Primary Sclerosing Cholangitis Risk Research Articles

P0443 Prognosis of primary sclerosing cholangitis (PSC) in Hungary is independent of coexisting inflammatory bowel disease (IBD) and prognostic ability of the currently used PSC risk scores are limited

Abstract Background Primary sclerosing cholangitis (PSC) is a rare, chronic disorder of the intra- and extrahepatic biliary tree characterized by cholestasis, periductal inflammation and fibrosis. Currently, there is very limited epidemiological data from the Central-Eastern European region. We assessed disease characteristics and natural history of PSC in a bicentre Hungarian cohort and compared its outcome with respect to co-existing inflammatory bowel disease (IBD). Methods Imaging, laboratory and clinical data including presence of IBD, variant syndrome, disease course and outcome were prospectively collected in two large Hungarian Clinical Centre Patients were followed on a yearly basis. Median diseases follow-up (FUP) time was 8.82 (IQR: 5.2-13.5) years. A wide range of clinical scoring systems were applied. Poor disease outcome was defined as orthotopic liver transplantation (LT) and/or liver-related death during the FUP. Results Of 135 patients (57.8% males; median age at diagnosis: 31 [IQR: 20-47] yrs) with confirmed PSC, 73 (54.1%) had coexisting IBD. Nineteen patients already had cirrhosis at diagnosis and 31 more developed it during the FUP. A total of 21 (15.6%) patients died of which 85.7% were liver-related deaths. Twenty-five patients (18.5%) underwent liver transplantation (LT). Twenty-three (17%) patients developed malignancy (9 cholangiocarcinoma, 3 hepatocellular carcinoma, 6 colorectal carcinoma and 6 non-gastrointestinal malignancy) during the FUP. Patients with IBD were younger and had higher Mayo and Amsterdam-Oxford scores at diagnosis compared to those without, however there was no difference in disease outcomes in these groups (p=0.133). Clinical scores at diagnosis had moderate prognostic ability for poor disease outcome (AUROC [95%CI], Mayo score: 0.637 [0.521-0.753]; p=0.018; Amsterdam-Oxford: 0.687 [0.576-0.798]; p=0.002; p<0.001; UK-long: 0.695 [0.588-0.803]; p<0.001), except UK-short PSC risk score (0.745 [0.643-0.847]). Persistent alkaline phosphatase (ALP) increase, despite ursodeoxycholic acid (UDCA) treatment, especially within the first two years of diagnosis had good prognostic ability (AUROC [95%C], at diagnosis: 0.656 [0.556-0.757], p= 0.006; after one year: 0.724 [0.602-0.847], p<0.001; after two years: 0.746 [0.617-0.875], p<0.001). Conclusion Prognosis of PSC is independent of coexisting IBD in our large Hungarian prospective PSC cohort. Prognostic ability of the currently used PSC risk scores is limited. The UK-short PSC risk score and early ALP response to UDCA treatment showed to have the best accuracy.

Risk of comorbidity of autoimmune liver disease in patients with inflammatory bowel disease: A single-center case-control study in China.

To investigate the prevalence of autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC), and the impact of comorbidity of AIH, PBC, and PSC on hospitalization burden in patients with inflammatory bowel disease (IBD). Inpatients admitted to Peking Union Medical College Hospital from January 1, 1998 to December 31, 2021 were included. Odds ratio (OR) and the corresponding 95% confidence interval (CI) were calculated to compare the risk of AIH, PBC, and PSC between IBD and non-IBD patients. Medical cost and length of hospitalization were compared between IBD patients with and without AIH, PBC, or PSC. Among the included 858 967 inpatients, there were 3059 patients with IBD. Additionally, there were 117 patients with AIH, 879 patients with PBC, and 35 patients with PSC, regardless of having IBD or not. Patients with IBD had a significantly higher risk of AIH (OR 4.87, 95% CI 1.20-19.71, p = 0.03) and PSC (OR 112.28, 95% CI 53.88-233.98, p < 0.01) than those without IBD. While there was no significant difference in the risk of PBC between patients with and without IBD (OR 1.60, 95% CI 0.67-3.86, p = 0.29). The medical cost of each hospitalization did not differ between IBD patients with and without AIH, PBC, or PSC. IBD patients had a higher risk of AIH and PSC. Comorbidity of AIH, PBC, or PSC has no significant effect on the average cost of each hospitalization in IBD patients.

