norUrsodeoxycholic acid improves cholestasis in primary sclerosing cholangitis.

BACKGROUND & AIM: Primary sclerosing cholangitis (PSC) represents a devastating bile duct disease, currently lacking effective medical therapy. 24-norursodeoxycholic acid (norUDCA) is a side chain-shortened C23 homologue of UDCA and has shown potent anti-cholestatic, anti-inflammatory and anti-fibrotic properties in a preclinical PSC mouse model. A randomized controlled trial, including 38 centers from 12 European countries, evaluated the safety and efficacy of three doses of oral norUDCA (500mg/d, 1,000mg/d or 1,500mg/d) compared with placebo in patients with PSC. METHODS: One hundred sixty-one PSC patients without concomitant UDCA therapy and with elevated serum alkaline phosphatase (ALP) levels were randomized for a 12-week treatment followed by a 4-week follow-up. The primary efficacy endpoint was the mean relative change in ALP levels between baseline and end of treatment visit. RESULTS: norUDCA reduced ALP levels by -12.3%, -17.3%, and -26.0% in the 500, 1,000, and 1,500mg/d groups (p=0.029, p=0.003, and p<0.0001 when compared to placebo), respectively, while a +1.2% increase was observed in the placebo group. Similar dose-dependent results were found for secondary endpoints, such as ALT, AST, γ-GT, or the rate of patients achieving ALP levels <1.5× ULN. Serious adverse events occurred in seven patients in the 500mg/d, five patients in the 1,000mg/d, two patients in the 1500mg/d group, and three in the placebo group. There was no difference in reported pruritus between treatment and placebo groups. CONCLUSIONS: norUDCA significantly reduced ALP values dose-dependently in all treatment arms. The safety profile of norUDCA was excellent and comparable to placebo. Consequently, these results justify a phase III trial of norUDCA in PSC patients. Lay summary: Effective medical therapy for primary sclerosing cholangitis (PSC) is urgently needed. In this phase II clinical study in PSC patients, a side chain-shortened derivative of ursodeoxycholic acid, norursodeoxycholic acid (norUDCA), significantly reduced serum alkaline phosphatase levels in a dose-dependent manner during a 12-week treatment. Importantly, norUDCA showed a favorable safety profile, which was similar to placebo. The use of norUDCA in PSC patients is promising and will be further evaluated in a phase III clinical study. ClinicalTrials.gov number: NCT01755507.

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

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

The gut microbial profile in patients with primary sclerosing cholangitis is distinct from patients with ulcerative colitis without biliary disease and healthy controls.

OBJECTIVE: Gut microbiota could influence gut, as well as hepatic and biliary immune responses. We therefore thoroughly characterised the gut microbiota in primary sclerosing cholangitis (PSC) compared with healthy controls (HC) and patients with ulcerative colitis without liver disease. DESIGN: We prospectively collected 543 stool samples. After a stringent exclusion process, bacterial DNA was submitted for 16S rRNA gene sequencing. PSC and HC were randomised to an exploration panel or a validation panel, and only significant results (p<0.05, QFDR<0.20) in both panels were reported, followed by a combined comparison of all samples against UC. RESULTS: Patients with PSC (N=85) had markedly reduced bacterial diversity compared with HC (N=263, p<0.0001), and a different global microbial composition compared with both HC (p<0.001) and UC (N=36, p<0.01). The microbiota of patients with PSC with and without IBD was similar. Twelve genera separated PSC and HC, out of which 11 were reduced in PSC. However, the Veillonella genus showed a marked increase in PSC compared with both HC (p<0.0001) and UC (p<0.02). Using receiver operating characteristic analysis, Veillonella abundance yielded an area under the curve (AUC) of 0.64 to discriminate PSC from HC, while a combination of PSC-associated genera yielded an AUC of 0.78. CONCLUSIONS: Patients with PSC exhibited a gut microbial signature distinct from both HC and UC without liver disease, but similar in PSC with and without IBD. The Veillonella genus, which is also associated with other chronic inflammatory and fibrotic conditions, was enriched in PSC.

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.

Surrogate endpoints for clinical trials in primary sclerosing cholangitis: Review and results from an International PSC Study Group consensus process.

