Early Onset Inflammatory Bowel Disease Research Articles

Genomic Testing Identifies Monogenic Causes in Patients with Very Early-Onset Inflammatory Bowel Disease: A Multi-center Survey in an Iranian Cohort.

Patients with very early-onset inflammatory bowel disease (VEO-IBD) may present because of underlying monogenic inborn errors of immunity (IEI). Strong differences have been observed in the causes of monogenic IBD among ethnic populations. This multi-center study was carried out on 16 Iranian patients with VEO-IBD. We reviewed clinical and basic immunologic evaluation including flow cytometry and immunoglobulin levels. All patients underwent clinical whole exome sequencing (WES). Sixteen patients (8 females and 8 males) with a median age of 43.5 months were enrolled. The median age at the onset of symptoms was 4 months. Most patients (12, 75%) had consanguineous parents. Chronic non-bloody diarrhea (13, 81.3%) and perianal diseases including perianal abscess (6, 37.5%), anal fissure (6, 37.5%), or anal fistula (2, 12.5%) were the most common manifestations. WES identified a spectrum of genetic variants in 13 patients (81.3%): IL10RB (6, 37.5%), MVK (3, 18.8%), and CASP8, SLC35C1, G6PC3, and IKBKB in one patient, respectively. In 3 patients (18.7%) no variant was identified. Flow cytometry identified a spectrum of abnormalities that helped to assess the evidence of genetic diagnosis. At the end of the survey, 3 (18.8%) patients were deceased. This high rate of monogenic defects with a broad spectrum of genes reiterates the importance of investigating IEI in patients with infantile-onset IBD.

136 Hematopoietic stem cell transplantation for very early onset inflammatory bowel disease caused by IL10RA deficiency – preparation is the key to success

136 Hematopoietic stem cell transplantation for very early onset inflammatory bowel disease caused by IL10RA deficiency – preparation is the key to success

207 The Use of Tofacitinib and Upadacitinib in Very Early Onset IBD

207 The Use of Tofacitinib and Upadacitinib in Very Early Onset IBD

Ustekinumab Offers Long-Term Clinical Remission With Safety in Very Early-Onset Inflammatory Bowel Disease.

Lay Summary We observed efficacy and safety of ustekinumab in very early-onset inflammatory bowel disease, which has not been previously reported. Clinical remission at 52% was 75%, often persisting beyond 2 years. Further studies including larger numbers of cases are needed to confirm this observation.

Multicenter registry of pediatric inflammatory bowel disease from a developing country

BackgroundDespite the rising incidence of pediatric inflammatory bowel disease (PIBD) globally, multicenter collaborative studies of PIBD children among developing countries remain sparse. We therefore aimed to define the initial presentation and short-term outcomes of Thai children with PIBD from a multicenter registry.MethodsFour teaching hospitals participated in this study. A diagnosis of PIBD requires gastrointestinal endoscopy and histopathology in children aged < 19 years. Besides demographics, we collected clinical information and treatment with the data at 1-year follow up.ResultsWe included 35 Crohn’s disease (CD), one IBD-unclassified, and 36 ulcerative colitis (UC) children (total n = 72 with 60.6% males). The mean age at diagnosis was 7.9 years (SD 4.1) with 38% being very early onset IBD (VEO-IBD). When compared with UC, the CD children were more likely to exhibit fever (42.3 vs. 13.9%), weight loss/failure to thrive (68.6 vs. 33.3%), and hypoalbuminemia (62.9 vs. 36.1%) but less likely to have bloody stools (51.4 vs. 91.7%) (all P < 0.05). No significant differences in demographics, clinical data and medications used with regards to VEO-IBD status. At 1 year after diagnosis (n = 62), 30.7% failed to enter clinical remission and 43.7% remained on systemic corticosteroids. Diarrhea (OR 9.32) and weight issues (OR 4.92) at presentation were independent predictors of failure to enter clinical remission; and females (OR 3.08) and CD (vs. UC) (OR 3.03) were predictors of corticosteroids use at 1-year follow-up.ConclusionsA high proportion of VEOIBD is noted, and CD was more likely to present with significant inflammatory burden. Diarrhea and weight issues at presentation were independent predictors of failure to enter clinical remission; and females and CD (vs. UC) were predictors of corticosteroids use at 1-year follow-up.

