Small duct primary sclerosing cholangitis without inflammatory bowel disease is genetically different from large duct disease

Identifying a therapeutic window of opportunity for people living with primary sclerosing cholangitis: Embryology and the overlap of inflammatory bowel disease with immune-mediated liver injury

Primary sclerosing cholangitis (PSC) is a variably progressive, fibrosis-causing autoimmune disorder of the intrahepatic and extrahepatic bile ducts of unclear etiology. PSC is commonly (in 60%-90% of cases) associated with an inflammatory bowel disease (IBD) like PSC-IBD and less commonly with an autoimmune hepatitis (AIH) like PSC-AIH or AIH-overlap disorder. Hepatologists and Gastroenterologists often consider these combined conditions as distinctly different from the classical forms in isolation. Here, we review recent epidemiologic observations and highlight that PSC-IBD and PSC-AIH overlap appear to represent aspects of a common PSC clinico-pathological pathway and manifest in an age-of-presentation-dependent manner. Particularly from the pediatric experience, we hypothesize that all cases of PSC likely originate from a complex "Early PSC"-"IBD"-"AIH" overlap in which PSC defines the uniquely and variably associated "AIH" and "IBD" components along an individualized lifetime continuum. We speculate that a distinctly unique, "diverticular autoimmunity" against the embryonic cecal- and hepatic diverticulum-derived tissues may be the origin of this combined syndrome, where "AIH" and "IBD" variably commence then variably fade while PSC progresses with age. Our hypothesis provides an explanation for the age-dependent variation in the presentation and progression of PSC. This is critical for the optimal targeting of studies into PSC etiopathogenesis and emphasizes the concept of a "developmental window of opportunity for therapeutic mitigation" in what is currently recognized as an irreversible disease process. The discovery of such a window would be critically important for the targeting of interventions, both the administration of current therapies and therapeutic trial planning.

Phenotypes of Primary Sclerosing Cholangitis and Differential Diagnosis

Primary sclerosing cholangitis is a heterogenous immune-mediated disorder characterized by chronic inflammation and stricturing of the bile ducts. Though the driving pathophysiologic mechanisms remain elusive, there are several observed clinical phenotypes of the disease. The distribution of bile duct involvement, presence of concomitant inflammatory bowel disease, significant infiltration of IgG4-positive plasma cells, and overlapping features with other autoimmune disease has significant implications for prognosis and treatment. As there remains no pathognomonic finding for primary sclerosing cholangitis, a broad differential diagnosis and extensive evaluation of other underlying causes is critical to appropriate management.

Analysis of various ATP-binding cassette transporters revealed quantification of ABCB4 as a potential diagnostic tool in primary sclerosing cholangitis (PSC)

AIMS

ATP-binding cassette transporters are important proteins in regulating bile constituent transport between hepatocytes and the bile canalicular system. Dysfunctional transporters lead to accumulation of toxic bile components within hepatocytes or the biliary system, known as cholestasis, resulting in liver damage. It has been previously reported that two particular ATP-binding cassette transporters, ABCB4 and ABCB11, have altered expression in patients with primary sclerosing cholangitis (PSC). Interested in further analysis of expression patterns of ATP-binding cassette transporters in PSC patients, we investigated liver samples from 201 patients, including 43 patients with PSC and 51 patients with primary biliary cholangitis patients (PBC). In addition to ABCB4 and ABCB11, we also included other ATP-binding cassette transporters, to determine if upregulation of ABCB4 and ABCB11 is specifically found in the liver of patients with PSC.

METHODS AND RESULTS

Retrospectively, formalin-fixed and paraffin-embedded liver biopsies, resections, and explants were selected to investigate the expression of ABCB1, ABCB4, ABCB11, ABCG5/8, and FXR1 using nanoString nCounter and immunohistochemistry for validation of differently expressed transporters seen in PSC liver samples in comparison to non-PSC liver specimens. Strikingly, ABCB4 was the only ATP-binding cassette transporter showing increased gene and protein expression in hepatocytes of PSC livers when compared to non-PSC liver specimens. Furthermore, ABCB4 protein expression also correlated with disease stage in PSC.

CONCLUSION

Our study concluded that altered ABCB4 expression is specifically seen in liver specimens of PSC patients. Therefore, quantitative ABCB4 analysis may be an additional useful tool for the histopathological diagnosis of PSC to distinguish this entity from other cholangiopathies.