UNLABELLED: Primary sclerosing cholangitis (PSC) is a rare, but serious, cholestatic disease for which, to date, no effective therapy exists to halt disease progression toward end-stage liver disease. Clinical trial design to study drugs that improve prognosis is hampered by the relatively low event rate of clinically relevant endpoints. To overcome this shortcoming, there is an urgent need to identify appropriate surrogate endpoints. At present, there are no established surrogate endpoints. This article provides a critical review and describes the results of a consensus process initiated by the International PSC Study Group to delineate appropriate candidate surrogate endpoints at present for clinical trials in this frequently dismal disease. The consensus process resulted in a shortlist of five candidates as surrogate endpoints for measuring disease progression: alkaline phosphatase (ALP); transient elastography (TE); histology; combination of ALP+histology; and bilirubin. Of these, histology, ALP, and TE came out as the most promising. However, the expert panel concluded that no biomarker currently exceeds level 3 validation. Combining multiple endpoints is advisable. CONCLUSION: At present, there are insufficient data to support level 2 validation for any surrogate endpoint in PSC. Concerted efforts by all stakeholders are highly needed. Novel, promising noninvasive biomarkers are under study and should be incorporated as exploratory endpoints in clinical trials.

Liver transplantation in the Nordic countries - An intention to treat and post-transplant analysis from The Nordic Liver Transplant Registry 1982-2013.

AIM AND BACKGROUND: The Nordic Liver Transplant Registry (NLTR) accounts for all liver transplants performed in the Nordic countries since the start of the transplant program in 1982. Due to short waiting times, donor liver allocation has been made without considerations of the model of end-stage liver disease (MELD) score. We aimed to summarize key outcome measures and developments for the activity up to December 2013. MATERIALS AND METHODS: The registry is integrated with the operational waiting-list and liver allocation system of Scandiatransplant (www.scandiatransplant.org) and accounted at the end of 2013 for 6019 patients out of whom 5198 were transplanted. Data for recipient and donor characteristics and relevant end-points retransplantation and death are manually curated on an annual basis to allow for statistical analysis and the annual report. RESULTS: Primary sclerosing cholangitis, acute hepatic failure, alcoholic liver disease, primary biliary cirrhosis and hepatocellular carcinoma are the five most frequent diagnoses (accounting for 15.3%, 10.8%, 10.6%, 9.3% and 9.0% of all transplants, respectively). Median waiting time for non-urgent liver transplantation during the last 10-year period was 39 days. Outcome has improved over time, and for patients transplanted during 2004-2013, overall one-, five- and 10-year survival rates were 91%, 80% and 71%, respectively. In an intention-to-treat analysis, corresponding numbers during the same time period were 87%, 75% and 66%, respectively. CONCLUSION: The liver transplant program in the Nordic countries provides comparable outcomes to programs with a MELD-based donor liver allocation system. Unique features comprise the diagnostic spectrum, waiting times and the availability of an integrated waiting list and transplant registry (NLTR).

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.

Enhanced liver fibrosis score predicts transplant-free survival in primary sclerosing cholangitis.

UNLABELLED: There is a need to determine biomarkers reflecting disease activity and prognosis in primary sclerosing cholangitis (PSC). We evaluated the prognostic utility of the enhanced liver fibrosis (ELF) score in Norwegian PSC patients. Serum samples were available from 305 well-characterized large-duct PSC patients, 96 ulcerative colitis patients, and 100 healthy controls. The PSC patients constituted a derivation panel (recruited 1992-2006 [n = 167]; median age 41 years, 74% male) and a validation panel (recruited 2008-2012 [n = 138]; median age 40 years, 78% male). We used commercial kits to analyze serum levels of hyaluronic acid, tissue inhibitor of metalloproteinases-1, and propeptide of type III procollagen and calculated ELF scores by the previously published algorithm. Results were also validated by analysis of ELF tests using the ADVIA Centaur XP system and its commercially available reagents. We found that PSC patients stratified by ELF score tertiles exhibited significantly different transplant-free survival in both panels (P < 0.001), with higher scores associated with shorter survival, which was confirmed in the validation panel stratified by ELF test tertiles (P = 0.003). The ELF test distinguished between mild and severe disease defined by clinical outcome (transplantation or death) with an area under the curve of 0.81 (95% confidence interval [CI] 0.73-0.87) and optimal cutoff of 10.6 (sensitivity 70.2%, specificity 79.1%). In multivariate Cox regression analysis in both panels, ELF score (hazard ratio = 1.9, 95% CI 1.4-2.5, and 1.5, 95% CI 1.1-2.1, respectively) was associated with transplant-free survival independently of the Mayo risk score (hazard ratio = 1.3, 95% CI 1.1-1.6, and 1.6, 95% CI 1.2-2.1, respectively). The ELF test correlated with ultrasound elastography in separate assessments. CONCLUSION: The ELF score is a potent prognostic marker in PSC, independent of the Mayo risk score.

