Background, & Aims Studies of primary biliary cirrhosis (PBC) phenotypes largely have been performed using small and selected populations. Study size has precluded investigation of important disease ...subgroups, such as men and young patients. We used a national patient cohort to obtain a better picture of PBC phenotypes. Methods We performed a cross-sectional study using the United Kingdom-PBC, patient cohort. Comprehensive data were collected for 2353 patients on diagnosis reports, response to therapy with ursodeoxycholic acid (UDCA), laboratory results, and symptom impact (assessed using the PBC-40 and other related measures). Results Seventy-nine percent of the patients reported current UDCA, therapy, with 80% meeting Paris response criteria. Men were significantly less likely to have responded to UDCA than women (72% vs 80% response rate; P < .05); male sex was an independent predictor of nonresponse on multivariate analysis. Age at diagnosis was associated strongly and independently with response to UDCA; response rates ranged from 90% among patients who presented with PBC when they were older than age 70, to less than 50% for those younger than age 30 ( P < .0001). Patients who presented at younger ages also were significantly more likely not to respond to UDCA therapy, based on alanine aminotransferase and aspartate aminotransferase response criteria, and more likely to report fatigue and pruritus. Women had mean fatigue scores 32% higher than men's ( P < .0001). The increase in fatigue severity in women was related strongly (r = 0.58; P < .0001) to higher levels of autonomic symptoms ( P < .0001). Conclusions Among patients with PBC, response to UDCA, treatment and symptoms are related to sex and age at presentation, with the lowest response rates and highest levels of symptoms in women presenting at younger than age 50. Increased severity of fatigue in women is related to increased autonomic symptoms, making dysautonomia a plausible therapeutic target.
Abstract Autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are complex disorders, resulting from the interaction of genetic and environmental ...factors. For many years, investigators have attempted to delineate the genetic architecture of these conditions, aiming to elucidate disease pathogenesis and identify molecular targets for pharmacotherapy. Early genetic studies consisted of HLA association studies and non-HLA candidate gene association studies, designed to identify association with selected HLA or non-HLA loci. HLA association studies identified HLA risk loci that are now well-established. Non-HLA candidate gene studies were less fruitful because they were mostly underpowered to detect modest effects and were frequently designed to investigate one or two functional polymorphisms, meaning that gene coverage was poor. Furthermore, weak associations detected in one small cohort were often never validated. If replication studies were undertaken, the results were often conflicting. More recently, a series of genome-wide association studies (GWAS) and related study designs have evaluated the impact of common genetic variants (frequency >5% in the general population) across the entire genome. These studies have identified several non-HLA risk loci for autoimmune liver disease. The majority of risk loci detected are similar to those of non-hepatic immune-mediated diseases, suggesting that outcomes from GWAS and related genetic studies reflect broad phenotypic themes rather than traditional clinical conditions. The specific genetic basis of these PBC and PSC associated inflammatory themes as determined by GWAS is described and discussed in the context of interacting genetic and non-genetic (including environmental) factors.
Organoid technology holds great promise for regenerative medicine but has not yet been applied to humans. We address this challenge using cholangiocyte organoids in the context of cholangiopathies, ...which represent a key reason for liver transplantation. Using single-cell RNA sequencing, we show that primary human cholangiocytes display transcriptional diversity that is lost in organoid culture. However, cholangiocyte organoids remain plastic and resume their in vivo signatures when transplanted back in the biliary tree. We then utilize a model of cell engraftment in human livers undergoing ex vivo normothermic perfusion to demonstrate that this property allows extrahepatic organoids to repair human intrahepatic ducts after transplantation. Our results provide proof of principle that cholangiocyte organoids can be used to repair human biliary epithelium.