The mediating role of primary sclerosing cholangitis in the association between ulcerative colitis and hepatobiliary cancer investigated through Mendelian randomization

This study explored the causal relationships among primary sclerosing cholangitis (PSC), ulcerative colitis (UC), and hepatobiliary cancer (HBC) by using bidirectional two-sample, two-step Mendelian randomization (MR) analysis. Genetic variants associated with PSC and UC from the FinnGen research database were used for instrumental variable-based analyses. Mediation analyses were conducted to examine the role of PSC and UC in HBC risk. The findings revealed a causal effect of genetic predisposition to UC on PSC risk (inverse-variance-weighted [IVW] analysis odds ratio [OR] 1.145, p < 0.001), whereas no reverse causality was observed. Although UC showed no direct causal effect on HBC risk, genetic susceptibility to PSC significantly increased the risk of HBC (IVW analysis OR = 1.855, p < 0.001). Mediation analysis further identified PSC as a significant mediator amplifying the causal effect of UC on HBC risk (effect size = 0.083). These results established a causal link between genetic susceptibility to UC and increased risk of PSC, and highlighted the critical role of PSC in mediating the impact of UC on HBC risk.

Causal effect of primary sclerosing cholangitis on diffuse large B-cell lymphoma: A two-sample Mendelian randomized study.

The connection between Primary sclerosing cholangitis (PSC) and lymphoma remains uncertain. To address this, Mendelian randomization (MR) was utilized to investigate the potential causal links between PSC and lymphoma. A 2-sample MR analysis was conducted utilizing summary-level data obtained from genome-wide association study datasets. Four complementary MR methods were performed, including inverse-variance weighting (IVW), MR-Egger, weighted median, and MR-robust adjusted profile score (MR-RAPS). Several sensitivity analyses were also employed to further validate the results. The results of IVW estimates showed that there was a potential causal association between PSC and diffuse large B-cell lymphoma (DLBCL) risk (OR = 1.138, 95% CI = 1.052-1.230, P = .001). No causal association was observed between PSC and other lymphoma subtypes. No horizontal and directional pleiotropy was observed in the MR studies. This study represents the inaugural utilization of MR analysis to investigate the causal associations between PSC and DLBCL. Further investigation is warranted to elucidate the underlying mechanism of this causal relationship.

Long-term (15y) complications and outcomes after liver transplantation for primary sclerosing cholangitis: Impact of donor and recipient factors.

With longer survival of patients with primary sclerosing cholangitis (PSC) undergoing liver transplantation (LT), the frequency and risk factors associated with vascular and biliary complications in the allograft and the impact on long-term outcomes are poorly understood. To assess frequency and risk factors for long-term outcomes in patients after LT for PSC. All recipients of LT for advanced stage PSC for a non-cholangiocarcinoma indication from 1984 to 2012, with follow-up through March 2022 (>10+y follow-up), were identified. One-, 5-, and 10-year cumulative risks of complications were estimated using the Aalen-Johansen method, where death was considered a competing risk. Two hundred ninety-three patients (mean age, 47.3 ± 12y) formed our study cohort. One hundred and thirty-four patients received LT before 1995, and 159 were transplanted after 1995. Over a median (IQR) follow-up of 15.0 (10.3-22.1) years, LT was complicated by hepatic artery thrombosis (N = 30), portal vein stenosis/thrombosis (N = 48), biliary leak (N = 47), biliary strictures (N = 87), recurrent PSC (N=107), and graft failure (N=70). The 1-, 5-, 10-, and 15-year cumulative incidence of recurrent PSC was 1.0%, 8.0%, 23.5%, and 34.3%, respectively. The type of donor and older donor age were associated with an increased risk of biliary strictures. Donor age >60 years was associated with an increased risk of recurrent PSC. Long-term patient and graft survival have not changed significantly for patients transplanted for PSC. Controlling transplant-related factors, such as donor age, prompt identification of vascular and biliary complications early, and long-term rigorous follow-up, is recommended to continue to improve on these outcomes.

Recurrence of Primary Sclerosing Cholangitis and De Novo Cholangiocarcinoma After Liver Transplantation: Results From the Brazilian Cholestasis Consortium.

