Increased prevalence of primary sclerosing cholangitis among first-degree relatives

HLA alleles predisposing to autoimmunity are linked to impaired immunoregulation in patients with juvenile autoimmune liver disease and in their first-degree relatives

BACKGROUND & AIMS

Juvenile autoimmune liver disease (JAILD) comprises autoimmune hepatitis and autoimmune sclerosing cholangitis. JAILD-predisposing genes include HLA-DR3,DR7, DR13 and haplotype A1-B8-DR3. Mechanisms leading to liver autoimmunity remain elusive, though JAILD patients have aberrated immunoregulation. We investigated the influence of HLA genes on immune cells, focusing on T-cells and frequency and function of T regulatory cells (Tregs) in JAILD patients, their first-degree-relatives (FDRs) and healthy controls (HCs).

METHODS

HLA class I and II genotypes were defined by PCR and peripheral blood mononuclear cells were immunophenotyped by FACS in 82 patients, 72 FDRs, 50 HCs. Treg function was tested by inhibition of CD4posCD25neg T-cell proliferation. Links between HLA genes, Treg frequency/function, pro-inflammatory/immunoregulatory cytokines, soluble and membrane-bound programmed cell death-1 (PD-1) were investigated.

RESULTS

Proportion of subjects carrying HLA DR3/DR7/DR13 was 88 %, 92 %, 64 % in patients, FDRs and HCs. Circulating Treg frequency was lower in patients and FDRs than HCs. Inhibitory capacity of Tregs was lower in patients but similar in FDRs compared to HCs. FDRs possessing HLA DR3/DR7/DR13 genes had Treg frequencies lower than those without. PD-1 posCD4pos T-cells were fewer in patients than HCs; PD-1posCD8pos T-cells were fewer in patients and FDRs than HCs. Patient plasma levels of IFN-γ were higher, and ratios of IFN-γ/IL-10 and IFN-γ/IL-2 lower than in HCs. All nine FDRs with autoimmune disorders had HLA DR3/DR7/DR13 genes and lower Treg frequency than those without autoimmune disorders and HCs.

CONCLUSION

We show a link between HLA disease-predisposing genes and defective immunoregulation not only in JAILD patients, but also in their FDRs, who are prone to autoimmune disorders.

Autoimmune diseases in primary sclerosing cholangitis and their first-degree relatives

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is linked to inflammatory bowel disease (IBD). However, there is limited overlap between IBD and PSC risk genes, but a stronger association between PSC and other autoimmune conditions. We aimed to assess the coexistence and familial association of autoimmune disorders in PSC, and the influence of autoimmune comorbidity on severe outcomes.

APPROACH AND RESULTS

In a matched cohort study, 1378 individuals with PSC and 13,549 general population comparators and their first-degree relatives were evaluated. National registries provided data on diagnoses and outcomes (liver transplantation, hepatobiliary cancer, and liver-related death). The OR of autoimmune disease was estimated by logistic regression. The Fine and Gray competing risk regression estimated HRs for severe outcomes. The prevalence of non-IBD, non-autoimmune hepatitis, and autoimmune disease was 18% in PSC and 11% in comparators, OR: 1.77 (95% CI: 1.53-2.05). Highest odds were seen for celiac disease [OR: 4.36 (95% CI: 2.44-7.49)], sarcoidosis [OR: 2.74 (95% CI: 1.29-5.33)], diabetes type 1 [OR: 2.91 (95% CI: 2.05-4.05)], and autoimmune skin disease [OR: 2.15 (95% CI: 1.52-2.96)]. First-degree relatives of individuals with PSC had higher odds of developing IBD, autoimmune hepatitis, and any autoimmune disease than relatives of the comparators [OR: 3.25 (95% CI: 2.68-3.91); OR: 5.94 (95% CI: 2.82-12.02); OR: 1.34 (95% CI: 1.19-1.50)]. Autoimmune comorbidity in PSC was not associated with poorer outcomes [HR: 0.96 (95% CI: 0.71-1.28)].

CONCLUSIONS

Individuals with PSC and their first-degree relatives had higher odds of autoimmune disease compared to matched comparators. This finding provides validation for prior genetic discoveries at a phenotypic level. Autoimmune comorbidity did not impact severe outcomes.

Primary Sclerosing Cholangitis: Epidemiology, Diagnosis, and Presentation

Primary sclerosing cholangitis (PSC) is considered an immunologically mediated disease. However, some of its features are not consistent with the typical profile of autoimmune conditions. PSC is characterized by progressive biliary fibrosis that may ultimately result in the eventual development of cirrhosis. In recent years, multiple studies have reported that the incidence and prevalence of this disease are on the rise. Consequently, patients are often diagnosed without symptoms or signs of advanced liver disease, although many still present with signs of decompensated liver disease. This article discusses the epidemiology, clinical presentation, and diagnostic workup in patients with PSC.

Immune-mediated cholangiopathies in children: the need to better understand the pathophysiology for finding the future possible treatment targets

Cholangiopathies are defined as focal or extensive damage of the bile ducts. According to the pathogenetic mechanism, it may be immune-mediated or due to genetic, infectious, toxic, vascular, and obstructive causes. Their chronic evolution is characterized by inflammation, obstruction of bile flow, cholangiocyte proliferation, and progression toward fibrosis and cirrhosis. Immune-mediated cholangiopathies comprise primary sclerosing cholangitis (PSC), autoimmune cholangitis and IgG4-associated cholangitis in adults and biliary atresia (BA), neonatal sclerosing cholangitis (NSC) in children. The main purpose of this narrative review was to highlight the similarities and differences among immune-mediated cholangiopathies, especially those frequent in children in which cholangiocyte senescence plays a key role (BA, NSC, and PSC). These three entities have many similarities in terms of clinical and histopathological manifestations, and the distinction between them can be hard to achieve. In BA, bile duct destruction occurs due to aggression of the biliary cells due to viral infections or toxins during the intrauterine period or immediately after birth. The consequence is the activation of the immune system leading to severe inflammation and fibrosis of the extrahepatic biliary tract, lumen stenosis, and impairment of the biliary flow. PSC is characterized by inflammation and fibrosis of intra- and extrahepatic bile ducts, leading to secondary biliary cirrhosis. It is a multifactorial disease that occurs because of genetic predisposition [human leukocyte antigen (HLA) and non-HLA haplotypes], autoimmunity (cellular immune response, autoantibodies, association with inflammatory bowel disease), environmental factors (infections or toxic bile), and host factors (intestinal microbiota). NSC seems to be a distinct subgroup of childhood PSC that appears due to the interaction between genetic predisposition (HLA B8 and DR3) and the disruption of the immune system, validated by elevated IgG levels or specific antibodies [antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA)]. Currently, the exact mechanism of immune cholangiopathy is not fully understood, and further data are required to identify individuals at high risk of developing these conditions. A better understanding of the immune mechanisms and pathophysiology of BA, NSC, and PSC will open new perspectives for future treatments and better methods of preventing severe evolution.

