Primary sclerosing cholangitis is associated with abnormalities in CFTR.

BACKGROUND: The etiology of primary sclerosing cholangitis (PSC) is unknown. PSC and Cystic Fibrosis related liver disease have common features: chronic inflammation, biliary damage and similar cholangiographic findings. It is unknown whether or not PSC is related to cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction. We hypothesize that a sub-group of PSC patients may be a "single-organ" presentation of CF. METHODS: Patients with PSC underwent nasal potential difference (NPD) measurement, sweat chloride measurement and complete CFTR sequencing by new generation sequencing. RESULTS: 6/32 patients aged 46 ±â€¯13 yrs. had CFTR causing mutations on one allele and 19 had CFTR polymorphisms; 6/23 tested had abnormal and 21 had intermediate sweat tests; 4/32 patients had abnormal NPD. One patient had chronic pancreatitis and was infertile. CONCLUSIONS: 19% of PSC patients had features of CFTR related disorder, 19% carry CFTR mutations and 50% had CFTR polymorphisms. In some patients, PSC may be a single organ presentation of CF or a CFTR-related disorder.

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.

Differences in Phenotypes and Liver Transplantation Outcomes by Age Group in Patients with Primary Sclerosing Cholangitis.

BACKGROUND: There is increasing evidence for a heterogeneity of phenotypes in primary sclerosing cholangitis (PSC), but differences across the age spectrum in adults with PSC have not been well characterized. AIMS: To characterize phenotypic variations and liver transplantation outcomes by age group in adults with PSC. METHODS: The United Network for Organ Sharing database was used to identify waitlist registrations for primary liver transplantation in adults with PSC. Patients were split into three age groups: 18-39 (young), 40-59 (middle-aged), and ≥60 (older). Their clinical characteristics and outcomes on the waitlist and post-transplant were compared. RESULTS: Overall, 8272 adults with PSC were listed for liver transplantation during the study period, of which 28.9% were young, 52.0% were middle-aged, and 19.1% were older. The young age group had the greatest male predominance (70.0 vs. 66.2 vs. 65.1%, p = 0.001), the highest proportion of black individuals (20.0 vs. 11.0 vs. 5.5%, p < 0.001), and the most patients listed with concomitant autoimmune hepatitis (2.2 vs. 1.0 vs. 0.8%, p < 0.001). Older patients experienced the greatest waitlist and post-transplant mortality. Graft survival was greatest in the middle-aged group. Young patients were most likely to experience acute rejection (31 vs. 22.8 vs. 18.0%, p < 0.001) and have graft failure due to chronic rejection or PSC recurrence (47.8 vs. 42.3 vs. 17.9%, p < 0.001). CONCLUSIONS: Age-related differences exist among adults with PSC and are associated with outcomes pre- and post-transplant. Young patients may have a more robust immune-related phenotype that is associated with poorer graft survival. Future studies are needed to further investigate these 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 and its relationship to the colon in a black cohort of inflammatory bowel disease patients.

BACKGROUND: Recent studies have identified subgroups of inflammatory bowel disease (IBD) patients at increased likelihood for developing primary sclerosing cholangitis (PSC). Most studies look at predominantly white populations. GOALS: The aim of our study was to determine the characteristics of PSC in a black cohort of patients and its relationship to disease location in IBD. STUDY: A retrospective analysis was performed on IBD patients over the age of 18 years. RESULTS: Of the 209 black patients identified as having IBD, 7 (3.5%) had a concomitant diagnosis of PSC; 5/138 (3.6%) ulcerative colitis (UC) patients, and 2/71 (2.8%) Crohn's disease patients (CD). Numerically, more males developed PSC in both the UC and CD subgroups. Age at diagnosis of IBD tended to be younger among PSC cohorts. All PSC-UC patients had pancolitis (P<0.0001), and all PSC-CD patients had a colonic component to their disease. In the UC cohort, PSC patients were statistically more likely to be on immunosuppressive therapy (P<0.0001). CONCLUSIONS: With greater research, physicians will better recognize IBD phenotypes at highest risk of PSC and hopefully identify complications of PSC, including cholangiocarcinoma.

Genome-wide association analysis in primary sclerosing cholangitis and ulcerative colitis identifies risk loci at GPR35 and TCF4.