Primary sclerosing cholangitis (PSC) has been shown to recur after liver transplantation (LT). Some studies have identified certain clinical and laboratory variables associated with an increased risk for recurrent PSC (rPSC) in Caucasians. Furthermore, de novo cholangiocarcinoma (CCA) has been reported anecdotally in patients with rPSC. This study aims to assess the prevalence of rPSC, identify its associated risk factors, and investigate the occurrence of de novo CCA in a highly admixed population from Brazil. All patients submitted to LT for PSC enrolled in the Brazilian Cholestasis Study Group database were retrospectively reviewed for the occurrence of rPSC and de novo CCA. Ninety-six (58 males, mean age 32 ± 13 years) patients with PSC underwent LT. After 90 (39-154) months of follow-up (FU), rPSC was observed in 29 (30%) subjects. There were no significant associations between rPSC and age, gender, concurrent or de novo inflammatory bowel disease, MELD score at the time of LT or allograft rejection. The only factor associated with an increased risk of disease recurrence was time after LT. Although survival was decreased in patients who developed rPSC, this difference was not significant. Only one female patient developed de novo CCA after rPSC, 11 years after LT. Recurrent PSC was observed in one-third of PSC LT patients in Brazil and was associated with longer time after LT. Despite its frequency, rPSC was not associated with a higher risk of graft loss or a significant reduction in posttransplant survival.

Anti-integrin αvβ6 Autoantibodies are Increased in Primary Sclerosing Cholangitis Patients With Concomitant Inflammatory Bowel Disease and Correlate With Liver Disease Severity

Anti-integrin αvβ6 autoantibodies (anti-αvβ6) are found in more than 50% of individuals with ulcerative colitis (UC). We aimed to determine the prevalence of anti-αvβ6 in patients with primary sclerosing cholangitis (PSC) and their association with liver disease severity. Four cohorts of pre-liver transplant patients with PSC were recruited. Patients with inflammatory bowel disease (IBD) and healthy controls (HCs) served as comparators. Total IgG and anti-αvβ6 levels were measured using enzyme-linked immunosorbent assay. Olink inflammation panel was run on a subset of samples. Multivariable linear regression analysis was performed to assess the association between anti-αvβ6 and indices of liver disease severity. A total of 137 patients with PSC (including 76 with PSC-UC, 33 with PSC-Crohn's disease (CD), and 28 with PSC alone) and 160 controls (including 91 with IBD and 69 HCs) were enrolled. Anti-αvβ6 levels were significantly higher in PSC-UC and PSC-CD compared with PSC alone (P<.0001 and P<.003) and HCs (P < .0001 and P < .0001). However, anti-αvβ6 levels in PSC alone were not increased compared with HCs. In patients with PSC-IBD, anti-αvβ6 levels correlated with markers of liver disease severity, including alkaline phosphatase level (r=0.32; P= .004), the revised Mayo PSC risk score (r= 0.25; P= .02), and liver stiffness measurement (r= 0.43; P= .008) after adjusting for age, gender, race/ethnicity, and IBD subtype. Additionally, anti-αvβ6 levels were associated with markers of systemic inflammation and tissue remodeling. Anti-αvβ6 autoantibodies identify a subset of patients with PSC with concomitant IBD.

Causality of immune cells on primary sclerosing cholangitis: a bidirectional two-sample Mendelian randomization study.

Observational studies have indicated that immune dysregulation in primary sclerosing cholangitis (PSC) primarily involves intestinal-derived immune cells. However, the causal relationship between peripheral blood immune cells and PSC remains insufficiently understood. A bidirectional two-sample Mendelian randomization (MR) analysis was implemented to determine the causal effect between PBC and 731 immune cells. All datasets were extracted from a publicly available genetic database. The standard inverse variance weighted (IVW) method was selected as the main method for the causality analysis. Cochran's Q statistics and MR-Egger intercept were performed to evaluate heterogeneity and pleiotropy. In forward MR analysis, the expression ratios of CD11c on CD62L+ myeloid DC (OR = 1.136, 95% CI = 1.032-1.250, p = 0.009) and CD62L-myeloid DC AC (OR = 1.267, 95% CI = 1.086-1.477, p = 0.003) were correlated with a higher risk of PSC. Each one standard deviation increase of CD28 on resting regulatory T cells (Treg) (OR = 0.724, 95% CI = 0.630-0.833, p < 0.001) and CD3 on secreting Treg (OR = 0.893, 95% CI = 0.823-0.969, p = 0.007) negatively associated with the risk of PSC. In reverse MR analysis, PSC was identified with a genetic causal effect on EM CD8+ T cell AC, CD8+ T cell AC, CD28- CD127- CD25++ CD8+ T cell AC, CD28- CD25++ CD8+ T cell AC, CD28- CD8+ T cell/CD8+ T cell, CD28- CD8+ T cell AC, and CD45 RA- CD28- CD8+ T cell AC. Our study indicated the evidence of causal effects between PSC and immune cells, which may provide a potential foundation for future diagnosis and treatment of PSC.