Novel Genetic Risk Variants and Clinical Predictors Associated With Primary Sclerosing Cholangitis in Patients With Ulcerative Colitis

INTRODUCTION

Patients with ulcerative colitis (UC) who are likely to have primary sclerosing cholangitis (PSC) should be identified because PSC can influence UC clinical behavior and outcomes.The aim of this study was to establish a model incorporating clinical and genetic risk predictors that identifies patients with UC at risk of developing PSC.

METHODS

We conducted a retrospective case-control study. Inflammatory bowel disease cohorts from multiple institutions were used as discovery and replicate datasets. Quality control criteria, including minor allele frequency, call rates, Hardy-Weinberg equilibrium, cryptic relatedness, and population stratification (through principal components), were used. Discriminative accuracy was evaluated with area under the receiver operating characteristic curve.

RESULTS

Fifty-seven of 581 patients (9.8%) with UC had PSC. Multivariate analysis showed that patients with UC-PSC had more extensive disease (odds ratio [OR], 5.42; P = 1.57E-04), younger diagnosis age (younger than 20 years; OR, 2.22; P = 0.02), and less smoking (OR, 0.42; P = 0.02) than those with UC. After linkage disequilibrium pruning and multivariate analyses, 3 SNPs (rs3131621 at 6p21.33; rs9275596 and rs11244 at 6p21.32) at the HLA region were found associated with a 2- to 3-fold increased risk of PSC. Our model demonstrated good discriminatory power (area under the receiver operating characteristic curve, 88%).

DISCUSSION

Three variants in HLA (6p21.3) region significantly distinguished patients with UC-PSC from patients with UC alone. Once further validated in an independent large cohort, our model could be used to identify patients with UC at risk of PSC, and it could also help guide disease management.

Primary Sclerosing Cholangitis and Inflammatory Bowel Disease: A Review

Primary sclerosing cholangitis is a disease affecting around 0.006-0.016% of the population. Of these, around 75% have concomitant inflammatory bowel disease (IBD) according to the most recent epidemiological studies. Several theories have been proposed regarding the pathogenesis of primary sclerosing cholangitis (PSC). These include changes in the function of cholangiocytes, effects of the gut microbiome, association with specific human leukocyte antigen haplotypes and dysregulation of the immune system. However, these do not explain the observed association with IBD. Moreover, there are considerable differences in the frequency and outcomes between patients with PSC and ulcerative colitis compared with PSC and Crohn's disease. The aim of this review is to appraise the most recent studies that have contributed to the epidemiology, advances in the pathophysiology, and characterization of important clinical aspects of the association of PSC and IBD.

Environmental exposure as a risk-modifying factor in liver diseases: Knowns and unknowns

Liver diseases are considered to predominantly possess an inherited or xenobiotic etiology. However, inheritance drives the ability to appropriately adapt to environmental stressors, and disease is the culmination of a maladaptive response. Thus “pure” genetic and “pure” xenobiotic liver diseases are modified by each other and other factors, identified or unknown. The purpose of this review is to highlight the knowledgebase of environmental exposure as a potential risk modifying agent for the development of liver disease by other causes. This exercise is not to argue that all liver diseases have an environmental component, but to challenge the assumption that the current state of our knowledge is sufficient in all cases to conclusively dismiss this as a possibility. This review also discusses key new tools and approaches that will likely be critical to address this question in the future. Taken together, identifying the key gaps in our understanding is critical for the field to move forward, or at the very least to “know what we don't know.”

Recent advances in clinical practice: epidemiology of autoimmune liver diseases

Autoimmune liver diseases are chronic inflammatory hepatobiliary disorders that when classically defined encompass three distinctive clinical presentations; primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH). Meaningful changes in disease epidemiology are reported, with increasing incidence and prevalence of AIH and PSC in Europe, and rising prevalence of PBC across Europe, North America and the Asia-Pacific region. However, there appears to be very significant global variation with contemporary incidence rates of disease per 100 000 ranging from 0.84 to 2.75 for PBC, 0.1 to 4.39 for PSC and 0.4 to 2.39 for AIH. Prevalence corresponds, and per 100 000 estimates for PBC range from 1.91 to 40.2, for PSC between 0.78 and 31.7 and for AIH from 4.8 to 42.9. Population-based studies and multicentre observational cohort series provide improved understanding of the clinical course that patients experience, highlighting variations in presenting phenotypes geographically and temporally. Collectively, while autoimmune liver diseases are rare, the clinical burden is disproportionately high relative to population incidence and prevalence. Age, sex and race also impact clinical outcomes, and patient morbidity and mortality are reflected by high need for gastroenterology, hepatology and organ transplant services.

Geo-epidemiology and environmental co-variate mapping of primary biliary cholangitis and primary sclerosing cholangitis

Background & Aims

Autoimmune liver disease (AILD) is thought to result from a complex interplay between genetics and the environment. Studies to date have focussed on primary biliary cholangitis (PBC) and demonstrated higher disease prevalence in more urban, polluted, and socially deprived areas. This study utilises a large cohort of patients with PBC and primary sclerosing cholangitis (PSC) to investigate potential environmental contributors to disease and to explore whether the geo-epidemiology of PBC and PSC are disease-specific or pertain to cholestatic AILD in general.

Methods

All adult patients with PBC and PSC in a tightly defined geographical area within the UK were identified. Point- and area-based analyses and structural equation modelling (SEM) were used to investigate for disease clustering and examine for relationships between prevalence, distribution of environmental contaminants, and socio-economic status.

Results

We identified 2,150 patients with PBC and 472 with PSC. Significant spatial clustering was seen for each disease. A high prevalence of PBC was found in urban, post-industrial areas with a strong coal-mining heritage and increased environmental cadmium levels, whereas a high PSC prevalence was found in rural areas and inversely associated with social deprivation.

Conclusions

This study demonstrates spatial clustering of PBC and PSC and adds to our understanding of potential environmental co-variates for both diseases. Disease clustering, within the same geographical area but over different scales, is confirmed for each disease with distinct risk profiles identified and associations with separate putative environmental factors and socio-economic status. This suggests that different triggers and alternative pathways determine phenotypic expression of autoimmunity in the affected population. Co-variate analysis points towards the existence of specific disease triggers.

Lay summary

This study looked for potential environmental triggers in patients with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) living in the north-east of England and north Cumbria. We found that PBC was more common in urban areas with a history of coal mining and high levels of cadmium whereas PSC was more common in rural areas with lower levels of social deprivation.

