantibodies to four GP2 isoforms (aGP21-4) were found in patients with inflammatory bowel diseases but reactivity against specific GP2 epitopes has not been investigated in PSC yet. Hence, the prevalence of aGP21-4 and their association with the PSC phenotype for risk prediction were examined. Methods: GP2 isoforms were stably expressed as glycosylphosphatidyl - inositol-anchored molecules in the membrane of HEp-2 cells and used as autoantigenic targets in indirect immunofluorescence assay (IFA). aGP21-4 IgA and IgG were detected by IFA in 212 PSC patients of four European university hospitals and 145 controls comprising 95 patients with cystic fibrosis and 50 healthy subjects. Results: Combined aGP21 and aGP24 IgA testing with a sensitivity of 66.0% and a specificity of 97.9% resulted in the best diagnostic performance (Youden index: 0.64) regarding all aGP2 and combinations thereof. aGP24 IgA positivity is significantly associated with the presence of cirrhosis in PSC (p = 0.0056). Logistic regression revealed the occurrence of aGP21 IgA (odds ratio [OR] 1.38, 95% confidence interval [CI]: 1.03-1.86) and aGP24 IgA (OR 1.52, 95%CI: 1.07-2.15) along with male gender (OR 0.51, 95%CI: 0.27-0.97) and older age (OR 1.03 95%CI: 1.01-1.05) as significant risks for the concomitant presence of cirrhosis in PSC. Conclusions: Combined aGP21 and aGP24 IgA analysis is preferred to single aGP2 isoform analysis for sensitive PSC autoantibody testing. Positivity for aGP21 and aGP24 IgA is associated with cirrhosis in PSC and could be used for risk stratification.

Role of colectomy in preventing recurrent primary sclerosing cholangitis in liver transplant recipients

AIM

To study the published evidence on the impact of colectomy in preventing recurrent primary sclerosing cholangitis (rPSC).

METHODS

An unrestricted systematic literature search in PubMed, EMBASE, Medline OvidSP, ISI Web of Science, Lista (EBSCO) and the Cochrane library was performed on clinical studies investigating colectomy in liver transplantation (LT) recipients with and without rPSC in the liver allograft. Study quality was evaluated according to a modification of the methodological index for non-randomized studies (MINORS) criteria. Primary endpoints were the impact of presence, timing and type of colectomy on rPSC. Overall presence of inflammatory bowel disease (IBD), time of IBD diagnosis, posttransplant IBD and immunosuppressive regimen were investigated as secondary outcome.

RESULTS

The literature search yielded a total of 180 publications. No randomized controlled trial was identified. Six retrospective studies met the inclusion criteria of which 5 studies were graded as high quality articles. Reporting of IBD was heterogenous but in four publications, either inflammatory bowel disease, ulcerative colitis or in particular active colitis post-LT significantly increased the risk of rPSC. The presence of an intact (i.e., retained) colon at LT was identified as risk factor for rPSC in two of the high quality studies while four studies found no effect. Type of colectomy was not associated with rPSC but this endpoint was underreported (only in 33% of included studies). Neither tacrolimus nor cyclosporine A yielded a significant benefit in disease recurrence of primary sclerosing cholangitis (PSC).

CONCLUSION

The data favours a protective role of pre-/peri-LT colectomy in rPSC but the current evidence is not strong enough to recommend routine colectomy for rPSC prevention.

Primary sclerosing cholangitis

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

Alterations in Intestinal Microbiota Lead to Production of Interleukin 17 by Intrahepatic γδ T-Cell Receptor-Positive Cells and Pathogenesis of Cholestatic Liver Disease

BACKGROUND & AIMS

Variants at the ABCB4 or MDR2 locus, which encodes a biliary transport protein, are associated with a spectrum of cholestatic liver diseases. Exacerbation of liver disease has been linked to increased hepatic levels of interleukin (IL) 17, yet the mechanisms of this increase are not understood. We studied mice with disruption of Mdr2 to determine how defects in liver and alteration in the microbiota contribute to production of IL17 by intrahepatic γδ T cells.