Four DNA methylation biomarkers in biliary brush samples accurately identify the presence of cholangiocarcinoma.

UNLABELLED: Early detection of the highly aggressive malignancy cholangiocarcinoma (CCA) remains a challenge but has the potential to render the tumor curable by surgical removal. This study evaluates a biomarker panel for the diagnosis of CCA by DNA methylation analyses of biliary brush samples. The methylation status of 13 candidate genes (CDO1, CNRIP1, DCLK1, FBN1, INA, MAL, SEPT9, SFRP1, SNCA, SPG20, TMEFF2, VIM, and ZSCAN18) was investigated in 93 tissue samples (39 CCAs and 54 nonmalignant controls) using quantitative methylation-specific polymerase chain reaction. The 13 genes were further analyzed in a test series of biliary brush samples (15 CCAs and 20 nonmalignant primary sclerosing cholangitis controls), and the methylation status of the four best performing markers was validated (34 CCAs and 34 primary sclerosing cholangitis controls). Receiver operating characteristic curve analyses were used to evaluate the performance of individual biomarkers and the combination of biomarkers. The 13 candidate genes displayed a methylation frequency of 26%-82% in tissue samples. The four best-performing genes (CDO1, CNRIP1, SEPT9, and VIM) displayed individual methylation frequencies of 45%-77% in biliary brushes from CCA patients. Across the test and validation biliary brush series, this four-gene biomarker panel achieved a sensitivity of 85% and a specificity of 98%, with an area under the receiver operating characteristic curve of 0.944. CONCLUSION: We report a straightforward biomarker assay with high sensitivity and specificity for CCA, outperforming standard brush cytology, and suggest that the biomarker panel, potentially in combination with cytological evaluation, may improve CCA detection, particularly among primary sclerosing cholangitis patients.

Indications and Outcomes in Liver Transplantation in Patients With Primary Sclerosing Cholangitis in Norway.

BACKGROUND: Primary sclerosing cholangitis (PSC) is 1 of the leading causes of liver transplantation (LTX) in Scandinavia, and an increasing number of PSC patients have been transplanted in Norway during the last 2 decades. This trend is partly attributable to the recently established practice in Norway of offering LTX to PSC patients with cholangiocellular dysplasia. Based on the controversy associated with this practice, we herein aimed to report the main features and outcomes of our LTX program in PSC. METHODS: The primary indication for LTX (quality of life/end-stage liver disease or suspected neoplasia) was retrospectively determined for 222 patients undergoing LTX for PSC or other autoimmune liver diseases (primary biliary cirrhosis/autoimmune hepatitis) with at least 5 years of follow-up. RESULTS: In PSC patients impaired quality of life (43.5%) and end-stage liver disease (38.4%) were the most frequent indications for LTX, whereas suspected neoplasia accounted for 18.1%. The proportion of PSC patients with manifest encephalopathy, variceal bleeding, or ascites declined over time. In patients with suspected neoplasia as the primary indication for LTX (n = 25), neoplasia was confirmed in the explanted liver in 20 patients (80%). Five-year survival rates for PSC patients transplanted between 2001 and 2009 were 91.9% for patients receiving LTX due to impaired quality of life or end-stage liver disease and 83.3% for suspected neoplasia. CONCLUSIONS: The PSC patients are increasingly listed for LTX at an earlier stage of their liver disease. In patients with suspected neoplasia before LTX, 5-year survival was acceptable, despite confirmation of neoplasia in 80% of the liver explants.

Refinement of the MHC risk map in a scandinavian primary sclerosing cholangitis population.