Morphological aspects of small-duct cholangiopathies: A minireview

The biliary system consists of intrahepatic and extrahepatic bile ducts lined by biliary epithelial cells (cholangiocytes). Bile ducts and cholangiocytes are affected by a variety of disorders called cholangiopathies, which differ in aetiology, pathogenesis, and morphology. Classification of cholangiopathies is complex and reflects pathogenic mechanisms (immune-mediated, genetic, drug- and toxin-induced, ischaemic, infectious, neoplastic), predominant morphological patterns of biliary injury (suppurative and non-suppurative cholangitis, cholangiopathy), and specific segments of the biliary tree affected by the disease process. While the involvement of large extrahepatic and intrahepatic bile ducts is typically visualised using radiology imaging, histopathological examination of liver tissue obtained by percutaneous liver biopsy still plays an important role in the diagnosis of cholangiopathies affecting the small intrahepatic bile ducts. To increase the diagnostic yield of a liver biopsy and determine the optimal therapeutic approach, the referring clinician is tasked with interpreting the results of histopathological examination. This requires knowledge and understanding of basic morphological patterns of hepatobiliary injury and an ability to correlate microscopic findings with results obtained by imaging and laboratory methods. This minireview describes the morphological aspects of small-duct cholangiopathies pertaining to the diagnostic process.

Primary sclerosing cholangitis: review for radiologists

Primary sclerosing cholangitis is a rare chronic inflammatory disease affecting the bile ducts, which can eventually result in bile duct strictures, cholestasis and cirrhosis. Patients are often asymptomatic but may present with clinical features of cholestasis. Imaging plays an important role in the diagnosis and management. This review covers the pathophysiology, clinical features, imaging findings as well as methods of surveillance and post-transplant appearance.

EASL Clinical Practice Guidelines on sclerosing cholangitis

Management of primary or secondary sclerosing cholangitis is challenging. These Clinical Practice Guidelines have been developed to provide practical guidance on debated topics including diagnostic methods, prognostic assessment, early detection of complications, optimal care pathways and therapeutic (pharmacological, endoscopic or surgical) options both in adults and children.

Small duct primary sclerosing cholangitis: A discrete variant or a bridge to large duct disease, a practical review

The natural history, associations with inflammatory bowel disease (IBD), and long-term outcomes of large duct primary sclerosing cholangitis (ldPSC) have been well documented. Small duct primary sclerosing cholangitis (sdPSC) is a much less common and relatively more benign variant. The natural history of sdPSC has been difficult to characterize given the limited number of studies in the literature especially with regards to the subset of patients who progress to large duct involvement. It has been unclear whether sdPSC represented a subset of ldPSC, an earlier staging of ldPSC, or a completely separate and distinct entity of its own. Strong associations between sdPSC and IBD have been established with suspicion that concurrent sdPSC-IBD may be a key prognostic factor in determining which patients are at risk of progression to ldPSC. Little is known regarding the discrete circumstances that predisposes some patients with sdPSC to progress to ldPSC. It has been suspected that progression to large biliary duct involvement subjects this subset of patients to potentially developing life-threatening complications. Here the authors conducted a thorough review of the published sdPSC literature using Pubmed searches and cross-referencing to compile all accessible studies regarding cohorts of sdPSC patients in order better characterize the subset of sdPSC patients who progress to ldPSC and the associated outcomes.

Racial differences in primary sclerosing cholangitis mortality is associated with community socioeconomic status

BACKGROUND AND AIMS

Natural history and outcomes data in PSC are mostly derived from cohorts where Blacks have been underrepresented. It is unknown if there are differences in mortality between Blacks and Whites with PSC.

METHODS

PSC patients seen at our institution from June 1988 to Jan 2019 were identified by merging prospective ERCP hepatology-clinic databases and liver-transplant registry. Data on race, clinical events, and death was obtained through chart review. Data on community health were collected using indices from county health rankings. Cumulative incidence of death was calculated using liver transplant (LT) as a competing risk.