METHODS

We performed studies with Mdr2-/- and littermate FVB/NJ (control) mice. IL17 was measured in serum samples by an enzyme-linked immunosorbent assay. Mice were injected with neutralizing antibodies against the γδ T-cell receptor (TCR; anti-γδ TCR) or mouse IL17A (anti-IL17A). Livers were collected and bacteria were identified in homogenates by culture procedures; TCRγδ+ cells were isolated by flow cytometry. Fecal samples were collected from mice and analyzed by 16S ribosomal DNA sequencing. Cells were stimulated with antibodies or bacteria, and cytokine production was measured. We obtained tissues from 10 patients undergoing liver transplantation for primary sclerosing cholangitis or chronic hepatitis C virus infection. Tissues were analyzed for cytokine production by γδ TCR+ cells.

RESULTS

Mdr2-/- mice had collagen deposition around hepatic bile ducts and periportal-bridging fibrosis with influx of inflammatory cells and increased serum levels of IL17 compared with control mice. Administration of anti-IL17A reduced hepatic fibrosis. Livers from Mdr2-/- mice had increased numbers of IL17A+ γδTCR+ cells-particularly of IL17A+ Vγ6Jγ1 γδ TCR+ cells. Fecal samples from Mdr2-/- mice were enriched in Lactobacillus, and liver tissues were enriched in Lactobacillus gasseri compared with control mice. Mdr2-/- mice also had increased intestinal permeability. The γδ TCR+ cells isolated from Mdr2-/- livers produced IL17 in response to heat-killed L gasseri. Intraperitoneal injection of control mice with L gasseri led to increased serum levels of IL17 and liver infiltration by inflammatory cells; injection of these mice with anti-γδ TCR reduced serum level of IL17. Intravenous injections of Mdr2-/- mice with anti-γδ TCR reduced fibrosis; liver levels of IL17, and inflammatory cells; and serum levels of IL17. γδTCR+ cells isolated from livers of patients with primary sclerosing cholangitis, but not hepatitis C virus infection, produced IL17.

CONCLUSIONS

In Mdr2-/- mice, we found development of liver fibrosis and inflammation to require hepatic activation of γδ TCR+ cells and production of IL17 mediated by exposure to L gasseri. This pathway appears to contribute to development of cholestatic liver disease in patients.

Biliary Tract Cancer: Implicated Immune-Mediated Pathways and Their Associated Potential Targets

There is a well-established link between biliary tract cancers (BTC) and chronic inflammatory conditions such as primary sclerosing cholangitis, chronic cholecystitis, chronic cholelithiasis, liver fluke-associated infestations, and chronic viral hepatic infections. These associated risk factors highlight the potential for development of immune-modulatory agents in this poor-prognostic disease group with limited treatment options. Clinical trials have evaluated the role of immune cells, inflammatory biomarkers, vaccines, cytokines, adoptive cell therapy, and immune checkpoint inhibitors in patients with BTC. Although these have demonstrated the importance of the immune environment in BTC, currently none of the immune-based therapies have been approved for use in this disease group. The role of immunomodulatory agents is a developing field and has yet to find its way 'from bench to bedside' in BTC.

Paracrine cellular senescence exacerbates biliary injury and impairs regeneration

Cellular senescence is a mechanism that provides an irreversible barrier to cell cycle progression to prevent undesired proliferation. However, under pathological circumstances, senescence can adversely affect organ function, viability and regeneration. We have developed a mouse model of biliary senescence, based on the conditional deletion of Mdm2 in bile ducts under the control of the Krt19 promoter, that exhibits features of biliary disease. Here we report that senescent cholangiocytes induce profound alterations in the cellular and signalling microenvironment, with recruitment of myofibroblasts and macrophages causing collagen deposition, TGFβ production and induction of senescence in surrounding cholangiocytes and hepatocytes. Finally, we study how inhibition of TGFβ-signalling disrupts the transmission of senescence and restores liver function. We identify cellular senescence as a detrimental mechanism in the development of biliary injury. Our results identify TGFβ as a potential therapeutic target to limit senescence-dependent aggravation in human cholangiopathies.

