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

Immunochip analyses identify a novel risk locus for primary biliary cirrhosis at 13q14, multiple independent associations at four established risk loci and epistasis between 1p31 and 7q32 risk variants.

To further characterize the genetic basis of primary biliary cirrhosis (PBC), we genotyped 2426 PBC patients and 5731 unaffected controls from three independent cohorts using a single nucleotide polymorphism (SNP) array (Immunochip) enriched for autoimmune disease risk loci. Meta-analysis of the genotype data sets identified a novel disease-associated locus near the TNFSF11 gene at 13q14, provided evidence for association at six additional immune-related loci not previously implicated in PBC and confirmed associations at 19 of 22 established risk loci. Results of conditional analyses also provided evidence for multiple independent association signals at four risk loci, with haplotype analyses suggesting independent SNP effects at the 2q32 and 16p13 loci, but complex haplotype driven effects at the 3q25 and 6p21 loci. By imputing classical HLA alleles from this data set, four class II alleles independently contributing to the association signal from this region were identified. Imputation of genotypes at the non-HLA loci also provided additional associations, but none with stronger effects than the genotyped variants. An epistatic interaction between the IL12RB2 risk locus at 1p31and the IRF5 risk locus at 7q32 was also identified and suggests a complementary effect of these loci in predisposing to disease. These data expand the repertoire of genes with potential roles in PBC pathogenesis that need to be explored by follow-up biological studies

Trends in chronic hepatitis B virus infection in Italy over a 10-year period: Clues from the nationwide PITER and MASTER cohorts toward elimination

Objectives: The study measures trends in the profile of patients with chronic hepatitis B virus linked to care in Italy. Methods: A cross-sectional, multicenter, observational cohort (PITER cohort) of consecutive patients with hepatitis B surface antigen (HBsAg) over the period 2019-2021 from 46 centers was evaluated. The reference was the MASTER cohort collected over the years 2012-2015. Standard statistical methods were used. Results: The PITER cohort enrolled 4583 patients, of whom 21.8% were non-Italian natives. Compared with those in MASTER, the patients were older and more often female. The prevalence of hepatitis B e antigen (HBeAg) declined (7.2% vs 12.3; P <0.0001) and that of anti-hepatitis D virus (HDV) remained stable (9.3% vs 8.3%). In both cohorts, about 25% of the patients had cirrhosis, and those in the PITER cohort were older. HBeAg-positive was 5.0% vs 12.6% (P <0.0001) and anti-HDV positive 24.8% vs 17.5% (P <0.0017). In the logistic model, the variables associated with cirrhosis were anti-HDV-positive (odds ratio = 10.08; confidence interval 7.63-13.43), age, sex, and body mass index; the likelihood of cirrhosis was reduced by 40% in the PITER cohort. Among non-Italians, 12.3% were HBeAg-positive (vs 23.4% in the MASTER cohort; P <0.0001), and 12.3% were anti-HDV-positive (vs 11.1%). Overall, the adherence to the European Association for the Study of the Liver recommendations for antiviral treatment increased over time. Conclusion: Chronic hepatitis B virus infection appears to be in the process of becoming under control in Italy; however, HDV infection is still a health concern in patients with cirrhosis and in migrants

Classical HLA-DRB1 and DPB1 alleles account for HLA associations with primary biliary cirrhosis.

Susceptibility to primary biliary cirrhosis (PBC) is strongly associated with human leukocyte antigen (HLA)-region polymorphisms. To determine if associations can be explained by classical HLA determinants, we studied Italian, 676 cases and 1440 controls, genotyped with dense single-nucleotide polymorphisms (SNPs) for which classical HLA alleles and amino acids were imputed. Although previous genome-wide association studies and our results show stronger SNP associations near DQB1, we demonstrate that the HLA signals can be attributed to classical DRB1 and DPB1 genes. Strong support for the predominant role of DRB1 is provided by our conditional analyses. We also demonstrate an independent association of DPB1. Specific HLA-DRB1 genes (*08, *11 and *14) account for most of the DRB1 association signal. Consistent with previous studies, DRB1*08 (P=1.59 7 10(-11)) was the strongest predisposing allele, whereas DRB1*11 (P=1.42 7 10(-10)) was protective. Additionally, DRB1*14 and the DPB1 association (DPB1*03:01; P=9.18 7 10(-7)) were predisposing risk alleles. No signal was observed in the HLA class 1 or class 3 regions. These findings better define the association of PBC with HLA and specifically support the role of classical HLA-DRB1 and DPB1 genes and alleles in susceptibility to PBC