Retinoid orphan receptor gamma t (rorγt) promotes inflammatory eosinophilia but is dispensable for innate immune-mediated colitis.

Inflammatory bowel diseases (IBD) result from uncontrolled inflammation in the intestinal mucosa leading to damage and loss of function. Both innate and adaptive immunity contribute to the inflammation of IBD and innate and adaptive immune cells reciprocally activate each other in a forward feedback loop. In order to better understand innate immune contributions to IBD, we developed a model of spontaneous 100% penetrant, early onset colitis that occurs in the absence of adaptive immunity by crossing villin-TNFAIP3 mice to RAG1-/- mice (TRAG mice). This model is driven by microbes and features increased levels of innate lymphoid cells in the intestinal mucosa. To investigate the role of type 3 innate lymphoid cells (ILC3) in the innate colitis of TRAG mice, we crossed them to retinoid orphan receptor gamma t deficient (Rorγt-/-) mice. Rorγt-/- x TRAG mice exhibited markedly reduced eosinophilia in the colonic mucosa, but colitis persisted in these mice. Colitis in Rorγt-/- x TRAG mice was characterized by increased infiltration of the intestinal mucosa by neutrophils, inflammatory monocytes, macrophages and other innate cells. RNA and cellular profiles of Rorγt-/- x TRAG mice were consistent with a lack of ILC3 and ILC3 derived cytokines, reduced antimicrobial factors, increased activation oof epithelial repair processes and reduced activation of epithelial cell STAT3. The colitis in Rorγt-/- x TRAG mice was ameliorated by antibiotic treatment indicating that microbes contribute to the ILC3-independent colitis of these mice. Together, these gene expression and cell signaling signatures reflect the double-edged sword of ILC3 in the intestine, inducing both proinflammatory and antimicrobial protective responses. Thus, Rorγt promotes eosinophilia but Rorγt and Rorγt-dependent ILC3 are dispensable for the innate colitis in TRAG mice.

Children and Adolescents Diagnosed With Inflammatory Bowel Disease Are at Increased Risk of Developing Diseases With a Possible Autoimmune Pathogenesis.

The development of diseases with a possible autoimmune pathogenesis is common in adults with inflammatory bowel disease (IBD). In early onset IBD, it may differ but the evidence is sparse. We aimed to investigate the risk and time span from IBD diagnosis to outcomes with different associated disorders with possible autoimmune pathogenesis. A register-based study included all Danish patients with early onset of IBD (≤18 years) between 1980 and 2021 and 50 matched references without IBD for each case. We examined the risk of type 1 and type 2 diabetes, celiac disease, thyroid disease, rheumatoid arthritis, psoriatic arthritis, and spondyloarthritis in Cox regression models. In total, 6822 patients with IBD were identified, and 337 728 matched references. The median age at the time of IBD diagnosis or index date for the matched references was 16 years (25-75 percentile: 13-18 years), and the median age at the time of an outcome or at the end of follow-up was 28.1 years (25-75 percentile: 21.5-37.0 years). According to the cumulative incidence plots psoriatic arthritis, and spondyloarthritis was diagnosed approximately 10 years after the IBD onset, and the remaining outcomes later. The adjusted hazard ratio after full follow-up was 4.72 (95% CI, 3.85-5.80) for psoriatic arthritis, 5.21 (95% CI, 4.17-6.50) for spondyloarthritis, 2.77 (95% CI, 1.92-4.00) for celiac disease, 2.15 (95% CI, 1.54-3.01) for rheumatoid arthritis, 1.69 (95% CI, 1.23-2.32) and 1.64 (95% CI, 1.21-2.21) for type 1 and type 2 diabetes, respectively. For thyroid disease, it was 1.16 (95% CI, 0.97-1.40). The risk estimates were significantly increased for all outcomes at the end of follow-up, except for thyroid disease, but according to the cumulative incidence plots, only psoriatic arthritis and spondyloarthritis occurred earlier in the IBD cohort than in the matched references.

