Citations

Abstract Inflammatory bowel diseases (IBD), principally Crohn’s disease (CD) and ulcerative colitis (UC), are common chronic disorders involving inflammation and often progressive tissue damage. Genome-wide association studies have mapped many risk signals, but the causal variants, effector genes and relevant cellular contexts remain difficult to resolve, limiting mechanistic interpretation and therapeutic translation. Here we performed a multi-ancestry GWAS meta-analysis of 125,992 individuals with IBD and more than 1.2 million controls, identifying 619 independent association signals (374 novel) at 420 IBD regions that account for 77–80% of SNP-based heritability. Fine-mapping resolved 81 high-confidence variants, 41 not previously reported. Although most signals were shared between CD and UC, 39% showed IBD subtype specificity, with UC signals showing stronger enrichment in functional annotations from intestinal epithelial, secretory and enteroendocrine cells, and CD showing stronger genetic correlations with circulating inflammatory biomarkers, including C-reactive protein and glycoprotein acetylation. Latent causal modelling supported a causal effect of decreased high-density lipoprotein on CD risk. By integrating bulk and single-cell eQTL and pQTL resources using colocalisation and Mendelian randomisation, together with coding-variant evidence from exome sequencing, we prioritised 664 candidate effector genes across 341 signals, including 390 newly implicated IBD genes, revealing new biological mechanisms and candidate therapeutic targets supported by human genetics.

Abstract Inflammatory bowel disease (IBD) is a chronic immune-mediated disorder of the gastrointestinal tract whose genetic basis is only partly resolved because most risk variants identified by genome-wide association studies (GWAS) lie in non-coding regions, limiting direct gene assignment and biological interpretation 1,2 . Here we analysed whole-exome and whole-genome sequencing data from 86,213 IBD cases and 478,363 controls of European ancestry. We identified 68 IBD genes directly implicated by conditionally independent protein-coding associations across the allele frequency spectrum. Many newly implicated IBD genes are supported by orthogonal genomic or pleiotropic evidence, pointing to disease-related pathways and nominating targets with therapeutic relevance. We further identified allelic series and non-additive effects at key loci such as NOD2 and TYK2. These results show that large-scale sequencing can resolve disease genes and pathways that remain ambiguous from non-coding association alone, providing a more direct route from human genetics to biological insight and therapeutic hypotheses.

Abstract Endoscopic mucosal resection (EMR) techniques for large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) have expanded with the introduction of ablation and cold EMR. This study assessed adverse events (AEs) for the newer EMR techniques, including cold EMR, compared with hot EMR. We conducted a secondary analysis of four prospective multicenter studies of consecutive patients with LNPCPs undergoing EMR from 2019 to 2024. The primary outcome was serious AEs (SAEs) with cold and hot EMR. Secondary outcomes included SAEs in the hot EMR subgroups (no ablation [hEMR], margin ablation [hEMR-m], margin and base ablation [hEMR-mb]). 1762 patients (mean age 65.8; 1890 LNPCPs) were included: 522 cold and 1368 hot EMRs (368 hEMR, 770 hEMR-m, 230 hEMR-mb). SAEs were higher with hot EMR (4.7%, 95%CI 3.6%–5.9%) vs. cold EMR (1.9%, 95%CI 0.9%–3.5%), also for the subgroups of hEMR (6.0%, 95%CI 3.8%–8.9%), hEMR-m (3.9%, 95%CI 2.6%–5.5%), and hEMR-mb (5.2%, 95%CI 2.7%–8.9%). Serious postendoscopic bleeding (PEB) was numerically higher with hot EMR (2.3%, 95%CI 1.6%–3.3%) vs. cold EMR (1.3%, 95%CI 0.5%–2.7%), also for the subgroups of hEMR (3.0%, 95%CI 1.5%–5.3%), hEMR-m (1.9%, 95%CI 1.1%–3.2%), and hEMR-mb (2.6%, 95%CI 1.0%–5.6%). Perforation, intraprocedural and post-procedural, was numerically higher with hot EMR (1.2%, 95%CI 0.7%–2.0%) vs. cold EMR (0.2%, 95%CI 0.0%–1.1%). hEMR-m and hEMR-mb with clipping had lower rates of serious and overall PEB than no clipping. Cold EMR demonstrated lower rates of SAEs, serious PEB, and perforation compared with hot EMR. Perforation and mortality occurred almost exclusively after hot EMR. Hot EMR with margin +/− base ablation did not increase SAEs compared with hot EMR without ablation.

Background Complications of endoscopic mucosal resection (EMR) of large colorectal polyps remain a concern. Objective We aimed to compare safety and efficacy of cold EMR (without electrocautery) to hot EMR (with electrocautery) of large colorectal polyps. Design In this multicentre randomised trial, patients with any large (≥20 mm) non-pedunculated colon polyp were assigned to cold or hot EMR (primary intervention), and to submucosal injection with a viscous or non-viscous solution (secondary intervention) following a 2×2 design. The primary outcome was the rate of severe adverse events (SAEs). The secondary outcome was polyp recurrence. In this study, we report results of the primary intervention. Results 660 patients were randomised and analysed. An SAE was observed in 2.1% of patients in the cold EMR group and in 4.3% in the hot EMR group (p=0.10) (per protocol analysis 1.4 vs 5.0%, p=0.017) with fewer perforations following cold EMR (0%) compared with hot EMR (1.6%, p=0.028). Postprocedure bleeding did not differ (1.5% vs 2.2%, p=0.57). The effect of cold resection was independent of the type of submucosal injection solution, polyp size or antithrombotic medications. Recurrence was detected in 27.6% and 13.6% in the cold and hot EMR groups, respectively (p<0.001). Recurrence was not significantly different for 20–29 mm polyps (18.6% vs 13.4%, p=0.24) and for sessile serrated polyps (14.1% vs 8.5%, p=0.33). Conclusion Universal application of cold EMR did not significantly lower SAEs (unless cold EMR could be completed) and doubled the recurrence rate compared with hot EMR. Trial registration details ClinicalTrials.gov, number: NCT03865537 .