Progression Of Primary Sclerosing Cholangitis Research Articles

Downregulation of hepatic stem cell factor by Vivo-Morpholino treatment inhibits mast cell migration and decreases biliary damage/senescence and liver fibrosis in Mdr2−/− mice

Primary sclerosing cholangitis (PSC) is characterized by increased mast cell (MC) infiltration, biliary damage and hepatic fibrosis. Cholangiocytes secrete stem cell factor (SCF), which is a chemoattractant for c-kit expressed on MCs. We aimed to determine if blocking SCF inhibits MC migration, biliary damage and hepatic fibrosis. MethodsFVB/NJ and Mdr2−/− mice were treated with Mismatch or SCF Vivo-Morpholinos. We measured (i) SCF expression and secretion; (ii) hepatic damage; (iii) MC migration/activation and histamine signaling; (iv) ductular reaction and biliary senescence; and (v) hepatic fibrosis. In human PSC patients, SCF expression and secretion were measured. In vitro, cholangiocytes were evaluated for SCF expression and secretion. Biliary proliferation/senescence was measured in cholangiocytes pretreated with 0.1% BSA or the SCF inhibitor, ISK03. Cultured HSCs were stimulated with cholangiocyte supernatant and activation measured. MC migration was determined with cholangiocytes pretreated with BSA or ISK03 loaded into the bottom of Boyden chambers and MCs into top chamber. ResultsBiliary SCF expression and SCF serum levels increase in human PSC. Cholangiocytes, but not hepatocytes, from SCF Mismatch Mdr2−/− mice have increased SCF expression and secretion. Inhibition of SCF in Mdr2−/− mice reduced (i) hepatic damage; (ii) MC migration; (iii) histamine and SCF serum levels; and (iv) ductular reaction/biliary senescence/hepatic fibrosis. In vitro, cholangiocytes express and secrete SCF. Blocking biliary SCF decreased MC migration, biliary proliferation/senescence, and HSC activation. ConclusionCholangiocytes secrete increased levels of SCF inducing MC migration, contributing to biliary damage/hepatic fibrosis. Targeting MC infiltration may be an option to ameliorate PSC progression.

Rate of Spleen Length Progression Is a Marker of Outcome in Patients With Primary Sclerosing Cholangitis

Patients with primary sclerosing cholangitis (PSC) tend to develop progressive liver fibrosis and end-stage liver disease within 10-20 years.1 The International PSC Study Group declared research on surrogate endpoints a high-priority task not least for ongoing clinical trials on novel treatment options.2 The spleen in patients with PSC often enlarges even before cirrhosis develops. Transient elastography (TE) has been investigated as a dynamic and prognostic marker in PSC.3,4 However, TE is not generally accessible, measures only a small part of the right liver, and is prone to errors in obese patients, and liver stiffness is related to postprandial status, liver inflammation, and biliary obstruction.5 We have recently demonstrated that single-point spleen length (SL) measurement has a prognostic performance similar to liver stiffness measured by TE.3,4,6 SL measurement is a fast, simple, and ubiquitously available method. However, absolute spleen size depends on body height and sex,7 and single-point measurement of SL cannot be used to assess the effects of therapeutic interventions. To overcome these issues, we assessed the intra-individual development of spleen size over time (delta spleen length: dSL= SL2 - SL1) to evaluate its role as a novel surrogate marker, which accounts for the dynamic nature of PSC progression.

The role of imaging in determining prognosis for primary sclerosing cholangitis: A systematic review

Background/Aims:Primary sclerosing cholangitis (PSC) is a chronic, progressive, fibrotic bile duct disease. Resultant complications include infection, progressive liver disease and cancer. While diagnosis relies extensively on imaging, the role of imaging in determining prognosis is unclear. The aim of this study was to systematically review existing imaging indices and features that predict PSC progression.Materials and Methods:We performed a systematic review of imaging features that predict PSC progression. PubMed, EMBASE, MEDLINE, Clinicaltrials.gov and the Cochrane Library were searched from inception to November 2018 for relevant studies. Pertinent data were extracted and assessed. Study quality was evaluated using the Newcastle-Ottawa scale (NOS).Results:The search returned 2504 results. Nine studies were included in the final review. Four studies evaluated the prognostic value of imaging features and five evaluated prognostic algorithms. The mean NOS score was 4.44 ± 0.98 on a scale of 0 to 9. Imaging features that were of prognostic value were degree of intrahepatic duct narrowing, the presence of a dominant biliary duct stricture and percentage of narrowed intraheptic ducts. Three imaging indices (one endoscopic retrograde cholangiopancreatography (ERCP)-based and two magnetic resonance-based) had been derived. The ERCP index was validated in a second cohort and subsequently updated to improve its predictive ability. The magnetic resonance cholangiopancreatography (MRCP) index was validated in two studies and was found to be predicative of transplant-free survival. A modified MRCP index (MRCP-risk score) was evaluated in a prospective multicenter study and was found to be predicative of PSC-related disease progression.Conclusion:In conclusion, ERCP and MRCP-based indices have short-term prognostic value in PSC. However, more studies are required to validate their predictability of disease-related progression, such as liver decompensation, ascending cholangitis, cholangiocarcinoma and liver transplantation.