Infantile inflammatory bowel disease in three Syrian infants: a case series

BackgroundInflammatory bowel diseases, consisting of Crohn’s disease and ulcerative colitis, are chronic bowel relapsing inflammatory disorders. Inflammatory bowel diseases begin rarely in infants. Approximately 25% of patients with inflammatory bowel diseases present before the age of 20 years. Very early-onset inflammatory bowel disease occurs before the age of 6 years; infantile inflammatory bowel diseases occurs before the age of 2 years, and is extremely rare in infants under 1 year of age.Case presentationHerein, we report a case series of 7-month-, 11-month-, and 12-month-old Syrian infants that presented with diarrhea, hematochezia, and pale appearance and were finally diagnosed with infantile inflammatory bowel disease and treated.ConclusionsEarly diagnosis and ruling out infantile inflammatory bowel diseases despite its rarity are recommended. Over and above that, new drugs such as vedolizumab, golimumab, and less invasive treatment methods should also be taken into consideration for better response and adequate remission with improved quality of life.

The intestinal microbiome of inflammatory bowel disease across the pediatric age range

ABSTRACT Dysbiosis is associated with pediatric and adult-onset inflammatory bowel disease (IBD), but the role of dysbiosis and the microbiome in very early onset IBD (VEO-IBD) has not yet been described. Here, we aimed to demonstrate the impact of age and inflammation on microbial community structure using shotgun metagenomic sequencing in children with VEO-IBD, pediatric-onset IBD, and age-matched pediatric healthy controls (HC) observed longitudinally over the course of 8 weeks. We found disease-related differences in alpha and beta diversity between HC and children with IBD or VEO-IBD. Using a healthy microbial maturity index modeled from HC across the age range to characterize their gut microbiota, we found that children with pediatric-onset IBD and VEO-IBD had lower maturity than their age-matched HC groups, suggesting a disease effect on the microbial community. In addition, patients with pediatric IBD had significantly lower maturity than those with VEO-IBD, who had more heterogeneity at the youngest ages, highlighting differences in these two cohorts that were not captured in standard comparisons of alpha and beta diversity. These results demonstrate that young age and inflammation independently impact microbial community structure. However, the effect is not additive in the youngest patients, likely because of the heterogeneous and dynamic stool microbiome in this population.

Cord Blood Transplantation for Very Early-Onset Inflammatory Bowel Disease Caused by Interleukin-10 Receptor Deficiency.

Interleukin-10 receptor (IL-10R) deficiency can result in life-threatening very early-onset inflammatory bowel disease (VEO-IBD). Umbilical cord blood transplantation (UCBT) is a curative therapy for patients with IL-10R deficiency. This study aimed to investigate the efficacy of UCBT in treating IL-10R deficiency and develop a predictive model based on pre-transplant factors. Eighty patients with IL-10R deficiency who underwent UCBT between July 2015 and April 2023 were retrospectively analyzed. Cox proportional hazards regression and random survival forest were used to develop a predictive model. Median age at transplant was 13.0months (interquartile range [IQR], 8.8-25.3months). With a median follow-up time of 29.4months (IQR, 3.2-57.1months), the overall survival (OS) rate was 65.0% (95% confidence interval [CI], 55.3%-76.3%). The engraftment rate was 85% (95% CI, 77%-93%). The cumulative incidences of acute and chronic graft-versus-host disease were 48.2% (95% CI, 37.1%-59.4%) and 12.2% (95% CI, 4.7%-19.8%), respectively. VEO-IBD-associated clinical symptoms were resolved in all survivors. The multivariate analysis showed that IL-6 and stool occult blood were independent prognostic risk factors. The multivariate Cox proportional hazards regression model with stool occult blood, length- or height-for-age Z-score, medical history of sepsis, and cord blood total nucleated cells showed good discrimination ability, with a bootstrap concordance index of 0.767-0.775 in predicting OS. Better inflammation control before transplantation and higher cord blood total nucleated cell levels can improve patient prognosis. The nomogram can successfully predict OS in patients with IL-10R deficiency undergoing UCBT.

Sustained Increase in Pediatric Inflammatory Bowel Disease Incidence Across the South West United Kingdom Over the Last 10 Years.