RESULTS

Of 449 patients, 404 were White and 45 were Black. The median-duration of follow-up was 7 years (IQR:3, 13). Black patients were younger at presentation than White patients (36.3 vs 42.5 years., P = .013). Disease severity as indicated by Mayo Risk Score categories (low 27% vs 31%, intermediate 54% vs 49% and high 19% vs 19%, P = .690), comorbidity burden and frequency of cirrhosis (42% vs 35%, P = .411) were similar between Blacks and Whites. Cumulative incidence of liver-related death, with LT as a competing risk was significantly higher in Blacks compared to Whites (sHR 1.80, 95%CI 1.25, 2.61, P = .002). There was a significant interaction between race and community socioeconomic factors that attenuated the racial difference in mortality (sHR 1.01, 95%CI 0.99, 1.04, P = .345).

CONCLUSIONS

Blacks with PSC present at a younger age with a similar disease severity as Whites but have higher liver related mortality that is mediated in part through community health.

Analysis of the Clinical Course of Primary Sclerosing Cholangitis in Paediatric Population-Single Center Study

Background and Objectives: Primary sclerosing cholangitis (PSC) is a rare cholestatic disease of the liver of unknown etiology, severe course and poor prognosis. PSC most often co-occurs with inflammatory bowel diseases (IBD), especially with ulcerative colitis (UC). The aim of the study was the analysis of the clinical course of primary sclerosing cholangitis in children, hospitalized in the Gastroenterology Unit in Katowice. Materials and Methods: The analysis included 30 patients, aged from 7 to 18 years, 21/30 boys (70%) and 9/30 girls (30%), diagnosed with PSC in the years 2009–2019. The analysis included the age at diagnosis, clinical symptoms, course of the disease, coexisting diseases, laboratory and imaging results, and complications. Results: The average age at diagnosis was 13 years. 22/30 (73.3%) patients suffered from UC, 4/30 (13.3%) were diagnosed with Crohn’s disease (CD), 2/30 (6.66%) with Eosinophilic Colitis (EC). 2/30 patients (6.66%) had no clinical evidence of coexistent IBD to date. In addition, 7/30 (23.3%) had an overlap syndrome of primary sclerosing cholangitis/autoimmune hepatitis. When PSC was detected before IBD (6/30–20%), patients had complications more often compared to those diagnosed with IBD first or PSC and IBD at the same time. At the moment of diagnosis 6/30 (20%) patients presented with abdominal pain, which was the most common symptom, 3/30 (10%) jaundice, while 17/30 (56.6%) were asymptomatic but had abnormal results of the laboratory tests. Conclusions: Monitoring liver markers in IBD patients is important since most PSC cases are asymptomatic and their elevation might be the first sign of the disease. Patients diagnosed with PSC before IBD diagnosis are more likely to have a more aggressive course of the disease.

Diagnostic and conservative treatment nuances in patients with obstructive jaundice: in the wake of Russian consensus

The research was performed at the Loginov Moscow Clinical Scientific Center. It is based on Russian obstructive jaundice (OJ) consensus results, considered at the 45th annual Central Research Institute of Gastroenterology Scientific session Oncological issues in the gastroenterologist practice (1 March 2019). The article objective is to note the diagnostic and conservative treatment current issues in patients with OJ. The increase in the number of patients with OJ of different etiology provides problem actuality. In a large number of cases, medical treatment is delayed due to inadequate diagnostic and management, while correct patients routing today can be provided regardless of medical institution level. In this article the examination steps and conservative treatment role in patients with biliary obstruction management are presented.

ABCB4 disease: Many faces of one gene deficiency

ATP-binding cassette (ABC) subfamily B member 4 (ABCB4), also known as multidrug resistance protein 3 (MDR3), encoded by ABCB4, is involved in biliary phospholipid secretion, protecting hepatobiliary system from deleterious detergent and lithogenic properties of the bile. ABCB4 mutations altering canalicular ABCB4 protein function and expression may have variable clinical presentation and predispose to several human liver diseases. Well-established phenotypes of ABCB4 deficit are: progressive familial intrahepatic cholestasis type 3, gallbladder disease 1 (syn. low phospholipid associated cholelithiasis syndrome), high ɣ-glutamyl transferase intrahepatic cholestasis of pregnancy, chronic cholangiopathy, and adult biliary fibrosis/cirrhosis. Moreover, ABCB4 aberrations may be involved in some cases of drug induced cholestasis, transient neonatal cholestasis, and parenteral nutrition-associated liver disease. Recently, genome-wide association studies have documented occurrence of malignant tumours, predominantly hepatobiliary malignancies, in patients with ABCB4/MDR3 deficit. The patient's age at the time of the first presentation of cholestatic disease, as well as the severity of liver disorder and response to treatment are related to the ABCB4 allelic status. Mutational analysis of ABCB4 in patients and their families should be considered in all individuals with cholestasis of unknown aetiology, regardless of age and/or time of onset of the first symptoms.