Dissecting the causal role of immunophenotypes in primary sclerosing cholangitis risk: A Mendelian randomization study.

Primary sclerosing cholangitis (PSC), a chronic cholestatic liver condition, is frequently associated with inflammatory bowel disease. Specific immune cells have been implicated in PSC pathogenesis with the emergence of the "microbiota" and "gut lymphocyte homing" hypotheses, albeit their identities remain controversial. The first genome-wide association analysis leveraged nonoverlapping data from 3757 Europeans to evaluate 731 immunophenotypes. A genome-wide association analysis comprising 2871 cases and 12,019 controls yielded summary statistics for PSC. An inverse-variance weighted (IVW) analysis was performed to identify immunophenotypes causally related to PSC, and the results were validated using weighted mode, MR-Egger, and weighted median methods. Comprehensive sensitivity analyses were performed to verify the robustness, heterogeneity, and horizontal pleiotropy of the results. IVW analysis revealed 26 immune traits exhibiting causal associations with PSC. CD3 on HLA-DR+ CD4+ (IVW odds ratio [OR]: 0.904; 95% confidence interval [CI]: 0.828-0.986, P = .023) and CD3 on secreting Treg (IVW OR: 0.893; 95% CI: 0.823-0.969, P = .007) were negatively associated with PSC susceptibility and demonstrated high consistency across the 3 validation methods. Moreover, 7 other immune traits, including CD39+ resting Treg absolute cell (IVW OR = 1.083, 95% CI: 1.013-1.157, P = .019), CD39+ secreting Treg absolute cell (IVW OR = 1.063, 95% CI: 1.012-1.118, P = .015), CD3 on naive CD8br (IVW OR = 0.907, 95% CI: 0.835-0.986, P = .022), CD3 on CD39+ activated Treg (IVW OR = 0.927, 95% CI: 0.864-0.994, P = .034), CD28 on resting Treg (IVW OR = 0.724, 95% CI: 0.630-0.833, P = 5.95E-06), and CD39 on CD39+ CD4+ (IVW OR = 1.055, 95% CI: 1.001-1.112, P = .044) exhibited consistent results in the Weighted Median and Weighted Mode validation methods. Moreover, no significant heterogeneity or horizontal pleiotropy was observed across the single nucleotide polymorphisms. The leave-one-out results revealed that sequentially eliminating each single nucleotide polymorphism had no significant influence on model effect estimates or qualitative inference. This study evaluated potential causal links between 731 immune traits and PSC susceptibility. Twenty-six immune traits were identified using the IVW method. Verification across multiple methods revealed 9 immune traits with a plausible causal connection to PSC. These findings may uncover mechanistic pathways and novel therapeutic approaches.

Genetic association and causal relationship between multiple modifiable risk factors and autoimmune liver disease: a two-sample mendelian randomization study