Two simple magnetic resonance scores are able to predict survival in patients with Primary Sclerosing Cholangitis

Background: Primary sclerosing cholangitis (PSC) has a variable course. To predict clinical outcome in a single patient is a major need. Magnetic resonance (MR) imaging with 3D-MR cholangiography is the modality of choice for diagnosis. Two MR scores are able to predict radiologic progression of PSC.

An Imaging Biomarker for Assessing Hepatic Function in Patients With Primary Sclerosing Cholangitis

We aimed to evaluate the potential of hepatobiliary phase magnetic resonance imaging (MRI) as parameter for assessment of hepatocellular function in patients with primary sclerosing cholangitis (PSC). We collected data from 111 patients (83 male, 28 female; median, 44 years old), from March 2012 through March 2016, with a confirmed diagnosis of PSC who underwent MRI evaluation before and after injection (hepatobiliary phase) of a hepatocyte-specific contrast agent (gadoxetate disodium). Signal intensities were measured in each liver segment. Mean relative enhancement values were calculated and correlated with findings from liver functions tests, prognostic scoring systems (model for end-stage liver disease [MELD] score; Mayo risk score; Amsterdam-Oxford-PSC score), abnormalities detected by endoscopic retrograde cholangiopancreatography (using the Amsterdam cholangiographic classification system), andclinical endpoints (liver transplantation, cholangiocarcinoma, liver-related death). Ourprimary aim was to associate relative enhancement values with liver function and patient outcomes. Most patients had moderate-stage disease and had intermediate levels of risk (median MELD score, 8 and median Mayo score, 0.27). Clinical endpoints were reached by 21 patients (6developed cholangiocarcinoma, 8 underwent liver transplantation, and 7 patients died). The highest levels of correlations were observed for relative enhancement 20 min after contrast injection and level of alkaline phosphatase (r= -0.636), bilirubin (r= -0.646), albumin (r= 0.538); as well as international normalized ratio (r= 0.456); MELD score (r=-0.587); Mayo risk score (r= -0.535), and Amsterdam-Oxford model score (r= -0.595) (P < .0001). Relative enhancement correlated with all clinical endpoints (all P < .05). A cutoff relative enhancement value of 0.65 identified patients with a clinical endpoint with 73.9% sensitivity 92.9% specificity (area under the receiver operating characteristic curve, 0.901; likelihood ratio, 10.34; P < .0001). In an analysis of 111 patients with PSC, we found MRI-measured relative enhancement, using a hepatocyte-specific contrast agent, to identify patients with clinical outcomes with 73.9% sensitivity 92.9% specificity. Long-term, multicenter studies are needed to further evaluate this marker of PSC progression.

Effects of vedolizumab, adalimumab and infliximab on biliary inflammation in individuals with primary sclerosing cholangitis and inflammatory bowel disease.

