A unique serum IgG glycosylation signature predicts development of Crohn's disease and is associated with pathogenic antibodies to mannose glycan.

Inflammatory bowel disease (IBD) is characterized by chronic inflammation in the gut. There is growing evidence in Crohn's disease (CD) of the existence of a preclinical period characterized by immunological changes preceding symptom onset that starts years before diagnosis. Gaining insight into this preclinical phase will allow disease prediction and prevention. Analysis of preclinical serum samples, up to 6 years before IBD diagnosis (from the PREDICTS cohort), revealed the identification of a unique glycosylation signature on circulating antibodies (IgGs) characterized by lower galactosylation levels of the IgG fragment crystallizable (Fc) domain that remained stable until disease diagnosis. This specific IgG2 Fc glycan trait correlated with increased levels of antimicrobial antibodies, specifically anti-Saccharomyces cerevisiae (ASCA), pinpointing a glycome-ASCA hub detected in serum that predates by years the development of CD. Mechanistically, we demonstrated that this agalactosylated glycoform of ASCA IgG, detected in the preclinical phase, elicits a proinflammatory immune pathway through the activation and reprogramming of innate immune cells, such as dendritic cells and natural killer cells, via an FcγR-dependent mechanism, triggering NF-κB and CARD9 signaling and leading to inflammasome activation. This proinflammatory role of ASCA was demonstrated to be dependent on mannose glycan recognition and galactosylation levels in the IgG Fc domain. The pathogenic properties of (anti-mannose) ASCA IgG were validated in vivo. Adoptive transfer of antibodies to mannan (ASCA) to recipient wild-type mice resulted in increased susceptibility to intestinal inflammation that was recovered in recipient FcγR-deficient mice. Here we identify a glycosylation signature in circulating IgGs that precedes CD onset and pinpoint a specific glycome-ASCA pathway as a central player in the initiation of inflammation many years before CD diagnosis. This pathogenic glyco-hub may constitute a promising new serum biomarker for CD prediction and a potential target for disease prevention.

Crohn's disease.

Crohn's disease is a chronic inflammatory disease of the gastrointestinal tract that might lead to progressive bowel damage and disability. The exact cause of Crohn's disease is unknown, but evidence points towards multifactorial events causing dysregulation of the innate immune system in genetically susceptible people. Commonly affecting the terminal ileum and proximal colon, Crohn's disease inflammation is often discontinuous and patchy, segmental, and transmural. Identification of characteristic findings on ileocolonoscopy and histology remains the diagnostic gold standard, but complete assessment involves laboratory abnormalities, including micronutrient deficiencies, cross-sectional imaging to identify transmural disease extent, severity and complications, and a psychosocial assessment. Treatment strategies for patients with Crohn's disease now go beyond achieving clinical remission to include deeper targets of endoscopic healing and consideration of adjunctive histological and transmural targets to alter disease progression potentially further. The use of early effective advanced therapies and development of therapies targeting alternative novel pathways with improved safety profiles have resulted in a new era of healing in Crohn's disease management. Future combination of advanced therapies with diet or other biological drugs and small molecules, together with improvements in tight control monitoring tools and predictive biomarkers might continue to improve outcomes for patients with Crohn's disease.

Impact of prenatal and postnatal maternal IBD status on offspring's risk of IBD: a population-based cohort study.