Pediatric inflammatory bowel disease (pIBD) incidence has increased over the last 25 years. We aim to report contemporaneous trends across the South West United Kingdom. Data were provided from centers covering the South West United Kingdom (Bristol, Oxford, Cardiff, Exeter, and Southampton), with a total area at-risk population (<18 years of age) of 2 947 534. Cases were retrieved from 2013 to 2022. Incident rates were reported per 100 000 at-risk population, with temporal trends analyzed through correlation. Subgroup analysis was undertaken for age groups (0-6, 6-11, and 12-17 years of age), sex, and disease subtype. Choropleth maps were created for local districts. In total, 2497 pIBD cases were diagnosed between 2013 and 2022, with a mean age of 12.6 years (38.7% female). Diagnosis numbers increased from 187 to 376, with corresponding incidence rates of 6.0 per 100 000 population per year (2013) to 12.4 per 100 000 population per year (2022) (b = 0.918, P < .01). Female rates increased from 5.1 per 100 000 population per year in 2013 to 11.0 per 100 000 population per year in 2022 (b = 0.865, P = .01). Male rates increased from 5.7 per 100 000 population per year to 14.4 per 100 000 population per year (b = 0.832, P = .03). Crohn's disease incidence increased from 3.1 per 100 000 population per year to 6.3 per 100 000 population per year (b = 0.897, P < .01). Ulcerative colitis increased from 2.3 per 100 000 population per year to 4.3 per 100 000 population per year (b = 0.813, P = .04). Inflammatory bowel disease unclassified also increased, from 0.6 per 100 000 population per year to 1.8 per 100 000 population per year (b = 0.851, P = .02). Statistically significant increases were seen in those ≥12 to 17 years of age, from 11.2 per 100 000 population per year to 24.6 per 100 000 population per year (b = 0.912, P < .01), and the 7- to 11-year-old age group, with incidence rising from 4.4 per 100 000 population per year to 7.6 per 100 000 population per year (b = 0.878, P = .01). There was no statistically significant increase in very early onset inflammatory bowel disease (≤6 years of age) (b = 0.417, P = .231). We demonstrate significant increases in pIBD incidence across a large geographical area including multiple referral centers. Increasing incidence has implications for service provision for services managing pIBD.

Evolving a Single Institution’s Approach to Very Early Onset Inflammatory Bowel Disease (VEO-IBD) through Literature Review and Collaborative Efforts

Evolving a Single Institution’s Approach to Very Early Onset Inflammatory Bowel Disease (VEO-IBD) through Literature Review and Collaborative Efforts

Humoral immune response and safety of SARS-CoV-2 vaccination in very early onset inflammatory bowel disease.

Children with very early onset inflammatory bowel disease (VEO-IBD) may respond differently to coronavirus disease 2019 (COVID-19) immunization compared to healthy children or other patients with IBD. We recruited children with VEO-IBD<6 years of age and younger following receipt of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. Demographics, IBD characteristics, medication use, adverse events (AEs) and IBD exacerbations were collected. Blood draws (optional) were obtained for measurement of antireceptor binding domain (RBD) IgG antibodies following vaccination. Of 41 participants, none required emergency department visit or hospitalization due to AE, and only one experienced IBD exacerbation. Detectable antibody was present in 19/19 participants who provided blood sample; 6/7 participants (86%) had durable humoral response 12 months postvaccination. Children with VEO-IBD experience robust humoral immune response to COVID-19 immunization. Severe AEs were rare. These findings provide reassurance that children with VEO-IBD respond well and safely to SARS-CoV-2 vaccination.

[Clinical features and genetic analysis of three patients with Immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome due to variants of FOXP3 gene].