Open-label prospective therapeutic clinical trials: oral vancomycin in children and adults with primary sclerosing cholangitis

BACKGROUND

Oral vancomycin (OV) in primary sclerosing cholangitis (PSC) has been evaluated as a potential therapeutic agent. We report the long-term biochemical course and outcomes of patients with PSC treated with OV.

METHODS

Patients were enrolled in 2 open-label clinical trials (ClinicalTrials.gov Identifier: NCT01802073 and NCT01322386) and offered OV at 50 mg/kg/day in 3 divided doses if weight <30kg, and 500 mg 3 times/day if weight ≥30kg. Patients with biliary strictures requiring stenting or awaiting liver transplant were excluded. Liver biochemistry, MRCP and histology were documented at baseline and while on OV. The primary outcome was a decrease in elevated gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), and/or alanine aminotransferase (ALT) from baseline.

RESULTS

30 subjects were enrolled, and 29 additional subjects who learned of the clinical trial requested OV (total n = 59; median age was 13.5 years [range, 1.5-44 years]; 64.4% were male; and 94.9% had inflammatory bowel disease [IBD]). The median treatment duration was 2.7 years (range, 0.2-14 years). Ninety-six percent (57/59), 81.3% (48/59), and 94.9% (56/59) experienced reduction of GGT, ALP, and ALT, respectively. Furthermore, 39% (23/59), 22% (13/59), and 55.9% (33/59) experienced normalization of GGT, ALP, and ALT, respectively, within the first 6 months of OV treatment. One patient underwent liver transplantation 8 years after beginning OV treatment, and one developed biliary strictures requiring endoscopic intervention. OV was well-tolerated by patients, and no patient developed treatment-related adverse events.

CONCLUSION

In PSC, OV was well-tolerated and was associated with improvement in liver chemistry. A randomized placebo-controlled clinical trial is warranted.

[Russian consensus on current issues in the diagnosis and treatment of obstructive jaundice syndrome]

The Russian consensus document on topical issues of the diagnosis and treatment of obstructive jaundice syndrome was prepared by a group of experts in various fields of surgery, endoscopy, interventional radiology, radiological diagnosis and intensive care. The goal of this document is to clarify and consolidate the opinions of national experts on the following issues: timing of diagnosis of obstructive jaundice, features of diagnostic measures, the need and possibility of conservative measures for obstructive jaundice, and strategy of biliary decompression depending on the cause and level of biliary block.

Clinical features and MRI progression of small duct primary sclerosing cholangitis (PSC)

PURPOSE

First, to evaluate and describe the clinical and MRI progression of patients with small duct primary sclerosing cholangitis (sdPSC), and second, to look for MRI features associated with disease progression to large duct PSC.

METHOD

16 patients (7 female, 9 male; median age 27 years) with diagnosis of sdPSC and available MR imaging were included in this retrospective dual-center study. Liver function tests (LFTs) and imaging was reviewed in consensus by two radiologists at baseline and follow-up, and compared by means of non-parametric tests, with p < 0.05 deemed significant.

RESULTS

At baseline and follow-up patients had a cholestatic liver profile with elevated LFTs. Progressive liver deformity, heterogeneous enhancement and hilar lymphadenopathy were common findings. In 9 patients follow-up MRI was available with a mean interval between imaging of 10.6 years (range 3.6-15.3 years). 5 patients (55.5 %) developed cholangiographic changes diagnostic of large duct PSC. No correlation was observed between MRI findings or LFTs at baseline and the endpoint of developing PSC typical cholangiographic changes at follow-up imaging (p > 0.05).

CONCLUSIONS

More than half of sdPSC patients developed cholangiographic changes, supporting that sdPSC may be an early stage of large duct PSC rather than an entity of its own. Larger studies are needed to address the value of MRI for prediction of sdPSC disease progression.