OBJECTIVE: In utero exposure to maternal inflammation may impact immune system development and subsequent risk of disease. We investigated whether a maternal diagnosis of IBD before childbirth is linked to a higher risk of IBD in offspring compared with a diagnosis after childbirth. Further, we analysed paternal IBD status for comparison. DESIGN: Using Danish health registers, we identified all individuals born in Denmark between 1997 and 2022 and their legal parents, as well as their IBD status. Cox proportional hazards regression analyses adjusted for calendar period and mode of delivery were used to estimate offspring IBD risk by maternal and paternal IBD status before and after childbirth. RESULTS: Of 1 290 358 children, 10 041 (0.8%) had mothers with IBD diagnosis before childbirth and 9985 (0.8%) had mothers with IBD diagnosis after childbirth. Over 18 370 420 person-years, 3537 individuals were diagnosed with IBD. Offspring of mothers with IBD before childbirth had an adjusted HR of IBD of 6.27 (95% CI 5.21, 7.54) compared with those without maternal IBD, while offspring of mothers with IBD after childbirth had an adjusted HR of 3.88 (95% CI 3.27, 4.60). Corresponding adjusted HRs were 5.26 (95% CI 4.22, 6.56) among offspring with paternal IBD before childbirth and 3.73 (95% CI 3.10, 4.50) for paternal IBD after childbirth. CONCLUSION: Offspring had a greater risk of IBD when either parent was diagnosed before childbirth rather than later, emphasising genetic predisposition and environmental risk factors rather than maternal inflammation in utero as risk factors for IBD.

Age-related patterns of microbial dysbiosis in multiplex inflammatory bowel disease families.

OBJECTIVE: IBD is characterised by dysbiosis, but it remains unclear to what extent dysbiosis develops in unaffected at-risk individuals. To address this, we investigated age-related patterns of faecal and serum markers of dysbiosis in high-risk multiplex IBD families (two or more affected first-degree relatives). DESIGN: Faecal and serum samples were collected from multiplex IBD and control families (95 IBD, 292 unaffected, 51 controls). Findings were validated in independent cohorts of 616 and 1173 subjects including patients with IBD, infants born to mothers with IBD and controls. 16S rRNA gene sequencing and global untargeted metabolomics profiling of faeces and serum were performed. RESULTS: Microbial and metabolomic parameters of dysbiosis progressively decreased from infancy until age 8. This microbial maturation process was slower in infants born to mothers with IBD. After age 15, dysbiosis steadily increased in unaffected relatives throughout adulthood. Dysbiosis was accompanied by marked shifts in the faecal metabolome and, to a lesser extent, the serum metabolome. Faecal and serum metabolomics dysbiosis indices were validated in an independent cohort. Dysbiosis was associated with elevated antimicrobial serologies but not with faecal calprotectin. Dysbiosis metrics differentiated IBD from non-IBD comparably to serologies, with a model combining calprotectin, faecal metabolomics dysbiosis index and serology score demonstrating highest accuracy. CONCLUSION: These findings support that dysbiosis exists as a pre-disease state detectable by faecal and serum biomarkers for IBD risk prediction. Given the expansion of disease-modifying agents and non-invasive imaging, the indices developed here may facilitate earlier diagnoses and improved management in at-risk individuals.

Anti-Integrin αvß6 Autoantibodies Are a Novel Biomarker That Antedate Ulcerative Colitis.

BACKGROUND & AIMS: Better biomarkers for prediction of ulcerative colitis (UC) development and prognostication are needed. Anti-integrin αvß6 (anti-αvß6) autoantibodies have been described in patients with UC. We tested for the presence of anti-αvß6 antibodies in the preclinical phase of UC and studied their association with disease-related outcomes after diagnosis. METHODS: Anti-αvß6 autoantibodies were measured in 4 longitudinal serum samples collected from 82 subjects who later developed UC and 82 matched controls from a Department of Defense preclinical cohort (PREDICTS [Proteomic Evaluation and Discovery in an IBD Cohort of Tri-service Subjects]). In a distinct, external validation cohort (Crohn's and Colitis Canada Genetic Environmental Microbial project cohort), we tested 12 pre-UC subjects and 49 matched controls. Furthermore, anti-αvß6 autoantibodies were measured in 2 incident UC cohorts (COMPASS [Comprehensive Care for the Recently Diagnosed IBD Patients], n = 55 and OSCCAR [Ocean State Crohn's and Colitis Area Registry], n = 104) and associations between anti-αvß6 autoantibodies and UC-related outcomes were defined using Cox proportional hazards model. RESULTS: Anti-αvß6 autoantibodies were significantly higher among individuals who developed UC compared with controls up to 10 years before diagnosis in PREDICTS. The anti-αvß6 autoantibody seropositivity was 12.2% 10 years before diagnosis and increased to 52.4% at the time of diagnosis in subjects who developed UC compared with 2.7% in controls across the 4 time points. Anti-αvß6 autoantibodies predicted UC development with an area under the curve of at least 0.8 up to 10 years before diagnosis. The presence of anti-αvß6 autoantibodies in preclinical UC samples was validated in the GEM cohort. Finally, high anti-αvß6 autoantibodies was associated with a composite of adverse UC outcomes, including hospitalization, disease extension, colectomy, systemic steroid use, and/or escalation to biologic therapy in recently diagnosed UC. CONCLUSIONS: Anti-integrin αvß6 autoantibodies precede the clinical diagnosis of UC by up to 10 years and are associated with adverse UC-related outcomes.

