An international genome-wide meta-analysis of primary biliary cholangitis: novel risk loci and candidate drugs

Backgrounds & Aims Primary biliary cholangitis (PBC) is a chronic liver disease in which autoimmune destruction of the small intrahepatic bile ducts eventually leads to cirrhosis. Many patients have inadequate response to licensed medications, motivating the search for novel therapies. Previous genome-wide association studies (GWAS) and meta-analyses (GWMA) of PBC have identified numerous risk loci for this condition, providing insight into its aetiology. We undertook the largest GWMA of PBC to date, aiming to identify additional risk loci and prioritise candidate genes for in silico drug efficacy screening. Methods We combined new and existing genotype data for 10,516 cases and 20,772 controls from 5 European and 2 East Asian cohorts. Results We identified 56 genome-wide significant loci (20 novel) including 46 in European, 13 in Asian, and 41 in combined cohorts; and a 57th genome-wide significant locus (also novel) in conditional analysis of the European cohorts. Candidate genes at newly identified loci include FCRL3, INAVA, PRDM1, IRF7, CCR6, CD226, and IL12RB1, which each play key roles in immunity. Pathway analysis reiterated the likely importance of pattern recognition receptor and TNF signalling, JAK-STAT signalling, and differentiation of T helper (TH)1 and TH17 cells in the pathogenesis of this disease. Drug efficacy screening identified several medications predicted to be therapeutic in PBC, some of which are well-established in the treatment of other autoimmune disorders. Conclusions This study has identified additional risk loci for PBC, provided a hierarchy of agents that could be trialled in this condition, and emphasised the value of genetic and genomic approaches to drug discovery in complex disorders. Lay summary Primary biliary cholangitis (PBC) is a chronic liver disease that eventually leads to cirrhosis. In this study, we analysed genetic information from 10,516 people with PBC and 20,772 healthy individuals recruited in Canada, China, Italy, Japan, the UK, or the USA. We identified several genetic regions associated with PBC. Each of these regions contains several genes. For each region, we used diverse sources of evidence to help us choose the gene most likely to be involved in causing PBC. We used these ‘candidate genes’ to help us identify medications that are currently used for treatment of other conditions, which might also be useful for treatment of PBC

The inter-relationship of symptom severity and quality of life in 2055 patients with primary biliary cholangitis

BackgroundAge at presentation with primary biliary cholangitis (PBC) is associated with differ-ential response to ursodeoxycholic acid (UDCA) therapy. Younger-presentingpatients are less likely to respond to treatment and more likely to need transplantor die from the disease. PBC has a complex impact on quality of life (QoL), withsystemic symptoms often having significant impact.AimTo explain the impact of age at presentation on perceived QoL and the inter-related symptoms which impact upon it.MethodsUsing the UK-PBC cohort, symptoms were assessed using the PBC-40 and othervalidated tools. Data were available on 2055 patients.ResultsOf the 1990 patients reporting a global PBC-QoL score, 66% reported good/neutralscores and 34% reported poor scores. Each 10-year increase in age at presentationwas associated with a 14% decrease in risk of poor perceived QoL (OR = 0.86,95% CI: 0.75–0.98, P < 0.05). All sympto m domains were similarly age-associated(P < 0.01). Social dysfunction was the symptom factor with the greatest impa ct onQoL. Median (interquartile range) PBC-40 social scores for patient s with good per-ceived QoL were 18 (14–23) compared with 34 (29–39) for those with poor QoL.ConclusionThe majo rity of patients with primary biliary cholangitis do not feel their QoL isimpaired, although impairment is reported by a sizeable minority. Age at presenta-tion is associated with impact on per ceived QoL and the symptoms impairing it,with younger patients being more affected. Social dysfunction makes the greatestcontribution to QoL impairment, and it should be targeted in trials aimed atimproving life quality

The inter-relationship of symptom severity and quality of life in 2055 patients with primary biliary cholangitis.

BACKGROUND: Age at presentation with primary biliary cholangitis (PBC) is associated with differential response to ursodeoxycholic acid (UDCA) therapy. Younger-presenting patients are less likely to respond to treatment and more likely to need transplant or die from the disease. PBC has a complex impact on quality of life (QoL), with systemic symptoms often having significant impact. AIM: To explain the impact of age at presentation on perceived QoL and the inter-related symptoms which impact upon it. METHODS: Using the UK-PBC cohort, symptoms were assessed using the PBC-40 and other validated tools. Data were available on 2055 patients. RESULTS: Of the 1990 patients reporting a global PBC-QoL score, 66% reported good/neutral scores and 34% reported poor scores. Each 10-year increase in age at presentation was associated with a 14% decrease in risk of poor perceived QoL (OR = 0.86, 95% CI: 0.75-0.98, P < 0.05). All symptom domains were similarly age-associated (P < 0.01). Social dysfunction was the symptom factor with the greatest impact on QoL. Median (interquartile range) PBC-40 social scores for patients with good perceived QoL were 18 (14-23) compared with 34 (29-39) for those with poor QoL. CONCLUSION: The majority of patients with primary biliary cholangitis do not feel their QoL is impaired, although impairment is reported by a sizeable minority. Age at presentation is associated with impact on perceived QoL and the symptoms impairing it, with younger patients being more affected. Social dysfunction makes the greatest contribution to QoL impairment, and it should be targeted in trials aimed at improving life quality

The Serum Proteome and Ursodeoxycholic Acid Response in Primary Biliary Cholangitis.

Funder: UK‐PBC MRC Stratified MedicineFunder: Pfizer; Id: http://dx.doi.org/10.13039/100004319BACKGROUND AND AIMS: Stratified therapy has entered clinical practice in primary biliary cholangitis (PBC), with routine use of second-line therapy in nonresponders to first-line therapy with ursodeoxycholic acid (UDCA). The mechanism for nonresponse to UDCA remains, however, unclear and we lack mechanistic serum markers. The UK-PBC study was established to explore the biological basis of UDCA nonresponse in PBC and identify markers to enhance treatment. APPROACH AND RESULTS: Discovery serum proteomics (Olink) with targeted multiplex validation were carried out in 526 subjects from the UK-PBC cohort and 97 healthy controls. In the discovery phase, untreated PBC patients (n = 68) exhibited an inflammatory proteome that is typically reduced in scale, but not resolved, with UDCA therapy (n = 416 treated patients). Nineteen proteins remained at a significant expression level (defined using stringent criteria) in UDCA-treated patients, six of them representing a tightly linked profile of chemokines (including CCL20, known to be released by biliary epithelial cells (BECs) undergoing senescence in PBC). All showed significant differential expression between UDCA responders and nonresponders in both the discovery and validation cohorts. A linear discriminant analysis, using serum levels of C-X-C motif chemokine ligand 11 and C-C motif chemokine ligand 20 as markers of responder status, indicated a high level of discrimination with an AUC of 0.91 (CI, 0.83-0.91). CONCLUSIONS: UDCA under-response in PBC is characterized by elevation of serum chemokines potentially related to cellular senescence and was previously shown to be released by BECs in PBC, suggesting a potential role in the pathogenesis of high-risk disease. These also have potential for development as biomarkers for identification of high-risk disease, and their clinical utility as biomarkers should be evaluated further in prospective studies

International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist