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

Ten-year combination treatment with colchicine and ursodeoxycholic acid for primary biliary cirrhosis: a double-blind, placebo-controlled trial on symptomatic patients

Background: Combined medical treatment may provide further benefit to primary biliary cirrhosis (PBC) patients administered ursodeoxycholic acid (UDCA). Aim: To evaluate the long-term effects of colchicine and UDCA in symptomatic PBC patients. Patients/methods: We extended up to 10 years the double-blind treatment of 44 symptomatic PBC patients originally included in a 3-year multicentre study comparing UDCA and colchicine (U + C) versus UDCA and placebo (U + P). Outcome measures were death or liver transplantation; incidence of clinically relevant events; clinical and quantitative variables retaining prognostic information. Results: Mean follow-up was 7 +/- 3 years. One patient was lost, three withdrew because of jaundice (U + P); two patients stopped colchicine but remained on UDCA. Eleven patients (two for liver-unrelated reasons, U + P) and six patients (U + C) died, three and two patients, respectively, were transplanted (incidence rate difference, five cases per 100 patient-years; 95% CI, -1 to 11). Hepatocellular carcinoma developed in one (U + P) and four (U + C) patients (difference, -2; CI, -5 to 1), portal hypertension complications in nine patients from each group (difference, 1; CI, -5 to 6). Trends of serum bilirubin, Mayo score, antipyrine clearance were similar among treatment groups. Conclusions: In cirrhotic PBC patients, colchicine does not offer additional benefits to UDCA. In this population, UDCA does not obviate disease progression

LACK OF ASSOCIATION BETWEEN CIRCULATING HCV-RNA AND ANTI-HCV POSITIVITY IN PRIMARY BILIARY-CIRRHOSIS

PAtients with PBC have often false antiHCV-positivit

HEPATITIS-C VIRUS TESTING IN PRIMARY BILIARY-CIRRHOSIS

We retrospectively investigated anti-HCV prevalence in a series of 160 consecutive patients with primary biliary cirrhosis who presented between 1980 and 1989. Of these, 19 (12%) were positive for anti-HCV by C-100 ELISA. Serum IgG levels were significantly higher in anti-HCV-positive patients and correlated to optical density values. A serum sample was again collected from all the patients from the same series who were seen in 1990 for follow-up, after a median period of 32 months. Anti-HCV positivity was found to be substantially unchanged in this subgroup of patients when the freshly drawn blood samples were retested with C-100 ELISA, while it increased from 10% to 17% when second generation ELISA was used. Three of the C-100 ELISA positive samples were C-100 RIBA reactive, and six of the second generation ELISA positive samples were 4-RIBA reactive. The HCV genome was not detected in any of the seven anti-HCV C-100 ELISA and second generation ELISA positive sera which were studied by polymerase chain reaction, including four cases confirmed by 4-RIBA. Life expectancy, as determined by survival analysis, did not differ significantly between anti-HCV-positive and -negative patients. These findings suggest that anti-HCV positivity does not influence the clinical presentation and course of primary biliary cirrhosis