Pre-distortion adaptive optics for optical feeder links: simulations and performance analyses.

Optical feeder links offer immense utility in meeting future communication demands-however, atmospheric turbulence limits their performance. This work targets this challenge through analyses of a bidirectional free-space optical communication (FSOC) link that incorporates pre-distortion adaptive optics (AO) between the next-generation optical ground station at the German Aerospace Center (DLR) Oberpfaffenhofen and the laser communications terminal on Alphasat-a satellite in geostationary orbit (GEO). The analyses are performed via end-to-end Monte Carlo simulations that provide realistic performance estimates of the bidirectional FSOC link for a GEO feeder link scenario. We find that applying pre-distortion AO reduces the total uplink losses of the bidirectional FSOC link by up to 10 dB and lessens the scintillation at the GEO satellite by an order of magnitude. Moreover, applying pre-distortion AO eases the link budget requirements needed for maintaining 99.9% link uptime by as much as 20-40 dB, while its use with a laser guide star shows an additional performance improvement of up to 8 dB. These findings demonstrate the desirability and feasibility of utilizing pre-distortion AO for the realization of optical feeder links.

Managing IBD Patients with Concomitant HIV Infection - a Systematic Review.

PURPOSE OF REVIEW: Inflammatory Bowel Disease (IBD) is a chronic GI inflammatory condition induced by a dysregulated immune system activation, whereas HIV infection causes depletion of the immune system, inducing immunosuppression. Given the increasing incidence of IBD across the globe, including in developing countries, the co-prevalence of both conditions is expected to increase. Herein, we systematically review the data describing disease course when both pathologies co-exist. RECENT FINDINGS: Overall, the co-prevalence of IBD and HIV is around 0.1 to 2%. While IBD does not seem to affect HIV course, the opposite is controversial, as some studies report milder IBD phenotype, with fewer disease relapses especially when CD4 + counts are lower than 200 cells/µL. Despite growing evidence to support the safety of the use of immunosuppressants and biologics in IBD-HIV infected patients, these classes of drugs are used in less than 50% of patients, as compared to non-HIV infected IBD patients. There is a need for more studies on disease course and safety of IBD medications in the setting of IBD.

Is Prevention the Best Way to Modify Inflammatory Bowel Disease? How Close Are We?

Despite improved therapeutic strategies and expanding therapeutic targets, inflammatory bowel disease remains a disabling disease with potential to progress and lead to irreversible complications. Increased evidence supports the concept of a preclinical phase in inflammatory bowel disease, preceding clinical diagnosis, during which immune and inflammatory pathways are already altered. As knowledge about this prediagnosis period expands, it unlocks the possibility of disease prediction and ambition for disease prevention and interception. Targeting the early pathogenic events that promote the development of inflammatory bowel disease could prevent or attenuate disease onset and offer a true opportunity for disease modification.

What Does Disease Progression Look Like in Ulcerative Colitis, and How Might It Be Prevented?