BackgroundThe intricate etiology of autoimmune liver disease (AILD) involves genetic, environmental, and other factors that yet to be completely elucidated. This study comprehensively assessed the causal association between genetically predicted modifiable risk factors and AILD by employing Mendelian randomization.MethodsGenetic variants associated with 29 exposure factors were obtained from genome-wide association studies (GWAS). Genetic association data with autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) were also obtained from publicly available GWAS. Univariate and multivariate Mendelian randomization analyses were performed to identify potential risk factors for AILD.ResultsGenetically predicted rheumatoid arthritis (RA) (OR = 1.620, 95%CI 1.423–1.843, P = 2.506 × 10− 13) was significantly associated with an increased risk of AIH. Genetically predicted smoking initiation (OR = 1.637, 95%CI 1.055–2.540, P = 0.028), lower coffee intake (OR = 0.359, 95%CI 0.131–0.985, P = 0.047), cholelithiasis (OR = 1.134, 95%CI 1.023–1.257, P = 0.017) and higher C-reactive protein (CRP) (OR = 1.397, 95%CI 1.094–1.784, P = 0.007) were suggestively associated with an increased risk of AIH. Genetically predicted inflammatory bowel disease (IBD) (OR = 1.212, 95%CI 1.127–1.303, P = 2.015 × 10− 7) and RA (OR = 1.417, 95%CI 1.193–1.683, P = 7.193 × 10− 5) were significantly associated with increased risk of PBC. Genetically predicted smoking initiation (OR = 1.167, 95%CI 1.005–1.355, P = 0.043), systemic lupus erythematosus (SLE) (OR = 1.086, 95%CI 1.017–1.160, P = 0.014) and higher CRP (OR = 1.199, 95%CI 1.019–1.410, P = 0.028) were suggestively associated with an increased risk of PBC. Higher vitamin D3 (OR = 0.741, 95%CI 0.560–0.980, P = 0.036) and calcium (OR = 0.834, 95%CI 0.699–0.995, P = 0.044) levels were suggestive protective factors for PBC. Genetically predicted smoking initiation (OR = 0.630, 95%CI 0.462–0.860, P = 0.004) was suggestively associated with a decreased risk of PSC. Genetically predicted IBD (OR = 1.252, 95%CI 1.164–1.346, P = 1.394 × 10− 9), RA (OR = 1.543, 95%CI 1.279–1.861, P = 5.728 × 10− 6) and lower glycosylated hemoglobin (HbA1c) (OR = 0.268, 95%CI 0.141–0.510, P = 6.172 × 10− 5) were positively associated with an increased risk of PSC.ConclusionsEvidence on the causal relationship between 29 genetically predicted modifiable risk factors and the risk of AIH, PBC, and PSC is provided by this study. These findings provide fresh perspectives on the management and prevention strategies for AILD.

Association between gut microbiota and autoimmune cholestatic liver disease, a Mendelian randomization study.

Previous studies have suggested that the gut microbiota (GM) is closely associated with the development of autoimmune cholestatic liver disease (ACLD), but limitations, such as the presence of confounding factors, have resulted in a causal relationship between the gut microbiota and autoimmune cholestatic liver disease that remains uncertain. Thus, we used two-sample Mendelian randomization as a research method to explore the causal relationship between the two. Pooled statistics of gut microbiota from a meta-analysis of genome-wide association studies conducted by the MiBioGen consortium were used as an instrumental variable for exposure factors. The Pooled statistics for primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) were obtained from the R9 version of the FinnGen database (https://r9.finngen.fi/). Inverse-variance Weighted (IVW), cML-MA, MR-Egger regression, Weighted median (WME), Weighted mode (WM), and Simple mode (SM) were used to detect the association between intestinal flora and the causal relationship between intestinal flora and ACLD, in which IVW method was dominant, was assessed based on the effect indicator dominance ratio (odds ratio, OR) and 95% confidence interval (CI). Sensitivity analysis, heterogeneity test, gene pleiotropy test, MR pleiotropy residual sum and outlier test (MR-PRESSO) were combined to verify the stability and reliability of the results. Reverse Mendelian randomization analysis was performed on gut microbiota and found to be causally associated with ACLD. The IVW results showed that the relative abundance of the genus Clostridium innocuum group, genus Butyricicoccus, and genus Erysipelatoclostridium was negatively correlated with the risk of PBC, that is, increased abundance reduced the risk of PBC and was a protective, and the relative abundance of the genus Eubacterium hallii was positively correlated with the risk of PSC, which is a risk factor for PSC. Family Clostridiaceae1 and family Lachnospiraceae were negatively correlated with the risk of PSC, which is a protective factor for PSC. This study found a causal relationship between gut microbiota and ACLD. This may provide valuable insights into gut microbiota-mediated pathogenesis of ACLD. It is necessary to conduct a large-sample randomized controlled trial (RCT) at a later stage to validate the associated role of the relevant gut microbiota in the risk of ACLD development and to explore the associated mechanisms.

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

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. 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)]. 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.

Causal associations between gut microbiota and Cholestatic liver diseases: a Mendelian randomization study.