To analyze the clinical characteristics of three patients with Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome. Three patients with IPEX syndrome diagnosed at the Children's Hospital of Fudan University from January 24, 2013 to July 29, 2019 were selected as the study subjects. Their clinical features, laboratory investigations and results of genetic testing were summarized. Treatment and prognosis were also explored. All of the three children had developed the disorder during infancy. One child had initial features including diabetes and diabetic ketoacidosis, whilst the other two had initiated by diarrhea. All patients had gastrointestinal involvement, and one was diagnosed as very early onset inflammatory bowel disease by colonoscopy and biopsy. Two children also had endocrine glands involvement. One child had manifested type 1 diabetes and positivity for thyroglobulin and thyroid peroxidase antibodies, though his thyroid function had remained normal. Another one had hypothyroidism and was treated by levothyroxine. Genetic testing revealed that all children had harbored missense variants of the FOXP3 gene, including c.1222G>A (p.V408M), c.767T>C (p.M256T) and c.1021A>G (p.T341A). The clinical symptoms of one patient were alleviated following allogeneic hematopoietic stem cell transplantation. One patient was stable after treatment with infliximab plus insulin, and one child had died of refractory septic shock and multiple organ dysfunction syndrome at 3 months old. FOXP3 gene variant-associated IPEX syndrome may have very early onset and diverse clinical manifestations. For male patients with infantile onset chronic diarrhea, multiple endocrine or multiple system involvement, genetic testing is recommended, which may facilitate early diagnosis, treatment and genetic counseling.

BIOACTIVE INTERLEUKIN-1 DETECTED IN IBD PATIENT INTESTINAL BIOPSIES IS A HALLMARK OF ULCERS AND CORRELATES WITH TRANSCRIPTOMIC ASSESSMENTS, INCLUDING AN ULCER-ASSOCIATED GENE MODULE

Abstract BACKGROUND Interleukin (IL)-1 and its post-translationally modified and released forms, IL-1α and IL-1β, have been identified as key molecules to maintain mucosal homeostasis and to drive inflammatory bowel disease (IBD). Deep cellular phenotypic, transcriptional, and in vitro data highlight the importance of IL-1-associated cytokine networks and IL-1 producing cells in severe and anti-TNF non-responsive IBD. Nevertheless, little is known about the presence of bioactive IL-1 proteins within the cell-free gastrointestinal (GI) mucosal environment and associated function in severe IBD and ulceration. METHODS We established a highly sensitive functional assay (~500-fold greater than ELISA) to assess bioactive extracellular IL-1 protein from previously cryopreserved GI biopsies. We performed an ex vivo study in a cohort of Crohn’s disease (CD, n=23), ulcerative colitis (UC, n=18) and non-IBD (n=17) patients, with biopsies from paired inflamed and uninflamed intestinal regions per patient (primarily colon but also ileal). We assessed differential IL-1 bioactivity, including IL-1α vs IL-1β contributions, and performed RNA-seq of the matched cellular compartments of the samples. An ulcer-associated gene signature derived from RNA-seq analysis was evaluated in a single-cell RNA-seq cohort (n=42) of very early onset IBD including monogenic disorders. RESULTS The extent of bioactive intestinal mucosal IL-1α and IL-1β corresponded with disease and ulcer severity in both CD and UC. The most extreme signals were seen in select CD patients with deep ulceration. Bioactive IL-1α was the predominant contributor to total IL-1 signal in most patients although several with ulcers displayed an IL-1β-predominant signal. Matched RNA-seq analysis demonstrated enhanced IL-1 transcripts, correlating with IL-1 bioactivity, and a weighted gene co-expression network analysis (WGCNA) revealed a compelling ulcer-specific module enriched in IL-1 signaling genes and wound repair. We validated our findings in several published (e.g., RISK cohort of ileal CD) as well as unpublished independent adult and pediatric datasets from our group. Deconvolution of the ulcer-specific gene module and projection onto an unpublished single-cell RNA-seq cohort of very early onset IBD patients (including IBD-causative mutations such as IL-10R deficiency characterized by deep ulceration) implicated specific stromal and myeloid populations in ulcer biology. CONCLUSION Mucosal ulceration in IBD is associated with bioactive IL-1α and IL-1β proteins, and transcriptomic evaluation of the same correlates with bioactive signal. An ulcer-associated gene module, validated in other datasets, sheds light on IL-1 biology in intestinal epithelial repair. Results strongly suggest the IL-1 signaling pathway being an attractive and precision-based therapeutic target in subsets of IBD patients.