Ulcerative colitis (UC) has been characterized by inflammation limited to the mucosa. Although sustained and durable remission has been associated with mucosal healing, the recurrent phenomenon of persistent clinical disease activity despite mucosal healing has been observed in clinical practice and across pivotal trials. Over time, UC appears to confer an increased risk of progression, defined as changes of disease phenotype; adverse transmural effects on the bowel wall; increased risk of neoplasia development; worsening colorectal function; and increased risk of colectomy, hospitalizations, and other extraintestinal comorbidities. Although the treatment paradigm for Crohn's disease has shifted toward early aggressive intervention to prevent disease progression and irreversible bowel damage, such urgency in efforts to halt disease progression in UC have been largely overlooked. This review summarizes the multiple facets of UC contributing to a modified perception of the disease as a progressive one. We propose further study of the natural history and priorities for further treatment goals that include these considerations.

Preclinical Serological Signatures are Associated With Complicated Crohn's Disease Phenotype at Diagnosis.

BACKGROUND: At diagnosis, up to one-third of patients with Crohn's disease (CD) have a complicated phenotype with stricturing (B2) or penetrating (B3) behavior or require early surgery. We evaluated protein biomarkers and antimicrobial antibodies in serum archived years before CD diagnosis to assess whether complicated diagnoses were associated with a specific serological signature. METHODS: Prediagnosis serum was obtained from 201 patients with CD and 201 healthy controls. Samples were evaluated with a comprehensive panel of 1129 proteomic markers (SomaLogic) and antimicrobial antibodies. CD diagnosis and complications were defined by the International Classification of Diseases-Ninth Revision and Current Procedural Terminology codes. Cox regression models were utilized to assess the association between markers and the subsequent risk of being diagnosed with complicated CD. In addition, biological pathway and network analyses were performed. RESULTS: Forty-seven CD subjects (24%) had a B2 (n = 36) or B3 (n = 9) phenotype or CD-related surgery (n = 2) at diagnosis. Subjects presenting with complicated CD at diagnosis had higher levels of antimicrobial antibodies six years before diagnosis as compared with those diagnosed with noncomplicated CD. Twenty-two protein biomarkers (reflecting inflammatory, fibrosis, and tissue protection markers) were found to be associated with complicated CD. Pathway analysis of the altered protein biomarkers identified higher activation of the innate immune system and complement or coagulation cascades up to six years before diagnosis in complicated CD. CONCLUSIONS: Proteins and antimicrobial antibodies associated with dysregulated innate immunity, excessive adaptive response to microbial antigens, and fibrosis precede and predict a complicated phenotype at the time of diagnosis in CD patients.

Neutralizing Anti-Granulocyte Macrophage-Colony Stimulating Factor Autoantibodies Recognize Post-Translational Glycosylations on Granulocyte Macrophage-Colony Stimulating Factor Years Before Diagnosis and Predict Complicated Crohn's Disease.

BACKGROUND & AIMS: Anti-granulocyte macrophage-colony stimulating factor autoantibodies (aGMAbs) are detected in patients with ileal Crohn's disease (CD). Their induction and mode of action during or before disease are not well understood. We aimed to investigate the underlying mechanisms associated with aGMAb induction, from functional orientation to recognized epitopes, for their impact on intestinal immune homeostasis and use as a predictive biomarker for complicated CD. METHODS: We characterized using enzyme-linked immunosorbent assay naturally occurring aGMAbs in longitudinal serum samples from patients archived before the diagnosis of CD (n = 220) as well as from 400 healthy individuals (matched controls) as part of the US Defense Medical Surveillance System. We used biochemical, cellular, and transcriptional analysis to uncover a mechanism that governs the impaired immune balance in CD mucosa after diagnosis. RESULTS: Neutralizing aGMAbs were found to be specific for post-translational glycosylation on granulocyte macrophage-colony stimulating factor (GM-CSF), detectable years before diagnosis, and associated with complicated CD at presentation. Glycosylation of GM-CSF was altered in patients with CD, and aGMAb affected myeloid homeostasis and promoted group 1 innate lymphoid cells. Perturbations in immune homeostasis preceded the diagnosis in the serum of patients with CD presenting with aGMAb and were detectable in the noninflamed CD mucosa. CONCLUSIONS: Anti-GMAbs predict the diagnosis of complicated CD long before the diagnosis of disease, recognize uniquely glycosylated epitopes, and impair myeloid cell and innate lymphoid cell balance associated with altered intestinal immune homeostasis.