Association of gadolinium-enhanced magnetic resonance imaging with hepatic fibrosis and inflammation in primary sclerosing cholangitis

Objective

To evaluate magnetic resonance imaging (MRI) parameters T2 signal, contrast enhancement (CE), and relative liver enhancement (RLE) of extracellular gadolinium-based contrast agent (GBCA)-enhanced MRI as a marker for hepatic fibrosis and inflammation in patients with primary sclerosing cholangitis (PSC).

Methods

3.0-Tesla MRI scans and liver biopsies of 40 patients (41.2 ± 17.1 years) were retrospectively reviewed. Biopsies were obtained within a mean time of 54 ± 55 days to MRI scans and specimens were categorized according to Ishak modified hepatic activity index (mHAI) and Scheuer staging of fibrosis. T2 signal (N = 40), CE alterations (N = 29), and RLE (N = 29) were assessed by two raters. Mixed-effects regression models were applied to estimate the association between histopathology and MRI parameters.

Results

No significant association was observed between T2 signal or CE alterations with stages of fibrosis or mHAI grading. Regression models revealed significant positive associations of portal venous phase RLE with mHAI grade ≥ 7 points [β = 25.5; 95% CI (2.53; 48.62); p = 0.04] and delayed phase RLE with stages of fibrosis [stage 2: β = 35.13; 95% CI (11.35; 58.87); p = 0.007; stage 3/4: β = 69.24; 95% CI (45.77; 92.75); p < 0.001]. The optimal cut-off value of 66.6% delayed phase RLE distinguished fibrosis stages 0–2 from 3–4 with a sensitivity of 0.833 and specificity of 0.972. Inter-rater reliability (IRR) for quantification of RLE was ‘excellent’ (r = 0.90–0.98). IRR was ‘substantial’ for detection of T2 signal in the right liver lobe (RL) (Kappa = 0.77) and ‘almost perfect’ for T2 signal of the left liver lobe (LL) and CE of both lobes (Kappa = 0.87–1.0).

Conclusion

The simple and reproducible method of RLE quantification on standard extracellular GBCA-enhanced MRI may provide a correlate measure of advanced stages of hepatic fibrosis and potentially also inflammation in PSC patients, if validated in larger cohorts.

Neutralization of IL-15 abrogates experimental immune-mediated cholangitis in diet-induced obese mice

Obesity is a global epidemic affecting chronic inflammatory diseases. Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease that can occur as an extraintestinal manifestation of inflammatory bowel disease (IBD). Previously we reported that patients with PSC who are obese have a higher risk of advanced liver disease. Currently it is unknown how obesity accelerates or worsens PSC. We evaluated the progression of PSC in an antigen-driven cholangitis mouse model of diet-induced obesity. Obesity was induced in our murine model of immune-mediated cholangitis (OVAbil). OVAbil mice were fed standard chow or high-fat/sucrose diet for twelve weeks followed by induction of biliary inflammation by OVA-specific T cell transfer. Histopathological damage in portal tracts was scored and serum collected. Neutralizing antibodies against IL-15 were administered daily until study termination. Obese mice developed exacerbated liver inflammation and damage. Immune cell phenotyping in liver revealed greater numbers of neutrophils and CD8+ T cells in obese mice. Higher levels of cytokines and chemokines were found in obese mice with cholangitis. Immuno-neutralizing antibodies against IL-15 greatly attenuated cholangitis in obese mice. Obesity exacerbated experimental PSC in part by overproduction of IL-15. Timely targeting of IL-15 may slow the progression of PSC.