•

Clustering of PBC and PSC patients occurs with notable geographical differences.

•

A high prevalence of PBC is seen in urban, post-industrial areas.

•

PSC is more common in rural areas and inversely associated with social deprivation.

•

PBC risk is associated with proximity to coal mines and environmental cadmium levels.

•

Comprehensive epidemiological study can increase understanding of disease aetiology.

The MBOAT7 rs641738 variant is associated with an improved outcome in primary sclerosing cholangitis

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease that causes liver cirrhosis, leading to liver failure. Additionally, PSC is a risk factor for cholangiocarcinoma. Its mechanism is unknown, and liver transplantation remains the sole curative option. The membrane bound O-acyltransferase domain containing 7 (MBOAT7) rs641738 and rs626283 variant alleles have been associated with both an accelerated progression of the disease and a higher risk for developing a more severe phenotype in many chronic hepatic diseases. Thus, we analysed their effect on long-term outcomes and laboratory parameters in PSC patients.

METHODS

We determined MBOAT7 genotypes and estimated the actuarial survival rate free of liver transplantation, using the Kaplan-Meier estimator. The differences between the estimates were analysed using the log-rank test. Patient blood was drawn and analysed for different serum parameters including cholestatic markers. Additionally, MBOAT7 RNA expression in human hepatic cell lines MZCHA1 (a biliary adenocarcinoma cell line), HepG2 (a hepatocellular carcinoma cell line), LX-2 (hepatic stellate cell line) and H-69 (cholangiocyte cell line) was analysed.

RESULTS

Transplant-free survival was significantly prolonged in carriers of two rs641738 variant alleles, which was referred to as the TT genotype (mean 19.6 years; 95% confidence interval [CI]: 16.3-22.9 years) compared to the CC (mean 15.4 years, 95% CI 12.8-18.0 years) and heterozygous genotypes (mean 13.2 years, 95% CI 11.4-15.0 years) (P=0.017). This effect was restricted to male patients. We confirmed the high expression of MBOAT7 in hepatic stellate cells and found that MBOAT7 is less expressed in biliary epithelial cell lines, compared to parenchymal hepatic cells.

CONCLUSIONS

Unlike other chronic liver diseases, carrying two MBOAT7 variant alleles does not seem to affect PSC patients negatively, but seems to have a positive effect on transplant-free survival. This study could help improve individual prognosis in PSC patients and give some new perspective on the involvement of the immune system in PSC.

Primary Sclerosing Cholangitis and Primary Biliary Cirrhosis Overlap Syndrome: A Review

Primary sclerosing cholangitis (PSC) and primary biliary cirrhosis (PBC) are slow progressive diseases which have been increasing in prevalence. The pathogeneses of PBC and PSC are incompletely understood but the underlying mechanisms appear to be fundamentally autoimmune in origin. Although PBC and PSC appear to be separate entities, overlap has been described. Diagnosis depends on a combination of serological markers, imaging, and pathological criteria. The mainstay of treatment has been ursodeoxycholic acid and in some cases of extrahepatic biliary obstruction and overlap disorder, endoscopic retrograde cholangiopancreatography has been useful.

Primary Sclerosing Cholangitis: A Clinical Update

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

[Hepatobiliary Manifestation of Inflammatory Bowel Disease]

The hepatobiliary system is one of the most common sites of extraintestinal manifestation in patients with inflammatory bowel disease (IBD). The progression of IBD can lead to a primary hepatobiliary manifestation and can occur secondary to multiple drugs or accompanying viral infections. Primary sclerosing cholangitis is the representative hepatobiliary manifestation of IBD, particularly in ulcerative colitis. Although most agents used in the treatment of IBD are potentially hepatotoxic, the risk of serious hepatitis or liver failure is low. The prevalence of HBV and HCV in IBD is similar to the general population, but the clinical concern is HBV reactivation associated with immunosuppressive therapy. Patients undergoing cytotoxic chemotherapy or immunosuppressive therapy with a moderate to high risk of HBV reactivation require prophylactic antiviral therapy. On the other hand, HCV has little risk of reactivation. Patients with IBD are more likely to have nonalcoholic fatty liver disease than the general population and tend to occur at younger ages. IBD and cholelithiasis are closely related, especially in Crohn's disease.

Clinicopathological and Molecular Specificities of Inflammatory Bowel Disease-Related Colorectal Neoplastic Lesions: The Role of Inflammation

Compared with the general population, patients with inflammatory bowel disease [IBD] have an increased risk of developing colorectal cancer. Molecular mechanisms underlying colorectal carcinogenesis in the setting of IBD are not well understood. However, modern molecular investigative tools have facilitated the identification of features that help distinguish IBD-related carcinoma from sporadic carcinoma. Moreover, with advances in endoscopic technology and improved understanding of the natural history, the management of colorectal neoplastic lesions in IBD patients has evolved. This review discusses the clinicopathological and molecular features of colorectal neoplastic lesions complicating IBD. Chronic inflammation is believed to promote the development of neoplasia, partly by producing reactive oxygen and nitrogen species [ROS and NOS], which may interact with genes involved in carcinogenetic pathways. Furthermore, alterations in microbiota and in the innate and adaptive immune responses might contribute to this process, particularly by initiating, regulating, and sustaining chronic inflammation. Earlier detection and better characterization of neoplastic colorectal lesions complicating IBD and a better knowledge of the molecular mechanisms underlying carcinogenesis in this setting should facilitate improvements in the risk stratification of patients with longstanding IBD and in the management of dysplastic and malignant colorectal lesions that arise in this setting.

Autoimmune Hepatitis, Sclerosing Cholangitis, and Autoimmune Sclerosing Cholangitis or Overlap Syndrome

Autoimmune hepatitis (AIH) is characterized by elevated serum aminotransferases, immunoglobulin G, autoantibodies, and interface hepatitis, in the absence of a known diagnosis. Presentation is varied. Therapy is with immunosuppression. There is inflammation of the intrahepatic and/or extrahepatic bile ducts in Sclerosing cholangitis (SC) and when associated with inflammatory bowel disease, it is known as primary SC, with Ursodeoxycholic acid used for therapy. The overlap of clinical, biochemical and histological features of AIH and PSC is known as autoimmune sclerosing cholangitis (ASC) or overlap syndrome. Liver transplantation is performed when medical treatment fails and both AIH and PSC may recur post-transplantation.

Clinical guidelines for primary sclerosing cholangitis 2017

BACKGROUND

Primary sclerosing cholangitis (PSC) is relatively rare disease and pathogenesis and methods of treatments were still not established. Then, we had conducted the making clinical guidelines to manage patients with PSC based on the literature review and expert opinions. These clinical guidelines were made for the medical doctors on the management of PSC, except child case of PSC.