Recent advances in clinical practice: advances in cross-sectional imaging in inflammatory bowel disease.

Endoscopy remains the reference standard for the diagnosis and assessment of patients with inflammatory bowel disease (IBD), but it has several important limitations. Cross-sectional imaging techniques such as magnetic resonance enterography (MRE) and intestinal ultrasound (IUS) are better tolerated and safer. Moreover, they can examine the entire bowel, even in patients with stenoses and/or severe inflammation. A variety of cross-sectional imaging activity scores strongly correlate with endoscopic measures of mucosal inflammation in the colon and terminal ileum. Unlike endoscopy, cross-sectional techniques allow complete visualisation of the small-bowel and assess for extraintestinal disease, which occurs in nearly half of patients with IBD. Extramural findings may predict outcomes better than endoscopic mucosal assessment, so cross-sectional techniques might help identify more relevant therapeutic targets. Coupled with their high sensitivity, these advantages have made MRE and IUS the primary non-invasive options for diagnosing and monitoring Crohn's disease; they are appropriate first-line investigations, and have become viable alternatives to colonoscopy. This review discusses cross-sectional imaging in IBD in current clinical practice as well as research lines that will define the future role of these techniques.

Validation and Update of the Lémann Index to Measure Cumulative Structural Bowel Damage in Crohn's Disease.

BACKGROUND & AIMS: The Lémann Index is a tool measuring cumulative structural bowel damage in Crohn's disease (CD). We reported on its validation and updating. METHODS: This was an international, multicenter, prospective, cross-sectional observational study. At each center, 10 inclusions, stratified by CD duration and location, were planned. For each patient, the digestive tract was divided into 4 organs, upper tract, small bowel, colon/rectum, anus, and subsequently into segments, explored systematically by magnetic resonance imaging and by endoscopies in relation to disease location. For each segment, investigators retrieved information on previous surgical procedures, identified predefined strictures and penetrating lesions of maximal severity (grades 1-3) at each organ investigational method (gastroenterologist and radiologist for magnetic resonance imaging), provided segmental damage evaluation ranging from 0.0 to 10.0 (complete resection). Organ resection-free cumulative damage evaluation was then calculated from the sum of segmental damages. Then investigators provided a 0-10 global damage evaluation from the 4-organ standardized cumulative damage evaluations. Simple linear regressions of investigator damage evaluations on their corresponding Lémann Index were studied, as well as calibration plots. Finally, updated Lémann Index was derived through multiple linear mixed models applied to combined development and validation samples. RESULTS: In 15 centers, 134 patients were included. Correlation coefficients between investigator damage evaluations and Lémann Indexes were >0.80. When analyzing data in 272 patients from both samples and 27 centers, the unbiased correlation estimates were 0.89, 0,97, 0,94, 0.81, and 0.91 for the 4 organs and globally, and stable when applied to one sample or the other. CONCLUSIONS: The updated Lémann Index is a well-established index to assess cumulative bowel damage in CD that can be used in epidemiological studies and disease modification trials.

Longitudinal Changes in Fecal Calprotectin Levels Among Pregnant Women With and Without Inflammatory Bowel Disease and Their Babies.