BACKGROUND: Genetic variants within the major histocompatibility complex (MHC) represent the strongest genetic susceptibility factors for primary sclerosing cholangitis (PSC). Identifying the causal variants within this genetic complex represents a major challenge due to strong linkage disequilibrium and an overall high physical density of candidate variants. We aimed to refine the MHC association in a geographically restricted PSC patient panel. METHODOLOGY/PRINCIPAL FINDINGS: A total of 365 PSC cases and 368 healthy controls of Scandinavian ancestry were included in the study. We incorporated data from HLA typing (HLA-A, -B, -C, -DRB3, -DRB1, -DQB1) and single nucleotide polymorphisms across the MHC (n = 18,644; genotyped and imputed) alongside previously suggested PSC risk determinants in the MHC, i.e. amino acid variation of DRß, a MICA microsatellite polymorphism and HLA-C and HLA-B according to their ligand properties for killer immunoglobulin-like receptors. Breakdowns of the association signal by unconditional and conditional logistic regression analyses demarcated multiple PSC associated MHC haplotypes, and for eight of these classical HLA class I and II alleles represented the strongest association. A novel independent risk locus was detected near NOTCH4 in the HLA class III region, tagged by rs116212904 (odds ratio [95% confidence interval] = 2.32 [1.80, 3.00], P = 1.35×10-11). CONCLUSIONS/SIGNIFICANCE: Our study shows that classical HLA class I and II alleles, predominantly at HLA-B and HLA-DRB1, are the main risk factors for PSC in the MHC. In addition, the present assessments demonstrated for the first time an association near NOTCH4 in the HLA class III region.

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

BACKGROUND & AIMS: Small duct primary sclerosing cholangitis (PSC) is phenotypically a mild version of large duct PSC, but it is unknown whether these phenotypes share aetiology. We aimed to characterize their relationship by investigating genetic associations in the human leucocyte antigen (HLA) complex, which represent the strongest genetic risk factors in large duct PSC. METHODS: Four classical HLA loci (HLA-A, HLA-B, HLA-C and HLA-DRB1) were genotyped in 87 small duct PSC patients, 485 large duct PSC patients and 1117 controls across three geographical regions. RESULTS: HLA-DRB1*13:01 (OR = 2.0, 95% CI 1.2-3.4, P = 0.01) and HLA-B*08 (OR = 1.6, 95% CI 1.1-2.4, P = 0.02) were significantly associated with small duct PSC compared with healthy controls. Based on the observed frequency of HLA-B*08 in small duct PSC, the strongest risk factor in large duct PSC, an estimated 32% (95% CI 4-65%) of this population can be hypothesized to represent early stages or mild variants of large duct PSC. This subgroup may be constituted by small duct PSC patients with inflammatory bowel disease (IBD), which greatly resembled large duct PSC in its HLA association. In contrast, small duct PSC without IBD was only associated with HLA-DRB1*13:01(P = 0.03) and was otherwise distinctly dissimilar from large duct PSC. CONCLUSIONS: Small duct PSC with IBD resembles large duct PSC in its HLA association and may represent early stages or mild variants of large duct disease. Different HLA associations in small duct PSC without IBD could indicate that this subgroup is a different entity. HLA-DRB1*13:01 may represent a specific risk factor for inflammatory bile duct disease.

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.

Immunosuppression after liver transplantation for primary sclerosing cholangitis influences activity of inflammatory bowel disease.

BACKGROUND & AIMS: Previous studies have shown conflicting results regarding the course of inflammatory bowel disease (IBD) after liver transplantation in patients with primary sclerosing cholangitis (PSC). We studied the progression of IBD in patients with PSC who have undergone liver transplantation. We also studied risk factors, including medical therapy, that could influence on IBD disease activity. METHODS: In a longitudinal multicenter study, we analyzed data from the Nordic Liver Transplant Group on 439 patients with PSC who underwent liver transplantation from November 1984 through December 2006; 353 had IBD at the time of transplantation. We compared IBD activity before and after liver transplantation. Two hundred eighteen patients who had an intact colon and had undergone pretransplant and post-transplant colonoscopies were characterized further. RESULTS: Macroscopic colonic inflammation was more frequent after liver transplantation than before liver transplantation (153 vs 124 patients; P < .001). The degree of inflammation decreased in 37 patients (17%), was unchanged in 93 patients (43%), and increased in 88 patients (40%) (P < .001). The rate of relapse after transplantation was higher than that before transplantation (P < .001), and overall clinical IBD activity also increased (P < .001). Young age at diagnosis of IBD and dual treatment with tacrolimus and mycophenolate mofetil were significant risk factors for increased IBD activity after transplantation, whereas combination treatment with cyclosporin A and azathioprine had protective effects. CONCLUSIONS: Immunosuppression affects IBD activity after liver transplantation in patients with PSC; a shift from present standard maintenance treatment of tacrolimus and mycophenolate mofetil to cyclosporin A and azathioprine should be considered for these patients.