Role of Endoscopy in Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is a progressive disease of the bile ducts that usually results in chronic liver disease often requiring liver transplantation. Endoscopy remains crucial to the care of these patients, although magnetic resonance cholangiopancreatography has replaced endoscopic retrograde cholangiopancreatography (ERCP) as the primary imaging modality for diagnosis. For detection of dysplasia or cholangiocarcinoma, ERCP with intraductal sampling remains compulsory. Moreover, dominant strictures play an important part in the disease development, and management by balloon dilatation or stenting could contribute to long-term prognosis. In addition, endoscopy offers management for adverse events such as bile leaks and anastomotic strictures after liver transplantation. Finally, the special phenotype of inflammatory bowel disease associated with PSC as well as the frequent occurrence of portal hypertension mandates close follow-up with colonoscopy and upper endoscopy. With the emergence of novel techniques, the endoscopist remains a key member of the multidisciplinary team caring for PSC patients.

Clinical Characteristics, Associated Malignancies and Management of Primary Sclerosing Cholangitis in Inflammatory Bowel Disease Patients: A Multicentre Retrospective Cohort Study

BACKGROUND AND AIMS

Primary sclerosing cholangitis [PSC] is usually associated with inflammatory bowel disease [IBD]. An increased risk of malignancies, mainly colorectal cancer [CRC] and cholangiocarcinoma [CCA], has been reported in PSC-IBD patients. Our aim was to determine the clinical characteristics and management of PSC in IBD patients, and the factors associated with malignancies.

METHODS

PSC-IBD patients were identified from the Spanish ENEIDA registry of GETECCU. Additional data were collected using the AEG-REDCap electronic data capture tool.

RESULTS

In total, 277 PSC-IBD patients were included, with an incidence rate of 61 PSC cases per 100 000 IBD patient-years, 69.7% men, 67.5% ulcerative colitis and mean age at PSC diagnosis of 40 ± 16 years. Most patients [85.2%] were treated with ursodeoxycholic acid. Liver transplantation was required in 35 patients [12.6%] after 79 months (interquartile range [IQR] 50-139). It was more common in intra- and extrahepatic PSC compared with small-duct PSC (16.3% vs 3.3%; odds ratio [OR] 5.7: 95% confidence interval [CI] = 1.7-19.3). The incidence rate of CRC since PSC diagnosis was 3.3 cases per 1000 patient-years [95% CI = 1.9-5.6]. Having symptoms of PSC at PSC diagnosis was the only factor related to an increased risk of CRC after IBD diagnosis [hazard ratio= 3.3: 95% CI = 1.1-9.9]. CCA was detected in seven patients [2.5%] with intra- and extrahepatic PSC, with median age of 42 years [IQR 39-53], and presented a lower life expectancy compared with patients without CCA and patients with or without CRC.

CONCLUSIONS

PSC-IBD patients with symptoms of PSC at PSC diagnosis have an increased risk of CRC. CCA was only diagnosed in patients with intra- and extrahepatic PSC and was associated with poor survival.

Primary Biliary Cholangitis and Primary Sclerosing Cholangitis

Cholestatic liver diseases encompass a broad spectrum of pathologies, with the core injury occurring at the level of cholangiocytes and progressing to hepatic fibrosis and liver dysfunction. Primary biliary cholangitis and primary sclerosing cholangitis are the most significant progressive cholangiopathies in adults. Although rare, they commonly evolve to liver failure and need for liver transplantation. Despite recent advances in the basic knowledge of these cholangiopathies, the pathogenesis is still elusive. Targeted treatments to prevent disease progression and to preclude malignancy are not yet available. This review will address the general clinical features of both diseases, analyze their commonalities and differences, and provide a state-of-the art overview of the currently available therapeutics.

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.

Primary sclerosing cholangitis - a comprehensive review

Primary sclerosing cholangitis (PSC) is a rare disorder characterised by multi-focal bile duct strictures and progressive liver disease. Inflammatory bowel disease is usually present and there is a high risk of cholangiocarcinoma and colorectal cancer. Most patients ultimately require liver transplantation, after which disease recurrence may occur. With limited therapeutic options and a lack of proven surveillance strategies, patients currently have significant unmet needs. In the present seminar, we provide a comprehensive review of the status of the field. We emphasise developments related to patient stratification and disease behaviour, and provide an overview of management options from a practical, patient-centered perspective. We survey advances made in the understanding of PSC pathogenesis and summarise the ongoing efforts to develop an effective therapy based on these insights.