BACKGROUND & AIMS: The effect of pregnancy on inflammatory bowel disease (IBD) remains poorly understood. We aimed to monitor intestinal inflammation using fecal calprotectin (FC) in pregnant women and their babies during early life. METHODS: Pregnant women with or without IBD and their infants were prospectively enrolled. FC levels were measured at each trimester of pregnancy and in babies throughout the first 3 years of life. Repeated-measures analysis was applied to investigate changes in FC levels while adjusting for confounders. The FC levels were correlated with the bacterial abundance in both mothers and babies. RESULTS: Six hundred and fourteen fecal samples from 358 mothers (98 with IBD) and 1005 fecal samples from 289 infants (76 born to IBD mothers) were analyzed. Pregnant Patients with IBD maintained higher FC levels through pregnancy compared with controls (P = 7.5 × 10-54). FC gradually increased in controls and declined in Patients with IBD throughout pregnancy (P for interaction = 5.8 × 10-7). Babies born to mothers with IBD presented with significantly higher FC levels than those born to controls up to 3 years of age, after adjusting for sex, delivery mode, feeding behavior, and antibiotics exposure (2 weeks to 3 months of age, P = .015; 12-36 months of age, P = .00003). Subdoligranulum, Roseburia, Fusicatenibacter, and Alistipes negatively correlated, and Streptococcus, Prevotella, Escherichia-Shigella, and Bifidobacterium positively correlated with maternal FC levels at T3. Faecalibacterium, Bifidobacterium, and Alistipes showed negative correlations, and Streptococcus were positively correlated with FC levels within 3 months of birth. CONCLUSIONS: Pregnancy is associated with decreased inflammatory activity in mothers with IBD. Higher FC levels in babies born to mothers with IBD suggest subclinical inflammation in early life, the long-term consequences of which are uncertain.

Breastfeeding Is Associated with Lower Likelihood of Helicobacter Pylori Colonization in Babies, Based on a Prospective USA Maternal-Infant Cohort.

BACKGROUND: Mother-to-child transmission of Helicobacter pylori (H. pylori) is the primary source of intrafamilial spread in early childhood in regions of high H. pylori prevalence. However, early-in-life H. pylori colonization and associated protective or risk factors have not been fully evaluated in lower prevalence regions, such as the USA. AIMS: Therefore, from a well-characterized prospective US cohort, we selected women who provided fecal samples during pregnancy and had paired fecal samples from their babies up to 24 months postpartum. We evaluated maternal and baby factors associated with likelihood of H. pylori colonization in the babies. Fecal antigen testing was used to determine H. pylori status. We also evaluated the association between maternal breastmilk cytokines and H. pylori colonization in breastfed babies. RESULTS: Among included mother-baby pairs (n = 66), H. pylori prevalence was 31.8% in mothers and 19.7% in their babies. Dominant breastfeeding (adjusted odds ratio [aOR] 0.17, 95% CI 0.03-0.98) and maternal IBD (aOR 0.05, 95% CI 0.01-0.27) were associated with significantly lower likelihood of H. pylori colonization among babies; no other clinical factors were associated with H. pylori colonization in the babies. Matrix metalloproteinase-10 (MMP-10) and tumor necrosis factor-related activation-induced cytokine expression were significantly higher in breastmilk of mothers with H. pylori positive vs negative babies. CONCLUSIONS: Consistent with data from high H. pylori prevalence regions, our findings suggest dominant breastfeeding may protect against early H. pylori colonization. Downregulation of pro-inflammatory cytokines such as MMP-10 may be relevant in mediating this protection among breastfed babies, but more data are needed.

Serum Biomarkers Identify Patients Who Will Develop Inflammatory Bowel Diseases Up to 5 Years Before Diagnosis.