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.

Novel target genes and a valid biomarker panel identified for cholangiocarcinoma.

Cholangiocarcinoma is notoriously difficult to diagnose, and the mortality rate is high due to late clinical presentation. CpG island promoter methylation is frequently seen in cancer development. In the present study, we aimed at identifying novel epigenetic biomarkers with the potential to improve the diagnostic accuracy of cholangiocarcinoma. Microarray data analyses of cholangiocarcinoma cell lines treated with epigenetic drugs and their untreated counterparts were compared with previously published gene expression profiles of primary tumors and with non-malignant controls. Genes responding to the epigenetic treatment that were simultaneously downregulated in primary cholangiocarcinoma compared with controls (n = 43) were investigated for their promoter methylation status in cancer cell lines from the gastrointestinal tract. Genes commonly methylated in cholangiocarcinoma cell lines were subjected to quantitative methylation-specific polymerase chain reaction in a total of 93 clinical samples (cholangiocarcinomas and non-malignant controls). CDO1, DCLK1, SFRP1 and ZSCAN18, displayed high methylation frequencies in primary tumors and were unmethylated in controls. At least one of these four biomarkers was positive in 87% of the tumor samples, with a specificity of 100%. In conclusion, the novel methylation-based biomarker panel showed high sensitivity and specificity for cholangiocarcinoma. The potential of these markers in early diagnosis of this cancer type should be further explored.

Colorectal neoplasia in patients with primary sclerosing cholangitis undergoing liver transplantation: a Nordic multicenter study.

OBJECTIVE: Several studies have implicated primary sclerosing cholangitis (PSC) as an additional risk factor for colorectal neoplasia in inflammatory bowel disease (IBD). Some reports have indicated that the risk is even higher in PSC-IBD patients after liver transplantation (Ltx), but this issue is controversial. We aimed to compare the risk of colorectal neoplasia in PSC-IBD patients before and after Ltx and to identify risk factors for colorectal neoplasia post-transplant. MATERIAL AND METHODS: In a multicenter study within the Nordic Liver Transplant Group, we assessed the risk of colorectal neoplasia by using the competing risk regression analysis. RESULTS: Among the 439 PSC patients included, 353 (80%) had IBD at the time of Ltx and 15 (3%) patients developed de novo IBD post-Ltx. The median duration of IBD was 15 (0-50) years at the time of Ltx and follow-up after Ltx was 5 (0-20) years. Ninety-one (25%) PSC-IBD patients developed colorectal neoplasia. The cumulative risk of colorectal neoplasia was higher after than before Ltx (HR: 1.9, 95% CI: 1.3-2.9, p = 0.002). A multivariate analysis demonstrated aminosalicylates and ursodeoxycholic acid as significantly associated with an increased risk of colorectal neoplasia post-Ltx. Duration and activity of IBD did not significantly affect the risk of neoplasia. CONCLUSION: The even higher risk of colorectal neoplasia in PSC-IBD patients after when compared with that of before Ltx underscores the importance of regular surveillance colonoscopies post-Ltx. The association of aminosalicylates and ursodeoxycholic acid to the development of colorectal neoplasia after Ltx should be further investigated.

Extended analysis of a genome-wide association study in primary sclerosing cholangitis detects multiple novel risk loci.