Variations in primary sclerosing cholangitis across the age spectrum

BACKGROUND AND AIM

Primary sclerosing cholangitis (PSC) typically develops in middle-age adults. Little is known about phenotypic differences when PSC is diagnosed at various ages. Therefore, we sought to compare the clinical characteristics of a large PSC cohort based on the age when PSC was diagnosed.

METHODS

We performed a multicenter retrospective review to compare the features of PSC among those diagnosed between 1-19 (n = 95), 20-59 (n = 662), and 60-79 years (n = 102).

RESULTS

Those with an early diagnosis (ED) of PSC were more likely to have small-duct PSC (13%) than those with a middle-age diagnosis (MD) (5%) and late diagnosis (LD) groups (2%), P < 0.01, and appeared to have a decrease risk of hepatobiliary malignancies: ED versus MD: hazard ratio (HR), 0.25; 95% confidence interval (CI) 0.06-1.03, and ED versus LD: HR, 0.07; 95% CI 0.01-0.62. Cholangiocarcinoma was diagnosed in 78 subjects (ED n = 0, MD n = 66, and LD n = 12) and was more likely to be diagnosed within a year after the PSC diagnosis among those found to have PSC late in life: ED 0% (0/95), MD 2% (14/662), and LD 6% (6/102), P = 0.02. Similarly, hepatic decompensation was more common among those with LD-PSC versus younger individuals: LD versus MD: HR, 1.64; 95% CI 0.98-2.70, and LD versus ED: HR, 2.26; 95% CI 1.02-5.05.

CONCLUSIONS

Those diagnosed with PSC early in life are more likely to have small-duct PSC and less likely to have disease-related complications. Clinicians should be vigilant for underlying cholangiocarcinoma among those with PSC diagnosed late in life.

The natural history of primary sclerosing cholangitis in 781 children: A multicenter, international collaboration

There are limited data on the natural history of primary sclerosing cholangitis (PSC) in children. We aimed to describe the disease characteristics and long-term outcomes of pediatric PSC. We retrospectively collected all pediatric PSC cases from 36 participating institutions and conducted a survival analysis from the date of PSC diagnosis to dates of diagnosis of portal hypertensive or biliary complications, cholangiocarcinoma, liver transplantation, or death. We analyzed patients grouped by disease phenotype and laboratory studies at diagnosis to identify objective predictors of long-term outcome. We identified 781 patients, median age 12 years, with 4,277 person-years of follow-up; 33% with autoimmune hepatitis, 76% with inflammatory bowel disease, and 13% with small duct PSC. Portal hypertensive and biliary complications developed in 38% and 25%, respectively, after 10 years of disease. Once these complications developed, median survival with native liver was 2.8 and 3.5 years, respectively. Cholangiocarcinoma occurred in 1%. Overall event-free survival was 70% at 5 years and 53% at 10 years. Patient groups with the most elevated total bilirubin, gamma-glutamyltransferase, and aspartate aminotransferase-to-platelet ratio index at diagnosis had the worst outcomes. In multivariate analysis PSC-inflammatory bowel disease and small duct phenotypes were associated with favorable prognosis (hazard ratios 0.6, 95% confidence interval 0.5-0.9, and 0.7, 95% confidence interval 0.5-0.96, respectively). Age, gender, and autoimmune hepatitis overlap did not impact long-term outcome.

CONCLUSION

PSC has a chronic, progressive course in children, and nearly half of patients develop an adverse liver outcome after 10 years of disease; elevations in bilirubin, gamma-glutamyltransferase, and aspartate aminotransferase-to-platelet ratio index at diagnosis can identify patients at highest risk; small duct PSC and PSC-inflammatory bowel disease are more favorable disease phenotypes. (Hepatology 2017;66:518-527).

HLA haplotypes in primary sclerosing cholangitis patients of admixed and non-European ancestry

Primary sclerosing cholangitis (PSC) is strongly associated with several human leukocyte antigen (HLA) haplotypes. Due to extensive linkage disequilibrium and multiple polymorphic candidate genes in the HLA complex, identifying the alleles responsible for these associations has proven difficult. We aimed to evaluate whether studying populations of admixed or non-European descent could help in defining the causative HLA alleles. When assessing haplotypes carrying HLA-DRB1*13:01 (hypothesized to specifically increase the susceptibility to chronic cholangitis), we observed that every haplotype in the Scandinavian PSC population carried HLA-DQB1*06:03. In contrast, only 65% of HLA-DRB1*13:01 haplotypes in an admixed/non-European PSC population carried this allele, suggesting that further assessments of the PSC-associated haplotype HLA-DRB1*13:01-DQA1*01:03-DQB1*06:03 in admixed or multi-ethnic populations could aid in identifying the causative allele.