Primary sclerosing cholangitis (PSC) is a chronic, progressive cholestatic biliary disease associated with inflammatory bowel disease (IBD) with no known cure. To evaluate the effect of biological therapies on PSC progression in IBD patients. We performed a retrospective cohort study of 88 cases (75 unique patients with 12 patients treated >1 biologics) of IBD (48 ulcerative colitis, 24 Crohn's disease and 3 indeterminate colitis) with concomitant PSC who received biological therapy (42 infliximab, 19 adalimumab, 27 vedolizumab) between June 2002 and October 2017. Hepatic biochemistries were compared using the paired t-test (patients served as their own controls) ≤3months before and 6-8 and 12-14months after biological initiation. Radiographic information of biliary stenosis and liver fibrosis were obtained via abdominal ultrasound, abdominal magnetic resonance imaging and magnetic resonance elastography. Use of adalimumab was associated with a significant decrease in alkaline phosphatase (ALP) after 6-8 months (P=0.03; mean change -70U/L, standard deviation [SD] 88U/L) compared to vedolizumab (mean change +50U/L, SD 142 U/L) or infliximab (mean change +37 U/L, SD 183U/L) but the change was not significant after 12-14 months (P=0.24). No significant decreases were observed with AST, ALT, total or direct bilirubin, elastography score or radiographic imaging of biliary tree dilation/strictures with any biological therapy after 6-8 or 12-14 months. Current evidence suggests that biological therapies used for the treatment of IBD are not effective treatments for PSC. Further study is needed to elucidate any potential beneficial effect of adalimumab on PSC.

Characteristics and Outcomes Reported by Patients With Primary Sclerosing Cholangitis Through an Online Registry

Primary sclerosing cholangitis (PSC) is a fibrostenosing disease of the bile ducts associated with inflammatory bowel disease (IBD), for which the only treatment is liver transplantation. PSC progression has been defined in cohorts from referral centers or single-nation population databases. However, observations made from these cohorts have limited applicability owing to referral bias and demographic confounders. We analyzed data from the worldwide PSC Partners Patient Registry, an international online database established in 2014 to obtain information from individuals with PSC or their caretakers and compare symptoms, disease progression, and treatments of PSC in the United States and other countries. We analyzed demographic and clinical characteristics, symptoms, and clinical outcomes of patients with PSC using the PSC Partners Patient Registry. Participants completed an online standardized questionnaire and electronic case report, providing information on age, age at symptom onset, age at PSC diagnosis, methods of diagnosis, concurrent diagnoses, family history, and medication use. Of 873 registrants, 811 (92.9%) had completed questionnaires and 528 (65.1%) had their PSC diagnosis confirmed; we found no significant demographic or clinical differences between patients with vs without a confirmed diagnosis. In contrast to other studies, we found a higher proportion of individuals with PSC to be female (52.5%). However, the mean age at PSC diagnosis (32.4 ± 14.7 y) and the proportion of individuals with PSC and IBD (67.1%) were similar to those from prior reports. Most cases in the database were from the United States (74.9%). More than half of the participants reported having pruritus, abdominal pain, fatigue, or sleep disturbances; rates were not significantly different among participants within vs outside the United States. There was no significant difference in treatment with ursodeoxycholic acid between participants within vs outside the United States (50.0% and 57.8%; P= .07). The median time of transplant-free survival was 21 years; transplant-free survival was associated with female sex and Crohn's disease. Our findings from an analysis of data from the PSC Partners Patient Registry confirm those from previous studies, although we found a higher proportion of individuals with PSC to be female. In addition to allowing efficient collection of patient-reported outcomes, the patient-driven registry allows for inclusion of previously under-represented cases of PSC.

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.

Does colectomy affect the progression of primary sclerosing cholangitis? A systematic review and meta-analysis.

The aim of this systematic review was to determine if the human colon, through the lower gut-liver axis, drives PSC activity by assessing the progression of the disease in patients with and without colectomy for colonic disease. The gut-liver axis is involved in the pathogenesis of liver disease. Abnormal immune-mediated responses to intestinal microbiome are implicated in primary sclerosing cholangitis (PSC) however the mechanisms remain poorly understood. Currently, no single animal model recapitulates all attributes of PSC in humans and this limits further studies of gut-liver interactions. A systematic search of PubMed, Medline, and Scopus was performed for articles that contained the terms "colectomy" or "bowel resection" AND "primary sclerosing cholangitis" up to 15th April 2018. Articles were reviewed by 2 reviewers and raw data collated. A Forest plot was used to illustrate the effect of colectomy on subsequent liver transplantation for PSC. Linear regression was used to estimate mortality risk. Colectomy appeared to have no effect on PSC progression, although high-quality studies were lacking. Rates of liver transplantation or transjugular intrahepatic portosystemic shunt for PSC were not affected by colectomy (OR 0.59, 95% CI 0.14 - 2.53, p=0.48). Mortality risk following colectomy in patients with PSC is 2.11% per year (95% CI 0.03% - 4.18%, p=0.032, R2 = 0.722). Current evidence is limited but suggests colectomy does not affect the progression of PSC in patients with colonic disease. Pathogenic micro-organisms or antigens that drive PSC may not be limited to the lower gut.