BACKGROUND & AIMS: A limited number of genetic risk factors have been reported in primary sclerosing cholangitis (PSC). To discover further genetic susceptibility factors for PSC, we followed up on a second tier of single nucleotide polymorphisms (SNPs) from a genome-wide association study (GWAS). METHODS: We analyzed 45 SNPs in 1221 PSC cases and 3508 controls. The association results from the replication analysis and the original GWAS (715 PSC cases and 2962 controls) were combined in a meta-analysis comprising 1936 PSC cases and 6470 controls. We performed an analysis of bile microbial community composition in 39 PSC patients by 16S rRNA sequencing. RESULTS: Seventeen SNPs representing 12 distinct genetic loci achieved nominal significance (p(replication) <0.05) in the replication. The most robust novel association was detected at chromosome 1p36 (rs3748816; p(combined)=2.1 × 10(-8)) where the MMEL1 and TNFRSF14 genes represent potential disease genes. Eight additional novel loci showed suggestive evidence of association (p(repl) <0.05). FUT2 at chromosome 19q13 (rs602662; p(comb)=1.9 × 10(-6), rs281377; p(comb)=2.1 × 10(-6) and rs601338; p(comb)=2.7 × 10(-6)) is notable due to its implication in altered susceptibility to infectious agents. We found that FUT2 secretor status and genotype defined by rs601338 significantly influence biliary microbial community composition in PSC patients. CONCLUSIONS: We identify multiple new PSC risk loci by extended analysis of a PSC GWAS. FUT2 genotype needs to be taken into account when assessing the influence of microbiota on biliary pathology in PSC.

Inflammatory bowel disease in patients with primary sclerosing cholangitis: clinical characterization in liver transplanted and nontransplanted patients.

BACKGROUND: Inflammatory bowel disease (IBD) in patients with primary sclerosing cholangitis (PSC) seems to differ from IBD without PSC, but a systematic, prospective study of IBD in PSC has until now not been reported. We aimed to describe the clinical, endoscopic, and histopathologic features of PSC-IBD in liver-transplanted and nontransplanted patients. METHODS: PSC patients (n = 184) were included and underwent ileocolonoscopy with assessment of segmental histopathology. RESULTS: A total of 155 (84%) patients had IBD, of whom 39 (25%) had undergone colectomy. The patients with an intact colon and complete tissue samples (n = 110) were further investigated. Forty-two (38%) patients had undergone liver transplantation. The median IBD duration was 11 (range, 0-50) years. The majority (65%) had no or sparse IBD symptoms. Inflammatory findings were more frequent by histology than by endoscopy (89% versus 47%, P < 0.001). Histopathological signs of inflammation involved the right colon in 86% of patients and were purely right-sided in 23%. The findings of inflammation were higher in the right compared to the left colon (P < 0.001), but the general inflammatory activity was low. Backwash ileitis was demonstrated in 20% (17/87) of patients and rectal sparing in 65% (70/107). The liver-transplanted patients had lower clinical (P = 0.035) and histological (P = 0.013) IBD activity than the nontransplanted group. CONCLUSIONS: PSC-IBD may represent a distinct entity of colitis in which low endoscopic activity may mask an active histologic inflammation that possibly contributes to an increased risk of malignancy. Circumstances related to liver transplantation seem to act favorably on colonic inflammation in PSC.

TGR5 sequence variation in primary sclerosing cholangitis.

TGR5, the G-protein-coupled bile acid receptor 1 (GPBAR1), has been linked to inflammatory pathways and homeostasis, and could therefore be involved in primary sclerosing cholangitis (PSC), a chronic inflammatory bile duct disease associated with ulcerative colitis (UC). In addition, the TGR5 gene is localized at chromosome 2q35, close to a genetic variant associated with both PSC and UC in recent genome-wide association studies. This provided a strong rationale for a recent study searching for novel genetic variants of TGR5 in PSC. In the study, resequencing of TGR5 was performed in 267 PSC patients and 274 healthy controls. Six nonsynonymous mutations were identified in addition to 16 other novel single-nucleotide polymorphisms. In experimental studies, five of the nonsynonymous mutations were found to reduce or abolish TGR5 function by affecting localization or activity. Fine-mapping of the chromosome 2q35 locus in large patient panels revealed an overall association between a common TGR5 single-nucleotide polymorphism and PSC and UC, but strong linkage disequilibrium precluded demarcation of TGR5 from neighboring genes. In conclusion, the data from the experimental evaluation of novel nonsynonymous mutations represent an important insight into the structural biology of TGR5. In addition, the combination of the known roles of the receptor, the genetic associations and the mutations which affect receptor function, suggests that TGR5 variation may contribute to PSC and UC susceptibility. However, this conclusion needs to be strengthened in further research.