UNLABELLED: Approximately 60%-80% of patients with primary sclerosing cholangitis (PSC) have concurrent ulcerative colitis (UC). Previous genome-wide association studies (GWAS) in PSC have detected a number of susceptibility loci that also show associations in UC and other immune-mediated diseases. We aimed to systematically compare genetic associations in PSC with genotype data in UC patients with the aim of detecting new susceptibility loci for PSC. We performed combined analyses of GWAS for PSC and UC comprising 392 PSC cases, 987 UC cases, and 2,977 controls and followed up top association signals in an additional 1,012 PSC cases, 4,444 UC cases, and 11,659 controls. We discovered novel genome-wide significant associations with PSC at 2q37 [rs3749171 at G-protein-coupled receptor 35 (GPR35); P = 3.0 × 10(-9) in the overall study population, combined odds ratio [OR] and 95% confidence interval [CI] of 1.39 (1.24-1.55)] and at 18q21 [rs1452787 at transcription factor 4 (TCF4); P = 2.61 × 10(-8) , OR (95% CI) = 0.75 (0.68-0.83)]. In addition, several suggestive PSC associations were detected. The GPR35 rs3749171 is a missense single nucleotide polymorphism resulting in a shift from threonine to methionine. Structural modeling showed that rs3749171 is located in the third transmembrane helix of GPR35 and could possibly alter efficiency of signaling through the GPR35 receptor. CONCLUSION: By refining the analysis of a PSC GWAS by parallel assessments in a UC GWAS, we were able to detect two novel risk loci at genome-wide significance levels. GPR35 shows associations in both UC and PSC, whereas TCF4 represents a PSC risk locus not associated with UC. Both loci may represent previously unexplored aspects of PSC pathogenesis.

Primary sclerosing cholangitis, Crohn's disease and HLA-B27 in black South African women.

Crohn's disease is rare in South African black people and primary sclerosing cholangitis (PSC) is also rare in black patients with IBD, from South Africa. The presence of HLA-B27 is generally associated with seronegative spondylo-arthropathies and correlates with the occurrence of ankylosing spondylitis, recurrent mouth ulcers and uveitis, in patients with IBD. We describe two women with the combination of Crohn's disease, PSC and HLA-B27 from our cohort of the last 5 years of three black patients with Crohn's disease. Crohn's disease, PSC and HLA-B27 respectively, occur rarely in black South Africans and their concurrent presence in two black women suggests a pathogenetic link of HLA-B27 between Crohn's disease and PSC in this population. Female gender might be an additional determinant in this setting.

The prevalence, incidence and natural history of primary sclerosing cholangitis in an ethnically diverse population.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a rare chronic cholestatic liver disease often associated with inflammatory bowel diseases (IBD). Current epidemiological data are limited to studies of predominantly Caucasian populations. Our aim was to define the epidemiology of PSC in a large, ethnically diverse US population. METHODS: The Northern California Kaiser Permanente (KP) database includes records from over 3 million people and was searched for cases of PSC between January 2000 and October 2006. All identified charts were reviewed for diagnosis confirmation, IBD co-morbidity, and major natural history endpoints. RESULTS: We identified 169 (101 males) cases fulfilling PSC diagnostic criteria with a mean age at diagnosis of 44 years (range 11-81). The age-adjusted point prevalence was 4.15 per 100,000 on December 31, 2005. The age-adjusted incidence per 100,000 person-years was not significantly greater in men 0.45 (95% CI 0.33-0.61) than women 0.37 (95% CI 0.26-0.51). IBD was present in 109/169 (64.5%) cases and was significantly more frequent in men than women with PSC (73.3% and 51.5%, respectively, p = 0.005). The cumulative average yearly mortality rate was 1.9%. Age and serum sodium, creatinine and bilirubin at diagnosis and albumin at last entry were identified as significant factors associated with death, liver transplant or cholangiocarcinoma. CONCLUSIONS: The incidence and prevalence of PSC observed in a representative Northern California population are lower compared to previous studies in Caucasian populations and this might reflect differences in the incidence of PSC among various ethnic groups.

Three ulcerative colitis susceptibility loci are associated with primary sclerosing cholangitis and indicate a role for IL2, REL, and CARD9.