METHODS

We had employed modified Delphi method. The production committee decided guidelines, strength of recommendations and evidence level after reviewed literatures systematically, and The Expert panel evaluated those. The Scientific Committee of the Japan Biliary Association (JBA) evaluated revised guidelines, and the Public comments were collected on web site of JBA.

RESULTS

We had made 16 guidelines about epidemiology/pathophysiology, diagnostics, therapy and prognosis. Also, we had made both diagnostic and therapeutic flow chart.

CONCLUSIONS

We hope that these guidelines will contribute to the improvement and development of the medical care of PSC.

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).

Pathogenesis and clinical spectrum of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a disease of the biliary tract, which has been documented in the literature since 1867. This disease has a strong predilection for affecting men and can be seen in individuals as young as 2 years of age. PSC has a strong associated with inflammatory bowel disease, more commonly with ulcerative colitis, and is also part of the clinical spectrum of IgG4-related diseases. Small-duct PSC, a variant of PSC, also has an association with inflammatory bowel disease. The exact pathogenesis of PSC is not well understood at present, however, is likely a combination of a genetic predisposition with alteration of the molecular structure of the gut. Abnormal serum liver chemistry and presence of certain autoimmune markers are usually the first indicators leading to a diagnosis of PCS, however, these may often be normal in early stages of this disease. The diagnosis is made by cholangiography, which is now considered the gold standard. PSC is a known pre-malignant condition. Such patients have an increased risk of developing cholangiocarcinoma, gallbladder neoplasia, and colon cancer. Many new treatment modalities have emerged in the recent past, including anti-tumor necrosis factor- α and anti-integrins; however, liver transplantation is the only known cure for PSC. Despite past and present research, PSC remains an enigmatic biliary disease with few viable treatment options.

Hepatic manifestations of inflammatory bowel diseases

Inflammatory bowel diseases are associated with various hepatobiliary disorders, reported both in Crohn's disease and ulcerative colitis. They may occur at any moment in the natural course of the disease. The prevalence of liver dysfunction rises from 3% to 50% accordingly to definitions used in different studies. Fatty liver is considered as the most common hepatobiliary complication in inflammatory bowel diseases while primary sclerosing cholangitis is the most specific one. Less frequently, inflammatory bowel diseases-associated hepatobiliary disorders include: autoimmune hepatitis/ primary sclerosing cholangitis overlap syndrome, IgG4-associated cholangiopathy, primary biliary cholangitis, hepatic amyloidosis, granulomatous hepatitis, cholelithiasis, portal vein thrombosis and liver abscess. The spectrum of these manifestations varies according to the type of inflammatory bowel diseases. Treatments of inflammatory bowel diseases may cause liver toxicity, although incidence of serious complications remains low. However, early diagnosis of drug-induced liver injury is of major importance as it affects future clinical management. When facing abnormal liver tests, clinicians should undertake a full diagnostic work-up in order to determine whether the hepatic abnormalities are related to the inflammatory bowel diseases or not. Management of hepatic manifestations in inflammatory bowel diseases usually involves both hepatologists and gastroenterologists because of the complexity of some situations.

The Role of Genetic and Immune Factors for the Pathogenesis of Primary Sclerosing Cholangitis in Childhood

Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease characterized by chronic inflammation of the biliary tree resulting in liver fibrosis. PSC is more common in male less than 40 years of age. The diagnosis of PSC is based on clinical, laboratory, image, and histological findings. A biochemical profile of mild to severe chronic cholestasis can be observed. Endoscopic retrograde cholangiography is the golden standard method for diagnosis, but magnetic resonance cholangiography is currently also considered a first-line method of investigation. Differences in clinical and laboratory findings were observed in young patients, including higher incidence of overlap syndromes, mostly with autoimmune hepatitis, higher serum levels of aminotransferases and gamma-glutamyl transferase, and lower incidence of serious complications as cholangiocarcinoma. In spite of the detection of several HLA variants as associated factors in large multicenter cohorts of adult patients, the exact role and pathways of these susceptibility genes remain to be determined in pediatric population. In addition, the literature supports a role for an altered immune response to pathogens in the pathogenesis of PSC. This phenomenon contributes to abnormal immune system activation and perpetuation of the inflammatory process. In this article, we review the role of immune and genetic factors in the pathogenesis of PSC in pediatric patients.

Impact of Concurrent Non-IBD Immunological Diseases on the Outcome of Primary Sclerosing Cholangitis

BACKGROUND

The association between primary sclerosing cholangitis (PSC) and underlying inflammatory bowel disease (IBD) is well established. There are scant data on the association between non-IBD immunological diseases (NID) and PSC outcomes. Our objective was to investigate the impact of NID on the clinical outcomes in patients with PSC.

METHODS

We included 287 patients with PSC from 1985 to 2013 from our tertiary care data registry. Univariate and multivariate analyses were performed to assess the risk factors for liver transplantation.

RESULTS

Of the 287 patients with PSC, 38 (13.2%) patients had at least 1 concomitant immunological disease other than IBD; 241 patients (84.0%) had concurrent IBD. The most frequent NIDs were autoimmune thyroiditis, autoimmune hepatitis, and rheumatoid arthritis. The median follow-up time did not differ significantly between PSC patients with and without NID (10.5 years versus 7.0 years, P = 0.04). We did not find significant difference in the median time from PSC diagnosis to liver transplantation between PSC patients with and without NID (5.2 versus 6.3 years, P = 0.74). In the subgroup analysis, there was no significant difference in the median time from PSC diagnosis to liver transplantation between the PSC-only group, PSC with IBD group, and PSC with NID group (5.4 versus 6.4 versus 5.2 years, P = 0.22).

CONCLUSIONS

The association of NID in patients with PSC did not seem to affect the need for liver transplantation or transplantation-free survival. The findings suggest that the increased load of autoimmunity, including the presence of IBD or NID, has a minimum impact on the disease outcome of PSC.

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.

Genetics in PSC: what do the "risk genes" teach us?