Search for Genetic Modifiers of PSC: Time to Increase the Number of Needles in the Haystack

Primary sclerosing cholangitis (PSC) belongs to the most obscure liver diseases. Patients with progressive PSC require liver transplantation as only therapeutic option. Previously several HLA- and non-HLA-associated PSC risk variants have been discovered, however their involvement in the development of PSC seems to be minor in comparison to environmental determinants. Lately, variant rs853974 at the RSPO3 gene locus has been shown to modulate the course of PSC. Here we briefly discuss the phenotypes related to this polymorphism and propose alternative directions of research that might help to identify new genetic modifiers of PSC progression.

Knockdown of Hepatic Gonadotropin-Releasing Hormone by Vivo-Morpholino Decreases Liver Fibrosis in Multidrug Resistance Gene 2 Knockout Mice by Down-Regulation of miR-200b

Hepatic fibrosis occurs during the progression of primary sclerosing cholangitis (PSC) and is characterized by accumulation of extracellular matrix proteins. Proliferating cholangiocytes and activated hepatic stellate cells (HSCs) participate in the promotion of liver fibrosis during cholestasis. Gonadotropin-releasing hormone (GnRH) is a trophic peptide hormone synthesized by hypothalamic neurons and the biliary epithelium and exerts its biological effects on cholangiocytes by interaction with the receptor subtype (GnRHR1) expressed by cholangiocytes and HSCs. Previously, we demonstrated that administration of GnRH to normal rats increased intrahepatic biliary mass (IBDM) and hepatic fibrosis. Also, miR-200b is associated with the progression of hepatic fibrosis; however, the role of the GnRH/GnRHR1/miR-200b axis in the development of hepatic fibrosis in PSC is unknown. Herein, using the mouse model of PSC (multidrug resistance gene 2 knockout), the hepatic knockdown of GnRH decreased IBDM and liver fibrosis. Invivo and invitro administration of GnRH increased the expression of miR-200b and fibrosis markers. The GnRH/GnRHR1 axis and miR-200b were up-regulated in human PSC samples. Cetrorelix, a GnRHR1 antagonist, inhibited the expression of fibrotic genes invitro and decreased IBDM and hepatic fibrosis invivo. Inhibition of miR-200b decreased the expression of fibrosis genes invitro in cholangiocyte and HSC lines. Targeting the GnRH/GnRHR1/miR-200b axis may be key for the management of hepatic fibrosis during the progression of PSC.

Novel serum and bile protein markers predict primary sclerosing cholangitis disease severity and prognosis

Prognostic biomarkers are lacking in primary sclerosing cholangitis, hampering patient care and the development of therapy. We aimed to identify novel protein biomarkers of disease severity and prognosis in primary sclerosing cholangitis (PSC). Using a bead-based array targeting 63 proteins, we profiled a derivation panel of Norwegian endoscopic retrograde cholangiography bile samples (55 PSC, 20 disease controls) and a Finnish validation panel (34 PSC, 10 disease controls). Selected identified proteins were measured in serum from two Norwegian PSC cohorts (n=167 [1992-2006] and n=138 [2008-2012]), inflammatory bowel disease (n=96) and healthy controls (n=100). In the bile derivation panel, the levels of 14 proteins were different between PSC patients and controls (p<0.05); all were confirmed in the validation panel. Twenty-four proteins in the bile derivation panel were significantly (p<0.05) different between PSC patients with mild compared to severe cholangiographic changes (modified Amsterdam criteria); this was replicated for 18 proteins in the validation panel. Interleukin (IL)-8, matrix metallopeptidase (MMP)9/lipocalin (LCN)2-complex, S100A8/9, S100A12 and tryptophan hydroxylase (TPH)2 in the bile were associated with both a PSC diagnosis and grade of cholangiographic changes. Stratifying PSC patients according to tertiles of serum IL-8, but not MMP9/LCN2 and S100A12, provided excellent discrimination for transplant-free survival both in the serum derivation and validation cohort. Furthermore, IL-8 was associated with transplant-free survival in multivariable analyses in both serum panels independently of age and disease duration, indicating an independent influence on PSC progression. However, the Enhanced Liver Fibrosis (ELF®) test and Mayo risk score proved to be stronger predictors of transplant-free survival. Based on assaying of biliary proteins, we have identified novel biliary and serum biomarkers as indicators of severity and prognosis in PSC. Prognostic biomarkers are lacking in primary sclerosing cholangitis, hampering patient care and the development of therapy. We have identified inflammatory proteins including calprotectin and IL-8 as important indicators of disease severity and prognosis in bile and serum from patients with primary sclerosing cholangitis.