Antineutrophil antibodies define clinical and genetic subgroups in primary sclerosing cholangitis

BACKGROUND & AIMS

The strongest genetic risk factors in primary sclerosing cholangitis (PSC) are encoded in the HLA complex. Antineutrophil cytoplasmic antibodies (ANCA) have been reported in up to 94% of PSC patients, but their clinical significance and immunogenetic basis are ill defined. We aimed to characterize clinical and genetic associations of ANCA in PSC.

METHODS

Antineutrophil cytoplasmic antibodies were analysed with indirect immunofluorescence in 241 Norwegian PSC patients. HLA-B and HLA-DRB1 genotyping was performed in the patients and in 368 healthy controls. Data on perinuclear ANCA (pANCA) and HLA-DRB1 were available from 274 ulcerative colitis (UC) patients without known liver disease.

RESULTS

Antineutrophil cytoplasmic antibodies were found in 193 (80%) of the PSC patients, with pANCA in 169 (70%). ANCA-positive patients were younger than ANCA negative at diagnosis of PSC and had a lower frequency of biliary cancer (9% vs 19%, P=.047). There were no differences between PSC patients with and without inflammatory bowel disease. Genetically, the strong PSC risk factors HLA-B*08 (frequency in healthy 13%) and DRB1*03 (14%) were more prevalent in ANCA-positive than -negative patients (43% vs 25%, P=.0012 and 43% vs 25%, P=.0015 respectively). The results were similar when restricting the analysis to pANCA-positive patients. In UC patients without liver disease, HLA-DRB1*03 was more prevalent in pANCA-positive compared with -negative patients (P=.03).

CONCLUSIONS

Antineutrophil cytoplasmic antibodies identified PSC patients with particular clinical and genetic characteristics, suggesting that ANCA may mark a clinically relevant pathogenetic subgroup in the PSC-UC disease spectrum.

Ulcerative Colitis with and without Primary Sclerosing Cholangitis: Two Different Diseases?

Background

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown origin and an important hepatobiliary complication of inflammatory bowel diseases (IBD), especially ulcerative colitis (UC). When further differentiated, about 3-8% of UC patients suffer from PSC, whereas among Crohn's disease patients the reported prevalence of PSC is probably between 1 and 3.5%. Although it was reported from Japan that the frequency of PSC in UC was only 34%, the same registry data indicated that the prevalence was up to 57% among young patients with PSC even in Japan, which is comparable to the 60-80% in Europe and the US. Additionally, the clinical features of UC in patients with PSC are different from those in patients without PSC, for instance, rectal sparing and right-sided dominance.

Summary

The strong link between atypical IBD and PSC suggests that the pathogenesis of PSC involves pathology of the gut, including abnormal gut microbiota and aberrant activation of mucosal lymphocytes. These seem to be different in UC PSC as compared to the pathology of typical UC.

Key Messages

The key to solving the question 'Is there a difference between East and West?' are genetic studies, genome-wide association studies of PSC in particular, which have already been performed in the West and are strongly warranted in the East.

Patients with large-duct primary sclerosing cholangitis and Crohn's disease have a better outcome than those with ulcerative colitis, or without IBD

BACKGROUND

Approximately 20% of primary sclerosing cholangitis (PSC) patients with concomitant inflammatory bowel disease (IBD) have Crohn's disease (CD).

AIM

To compare PSC/CD with other PSC patients.

METHODS

Retrospective study of 240 PSC patients diagnosed between 1975 and 2012 (median follow-up 12 years). Activity of PSC at diagnosis was assessed by liver biopsy, Mayo risk and ERC scores. Survival without liver transplantation, number of transplantations and liver-related death were endpoints.