Beneficial long term effect of a phosphodiesterase-5-inhibitor in cirrhotic portal hypertension: A case report with 8 years follow-up

Non-selective beta-blockers are the mainstay of medical therapy for portal hypertension in liver cirrhosis. Inhibitors of phosphodiesterase-5 (PDE-5-inhibitors) reduce portal pressure in the acute setting by > 10% which may suggest a long-term beneficial effect. Currently, there is no available data on long-term treatment of portal hypertension with PDE-5-inhibitors. This case of a patient with liver cirrhosis secondary to autoimmune liver disease with episodes of bleeding from esophageal varices is the first documented case in which a treatment with a PDE-5-inhibitor for eight years was monitored. In the acute setting, the PDE-5-inhibitor Vardenafil lowered portal pressure by 13%. The portal blood flow increased by 28% based on Doppler sonography and by 16% using MRI technique. As maintenance medication the PDE-5-inhibitor Tadalafil was used for eight consecutive years with comparable effects on portal pressure and portal blood flow. There were no recurrence of bleeding and no formation of new varices. Influencing the NO-pathway by the use of PDE-5 inhibitors may have long-term beneficial effects in compensated cirrhosis.

Patients with primary biliary cholangitis and fatigue present with depressive symptoms and selected cognitive deficits, but with normal attention performance and brain structure

Background

In primary biliary cholangitis (PBC) fatigue is a major clinical challenge of unknown etiology. By demonstrating that fatigue in PBC is associated with an impaired cognitive performance, previous studies have pointed out the possibility of brain abnormalities underlying fatigue in PBC. Whether structural brain changes are present in PBC patients with fatigue, however, is unclear. To evaluate the role of structural brain abnormalities in PBC patients severely affected from fatigue we, therefore, performed a case-control cerebral magnetic resonance imaging (cMRI) study and correlated changes of white and grey brain matter with the cognitive and attention performance.

Methods

20 female patients with PBC and 20 female age-matched controls were examined in this study. The assessment of fatigue, psychological symptoms, cognitive and attention performance included clinical questionnaires, established cognition tests and a computerized test battery of attention performance. T1-weighted cMRI and diffusion tensor imaging (DTI) scans were acquired with a 3 Tesla scanner. Structural brain alterations were investigated with voxel-based morphometry (VBM) and DTI analyses. Results were correlated to the cognitive and attention performance.

Results

Compared to healthy controls, PBC patients had significantly higher levels of fatigue and associated psychological symptoms. Except for an impairment of verbal fluency, no cognitive or attention deficits were found in the PBC cohort. The VBM and DTI analyses revealed neither major structural brain abnormalities in the PBC cohort nor correlations with the cognitive and attention performance.

Conclusions

Despite the high burden of fatigue and selected cognitive deficits, the attention performance of PBC patients appears to be comparable to healthy people. As structural brain alterations do not seem to be present in PBC patients with fatigue, fatigue in PBC must be regarded as purely functional. Future studies should evaluate, whether functional brain changes underlie fatigue in PBC.

Dysregulation of antioxidant responses in patients diagnosed with concomitant Primary Sclerosing Cholangitis/Inflammatory Bowel Disease

OBJECTIVE

Primary Sclerosing Cholangitis (PSC) is a chronic cholestatic liver disease that is characterized by severe peri-biliary tract inflammation and fibrosis, elevated oxidative stress and hepatocellular injury. A hallmark of PSC patients is the concurrent diagnosis of Inflammatory Bowel Disease occurring in approximately 70%-80% of PSC patients (PSC/IBD). The objective of this study was to determine the impact of end stage PSC/IBD on cellular antioxidant responses and the formation of protein carbonylation.

METHODS

Using hepatic tissue and whole cell extracts isolated from age-matched healthy humans and patients diagnosed with end stage PSC/IBD, overall inflammation, oxidative stress, and protein carbonylation were assessed by Western blotting, and immunohistochemistry.