A role of genetics in primary sclerosing cholangitis (PSC) development is now firmly established. A total of 16 risk genes have been reported at highly robust ("genome-wide") significance levels, and ongoing efforts suggest that the list will ultimately be considerably longer. Importantly, this genetic risk pool so far accounts for less than 10 % of an estimated overall PSC susceptibility. The relative importance of genetic versus environmental factors (including gene-gene and gene-environment interactions) in remaining aspects of PSC pathogenesis is unknown, and other study designs than genome-wide association studies are needed to explore these aspects. For some of the loci, e.g. HLA and FUT2, distinct interacting environmental factors may exist, and working from the genetic associations may prove one valid path for determining the specific nature of environmental triggers. So far the biological implications for PSC risk genes are typically merely hypothesized based on previously published literature, and there is therefore a strong need for dedicated translational studies to determine their roles within the specific disease context of PSC. Apparently, most risk loci seem to involve in a subset of biological pathways for which genetic associations exist in a multitude of immune-mediated diseases, accounting for both inflammatory bowel disease as well as prototypical autoimmunity. In the present article, we will survey the current knowledge on PSC genetics with a particular emphasis on the pathophysiological insight potentially gained from genetic risk loci involving in this profound immunogenetic pleiotropy.

Fucosyltransferase 2: a genetic risk factor for primary sclerosing cholangitis and Crohn's disease--a comprehensive review

Fucosyltransferase 2 (FUT2) mediates the inclusion of fucose in sugar moieties of glycoproteins and glycolipids. ABO blood group antigens and host-microbe interactions are influenced by FUT2 activity. About 20 % of the population has a "non-secretor" status caused by inactivating variants of FUT2 on both alleles. The non-sense mutation G428A and the missense mutation A385T are responsible for the vast majority of the non-secretor status in Caucasians, Africans, and Asians, respectively. Non-secretor individuals do not secrete fucose-positive antigens and lack fucosylation in epithelia. They also appear to be protected against a number of infectious diseases, such as Norovirus and Rotavirus infections. In recent years, genome-wide association studies (GWAS) identified inactivating variants at the FUT2 locus to be associated with primary sclerosing cholangitis (PSC), Crohn's disease (CD), and biochemical markers of biliary damage. These associations are intriguing given the important roles of fucosylated glycans in host-microbe interactions and membrane stability. Non-secretors have a reduced fecal content of Bifidobacteria. The intestinal bacterial composition of CD patients resembles the one of non-secretors, with an increase in Firmicutes and decreases in Proteobacteria and Actinobacteria. Non-secretor individuals lack fucosylated glycans at the surface of biliary epithelium and display a different bacterial composition of bile compared to secretors. Notably, an intact biliary epithelial glycocalix is relevant for a stable 'biliary HCO3 (-) umbrella' to protect against toxic effects of hydrophobic bile salt monomers. Here, the biology of FUT2 will be discussed as well as hypotheses to explain the role of FUT2 in the pathophysiology of PSC and Crohn's disease.

Distinctive inflammatory bowel disease phenotype in primary sclerosing cholangitis

AIM: To review the current literature for the specific clinical characteristics of inflammatory bowel disease (IBD) associated with primary sclerosing cholangitis (PSC).

METHODS: A systematical review for clinical characteristics of IBD in PSC was performed by conducting a broad search for “primary sclerosing cholangitis” in Pubmed. “Clinical characteristics” were specified into five predefined subthemes: epidemiology of IBD in PSC, characteristics of IBD in PSC (i.e., location, disease behavior), risk of colorectal cancer development, IBD recurrence and de novo disease after liver transplantation for PSC, and safety and complications after proctocolectomy with ileal pouch-anal anastomosis. Papers were selected for inclusion based on their relevance to the subthemes, and were reviewed by two independent reviewers. Only full papers relevant to PSC-IBD were included. Additionally the references of recent reviews for PSC (< 5 years old) were scrutinized for relevant articles.

RESULTS: Initial literature search for PSC yielded 4704 results. After careful review 65 papers, comprising a total of 11406 PSC-IBD patients, were selected and divided according to subtheme. Four manuscripts overlapped and were included in two subthemes. Prevalence of IBD in PSC shows a large variance, ranging from 46.5% to 98.7% with ulcerative colitis (UC) being the most common type (> 75%). The highest IBD rates in PSC are found in papers reviewing both endoscopic and histological data for IBD diagnosis. Although IBD in PSC is found to be a quiescent disease, pancolitis occurs often, with rates varying from 35% to 95%. Both backwash ileitis and rectal sparing are observed infrequently. The development of dysplasia or colorectal carcinoma is increased in PSC-IBD; the cumulative 10 years risk varying between 0% and 11%. Exacerbation of IBD is common after liver transplantation for PSC and de novo disease is seen in 1.3% to 31.3% of PSC-IBD patients. The risk for development of pouchitis in PSC-IBD is found to be significant, affecting 13.8% to 90% of the patients after proctocolectomy with ileo anal-pouch anastomosis.

CONCLUSION: IBD in primary sclerosing cholangitis represents a distinct phenotype that differs from UC and Crohn’s disease and therefore requires specialized management.

Primary Biliary Cirrhosis and Primary Sclerosing Cholangitis: a Review Featuring a Women's Health Perspective

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are two major types of chronic cholestatic liver disease. Each disorder has distinguishing features and variable progression, but both may ultimately result in cirrhosis and hepatic failure. The following offers a review of PBC and PSC, beginning with a general overview of disease etiology, pathogenesis, diagnosis, clinical features, natural course, and treatment. In addition to commonly associated manifestations of fatigue, pruritus, and fat-soluble vitamin deficiency, select disease-related topics pertaining to women's health are discussed including metabolic bone disease, hyperlipidemia and cardiovascular risk, and pregnancy-related issues influencing maternal disease course and birth outcomes. This comprehensive review of PBC and PSC highlights some unique clinical considerations in the care of female patients with cholestatic liver disease.

Hepatobiliary manifestations of inflammatory bowel disease

Patients with inflammatory bowel diseases (IBDs) may present with several hepatic abnormalities. Some of these liver diseases are benign and only require observation, whereas others may cause liver failure and require liver transplantation. The aim of this review was to present and summarize the latest evidence on the most common liver diseases seen in patients with IBD. These manifestations can be divided in to 3 groups: those that are seen in association with IBD, those that are due to metabolic and physiologic changes induced by the IBD and those that are secondary to the drugs used in the treatment of IBD. Primary sclerosing cholangitis is one of the most common hepatobiliary manifestations of IBD that is more prevalent in patients with ulcerative colitis. There is no approved medical treatment for primary sclerosing cholangitis and about 50% of patients will require liver transplantation within 10 to 15 years from the time of diagnosis. Among the drugs that are commonly used in the treatment of IBD, thiopurines and methotrexate impose the higher risk of hepatotoxicity. In most cases, dose adjustment and avoidance of hepatotoxins will normalize the liver tests and discontinuation of the drug is required in a minority of cases. Reactivation of hepatitis B virus during immunosuppressive therapy is a major concern and adequate screening and vaccination is warranted. The approach to a patient with IBD who presents with abnormal liver chemistries can be challenging not only because 2 or more conditions can co-exist but also because management must be individualized.