Primary biliary cirrhosis (PBC) has a complex clinical phenotype, with debate about the extent and specificity of frequently described systemic symptoms such as fatigue. The aim of this study was to ...use a national patient cohort of 2,353 patients recruited from all clinical centers in the UK to explore the impact of disease on perceived life quality. Clinical data regarding diagnosis, therapy, and biochemical status were collected and have been reported previously. Detailed symptom phenotyping using recognized and validated symptom assessment tools including the PBC‐40 was also undertaken and is reported here. Perception of poor quality of life and impaired health status was common in PBC patients (35% and 46%, respectively) and more common than in an age‐matched and sex‐matched community control group (6% and 15%, P < 0.0001 for both). Fatigue and symptoms of social dysfunction were associated with impaired perceived quality of life using multivariate analysis. Fatigue was the symptom with the greatest impact. Depression was a significant factor, but appeared to be a manifestation of complex symptom burden rather than a primary event. Fatigue had its greatest impact on perceived quality of life when accompanied by symptoms of social dysfunction, suggesting that maintenance of social networks is critical for minimizing the impact of fatigue. Conclusion: The symptom burden in PBC, which is unrelated to disease severity or ursodeoxycholic acid response, is significant and complex and results in significant quality of life deficit. The complexity of symptom burden, and its lack of relation to disease severity and treatment response, suggest that specific approaches to symptom management are warranted that address both symptom biology and social impact. (Hepatology 2013;58:‐)
In addition to the HLA locus, six genetic risk factors for primary biliary cirrhosis (PBC) have been identified in recent genome-wide association studies (GWAS). To identify additional loci, we ...carried out a GWAS using 1,840 cases from the UK PBC Consortium and 5,163 UK population controls as part of the Wellcome Trust Case Control Consortium 3 (WTCCC3). We followed up 28 loci in an additional UK cohort of 620 PBC cases and 2,514 population controls. We identified 12 new susceptibility loci (at a genome-wide significance level of P < 5 × 10⁻⁸) and replicated all previously associated loci. We identified three further new loci in a meta-analysis of data from our study and previously published GWAS results. New candidate genes include STAT4, DENND1B, CD80, IL7R, CXCR5, TNFRSF1A, CLEC16A and NFKB1. This study has considerably expanded our knowledge of the genetic architecture of PBC.
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Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Autoimmune liver diseases (AILDs) are complex conditions, which arise from the interaction between a genetic susceptibility and unknown environmental triggers. They represent a relevant cause of ...liver failure and liver transplantation worldwide. As a testimony of our progress in understanding the biology of AILDs and the disease progression is the overall median survival which has increased over the last decade. However, there are still major challenges such as the lack of therapies and surveillance strategies in primary sclerosing cholangitis (PSC), the management and treatment of non-responders to first-line therapies in primary biliary cholangitis (PBC) and the need for tailoring immunosuppressive drugs in autoimmune hepatitis (AIH). The different disease course and treatment response in patients with AILDs might be related to a heterogeneous genetic background between individuals which translates in a heterogeneous clinical phenotype. Thus, it becomes essential to personalise management and treatment based on specific risk profiles, e.g. low-risk and high-risk, based on genetic and molecular signatures.
It is now possible, thanks to the development of large-scale AILDs patient cohorts, that such diseases can be analysed using various high-throughput methods like gene expression profiling, next generation sequencing and other omics technologies to identify unique fingerprints based on which a personalised or tailor-made management and therapy can be developed. The final aim being to facilitate treatment decision-making that balances patient-specific risks and preferences. This is critical especially now with the current and forthcoming availability of more efficacious medications. To reach this point we need specific interventions such as creating bigger biobanks, sequencing more genomes and linking biological information to health-related data.
We have already identified subsets of patients with different risk profiles among patients with PBC, PSC and AIH by using clinical tools such as liver histology, laboratory investigation and non-invasive methods. In this manuscript, we review the clinical features and investigations that already enable us to individualize the care of PBC patients and that might support the development of precision medicine (PM) in AILDs.
•Precision medicine and risk stratification have a great potential to change the paradigm of management of AILDs.•The current role of risk stratification and precision medicine are very different in different AILDs.•Several potential risk stratifiers has already been developed and identified in patients with PBC.•No tools to distinguish and identify patients with suboptimal treatment response to known treatments are available in AIH.•Lack of treatments in PSC has led to identification of risk stratifiers and surrogate endpoints to help conducting trials.