The Microbiome and Primary Sclerosing Cholangitis.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease with detrimental sequela. In many patients, PSC progresses to end-stage liver disease and hepatobiliary cancer. There is no medical therapy that is proven to halt or reverse the progression of PSC. Approximately 70 to 80% of PSC patients have inflammatory bowel disease, usually ulcerative colitis. The etiology of PSC is poorly understood. Several lines of evidence suggest that the intestinal microbiota plays an important role in the etiopathogenesis of PSC. Stemming from this theory, several antibiotics have been tried in PSC, some of which had shown promising results. Fecal microbiota transplantation is a novel therapy, and is currently being investigated as a potential therapeutic strategy in PSC along with probiotics. In this article, the authors discuss the current knowledge of the intestinal microbiota in PSC.

Biomarkers for disease progression of primary sclerosing cholangitis.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown origin. There is no medical treatment of proven benefit on survival; once patients have progressed to end-stage liver disease, the only treatment option is liver transplantation. Over the last years, some progress has been made in identifying biomarkers of PSC disease progression. Categories that can be distinguished include clinical and biochemical biomarkers, histology, imaging, prognostic modelling and genetics. With this review, we summarize biomarkers for progression of PSC from these six categories, which have been studied to date. Biomarkers for the progression of PSC disease course can be used for several purposes. First of all, they can be implemented as surrogate endpoints for clinical trials. Second, biomarkers of disease progression form the basis of prognostic modelling, which is needed for proper patient counselling and management. Lastly, these biomarkers may yield a better understanding of PSC pathogenesis.

Abstract 3618: Ikkα modulates primary sclerosing cholangitis and intrahepatic cholangiocarcinoma

Abstract Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer after hepatocellular carcinoma (HCC). The risk of ICC is higher in patients with primary sclerosing cholangitis (PSC). To date, the cellular and molecular mechanism underlying the pathological progression of PSC and ICC is poorly understood. IKKα is part of the IκB kinase (IKK) complex, which plays an important role in regulating inflammation- associated carcinogenesis through both NF-κB-dependent and independent pathways. Here, we show that IKKα mutant mice developed very serious PSC as early as four weeks of age. The ALT/AST and bilirubin levels were significantly increased in the serum of IKKα mutant mice along with lymphocytic and eosinophilic infiltration into the liver. Liver inflammation in the IKKα mutant mice, mediated by macrophages, neutrophils and CD4+ T cells, was associated with the death of cholangiocytes and hepatocytes, and obstruction of intrahepatic and extrahepatic bile ducts, which impeded bile flow and ultimately led to biliary fibrosis and cirrhosis. Additionally, upon activation of NOTCH signaling in the liver via hydrodynamic shear, we observed that NOTCH-induced ICC, with the PSC, developed significantly faster in IKKα mutant mice. To identify whether intrinsic IKKα dysfunction in hepatocytes promotes the NOTCH-induced ICC in IKKα mutant mice, we generated IKKα hep KO mice, in which IKKα is conditionally knocked out in hepatocytes. No biliary disease or liver injury was observed in these mice. We then established an accelerated ICC model utilizing hydrodynamic delivery of NICD and AKT expression vectors. Unexpectedly, ICC development was remarkably slower in the IKKα hep KO mice compared to the IKKα floxed control mice, and this delayed ICC development was associated with reduced activation or levels of AKT, NOTCH, MAPK/ERK and c-Myc. These data suggest that IKKα may play a protective role in PSC, while promote ICC derived from hepatocytes. In contrast to ICC, we also established the cMET/β-catenin-induced HCC model in the IKKα hep KO mice, which did not reveal any difference in tumor development between IKKα hep KO and control mice. Taken together, our findings suggest that IKKα plays complicated and important roles in PSC and ICC pathological progression. Citation Format: Qun Jiang, Zuoxiang Xiao, Timothy Back, Anthony Scarzello, Scott Roan, Jami Willette-Brown, Feng Zhu, Yinling Hu, Robert H. Wiltrout. Ikkα modulates primary sclerosing cholangitis and intrahepatic cholangiocarcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3618. doi:10.1158/1538-7445.AM2014-3618