Mechanisms of tissue injury in autoimmune liver diseases

Autoimmune diseases affecting the liver are mainly represented by autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). The characteristic morphologic patterns of injury are a chronic hepatitis pattern of damage in AIH, destruction of small intrahepatic bile ducts in PBC and periductal fibrosis and inflammation involving larger bile ducts in PSC. The factors responsible for initiation and perpetuation of the injury in all the three autoimmune liver diseases are not understood completely but are likely to be environmental triggers on the background of genetic variation in immune regulation. In this review, we summarise the current understanding of the mechanisms underlying the breakdown of self-tolerance in autoimmune liver diseases.

Update on inflammatory bowel disease in patients with primary sclerosing cholangitis

Patients with primary sclerosing cholangitis (PSC) complicated by inflammatory bowel disease (IBD) represent a distinct subset of patients with unique characteristics, which have serious clinical implications. The aim of this literature review was to shed light to the obscure clinical and molecular aspects of the two diseases combined utilizing current data available and putting issues of diagnosis and treatment into perspective. The prevalence of IBD, mainly ulcerative colitis in PSC patients is estimated to be 21%-80%, dependent on screening programs and nationality. PSC-associated colitis is likely to be extensive, characterized by rectal sparing, backwash ileitis, and generally mild symptoms. It is also more likely to progress to colorectal malignancy, making it imperative for clinicians to maintain a high level of suspicion when tackling PSC patients. There is no optimal surveillance strategy but current guidelines advocate that colonoscopy is necessary at the time of PSC diagnosis with annual endoscopic follow-up. Random biopsies have been criticized and a shift towards targeted biopsies using chromoendoscopy, laser endomicroscopy and narrow-band imaging has been noted. Techniques directed towards genetic mutations instead of histological abnormalities hold promise for easier, more accurate diagnosis of dysplastic lesions. Chemopreventive measures against colorectal cancer have been sought in these patients. Ursodeoxycholic acid seemed promising at first but subsequent studies yielded conflicting results showing anticarcinogenic effects in low doses (8-15 mg/kg per day) and carcinogenic properties in high doses (15-30 mg/kg per day).

Diagnosis and classification of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease of the liver and that is characterized by progressive inflammation, fibrosis, and stricturing of the intrahepatic and extrahepatic bile ducts. It is progressive in most patients and leads to cirrhosis. It is a rare disease, mostly affecting people of northern European descent, males greater than females. The diagnosis is best established by contrast cholangiography, which reveals a characteristic picture of diffuse, multifocal strictures and focal dilation of the bile ducts, leading to a beaded appearance. Inflammatory bowel disease (IBD) is present in ~75% of the patients with PSC, mostly ulcerative colitis (~85% of the cases). In addition to biliary cirrhosis, complications of PSC include dominant strictures of the bile ducts, cholangitis, cholangiocarcinoma, colon dysplasia and cancer in patients with IBD, gallbladder polyps and cancer, and hepatic osteodystrophy. The etiology of PSC is not clear, but studies are ongoing. The median survival without liver transplantation is 12 to 15 years after diagnosis. Currently there are no effective treatments except liver transplantation. Immunosuppressive medications have not been shown to be effective but antibiotics and anti-fibrotic agents seem promising.

Autoimmune liver disease, autoimmunity and liver transplantation

Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) represent the three major autoimmune liver diseases (AILD). PBC, PSC, and AIH are all complex disorders in that they result from the effects of multiple genes in combination with as yet unidentified environmental factors. Recent genome-wide association studies have identified numerous risk loci for PBC and PSC that host genes involved in innate or acquired immune responses. These loci may provide a clue as to the immune-based pathogenesis of AILD. Moreover, many significant risk loci for PBC and PSC are also risk loci for other autoimmune disorders, such type I diabetes, multiple sclerosis and rheumatoid arthritis, suggesting a shared genetic basis and possibly similar molecular pathways for diverse autoimmune conditions. There is no curative treatment for all three disorders, and a significant number of patients eventually progress to end-stage liver disease requiring liver transplantation (LT). LT in this context has a favourable overall outcome with current patient and graft survival exceeding 80% at 5years. Indications are as for other chronic liver disease although recent data suggest that while lethargy improves after transplantation, the effect is modest and variable so lethargy alone is not an indication. In contrast, pruritus rapidly responds. Cholangiocarcinoma, except under rigorous selection criteria, excludes LT because of the high risk of recurrence. All three conditions may recur after transplantation and are associated with a greater risk of both acute cellular and chronic ductopenic rejection. It is possible that a crosstalk between alloimmune and autoimmune response perpetuate each other. An immunological response toward self- or allo-antigens is well recognised after LT in patients transplanted for non-autoimmune indications and sometimes termed "de novo autoimmune hepatitis". Whether this is part of the spectrum of rejection or an autoimmune process is not clear. In this manuscript, we review novel findings about disease processes and mechanisms that lead to autoimmunity in the liver and their possible involvement in the immune response vs. the graft after LT.

Pathogenesis of primary sclerosing cholangitis and advances in diagnosis and management

Primary sclerosing cholangitis (PSC), first described in the mid-1850s, is a complex liver disease that is heterogeneous in its presentation. PSC is characterized by chronic cholestasis associated with chronic inflammation of the biliary epithelium, resulting in multifocal bile duct strictures that can affect the entire biliary tree. Chronic inflammation leads to fibrosis involving the hepatic parenchyma and biliary tree, which can lead to cirrhosis and malignancy. The etiology of PSC is not fully understood, which in part explains the lack of effective medical therapy for this condition. However, we have begun to better understand the molecular pathogenesis of PSC. The recognition of specific clinical subtypes and their pattern of progression could improve phenotypic and genotypic classification of the disease. We review our current understanding of this enigmatic disorder and discuss important topics for future studies.

Liver abnormalities in bowel diseases

Liver abnormalities are often seen in bowel diseases. Whether these represent aspects of two separate diseases, or if one is causing the other, is not always easy to decide. Extraintestinal manifestations of inflammatory bowel disease (IBD) or coeliac disease are frequently observed. Of these extraintestinal manifestations, hepatic disorders are among the most common. Primary sclerosing cholangitis (PSC) and primary biliary cirrhosis are the most frequent hepatic disorders in IBD and coeliac disease, respectively. Genetic studies have lately elucidated the associations between IBD and PSC, but there is still a long way until we have complete understanding of the molecular aetiology and pathophysiology of these conditions. There is no curative treatment available for PSC, besides liver transplantation. Steatosis and cholelithiasis are also common in IBD, as are signs of hepatic injury due to IBD treatment. Less common liver abnormalities include liver abscesses, hepatic thromboembolic events, granulomatous liver disease and hepatic amyloidosis.