The etiological factors of Cholestatic Liver Diseases especially primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC) are not fully illustrated. It has been reported in previous observational studies that gut microbiota are associated with cholestatic liver diseases. However, there is uncertainty regarding the causality of this association. By using Mendelian randomization, this study aimed to examine the causal impact of gut microbiota on cholestatic liver diseases. From large-scale genome-wide association studies, genetic instruments for each gut microbiota taxa as well as primary biliary cholangitis and primary sclerosing cholangitis were developed. Subsequently, we conducted a two-sample Mendelian randomization analysis, supplemented by multiple post hoc sensitivity analyses. Additionally, we performed reverse MR analyses to investigate the possibility of the reverse causal association. This two-sample MR study indicated that the order Bacillales, family Peptostreptococcaceae, family Ruminococcaceae, genus Anaerotruncu was associated with a decreased risk of developing PBC, and that order Selenomonadales, family Bifidobacteriaceae may be factors that increase the risk of PBC. On the other hand, we also identified order Selenomonadales, family Rhodospirillaceae, and genus RuminococcaceaeUCG013 were positively associated with PSC. The order Actinomycetales, family Actinomycetaceae, genus Actinomyces, genus Alloprevotella, genus Barnesiella, and genus Peptococcus were found negative associations with the risk of PSC. The reverse MR analysis demonstrated no statistically significant relationship between PBC, PSC and these specific gut microbial taxa. Our findings offered novel evidence that the abundance of particular bacteria contributes to the risk of PBC and PSC, which may contribute to more effective approaches to PBC and PSC therapy and prevention.

OP13 Anti-integrin αvβ6 autoantibodies are increased in PSC-IBD and correlate with liver disease severity

Abstract Background Anti-integrin αvβ6 autoantibodies (anti-αvβ6) are a novel biomarker of ulcerative colitis (UC) that precede disease diagnosis by up to 10 years. Given that integrin αvβ6 is also expressed on the biliary epithelium and that primary sclerosing cholangitis (PSC) co-occurs with inflammatory bowel disease (IBD) in up to 90% of patients, we aimed to determine the prevalence of anti-αvβ6 in patients with PSC and to understand the impact of anti-αvβ6 on PSC disease course. Methods Three cohorts of pre-liver transplant patients with PSC and controls (IBD and non-IBD) were recruited from New York, Lisbon and Miami. Anti-αvβ6 levels were measured using ELISA and normalized for serum IgG concentration. Statistical analyses across groups and clinical parameters were performed using the Kruskal-Wallis and Spearman correlation test. Multivariable linear regression was conducted to assess the association between anti-αvβ6 and liver disease severity, correcting for covariates. A mixed-effects model was applied to assess change in anti-αvβ6 over time. Results In total, 94 patients with PSC (53 (56.4%) PSC-UC, 20 (21.3%) PSC-Crohn’s disease (CD) and 21 (22.3%) PSC alone) and 129 controls (74 (57.4%) IBD and 55 (42.6%) non-IBD) were enrolled; table 1 shows the baseline characteristics of the patients with PSC. Follow-up samples (n=22) were collected from 1 up to 3 years after initial baseline sampling from 17 PSC patients. Median (IQR) age was similar in PSC patients (43, 33-56 years) and controls (47, 32-62 years; p=0.59). Median (IQR) anti-αvβ6 levels were significantly higher in PSC-UC (1.07, 0.48-2.65) and UC (1.83, 1.12-3.03) compared to PSC alone (0.40, 0.23-0.63; p=0.0004 and p&amp;lt;0.0001 respectively) and non-IBD controls (0.39, 0.17-0.65; p&amp;lt;0.0001 and p&amp;lt;0.0001 respectively). Anti-αvβ6 levels were comparable between PSC alone and non-IBD controls (p&amp;gt;0.999) (figure 1A). Anti-αvβ6 levels did not increase over time (p=0.23). A positive correlation between anti-αvβ6 levels and the Mayo PSC risk score (r=0.28, p=0.008) as well as alkaline phosphatase (r=0.29, p=0.007) was observed (figure 1B). These associations remain significant after correcting for covariates including age at diagnosis of PSC, gender, race/ethnicity and IBD type in a multivariable linear regression. Conclusion Anti-αvβ6 autoantibodies are a new biomarker of PSC-IBD and are associated with liver disease severity.