RESULTS

Increased immunohistochemical staining for CD3+ (lymphocyte), CD68 (Kupffer cell) and myeloperoxidase (neutrophil) colocalized with the extensive Picrosirius red stained fibrosis confirming the inflammatory aspect of PSC. Importantly, the increased inflammation also colocalized with elevated periportal post-translational modification by the reactive aldehydes 4-HNE, MDA and acrolein. 4-HNE, MDA and acrolein IHC all displayed a significant component in hepatocytes adjacent to fibrotic regions. Furthermore, acrolein was also elevated within the nuclei of periportal inflammatory cells whereas MDA staining was increased in hepatocytes across the lobule. Prussian Blue staining, when compared to the positive controls (ALD, NASH), did not display any evidence of iron accumulation in PSC/IBD livers. Western analysis of PSC/IBD anti-oxidant responses revealed elevated expression of SOD2, GSTπ as well as upregulation of Akt Ser473 phosphorylation. In contrast, expression of GSTμ, GSTA4, catalase, Gpx1 and Hsp70 were suppressed. These data were further supported by a significant decrease in measured GST activity. Dysregulation of anti-oxidant responses in the periportal region of the liver was supported by elevated SOD2 and GSTπ IHC signals in periportal hepatocytes and cholangiocytes. Expression of the Nrf2-regulated proteins HO-1, NAD(P)H quinone reductase (NQO1) and Gpx1 was primarily localized to macrophages. In contrast, catalase staining decreased within periportal hepatocytes and was not evident within cholangiocytes.

CONCLUSIONS

Results herein provide additional evidence that cholestasis induces significant increases in periportal oxidative stress and suggest that there are significant differences in the cellular and subcellular generation of reactive aldehydes formed during cholestatic liver injury. Furthermore, these data suggest that anti-oxidant responses are dysregulated during end-stage PSC/IBD supporting pathological data. This work was funded by NIH5R37AA009300-22 D.R.P.

Development and characterization of cholangioids from normal and diseased human cholangiocytes as an in vitro model to study primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is an incurable, fibroinflammatory biliary disease for which there is no effective pharmacotherapy. We recently reported cholangiocyte senescence as an important phenotype in PSC while others showed that portal macrophages accumulate in PSC. Unfortunately, our ability to explore cholangiocyte senescence and macrophage accumulation has been hampered by limited in vitro models. Thus, our aim was to develop and characterize a three-dimensional (3D) model of normal and diseased bile ducts (cholangioids) starting with normal human cholangiocytes (NHC), senescent NHC (NHC-sen), and cholangiocytes from PSC patients. In 3D culture, NHCs formed spheroids of ~5000 cells with a central lumen of ~150 μm. By confocal microscopy and western blot, cholangioids retained expression of cholangiocyte proteins (cytokeratin 7/19) and markers of epithelial polarity (secretin receptor and GM130). Cholangioids are functionally active, and upon secretin stimulation, luminal size increased by ~80%. Cholangioids exposed to hydrogen peroxide exhibited cellular senescence and the senescence-associated secretory phenotype (SASP; increased IL-6, p21, SA-β-Gal, yH2A.x and p16 expression). Furthermore, cholangioids derived from NHC-sen or PSC patients were smaller and had slower growth than the controls. When co-cultured with THP-1 macrophages, the number of macrophages associated with NHC-sen or PSC cholangioids was five- to seven-fold greater compared to co-culture with non-senescent NHC. We observed that NHC-sen and PSC cholangioids release greater number of extracellular vesicles (EVs) compared to controls. Moreover, conditioned media from NHC-sen cholangioids resulted in an ~2-fold increase in macrophage migration. In summary, we developed a method to generate normal and diseased cholangioids, characterized them morphologically and functionally, showed that they can be induced to senescence and SASP, and demonstrated both EV release and macrophage attraction. This novel model mimics several features of PSC, and thus will be useful for studying the pathogenesis of PSC and potentially identifying new therapeutic targets.

Suspicious brush cytology is an indication for liver transplantation evaluation in primary sclerosing cholangitis

AIM

To investigate markers for high-grade dysplasia for the optimal timing of liver transplantation in patients with primary sclerosing cholangitis (PSC).