TNF IS REQUIRED FOR SPONTANEOUS INNATE COLITIS IN MICE LACKING ADAPTIVE IMMUNITY

Abstract BACKGROUND Colitis involves excessive inflammation driven by the reciprocal interaction of innate and adaptive immune cells. To better understand how innate immunity contributes to colitis, we developed a spontaneous innate model of colitis that is highly penetrant, early onset, and driven by microbes. TNF is a cytokine produced predominantly by T cells but also by innate and non-immune cells and contributes to IBD in many patients. We therefore examined the role of TNF in innate immune mediated colitis. METHODOLOGY We developed a 100% penetrant mouse model of colitis by crossing villin transgenic expression of tnfaip3 (villin-tnfaip3) to rag1 null mice (rag1-/-), designated as TRAG mice (villin-tnfaip3 x rag1-/-). TRAG mice are characterized by inflammation of the colon in the absence of T and B cells. We crossed TRAG mice with tnfa-/- mice (tnfa-/- x TRAG) to elucidate the role of TNF in this model. The histopathological score of disease was evaluated by H&amp;E, and the innate immune populations characterized by multi-color flow cytometry. Apoptosis, necrosis, and cell death were evaluated histologically by localizing cleaved caspase-3, phosho-MLKL and TUNEL positive cells. Secretion of cytokines from intestinal tissue in culture was quantified by ELISA. RESULTS TRAG mice develop early-onset colitis that is driven by microbes but is not transmissible to rag1-/- littermates. TRAG mice showed histological signs of colitis and a high infiltration of leukocytes in the intestinal mucosa without concurrent systemic inflammation. This colitis was not observed in tnfa-/- x TRAG mice. TRAG mice exhibited a pro-inflammatory cytokine signature with elevated secretion of IL1a and IL1b but not IL-18 or IL-33, which was not observed in mucosa from tnfa-/- x TRAG mice. LPLs from TRAG colons indicated TNF production by inflammatory monocytes, monocytes, and neutrophils. Monocytes and macrophages from the TRAG mouse mucosa, but not the tnfa-/- x TRAG mucosa, showed an M1 profile defined by elevated iNOS and decreased arginase. Increased crypt cell death was evident in TRAG colons, and this was significantly diminished in the crypts of tnfa-/- x TRAG colons. Early aggressive treatment of TRAG mice with anti-TNF antibody, but not anti-IL1a antibody, prevented colitis in TRAG mice. CONCLUSIONS TNF drives innate colitis featuring increased infiltration of mucosal leukocytes, increased secretion of IL1a and IL1b, skewing of macrophages to an M1 profile, and increased cell death in colonic crypts. Even in the absence of T cell derived cytokines, including TNF, innate sources of TNF are sufficient to drive colitis and early use of anti-TNF therapy is effective against this innate form of colitis. We are currently investigating the signals and forms of cell death that are driven by TNF in this model.

P071 Neonatal levels of inflammatory markers in individuals who later develop early onset Inflammatory Bowel Disease

Abstract Background The early life period is suggested to be important in development of Inflammatory Bowel Disease (IBD). Studies in babies from mothers with IBD observed increased faecal calprotectin and changes in the microbial compartments compared to babies from healthy mothers1,2, which suggests that changes in early life might be associated with later disease development. Prospective studies of IBD risk following early life changes at the molecular level are sparse. We aimed to investigate if individuals with early onset (EO) IBD had changes in systemic inflammatory markers shortly after birth. Methods We measured the concentration of 9 cytokines in a cohort of 464 neonatal dried blood spot samples stored at the Danish National Biobank from individuals who later developed EO IBD (median age of diagnosis 11 years), as well as matched controls. Individuals who developed IBD were identified through the use of the Danish National Patient Registry. Uni- and multivariate logistic regression with adjustment for birth year, sex, and gestational age was conducted to assess the association between 6 of the inflammatory markers with later disease development (INF-γ, TNF-α, IL-1β, IL-4, IL-6 and IL-17a). Further exploratory analyses were performed investigating risk of very early onset (VEO) IBD (onset from 0-5 years) in 88 cases and their matched controls. Results No significant association with EO IBD was observed for any of the cytokines in uni- and multivariate models when adjusting for multiple testing. In the exploratory analysis of VEO IBD, increased IL-4 was associated with significantly reduced risk of IBD (OR=0.992, p-value=0.023) and increased IL-17a was borderline-significantly associated with increased risk of IBD (OR=1.002, p-value=0.063) in a multivariate logistic model including all 6 cytokines. This association did not remain significant when adjusting for multiple testing, which may reflect limited power. Conclusion In our unique study of 464 dried blood spots from later IBD patients and controls, we could not find an association between measured cytokines and EO IBD. In contrast, patients with VEO IBD had decreased levels of IL-4 and increased levels of IL-17a. This sub-cohort was small, and significance disappeared after adjusting for multiple testing. Still, we find it important to report these findings, as they are novel and may inspire future studies into the aetiology of VEO IBD. 1. Kim, E. S. et al. Longitudinal Changes in Fecal Calprotectin Levels Among Pregnant Women With and Without Inflammatory Bowel Disease and Their Babies. Gastroenterology (2021) 2. Torres, J. et al. Infants born to mothers with IBD present with altered gut microbiome that transfers abnormalities of the adaptive immune system to germ-free mice. Gut (2020)