Causal effects from inflammatory bowel disease on liver function and disease: a two-sample Mendelian randomization study.

Accumulating evidence has shown that patients with inflammatory bowel disease (IBD) have liver function abnormalities and are susceptible to liver diseases. However, the existence of a causal relationship between IBD and liver function or disease remains unclear. A two-sample Mendelian randomization (MR) analysis was performed using genetic associations from publicly available genome-wide association studies (GWAS). These associations encompass ulcerative colitis (UC), Crohn's disease (CD), liver function traits, and liver disease phenotypes. The liver function traits comprised hepatic biochemistries, percent liver fat, and liver iron content from the UK Biobank. Furthermore, the liver disease phenotypes included cholelithiasis, non-alcoholic fatty liver disease (NAFLD), primary sclerosing cholangitis (PSC), and primary biliary cholangitis (PBC) in cohorts of European ancestry. The primary estimation used the inverse-variance weighted method, with GWAS of C-reactive protein (CRP) in the UK Biobank serving as a positive control outcome. Genetically predicted UC is causally associated with decreased levels of albumin (ALB) and liver iron content, while genetically predicted CD is causally associated with increased levels of alkaline phosphatase (ALP). Moreover, genetically predicted UC or CD increases the risk of PSC, and CD increases the risk of PBC. Neither UC nor CD causally increases the risk of cholelithiasis and NAFLD. UC affects the levels of ALB and liver iron content, while CD affects the levels of ALP. Both UC and CD increase the risk of PSC, and CD increases the risk of PBC.

New target-HMGCR inhibitors for the treatment of primary sclerosing cholangitis: A drug Mendelian randomization study.

No intervention definitively extends transplant-free survival in primary sclerosing cholangitis (PSC). Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), may enhance PSC prognosis, but their efficacy is debated. We analyzed HMGCR single-nucleotide polymorphisms from published genome-wide association studies using Mendelian randomization to assess the causal relationship between HMGCR and PSC risk. Effects of HMGCR were compared with proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors, common lipid-lowering drugs, using coronary heart disease risk as a positive control. The inverse-variance weighted (IVW) method was the primary analysis, complemented by the weighted median method. Heterogeneity analysis, examination of horizontal pleiotropy, and leave-one-out sensitivity analysis were conducted for result robustness. Genetically predicted HMGCR exhibited a pronounced detrimental effect on PSC in both the IVW method (odds ratio [OR] [95%] = 2.43 [1.23-4.78], P = 0.010) and the weighted median method (OR [95%] = 2.36 [1.02-5.45], P = 0.044). However, PCSK9 did not reach statistical significance. Moreover, all analyses passed through heterogeneity analysis, horizontal pleiotropy analysis, and leave-one-out sensitivity analysis. This study has confirmed a causal relationship between HMGCR and PSC risk, suggesting statins targeting HMGCR could enhance PSC patient outcomes.

A bidirectional two-sample Mendelian randomization using the gut microbiota to reveal potential therapeutic targets for primary sclerosing cholangitis.

Previous studies indicate that gut microbiota correlates to primary sclerosing cholangitis (PSC), but the causation is still unclear. We sought to reveal the causal relationship between gut microbiota and PSC with a bidirectional two-sample Mendelian randomization (MR) analysis. The large-scale genome-wide association study (GWAS) summary statistics and a bidirectional two-sample MR study were used to assess the causality between gut microbiota and PSC. Multiple sensitivity analyses were used to identify the robustness of our results. Three microbial taxa causally correlated to PSC. Genus Ruminococcaceae UCG002 (OR: 1.855, 95% CI: 1.068-3.220, P = 0.028) increased the risk of PSC. Class Betaproteobacteria (OR: 0.360, 95% CI: 0.171-0.758, P = 0.007), and genus Ruminiclostridium6 (OR: 0.474, 95% CI: 0.219-0.820, P = 0.011) had protective effects on PSC. In addition, we found the causal relationship of PSC with higher abundance of genus Dialister (beta: 0.059, 95% CI: 0.017-0.102, P = 0.006), genus Veillonella (beta: 0.065, 95% CI: 0.016-0.113, P = 0.009), class Melainabacteria (beta: 0.073, 95% CI: 0.012-0.133, P = 0.019), and order Gastranaerophilales (beta: 0.072, 95% CI: 0.011-0.113, P = 0.133). Our study reveals the causality between gut microbiota and PSC, providing new insights into the pathological mechanisms of PSC and facilitating the development of novel biomarkers and disease-modifying therapeutics for PSC from the perspective of gut microbiota.