We genotyped 2,861 cases of primary biliary cirrhosis (PBC) from the UK PBC Consortium and 8,514 UK population controls across 196,524 variants within 186 known autoimmune risk loci. We identified 3 ...loci newly associated with PBC (at P<5×10(-8)), increasing the number of known susceptibility loci to 25. The most associated variant at 19p12 is a low-frequency nonsynonymous SNP in TYK2, further implicating JAK-STAT and cytokine signaling in disease pathogenesis. An additional five loci contained nonsynonymous variants in high linkage disequilibrium (LD; r2>0.8) with the most associated variant at the locus. We found multiple independent common, low-frequency and rare variant association signals at five loci. Of the 26 independent non-human leukocyte antigen (HLA) signals tagged on the Immunochip, 15 have SNPs in B-lymphoblastoid open chromatin regions in high LD (r2>0.8) with the most associated variant. This study shows how data from dense fine-mapping arrays coupled with functional genomic data can be used to identify candidate causal variants for functional follow-up.
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Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Primary Biliary Cholangitis (PBC) is a chronic autoimmune liver disease characterised by progressive destruction of intrahepatic bile ducts. The strongest genetic association is with HLA-DQA1*04:01, ...but at least three additional independent HLA haplotypes contribute to susceptibility. We used dense single nucleotide polymorphism (SNP) data in 2861 PBC cases and 8514 controls to impute classical HLA alleles and amino acid polymorphisms using state-of-the-art methodologies. We then demonstrated through stepwise regression that association in the HLA region can be largely explained by variation at five separate amino acid positions. Three-dimensional modelling of protein structures and calculation of electrostatic potentials for the implicated HLA alleles/amino acid substitutions demonstrated a correlation between the electrostatic potential of pocket P6 in HLA-DP molecules and the HLA-DPB1 alleles/amino acid substitutions conferring PBC susceptibility/protection, highlighting potential new avenues for future functional investigation.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Primary biliary cholangitis (PBC) is a chronic cholestatic autoimmune liver disease that appears to be strongly influenced by genetic factors. Recently, an international meta-analysis of genome-wide ...association studies (GWAS) identified CC-Motif Chemokine Receptor-6 (CCR6) and FGFR1 Oncogene-Partner (FGFR1OP) as PBC-susceptibility genes. However, the lead single nucleotide polymorphisms (SNPs) of CCR6/FGFR1OP showed low linkage disequilibrium with each other in East Asian and European populations. Additionally, the primary functional variants and the molecular mechanisms responsible for PBC-susceptibility remain unclear.
Here, among the PBC-susceptibility SNPs identified by high-density association mapping in our previous meta-GWAS (Patients: n = 10,516; healthy controls: n = 20,772) within the CCR6/FGFR1OP locus, rs9459874 and rs1012656 were identified as primary functional variants. These functional variants accounted for the effects of GWAS-identified lead SNPs in CCR6/FGFR1OP. Additionally, the roles of rs9459874 and rs1012656 in regulating FGFR1OP transcription and CCR6 translation, respectively, were supported by expression quantitative trait loci (eQTL) analysis and gene editing technology using the CRISPR/Cas9 system. Immunohistochemistry showed higher expression of CCR6 protein in the livers of patients with PBC than in those of a non-diseased control.
In conclusion, we identified primary functional variants in CCR6/FGFR1OP and revealed the molecular mechanisms by which these variants confer PBC-susceptibility in an eQTL-dependent or -independent manner. The approach in this study is applicable for the elucidation of the pathogenesis of other autoimmune disorders in which CCR6/FGFR1OP is known as a susceptibility locus, as well as PBC.
•Identification of novel primary functional variants for PBC in CCR6/FGFR1OP.•Increased FGFR1OP transcription by PBC-susceptibility allele of rs9459874.•Increased CCR6 translation by PBC-susceptibility allele of rs1012656.•Higher CCR6 in the liver of PBC patients than in those of a non-diseased control.•GWAS-identified lead SNPs in CCR6/FGFR1OP were accounted for by these variants.
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