P910 Salivary calprotectin as a prognostic biomarker in Early Onset Inflammatory Bowel Disease: a cohort study

Abstract Background Inflammatory Bowel Disease (IBD), including Ulcerative Colitis (UC) and Crohn’s Disease (CD) affects children in 25% of cases. In Early Onset IBD (EOIBD) oral involvement is common and oral manifestations (OM) are frequently the first presenting sign of disease. This study compared salivary calprotectin (SCp) between EOIBD and healthy controls (HC), differentiating patients based on their history of OM. Furthermore, this report correlated salivary and faecal calprotectin (FCp) in EOIBD and assessed the prognostic accuracy of SCp in predicting disease relapses. Methods A cohort study was conducted; 9 HC and 27 EOIBD (18 UC and 9 CD) were recruited at the University of Naples Federico II. EOIBD were divided in two subgroups based on the history of OM. A sample of stimulated whole saliva was collected by each participant by spitting. The samples were then processed by ELISA for determining SCp. For each patient clinical disease activity was measured through Paediatric Ulcerative Colitis Activity Index (PUCAI) and Paediatric Crohn’s Disease Activity Index (PCDAI), at baseline and during follow-up (4/8/12 weeks). At baseline, patients provided a stool specimen for FCp determination. SCp levels were compared between groups. In EOIBD SCp was correlated to clinical data and to FCp. Results At baseline all the patients were in treatment with immunosuppressive drugs; 19 were in clinical remission (PUCAI/PCDAI &amp;lt;10) and 8 had mild disease (PUCAI/PCDAI&amp;lt;35). 13 EOIBD had an history of OM: 12 suffered from aphthous-like manifestations while 3 reported granulomatous lesions; 10 experienced oral involvement before IBD diagnosis. OM were more prevalent in CD than in UC and were associated to ileocolic, perianal and upper gastrointestinal tract involvement. EOIBD with OM reported significantly higher SCp than EOIBD without OM and HC: 155,79±60,08 pg/mL in EOBD with OM vs 82,95±51,58 pg/mL in EOIBD without OM (P&amp;lt;0,01**) and 98,21±39,67 pg/mL in HC (P=0,21). Despite the systemic therapy and the clinical remission, in 7 EOIBD with OM oral lesions persisted. These patients had higher SCp compared to those who experienced OM remission (P&amp;lt;0,05*). In EOIBD with OM higher SCp was associated to higher FCp (P&amp;lt;0,05*) while in EOIBD without OM this correlation was not described. No correlation was found between SCp values and PUCAI/PCDAI at baseline. EOIBD with OM who reported higher SCp were found to have increased risk of relapse (P&amp;lt;0,05*) while no association was reported in EOIBD without OM. Conclusion In EOIBD with OM SCp is significantly higher, mirrors intestinal inflammation and predicts relapses. Our results suggest the use of SCp as a prognostic biomarker in EOIBD with OM although more studies are needed.