Genetic link between primary sclerosing cholangitis and thyroid dysfunction: a bidirectional two-sample Mendelian randomization study.

Observational studies have demonstrated an association between primary sclerosing cholangitis (PSC) and thyroid dysfunction (TD). However, the causal relationship between PSC and TD remains uncertain. The purpose of this study is to investigate the causal associations and specific direction between these two conditions. Gaining insight into the potential causal relationship between PSC and TD is valuable for elucidating the pathogenesis of PSC and for devising innovative approaches for the prevention and treatment of PSC and its associated complications. We conducted a bidirectional two-sample Mendelian randomization (MR) analysis to investigate the causal association between PSC and TD, such as autoimmune thyroid disease (AITD), thyroid cancer (TC), thyroid stimulating hormone (TSH), thyrotropin-releasing hormone (TRH), among others. PSC was the exposure variable, while TD was the outcome variable. To identify suitable instrumental variables (IVs), we utilized genome-wide association study (GWAS) datasets to select potential candidate single-nucleotide polymorphisms (SNPs). The primary statistical approach employed was the inverse-variance weighted (IVW) method, which was complemented by a series of sensitivity analyses to assess the robustness of the results by estimating heterogeneity and pleiotropy. We found that the causal associations between genetically predicted PSC and Graves' disease (GD), hyperthyroidism (IVW OR=1.230, 95%CI: 1.089-1.389, P=0.001; IVW OR=1.001, 95%CI: 1.000-1.002, P=0.000) were statistically significant. The reverse MR analysis indicated that genetic susceptibility to hyperthyroidism (P=0.000) and hypothyroidism (p=0.028) might be the risk of PSC. There was no statistically significant causal association observed between PSC and other TD (IVW P>0.05), with the exception of GD, hyperthyroidism, and hypothyroidism as determined through bidirectional two-sample analysis. To ensure the reliability of our findings, additional sensitivity analyses were conducted, including the leave-one-out (LOO) test, heterogeneity test, and pleiotropic test. In this study, we conducted an investigation into the causal association between PSC and TD. Our findings indicate that PSC significantly elevates the susceptibility to GD and hyperthyroidism from a statistical perspective. These results shed light on the etiology of PSC and have implications for the management of patients with PSC.

Polygenic risk score predicts risk of primary sclerosing cholangitis in inflammatory bowel disease

BackgroundForty distinct primary sclerosing cholangitis (PSC) genomic loci have been identified through multiancestry meta-analyses. The polygenic risk score (PRS) could serve as a promising tool to discover unique disease behaviour,...

Causal effects of gut microbiome on autoimmune liver disease: a two-sample Mendelian randomization study

BackgroundEpidemiological studies have indicated a potential link between the gut microbiome and autoimmune liver disease (AILD) such as autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC). The relationship between the gut microbiome and autoimmune liver disease is still uncertain due to confounding variables. In our study, we aim to shed light on this relationship by employing a two-sample Mendelian randomization approach.MethodsWe conducted a two-sample Mendelian randomization (MR) study using the R package "TwoSampleMR". The exposure data consisted of genetic variants associated with 194 bacterial traits obtained from the MiBioGen consortium. Summary statistics for AILD were obtained from the GWAS Catalog website. Furthermore, a series of sensitivity analyses were performed to validate the initial MR results.ResultsThere were two, four and three bacteria traits associated with an increased risk of AIH. PBC, and PSC respectively. In contrast, there were five, two and five bacteria traits associated with a decreased risk for AIH, PBC and PSC. Notably, the genus_Clostridium_innocuum_group showed a negative association with AIH (OR = 0.67, 95% CI: 0.49–0.93), and the genus_Actinomyces was found to be genetically associated with a decreased risk of PSC (OR = 0.62, 95% CI: 0.42–0.90).ConclusionsOur study identified the causal impact of specific bacterial features on the risk of AILD subtypes. Particularly, the genus_Clostridium_innocuum_group and the genus_Actinomyces demonstrated significant protective effects against AIH and PSC respectively. These findings provide further support for the potential use of targeted probiotics in the management of AILD.