Spyglass single-operator peroral cholangioscopy seems promising in the evaluation of primary sclerosing cholangitis-related biliary strictures

Early diagnosis of dysplastic changes and exclusion of cholangiocarcinoma (CCA) in patients with primary sclerosing cholangitis (PSC) remain a major clinical challenge. Although SpyGlass single-operator cholangioscopy (SOC) appears effective in diagnostics of indeterminate biliary strictures, there are only few studies on its safety in PSC-related strictures. Objective. The aim of this study was to assess the clinical feasibility of SOC and directed biopsies, flow cytometry, and brush cytology in PSC patients. Materials and methods. Eleven consecutive patients (median age 45 years, 5 females) undergoing SOC for progression of PSC in a single tertiary center were included in a prospective observational study. Results. Brush sample and directed biopsies were successfully acquired from strictures in all cases. Samples were adequate for cytological and histological diagnosis in 9 (82%) and 10 patients (91%), respectively. There were two cases of pancreatitis. In one patient, flow cytometry showed aneuploidy, which resulted in closer follow-up. Conclusions. SpyGlass SOC and directed biopsies seem to offer a feasible and promising method in evaluation of PSC-related strictures. However, the long-term prognostic value it adds to cytology and flow cytometry remains to be assessed in future trials.

Hepatology Highlights

Hepatology Highlights

Successful Treatment of Recurrent Primary Sclerosing Cholangitis after Orthotopic Liver Transplantation with Oral Vancomycin

Primary sclerosing cholangitis (PSC) is a progressive, cholestatic disease of the liver that is marked by inflammation of the bile ducts and damage to the hepatic biliary tree. Approximately 60–70% of patients also have inflammatory bowel disease and progression of PSC can lead to ulcerative colitis and cirrhosis of the liver. Due to limited understanding of the etiology and mechanism of PSC, the only existing treatment option is orthotopic liver transplantation (OLT); however, recurrence of PSC, after OLT is estimated to be between 5% and 35%. We discuss the successful treatment of a pediatric patient, with recurrent PSC, after OLT with oral Vancomycin.

Primary sclerosing cholangitis and bile acids

Primary sclerosing cholangitis (PSC) is a rare and complex chronic cholestatic liver disease, and its management is hindered by a very poor understanding of its pathogenesis. Endogenous bile acids are likely to play a role either directly or indirectly in the pathogenesis and/or progression of PSC ('toxic-bile'hypothesis). At present, no medical therapies have been proven to delay disease progression. Ursodeoxycholic acid (UDCA) is the agent that has received the most attention. Based on large randomized studies, it appears that UDCA at doses from 13 to 23 mg/kg/d has no proven benefit on survival, but is well tolerated and improves serum liver tests and surrogate markers of prognosis whereas, at higher doses (28-30 mg/kg/d), it is associated with a worsened outcome. However, except at very high doses and despite the controversies, many hepatologists still consider UDCA a reasonable treatment choice. Indeed, its use at dosages of 15-20 mg/kg/d has recently been approved for the treatment of PSC by the French National Health Authority. In addition, 24-nor-ursodeoxycholic acid, a side-chain-modified UDCA derivative, has shown promising results in animal models of PSC and is currently under investigation in humans.

Pathogenesis of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) represents a chronic cholestatic liver disease with fibroobliterative sclerosis of intra- and/or extrahepatic bile ducts, eventually leading to biliary cirrhosis.The association with human leukocyte antigen (HLA) and non-HLA haplotypes and the presence of autoantibodies in sera of PSC patients support a crucial role for immune-mediated mechanisms in the initiation and progression of PSC. The strong clinical association between PSC and inflammatory bowel diseases led to intriguing pathogenetic concepts, in which the inflamed gut with translocation of bacterial products and homing of gut-primed memory T lymphocytes via aberrantly expressed adhesion molecules plays a fundamental role. Genetically or chemically modified bile composition was shown to induce sclerosing cholangitis and liver fibrosis in a number of animal models ("toxic bile concept"). The potential role of vascular injury with ischemia of bile duct epithelium cells in the development of sclerosing cholangitis is supported by animal models of endothelial cell injury showing close morphological similarities with human PSC.