OP28 Defective STAT3 signaling in refractory Very Early Onset Inflammatory Bowel Disease is associated with a transcriptional signature which predicts response to anti-IL23-based therapies

Abstract Background Very early onset inflammatory bowel disease (VEOIBD) has a monogenic cause in &amp;gt;5% of cases. IL10R deficiency is among the more common causes of monogenic IBD and presents with severe disease refractory to conventional therapies. For most VEOIBD patients, the molecular basis of disease is unknown. We employed flow cytometry and bulk RNA-sequencing to localize pathway-level dysfunction in VEOIBD patients with unknown molecular basis. Methods VEOIBD patients prospectively enrolled in a biorepository were screened for IL10R deficiency using a flow cytometry assay. Patient peripheral blood mononuclear cells (PBMCs) were stimulated with IL10 and control cytokine IL21 and pSTAT3 activation was measured. RNA-sequencing was performed on 115 whole blood samples, comprising VEOIBD patients with either confirmed (n=35, IL10R deficient n=4), or unknown monogenic causes (n=70), and controls (n=10). Transcriptome analysis focused on patients with abnormal STAT3 activation as determined by flow cytometry. Results We identified 6 patients with refractory VEOIBD and defective phosphorylation of STAT3 upon stimulation with both IL10 and IL21 by flow cytometry (Fig 1A), a result confirmed by Western blot (Fig 1B). All six "STAT3-defective" (STAT3-def) patients lacked deleterious mutations in known VEOIBD genes as determined by whole exome sequencing. Principal component analysis of blood transcriptome data showed the STAT3-def and IL10R deficient patients generally clustered together (Fig 1C). Cell-type de-convolution analysis of the blood transcriptomes was used to infer cell-type abundance and cell-type specific differentially expressed genes (DEGs) for the STAT3-def and IL10R deficient groups relative to the rest. Genes downregulated in estimated M1 macrophages from the STAT3-def group were enriched in the Hallmark pathway "IL6-JAK-STAT3 signaling." STAT3-def M1 macrophage DEGs were then projected on an adult colonic Crohn’s disease Bayesian network and extended out a path length of 1. The resulting STAT3-def subnetwork of 440 genes included the known VEOIBD genes STAT3, STAT1, TYMP, and TRIM22 (Fig 1D) and the top enriched signaling pathways included IL23, IL6, and IL12. This is of significant interest given three STAT3-def patients with disease refractory to anti-TNF and vedolizumab achieved remission with anti-IL23-based therapies (Table 1). Conclusion We identified 6 patients with refractory VEOIBD and a shared biochemical phenotype and blood transcriptional signature. Network analysis revealed signaling pathways targeted by existing IBD medications, including anti-IL23-based therapies. Molecular analysis of IBD patient blood has exciting potential to localize pathway-level dysfunction and guide precision medicine approaches.

P293 Safety and diagnostic yield of wireless video capsule endoscopy in early onset inflammatory bowel disease (EOIBD) in children under the age of 6 years in a tertiary paediatric IBD centre

Abstract Background Wireless video capsule endoscopy (VCE) is a well-established diagnostic tool used in the evaluation of small bowel disease in paediatric IBD. Patients usually swallow the capsule. Young children are rarely able to swallow the capsule and these therefore need to be placed with the help of an OGD and an ACORN device. 2 capsule systems were used: PillCam and MiroCam. The aim of this study was to look at the safety of capsule insertion in children less than 6 years of age and to also look at the diagnostic yield. Methods We conducted a retrospective review of our VCE data base over a 7 year period from April 2016 to August 2023. Results We conducted a retrospective review of our VCE data base over a 7 year period from April 2016 to August 2023. 22 patients (14 male) and 27 capsule episodes were included into the study with a an age range at point of capsule insertion between 2 years and 5 months and 5 years and 8 months (median 5 years). All capsules were inserted with an ACORN device. All patients had a histologically proven diagnosis of EOIBD; during this period 4 patients had 2 VCEs and 1 patient 3 VCEs placed. All patient had genetic tests performed, only 1/24 patients had a monogenic mutation confirmed. 15/27 (56%) of all capsules were normal, 8/27 (30%) showed small bowel ulcerations only, 2/27 (7%) showed both small bowel and colonic ulcerations and 5/27 (19%) showed colitis only. We were able to insert the capsule in all 27 capsule episodes without any complications. All studies were complete with the capsule entering the colon and no capsule got stuck. Conclusion Wireless video capsule endoscopy in early onset inflammatory bowel disease in children under the age of 6 years is safe with a diagnostic yield of around 50%. This modality should be used in the diagnostic pathway of EOIBD.