RESULTS

Sixty-three per cent of patients had IBD: 105 UC, 32 CD and 14 IBD unclassified (IBDu). IBD was diagnosed before PSC in 50%. The yearly development of PSC after diagnosing IBD was similar in UC, CD or IBDu. Small-duct PSC was present in 28% of PSC/CD compared to 3% of PSC/UC. Small-duct PSC had a markedly better survival than large-duct PSC: no patient developed cholangiocarcinoma or liver-related death, but colorectal cancer occurred in three patients. In large-duct PSC, a more favourable outcome was evident in patients with CD. The liver disease was less progressive: one patient underwent liver transplantation compared to 28% and liver-related deaths were absent compared to 7% in the other PSC groups.

CONCLUSIONS

The prevalence of PSC with concomitant Crohn's disease is relatively rare, but the outcome is more benign than PSC with UC or without IBD. Approximately one-fourth has small-duct PSC. In large-duct PSC/CD, liver disease is less aggressive and the outcome is much better. The outcome of PSC patients with UC resembled that of PSC without IBD.

The Immunogenetics of Autoimmune Cholestasis

The immune-mediated hepatobiliary diseases, primary biliary cirrhosis and primary sclerosing cholangitis are relatively rare, albeit and account for a significant amount of liver transplant activity and liver-related mortality globally. Precise disease mechanisms are yet to be described although a contributory role of genetic predisposition is firmly established. In addition to links with the major histocompatibility complex, a number of associations outside this region harbor additional loci which underscore the fundamental role of breaks in immune tolerance and mucosal immunogenicity in the pathogenesis of autoimmune biliary disease. We provide an overview of these key discoveries before discussing putative avenues of therapeutic exploitation based on existing findings.

Primary Sclerosing Cholangitis: Multiple Phenotypes, Multiple Approaches

Primary sclerosing cholangitis (PSC) is a heterogeneous, idiopathic, inflammatory disorder frequently associated with inflammatory bowel diseases. PSC patients may be classified into several subphenotypes. Investigations of pediatric, nonwhite, and female PSC patients have revealed distinguishing features. The natural history of PSC is variable in progression with numerous possible clinical outcomes. PSC patients may suffer bacterial cholangitis, cholangiocarcinoma, or colorectal adenocarcinoma. Treatments focusing on bile acid therapy and immunosuppression have not proven beneficial. Interest in PSC and international collaboration has led to improved understanding of the heterogeneity and the genetic structure and introduced possible effective therapeutics.

Primary sclerosing cholangitis - the Norwegian experience

Research related to primary sclerosing cholangitis (PSC) has since 1980 been a major activity at the Oslo University Hospital Rikshospitalet. The purpose of this publication is to describe the development of this research, the impact of this research on the clinical handling of the patients, and finally to describe what we believe are the most urgent, remaining problems to be solved. During the early years, our research dealt primarily with clinical aspects of the disease. The concomitant inflammatory bowel disease (IBD) seen in most patients with PSC was a major interest and we also started looking into genetic associations of PSC. Prognosis, malignancy development and treatment with special emphasis on transplantation have later been dealt with. These activities has had impact on several aspects of PSC management; when and how to diagnose PSC and variant forms of PSC, how to handle IBD in PSC and how to deal with the increased rate of malignancy? The problems remaining to be solved are many. What is the role of the gut and the gut microbiota in the development of PSC? Do the PSC patients have an underlying disturbance in the bile homeostasis? And how does the characteristic type of fibrosis in PSC develop? The genetic studies have supported a role for the adaptive immune system in the disease development, but how should this be dealt with? Importantly, the development of malignancy in PSC is still not understood, and we lack appropriate medical treatment for our patients.

Association Between HLA Haplotypes and Increased Serum Levels of IgG4 in Patients With Primary Sclerosing Cholangitis

Increased serum levels of IgG4 have been reported in 9%-15% of patients with primary sclerosing cholangitis (PSC); it is not clear whether this increase contributes to pathogenesis. We performed genetic analyses of the HLA complex in patients with PSC from Norway, Sweden, and from the United States. We found an association between levels of IgG4 above the upper reference limit and specific HLA haplotypes. These patients had a significantly lower frequency of the strongest PSC risk factor, HLA-B*08, than patients without increased IgG4, and significantly higher frequencies of HLA-B*07 and HLA-DRB1*15. HLA genotype therefore might affect the serum concentration of IgG4, and increased IgG4 might be a marker of a distinct phenotype of PSC.