BACKGROUND & AIMS: Biomarkers are needed to identify patients at risk for development of inflammatory bowel diseases. We aimed to identify serum biomarkers of Crohn's disease and ulcerative colitis that can be detected and quantified before diagnosis. METHODS: We obtained serum samples from patients archived before a diagnosis of Crohn's disease (n = 200) or ulcerative colitis (n = 199), as well as from 200 healthy individuals (controls), collected from 1998 through 2013 as part of the US Defense Medical Surveillance System. We measured levels of antibodies against microbes (anti-Saccharomyces cerevisiae IgA or IgG, anti-Escherichiacoli outer membrane porin C, anti-CBir1, anti-flagellin 2, anti-flagellin X, and perinuclear anti-neutrophil cytoplasmic antibodies) and 1129 proteins in each sample. We then used functional principal component analysis to derive the time-varying trajectory for each marker, which then was used in a multivariate model to predict disease status. Predictive performances at different prediagnosis timepoints were evaluated using area under the receiver operating characteristic curves (AUROCs). Biological pathways that were up-regulated in serum from patients with Crohn's disease were identified based on changes in protein abundance at different time periods preceding diagnosis. RESULTS: We identified a panel of 51 protein biomarkers that were predictive of Crohn's disease within 5 years with an AUROC of 0.76 and a diagnosis within 1 year with an AUROC of 0.87. Based on the proteins included in the panel, imminent development of CD was associated with changes in the complement cascade, lysosomes, innate immune response, and glycosaminoglycan metabolism. Serum antibodies and proteins identified patients who received a diagnosis of ulcerative colitis within 5 years with an AUROC of only 0.56 and within 1 year with an AUROC of 0.72. CONCLUSIONS: We identified a panel of serum antibodies and proteins that were predictive of patients who will receive a diagnosis of Crohn's disease within 5 years with high accuracy. By contrast we did not identify biomarkers associated with future diagnosis of ulcerative colitis.

Collagenous Colitis Is Associated With HLA Signature and Shares Genetic Risks With Other Immune-Mediated Diseases.

BACKGROUND & AIMS: Collagenous colitis (CC) is an inflammatory bowel disorder with unknown etiopathogenesis involving HLA-related immune-mediated responses and environmental and genetic risk factors. We carried out an array-based genetic association study in a cohort of patients with CC and investigated the common genetic basis between CC and Crohn's disease (CD), ulcerative colitis (UC), and celiac disease. METHODS: DNA from 804 CC formalin-fixed, paraffin-embedded tissue samples was genotyped with Illumina Immunochip. Matching genotype data on control samples and CD, UC, and celiac disease cases were provided by the respective consortia. A discovery association study followed by meta-analysis with an independent cohort, polygenic risk score calculation, and cross-phenotype analyses were performed. Enrichment of regulatory expression quantitative trait loci among the CC variants was assessed in hemopoietic and intestinal cells. RESULTS: Three HLA alleles (HLA-B∗08:01, HLA-DRB1∗03:01, and HLA-DQB1∗02:01), related to the ancestral haplotype 8.1, were significantly associated with increased CC risk. We also identified an independent protective effect of HLA-DRB1∗04:01 on CC risk. Polygenic risk score quantifying the risk across multiple susceptibility loci was strongly associated with CC risk. An enrichment of expression quantitative trait loci was detected among the CC-susceptibility variants in various cell types. The cross-phenotype analysis identified a complex pattern of polygenic pleiotropy between CC and other immune-mediated diseases. CONCLUSIONS: In this largest genetic study of CC to date with histologically confirmed diagnosis, we strongly implicated the HLA locus and proposed potential non-HLA mechanisms in disease pathogenesis. We also detected a shared genetic risk between CC, celiac disease, CD, and UC, which supports clinical observations of comorbidity.

Histologic Features of Colon Biopsies (Geboes Score) Associated With Progression of Ulcerative Colitis for the First 36 Months After Biopsy.