UNLABELLED: Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by inflammation and fibrosis of the bile ducts. Both environmental and genetic factors contribute to its pathogenesis. To further clarify its genetic background, we investigated susceptibility loci recently identified for ulcerative colitis (UC) in a large cohort of 1,186 PSC patients and 1,748 controls. Single nucleotide polymorphisms (SNPs) tagging 13 UC susceptibility loci were initially genotyped in 854 PSC patients and 1,491 controls from Benelux (331 cases, 735 controls), Germany (265 cases, 368 controls), and Scandinavia (258 cases, 388 controls). Subsequently, a joint analysis was performed with an independent second Scandinavian cohort (332 cases, 257 controls). SNPs at chromosomes 2p16 (P-value 4.12 × 10(-4) ), 4q27 (P-value 4.10 × 10(-5) ), and 9q34 (P-value 8.41 × 10(-4) ) were associated with PSC in the joint analysis after correcting for multiple testing. In PSC patients without inflammatory bowel disease (IBD), SNPs at 4q27 and 9q34 were nominally associated (P < 0.05). We applied additional in silico analyses to identify likely candidate genes at PSC susceptibility loci. To identify nonrandom, evidence-based links we used GRAIL (Gene Relationships Across Implicated Loci) analysis showing interconnectivity between genes in six out of in total nine PSC-associated regions. Expression quantitative trait analysis from 1,469 Dutch and UK individuals demonstrated that five out of nine SNPs had an effect on cis-gene expression. These analyses prioritized IL2, CARD9, and REL as novel candidates. CONCLUSION: We have identified three UC susceptibility loci to be associated with PSC, harboring the putative candidate genes REL, IL2, and CARD9. These results add to the scarce knowledge on the genetic background of PSC and imply an important role for both innate and adaptive immunological factors.

Primary sclerosing cholangitis in genetically diverse populations listed for liver transplantation: unique clinical and human leukocyte antigen associations.

Primary sclerosing cholangitis (PSC) is well characterized in European populations. We aimed to characterize clinical characteristics and human leukocyte antigen (HLA) associations in a population of European American, Hispanic, and African American PSC patients listed for liver transplantation (LT). Population-stratified demographic, clinical, and HLA data from 6767 LT registrants of the United Network for Organ Sharing who had a diagnosis of PSC (4.7% of the registrants) were compared to data from registrants with other diagnoses. Compared to European Americans and Hispanics, African Americans were significantly younger (46.6 ± 13.7, 42.3 ± 15.9, and 39.7 ± 13.1 years, respectively; P = 0.002) and were listed with a higher Model for End-Stage Liver Disease score (15.2 ± 7.5, 14.9 ± 7.6, and 18.1 ± 9.3, respectively; P = 0.001); they were also less frequently noted to have inflammatory bowel disease in comparison with European Americans (71.4% versus 60.5%, P < 0.01). In multivariate analysis, African origin was a significant factor associated with listing for LT with PSC (odds ratio with respect to European Americans = 1.325, 95% confidence interval = 1.221-1.438). HLA associations in European Americans, Hispanics, and African Americans with PSC versus alcoholic liver disease were detected for HLA-B8, HLA-DR13, and protective HLA-DR4. However, HLA-DR3, which is in linkage disequilibrium with HLA-B8, showed associations only in European Americans and Hispanics. In conclusion, African Americans with PSC who are listed for LT differ clinically from European Americans and Hispanics. The association with HLA-B8 but not HLA-DR3 in African Americans should make possible the refinement of the HLA associations in PSC.

Primary sclerosing cholangitis--what is the difference between east and west?

Primary sclerosing cholangitis (PSC) is a chronic, progressive, cholestatic liver disease characterized by inflammation and fibrotic obliteration of the hepatic biliary tree. It is commonly associated with inflammatory bowel disease (IBD). A number of complications can occur which require special consideration, the most important of which is the development of cholangiocellular carcinoma (CCC). Unfortunately, no medical therapy is currently available for the underlying liver disease. Liver transplantation is an effective, life-extending option for patients with advanced PSC. Geographical variations between East and West include a second peak for age with a lower association with IBD in a Japanese population and female predominance in a lone study from Turkey. The clinical and biochemical Mayo criteria may not be universally applicable, as different patients show variations regarding the initial presentation and natural course of the disease. Directing research towards explaining these geographical differences and understanding the pathogenesis of PSC is required in order to develop better therapies for this devastating disease.

Autoimmune liver disease and the Canadian First Nations Aboriginal Communities of British Columbia's Pacific Northwest.

Primary biliary cirrhosis (PBC) is a well-known but uncommon chronic liver disease that is presumed to be of autoimmune etiology. Recently, investigations in British Columbia (BC), a province of Canada situated along the Pacific North-West of North America, have suggested that PBC is not a rare disease amongst BC's Aboriginal (i.e. First Nations) communities. Geographically, BC is adjacent to South East Alaska, an American state that has also reported an increased prevalence of PBC amongst its Aboriginal communities. In this article, the medical evidence supporting a hypothesis of increased risk of PBC amongst BC's First Nations communities is reviewed. Evidence suggesting that autoimmune hepatitis is also more likely amongst BC's First Nations communities is also presented.