Primary sclerosing cholangitis: diagnosis, prognosis, and management

Primary sclerosing cholangitis (PSC) is a chronic immune-mediated disease of the liver of unclear etiology, characterized by chronic inflammation and fibrosis of bile ducts. It primarily affects middle-aged men and is associated with 4-fold increased mortality as compared with an age- and sex-matched population. Progressive biliary and hepatic damage results in portal hypertension and hepatic failure in a significant majority of patients over a 10- to 15-year period from the initial diagnosis. In addition, PSC confers a markedly increased risk of hepatobiliary cancer, including cholangiocarcinoma and gallbladder cancer, as compared with the general population, and cancer is the leading cause of mortality in patients with PSC. It is associated with inflammatory bowel disease in 70% of patients and increases the risk of colorectal cancer almost 10-fold. Despite significant research efforts in this field, the pathogenic mechanisms of PSC are still incompletely understood, although growing evidence supports the role of genetic and immunologic factors. There are no proven medical therapies that alter the natural course of the disease. Thus, liver transplantation is the only available treatment for patients with advanced PSC, with excellent outcomes in this population.

The role of natural killer cells in autoimmune liver disease: a comprehensive review

Natural Killer (NK) cells are important players of the innate arm of the immune system and provide an early defense against pathogens and tumor-transformed cells. Peripheral blood NK (PB-NK) cells were first identified because of their ability to spontaneously kill tumor-cell targets in vitro without the need for specific antigen priming, which is the reason that they were named 'natural killer' cells. The characterization of NK cells in human tissues and body organs represented another important step forward to better understand their physiology and physiopathology. In this regard, many reports revealed over the past decade a differential anatomic distribution of NK cell subsets in several sites such as the intestine, lung, cervix, placenta and liver as well as in secondary lymphoid organs such as spleen, lymph nodes and tonsils. Among all these tissues, the liver is certainly unique as its parenchyma contains an unusually high number of infiltrating immune cells with 30-50% of total lymphocytes being NK cells. Given the constant liver intake of non-self antigens from the gastrointestinal tract via the portal vein, hepatic NK (H-NK) cells must retain a certain degree of tolerance in the context of their immune-surveillance against dangers to the host. Indeed, the breakdown of the tolerogenic state of the liver-associated immune system has been shown to induce autoimmunity. However, the role of NK cells during the course of autoimmune liver diseases is still being debated mainly because a complete characterization of H-NK cells normally resident in healthy human liver has not yet been fully disclosed. Furthermore, the differences in phenotype and functions between human and mouse H-NK cells often preclude translation of results obtained from murine models into experimental approaches to be performed in humans. Here, we provide an extensive characterization of the phenotype of H-NK cells physiologically resident in the human liver by both mentioning data available in literature and including a set of original results recently developed in our laboratory. We then review our current knowledge in regard to the contribution of H-NK cells in regulating local immune homeostasis and tolerance as well as in inducing the development of liver autoimmunity.

Primary sclerosing cholangitis is associated with autoreactive IgA antibodies against biliary epithelial cells

OBJECTIVE

Primary sclerosing cholangitis (PSC) is a chronic liver disease characterized by progressive destruction of the biliary tract system. Autoimmune reactions have been suggested to play a role in the etiology and pathogenesis of PSC, and a large number of different autoantibodies have been reported in PSC patients. However, the role of IgA, being the dominant immunoglobulin in bile and transported there via biliary epithelial cells, is still incompletely understood in PSC. The aim of this study was to evaluate the presence of autoreactive IgA in PSC patients.

MATERIAL AND METHODS

Cultures of biliary epithelial cells from healthy human liver tissue were established. Serum was collected from a total of 81 PSC patients and 42 healthy controls and tested for reactivity against biliary epithelial cells using flow cytometry. Patient characteristics were correlated with experimental findings.

RESULTS

The results showed that a majority of investigated PSC patients had autoreactive IgA against biliary epithelial cells, whereas these antibodies were almost absent in healthy individuals. Presence of autoreactive IgA in the PSC patients was not associated to gender, age, duration of disease, concomitant inflammatory bowel disease, or cholangiocarcinoma. Instead, the levels of autoreactive IgA correlated with higher total serum IgA levels and autoreactive IgA-positive patients progressed faster to a clinical endpoint (death or liver transplantation) compared to autoreactive IgA-negative patients.

CONCLUSIONS

The findings provide new insights into the role of IgA in PSC patients and opens up for future studies addressing pathogenic mechanisms of autoantibodies directed against biliary epithelial cells.

A frequent PNPLA3 variant is a sex specific disease modifier in PSC patients with bile duct stenosis

BACKGROUND AIMS

Primary sclerosing cholangitis predominantly affects males and is an important indication for liver transplantation. The rs738409 variant (I148M) of the PNPLA3 gene is associated with alcoholic and non-alcoholic liver disease and we evaluated its impact on the disease course of PSC.

METHODS

The I148M polymorphism was genotyped in 121 German PSC patients of a long-term prospective cohort and 347 Norwegian PSC patients.

RESULTS

In the prospective German cohort, actuarial survival free of liver transplantation was significantly reduced for I148M carriers (p = 0.011) compared to wildtype patients. This effect was restricted to patients with severe disease, as defined by development of dominant stenosis (DS) requiring endoscopic intervention. DS patients showed markedly decreased survival (p = 0.004) when carrying the I148M variant (I148M: mean 13.8 years; 95% confidence interval: 11.6-16.0 vs. wildtype: mean 18.6 years; 95% confidence interval: 16.3-20.9) while there was no impact on survival in patients without a DS (p = 0.87). In line with previous observations of sex specific effects of the I148M polymorphism, the effect on survival was further restricted to male patients (mean survival 11.9 years; 95% confidence interval: 10.0-14.0 in I148M carriers vs. 18.8 years; 95% confidence interval: 16.2-21.5 in wildtype; p<0.001) while female patients were unaffected by the polymorphism (p = 0.65). These sex specific findings were validated in the Norwegian cohort (p = 0.013).

CONCLUSIONS

In male PSC patients with severe disease with bile duct stenosis requiring intervention, the common I148M variant of the PNPLA3 gene is a risk factor for reduced survival.