METHODS

Earlier data support a dysplasia-carcinoma sequence, even low- to high-grade dysplasia, in PSC-associated cholangiocarcinoma (CCA). Surveillance using endoscopic retrograde cholangiography (ERC) and brush cytology aims to detect cases of biliary dysplasia, and liver transplantation is an option in cases with suspicion of malignancy in brushing. This study investigated markers to identify patients with high-grade biliary dysplasia for optimal timing in early liver transplantation. Patients undergoing surveillance using ERC and brush cytology during 2008-2014 and who were diagnosed with biliary dysplasia in explanted liver or CCA until February 2016 were included in the study. Demographic data, cholangiography findings, laboratory values, cytological morphology and DNA ploidy were analysed.

RESULTS

Thirty PSC patients had biliary neoplasia in the explanted liver during the study period. Sixteen of these patients had low-grade dysplasia, 10 patients had high-grade dysplasia, and 4 patients had CCA. Fifteen PSC patients diagnosed with CCA were not transplanted. Patients with low-grade dysplasia were younger. Alkaline phosphatase or carcinoembryonic antigen values did not differ between groups during surveillance, but carbohydrate antigen 19-9 was higher in CCA patients. No difference in PSC duration, ERC scores, suspicious cytology, or ploidy analysis was found between groups. No difference was observed between fibrosis stage in explanted livers. Low- and high-grade dysplasia could not be differentiated before liver transplantation based on liver enzymes, tumour markers, ERC scores, brush cytology or DNA ploidy.

CONCLUSION

Repeated suspicion of neoplasia in brush cytology should be an indication for evaluations of liver transplantation prior to the development of CCA.

Drug-induced bile duct injury

Drug-induced liver injury includes a spectrum of pathologies, some related to the mode of injury, some to the cell type primarily damaged. Among these, drug-induced bile duct injury is characterized by the destruction of the biliary epithelium following exposure to a drug. Most of the drugs associated with bile duct injury cause immune-mediated lesions to the epithelium of interlobular ducts. These share common histopathological features with primary biliary cholangitis, such as inflammation and necrosis at the expense of cholangiocytes and, if the insult persists, bile duct loss and biliary cirrhosis. Some drugs selectively target larger ducts. Such injury is often dose-dependent and thought to be the result of intrinsic drug toxicity. The histological changes resemble those seen in primary sclerosing cholangitis. This overview focuses on the clinical and pathological features of bile duct injury associated with drug treatment and on the immunological and biochemical effects that drugs exert on the biliary epithelium. 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.

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).

Case report: A female case of isolated IgG4-related sclerosing cholangitis mimicking cholangiocarcinoma

RATIONALE

IgG4-related disease is a newly recognized fibroinflammatory disorder, characterized by tumefactive lesions, storiform fibrosis and IgG4-positive plasma cells infiltration. IgG4-related sclerosing cholangitis (IgG4-SC) is the most common extrapancreatic manifestation of IgG4-related disease, but it is frequently associated with autoimmune pancreatitis(AIP). Only few case was reported to be diagnosed with IgG4-SC in the absence of AIP, with a striking male preponderance. Here we report a female case of isolated IgG4 related sclerosing cholangitis mimicking cholangiocarcinoma.

PATIENT CONCERNS

A 58-year-old woman complaint of one-month history of jaundice and right upper quadrant discomfort, and the biliary reconstruction showed full-length wall thickening and segmental stenosis.

DIAGNOSES

Cholangiocarcinoma was then diagnosed.

INTERVENTIONS

Choledochoplasty was performed, followed by Roux-en-Y anastomosis.

OUTCOMES

However, pathological examination revealed IgG4-related sclerosing cholangitis (IgG4-SC) and the retrospective measurement of serum IgG4 was 346 mg/dL post-operatively. The patient was followed for another nine monthswithout recurrence.

LESSONS

The differential diagnosis between cholangiocarcinoma and IgG4-SC is challenging due to significant overlap of clinical manifestations, lab tests and imaging characteristics. However, as an afterthought of this case, typical cholangiocarcinoma rarely presents full-length wall thickening. What the case taught us was pre-operative IgG4 measurement for patients with long bile duct involvement was highly recommended in order to rule out IgG4-SC.