Abreu, María T.

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 Background and Aims Over 10% of patients with Crohn’s disease require permanent ileostomy. We aimed to summarize the existing data on diagnosis, definitions of recurrence, and management of Crohn’s disease patients with permanent ileostomy. Methods MEDLINE, Embase, and CENTRAL databases were searched from inception to February 6, 2024. Randomized controlled trials, cohort and cross-sectional studies, and case series of more than 5 patients reporting on postoperative recurrence or the need for surgery in patients with Crohn’s disease and permanent ileostomy were included. Search results were independently screened, and full text of all titles meeting eligibility criteria was obtained. Outcomes of interest included diagnostic techniques, recurrence definitions, and management approaches. We estimated pooled rates (with 95% confidence interval [CI]) of recurrence. Results Thirty cohort studies including 2055 Crohn’s patients with permanent ileostomy were included (53% female, median age at the time of ileostomy creation 32 years, the most common reason for ileostomy was refractory disease). The postoperative recurrence rate was 27% (95% CI, 21.3–33.3, 26 studies, 451/1805 patients). Modalities for diagnosis of Crohn’s disease recurrence were symptoms (15 studies), endoscopy (4 studies), histology from endoscopic biopsies (2 studies), imaging (5 studies), and surgery (22 studies). The reported definitions of recurrence for each modality were heterogeneous. Conclusions There is a lack of standardized monitoring tools and criteria for diagnosing recurrence in patients with Crohn’s disease and permanent ileostomy. The results of this systematic review will form the basis of a global expert recommendation exercise focused on developing management standards and trial endpoints for this condition.

Abstract Background and Aims Previously published long-term safety data reported a favourable ustekinumab safety profile for the treatment of inflammatory bowel disease [IBD]. We present the final cumulative safety data from pooled ustekinumab IBD phase 2/3 clinical studies through 5 years in Crohn’s disease [CD] and 4 years in ulcerative colitis [UC]. Methods In phase 3 studies, patients received a single intravenous placebo or ustekinumab [130 mg or ~6 mg/kg] induction dose followed by subcutaneous maintenance doses of placebo or ustekinumab [90 mg q8w or q12w]. Analyses included all patients who received one dose of study treatment and included patients who were biologic-naïve and patients with a history of biologic failure. Safety outcomes are summarized and presented using number of events per 100 patient-years of follow-up and corresponding 95% confidence intervals. Results In this final pooled safety analysis, 2575 patients were treated with ustekinumab with 4826 patient-years of follow-up. Rates of key safety events, including major adverse cardiac events and malignancies, were similar between placebo and ustekinumab or not higher for ustekinumab. Opportunistic infections, including tuberculosis, and malignancies were reported infrequently. Rates of key safety events in the IBD group were no higher in the ustekinumab group than in the placebo group for both patients who were biologic-naïve or who had a history of biologic failure. No lymphomas or cases of posterior reversible encephalopathy syndrome [formerly known as reversible posterior leukoencephalopathy syndrome] were reported. Conclusion The final cumulative ustekinumab safety data through 5 years in CD and 4 years in UC demonstrated favourable safety compared to placebo and continue to support the well-established safety profile across all approved indications. Clinical trials.gov numbers NCT00265122, NCT00771667, NCT01369329, NCT01369342, NCT01369355, NCT02407236

Abstract During the 20th century, inflammatory bowel disease (IBD) was considered a disease of early-industrialized regions in North America, Europe, and Oceania. At the turn of the 21st century, incidence of IBD increased in newly-industrialized and emerging regions in Africa, Asia, and Latin America, while prevalence in early-industrialized regions started to grow steadily. Changes in incidence and prevalence denote evolution of IBD across four epidemiologic stages: Stage 1 (Emergence), characterized by low incidence and prevalence; stage 2 (Acceleration in Incidence), characterized by rapidly rising incidence and low prevalence; and stage 3 (Compounding Prevalence), characterized by decelerating, plateauing, or declining incidence and steadily rising prevalence. A fourth stage (Prevalence Equilibrium) has been proposed where the slope of prevalence plateaus due to shifting demographics of an aging IBD population, but it has not yet been evidenced. To date, these stages have been theoretical without specific incidence/prevalence indicators defining transition points. Using real-world data from 490 population-based studies comprising 80 global regions and spanning over a century (1920–2023), we show spatiotemporal transitions across stages 1–3 and model transition towards stage 4. Understanding the evolution of IBD across epidemiologic stages allows healthcare systems to better prepare for the future worldwide burden of IBD.

Therapeutic drug monitoring (TDM) of biologics is a rapidly evolving field. We aimed to provide a consensus statement regarding the clinical utility of TDM for biologics in inflammatory bowel disease (IBD). A modified Delphi method was applied to develop consensus statements. A comprehensive literature review was performed regarding TDM of biologic therapies in IBD, and 45 statements were subsequently formulated on the potential application of TDM in IBD. The statements, along with literature, were then presented to a panel of 10 gastroenterologists with expertise in IBD and TDM who anonymously rated them on a scale of 1–10 (1 = strongly disagree and 10 = strongly agree). An expert consensus development meeting was held virtually to review, discuss, refine, and reformulate statements that did not meet criteria for agreement or that were ambiguous. During the meeting, additional statements were proposed. Panelists then confidentially revoted, and statements rated ≥7 by 80% or more of the participants were accepted. During the virtual meeting, 8 statements were reworded, 7 new statements were proposed, and 19 statements were rerated. Consensus was finally reached in 48/49 statements. The panel agreed that reactive TDM should be used for all biologics for both primary nonresponse and secondary loss of response. It was recommended that treatment discontinuation should not be considered for infliximab or adalimumab until a drug concentration of at least 10–15 μg/mL was achieved. Consensus was also achieved regarding the utility of proactive TDM for anti–tumor necrosis factor therapy. It was recommended to perform proactive TDM after induction and at least once during maintenance. Consensus was achieved in most cases regarding the utility of TDM of biologics in IBD, specifically for reactive and proactive TDM of anti–tumor necrosis factors.