PSC, AIH and overlap syndrome in inflammatory bowel disease

Primary sclerosing cholangitis (PSC) is a progressive, cholestatic disorder characterised by chronic inflammation and stricture formation of the biliary tree. Symptoms include pruritus, fatigue and in advanced cases ascending cholangitis, cirrhosis and end-stage hepatic failure. Patients are at an increased risk of malignancy arising from the bile ducts, gallbladder, liver and colon. The majority (>80%) of Northern European patients with PSC also have inflammatory bowel disease (IBD), usually ulcerative colitis (UC). IBD commonly presents before the onset of PSC, although the opposite can occur and the onset of both conditions can be separated by many years. The colitis associated with PSC is characteristically mild although frequently involves the whole colon. Despite the majority of patients having relatively inactive colonic disease, paradoxically the risk of colorectal malignancy is substantially increased. Patients may also develop dominant, stenotic lesions of the biliary tree which may be difficult to differentiate from cholangiocarcinoma and the coexistence of IBD may influence the development of this complication. Ursodeoxycholic acid may offer a chemoprotective effect against colorectal malignancy and improve liver biochemical indices. Evidence of any beneficial effect on histological progression of hepatobiliary disease is less clear. High doses (∼25-30 mg/kg/d) may be harmful and should be avoided. Autoimmune hepatitis (AIH) is less common in patients with IBD than PSC, however, an association has been observed. A small subgroup may have an overlap syndrome between AIH and PSC and management should be individualised dependant on liver histology, serum immunoglobulin levels, autoantibodies, degree of biochemical cholestasis and cholangiography.

Cutting edge issues in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic inflammatory liver disease characterized by the destruction of medium- to large-sized bile ducts and intense concentric fibrosis. Complications from PSC include bacterial cholangitis, cirrhosis, and cholangiocarcinoma and a therapy that might alter the natural history of the disease remains lacking. Our understanding of the pathogenesis of PSC also remains rudimentary but the strong association between PSC and inflammatory bowel disease suggest causal links between the diseases. The male predominance in PSC, lack of a defined, pathogenic auto-antigen, and the potential role of the innate immune system suggest that PSC may be due to dysregulation of immunity rather than a classic autoimmune disease. However, PSC shares several genetic susceptibility loci with other autoimmune diseases including the human leukocyte antigen DRB01*03 haplotype. The precise immune response of PSC is largely unknown but likely involves activation of the innate immune system by bacterial components delivered to the liver via the portal vein. Induction of adhesion molecules and chemokines leads to the recruitment of intestinal lymphocytes. Bile duct injury results from the sustained inflammation and production of inflammatory cytokines. Biliary strictures may cause further damage as a result of bile stasis and recurrent secondary bacterial cholangitis. Progress in our basic understanding of PSC is desperately needed in order to rationally design new therapeutic approaches to this disease.

Primary sclerosing cholangitis as an intractable disease

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown origin which eventually results in liver cirrhosis. The disease is reported to be more common among the Western population than in the Asian population. Asian experience remains limited. Diagnosis and treatment standards in the Far East have largely followed those in the West, including liver transplantation. Unlike in the West, however, recent reports from Japan have presented with a higher recurrence rate of PSC after liver transplantation, suggesting the intractable nature of the disease even after the replacement of the entire affected organ.

Current update on primary and secondary sclerosing cholangitis

Sclerosing cholangitis can be idiopathic (primary) or secondary to an identifiable cause. Irrespective of cause, sclerosing cholangitis usually progresses to end-stage liver disease and warrants orthotopic liver transplantation. Recent studies provide new insights into the etiopathogenesis, natural history, diagnosis, and management of these different entities.

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.

Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic liver condition which may affect both intra and extrahepatic biliary tree. Etiology of PSC remains to be fully elucidated but genetic, autoimmune, inflammatory and possibly infective factors could all contribute to its development. More than two-thirds of patients are males and the most commonly associated condition is an inflammatory bowel disease which occurs in up to 70% of affected subjects. Endoscopic cholangiopancreatography (ERCP) and magnetic resonanse cholangiopancreatography (MRCP) remain a gold standard in the diagnosis of this condition. No curative treatment of PSC exists and a proportion of patients who develop liver failure or suffer from recurrent episodes of cholangitis requires liver transplantation. PSC is associated with increased risk of malignancies, in particular cholangiocarcinoma which may arise in 12% of patients. The main aim of this chapter is to review the current knowledge on pathogenesis and clinical aspects of PSC as well as its associated malignancies.

Immune-mediated diseases in primary sclerosing cholangitis

BACKGROUND

Primary sclerosing cholangitis is a chronic cholestatic liver disease. An immune aetiology is suggested by associations between PSC and inflammatory bowel disease. Data on concomitant prevalence of other immune-mediated diseases is limited.

AIM

To assess the prevalence of concomitant immune-mediated diseases and the impact on disease outcome in PSC.

METHODS

We included 241 patients and retrospectively reviewed medical charts.

RESULTS

Altogether 172 (71.4%) patients had concomitant immune-mediated disease, including IBD (149, 61.8%), autoimmune hepatitis (15, 6.2%) and other immune-mediated diseases (47, 19.5%). Thirty nine patients (22.7%) had more than one immune-mediated disease other than PSC. Most frequent extrahepatic non-IBD immune-mediated diseases were sarcoidosis, thyroid disease, and type I diabetes mellitus. Age at PSC diagnosis was lower in patients with IBD. In patients with other immune-mediated diseases than autoimmune hepatitis or IBD, age at PSC diagnosis was higher. Younger age at diagnosis and concomitant IBD related to longer survival till death or liver transplantation.

CONCLUSIONS

In a large PSC population, a high prevalence of concomitant immune-mediated diseases was found. IBD occurred more often in early-acquired PSC, and the other immune-mediated diseases more often in later-acquired PSC. No effect on outcome was found for non-IBD immune mediated disease.

Risk factors for recurrence of primary sclerosing cholangitis after living donor liver transplantation in Japanese registry

The outcomes of primary sclerosing cholangitis (PSC) after living donor liver transplantation (LDLT) in a large series have not been reported. We aimed to determine long-term patient and graft survival, risk factors for PSC recurrence, and the significance of recurrence after LDLT in a Japanese registry. Questionnaires concerning patient characteristics, treatments, and clinical courses were used. Data of 114 patients undergoing primary LDLT for PSC from July 1996 to December 2008 in 29 institutions were evaluated. For strict diagnoses of recurrence, patients with hepatic artery thrombosis (n = 8), ABO-blood-type-incompatible transplantation (n = 8), and established ductopenic rejection (n = 2) were excluded and 96 patients were analyzed for risk factors. Recurrence was diagnosed in 26 patients (27%) at 8 to 79 months after transplantation. Patient, graft, and recurrence-free survivals were 78, 74 and 57% at 5 years after LDLT, respectively. The graft loss rate was 69 versus 23% in patients with versus without recurrence, respectively. Multivariate analysis revealed that high MELD scores, first-degree-relative donors, postoperative CMV infection, and early biliary anastomotic complications were significant risk factors for recurrence. PSC recurrence was a significant risk factor of graft loss but not patient death. PSC recurrence was frequent and had significant impacts on outcomes after LDLT.