BACKGROUND & AIMS: In addition to findings from endoscopy, histologic features of colon biopsies have been associated with outcomes of patients with ulcerative colitis (UC). We investigated associations between Geboes scores (a system to quantify structural changes and inflammatory activity in colon biopsies) and UC progression, and the time period over which this association is valid. METHODS: We analyzed data from 399 asymptomatic patients with UC enrolled in the ACERTIVE study, followed at 13 inflammatory bowel disease (IBD) centers in Portugal through 31 December 2019. Blood and stool samples were collected and analyzed, and all patients underwent sigmoidoscopy within 24 h of sample collection. We assessed baseline endoscopic status (Mayo endoscopic subscore), histologic features of 2 sigmoid and 2 rectal biopsies (Geboes score), and concentration of fecal calprotectin (FC). The primary outcome was UC progression (surgical, pharmacologic, and clinical events). We generated survival curves for 36 months or less and more than 36 months after biopsy according to Geboes score using the Kaplan-Meier method and compared findings with those from a log rank test. Cox regression was adjusted for Mayo endoscopic subscore, Geboes score, and level of FC; results were expressed as adjusted hazard ratios (HR) with 95% CIs. RESULTS: Patients with Geboes scores >2B.0, Geboes scores >3.0, or Geboes scores >4.0 had a higher frequency of, and a shorter time to UC progression, than patients with Geboes scores ≤2B.0, Geboes scores ≤3.0, or Geboes score ≤4.0 (P < .001). Disease progression occurred earlier in patients with Geboes scores >2B.0, Geboes scores >3.0, or Geboes scores >4.0 compared with patients with Geboes scores ≤2B.0 (HR, 2.021; 95% CI, 1.158-3.526), Geboes scores ≤3.0 (HR, 2.007; 95% CI, 1.139-3.534), or Geboes scores ≤4.0 (HR, 2.349; 95% CI, 1.269-4.349), respectively, in the first 36 months after biopsy. Similar results were found for patients with concentrations of FC below 150 µg/g. CONCLUSIONS: We found histologic features of colon biopsies (Geboes score) to be an independent risk factor for progression of UC in the first 36 months after biopsy.

Mode of Delivery Does Not Affect the Risk of Inflammatory Bowel Disease.

BACKGROUND: Recent evidence suggests that exposures in early life that are known to influence microbiome development may affect the risk of developing inflammatory bowel disease (IBD). Cesarean section has been associated with altered colonization of commensal gut flora and is thought to predispose to immune-mediated diseases later in life. AIMS: To evaluate the risk of IBD, Crohn's Disease (CD), and Ulcerative Colitis (UC) according to mode of delivery (C-section vs vaginal delivery). METHODS: A systematic search was performed in PubMed and Embase. The primary outcome was the risk of IBD in individuals delivered vaginally compared to those born by C-section. Secondary outcomes were UC and CD risk according to mode of delivery and IBD risk in individuals born by emergent compared to elective C-section. Publication bias was evaluated by funnel plots and Egger's test. Study's quality was characterized using the Newcastle-Ottawa Scale. RESULTS: Ten studies fulfilled the inclusion criteria, of which seven were population-based. No publication bias was detected. Overall, 14.164 IBD patients and 4.206.763 controls were included. Being born by C-section was not associated with increased risk of IBD [OR 1.01, 95% CI (0.81-1.27), p = 0.92], CD [OR 1.15, 95% CI (0.94-1.42), p = 0.18] or UC [OR 0.94, 95% CI (0.61-1.45), p = 0.79]. No differences were found between emergent and elective C-section in IBD [OR 1.05, 95% CI (0.59-1,87), p = 0.87]. Substantial heterogeneity was found in statistical analysis, and further studies are needed. CONCLUSION: Overall, the risk of developing IBD was not affected by mode of delivery.

Signalling crosstalk during early tumorigenesis in the absence of Polycomb silencing.

In response to stress and injury a coordinated activation of conserved signalling modules, such as JNK and JAK/STAT, is critical to trigger regenerative tissue restoration. While these pathways rebuild homeostasis and promote faithful organ recovery, it is intriguing that they also become activated in various tumour conditions. Therefore, it is crucial to understand how similar pathways can achieve context-dependent functional outputs, likely depending on cellular states. Compromised chromatin regulation, upon removal of the Polycomb group member polyhomeotic, leads to tumour formation with ectopic activation of JNK signalling, mediated by egr/grnd, in addition to JAK/STAT and Notch. Employing quantitative analyses, we show that blocking ectopic signalling impairs ph tumour growth. Furthermore, JAK/STAT functions in parallel to JNK, while Notch relies on JNK. Here, we reveal a signalling hierarchy in ph tumours that is distinct from the regenerative processes regulated by these pathways. Absence of ph renders a permissive state for expression of target genes, but our results suggest that both loss of repression and the presence of activators may collectively regulate gene expression during tumorigenesis. Further dissecting the effect of signalling, developmental or stress-induced factors will thus elucidate the regulation of physiological responses and the contribution of context-specific cellular states.