Pre-Diagnosis Diet Predicts Response to Exclusive Enteral Nutrition and Correlates with Microbiome in Pediatric Crohn Disease

Exclusive enteral nutrition (EEN) is effective in inducing remission in pediatric Crohn disease (CD). EEN alters the intestinal microbiome, but precise mechanisms are unknown. We hypothesized that pre-diagnosis diet establishes a baseline gut microbiome, which then mediates response to EEN. We analyzed prospectively recorded food frequency questionnaires (FFQs) for pre-diagnosis dietary patterns. Fecal microbiota were sequenced (16SrRNA) at baseline and through an 18-month follow-up period. Dietary patterns, Mediterranean diet adherence, and stool microbiota were associated with EEN treatment outcomes, disease flare, need for anti-tumor necrosis factor (TNF)-α therapy, and long-term clinical outcomes. Ninety-eight patients were included. Baseline disease severity and microbiota were associated with diet. Four dietary patterns were identified by FFQs; a "mature diet" high in fruits, vegetables, and fish was linked to increased baseline microbial diversity, which was associated with fewer disease flares (p < 0.05) and a trend towards a delayed need for anti-TNF therapy (p = 0.086). Baseline stool microbial taxa were increased (Blautia and Faecalibacterium) or decreased (Ruminococcus gnavus group) with the mature diet compared to other diets. Surprisingly, a "pre-packaged" dietary pattern (rich in processed foods) was associated with delayed flares in males (p < 0.05). Long-term pre-diagnosis diet was associated with outcomes of EEN therapy in pediatric CD; diet-microbiota and microbiota-outcome associations may mediate this relationship.

Forecasting the Incidence and Prevalence of Inflammatory Bowel Disease: A Canadian Nationwide Analysis

INTRODUCTION

Canada has a high burden of inflammatory bowel disease (IBD). Historical trends of IBD incidence and prevalence were analyzed to forecast the Canadian burden over the next decade.

METHODS

Population-based surveillance cohorts in 8 provinces derived from health administrative data assessed the national incidence (2007-2014) and prevalence (2002-2014) of IBD. Autoregressive integrated moving average models were used to forecast incidence and prevalence, stratified by age, with 95% prediction intervals (PI), to 2035. The average annual percentage change (AAPC) with 95% confidence interval (CI) was calculated for the forecasted incidence and prevalence.

RESULTS

The national incidence of IBD is estimated to be 29.9 per 100,000 (95% PI 28.3-31.5) in 2023. With a stable AAPC of 0.36% (95% CI -0.05 to 0.72), the incidence of IBD is forecasted to be 31.2 per 100,000 (95% PI 28.1-34.3) in 2035. The incidence in pediatric patients (younger than 18 years) is increasing (AAPC 1.27%; 95% CI 0.82-1.67), but it is stable in adults (AAPC 0.26%; 95% CI -0.42 to 0.82). The prevalence of IBD in Canada was 843 per 100,000 (95% PI 716-735) in 2023 and is expected to steadily climb (AAPC 2.43%; 95% CI 2.32-2.54) to 1,098 per 100,000 (95% PI 1,068-1,127) by 2035. The highest prevalence is in seniors with IBD (1,174 per 100,000 in 2023; AAPC 2.78%; 95% CI 2.75-2.81).

DISCUSSION

Over the next decade, the Canadian health care systems will contend with the juxtaposition of rising incidence of pediatric IBD and a rising prevalence of overall IBD driven by the aging population.

Resistance management and integrated pest management insights from deployment of a Cry3Bb1+ Gpp34Ab1/Tpp35Ab1 pyramid in a resistant western corn rootworm landscape

In Nebraska USA, many populations of western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, now exhibit some level of resistance to all corn rootworm-active Bacillus thuringiensis Berliner (Bt) proteins expressed in commercial hybrids. Therefore, a study was conducted in northeast Nebraska from 2020-2022 to reevaluate current corn rootworm management options in continuous maize (consecutive planting for ≥2 years). Results from on-farm experiments to evaluate a standard soil-applied insecticide (Aztec® 4.67G) in combination with non-rootworm Bt or rootworm-active Bt pyramided maize (Cry3Bb1 + Gpp34Ab1/Tpp35Ab1) are reported within the context of WCR Bt resistance levels present. Corrected survival from Bt pyramid single-plant bioassays (<0.3, 0.3-0.49, >0.5) was used to place populations into 3 resistance categories. Variables evaluated included root injury, adult emergence, proportion lodged maize, and grain yield. Key results: A composite analysis of all populations across resistance levels indicated that addition of soil insecticide to Bt pyramid significantly reduced adult emergence and lodging but did not significantly increase root protection or yield. Within and among resistance category analyses of root injury revealed that the Bt pyramid remained highly efficacious at any non-rootworm Bt root injury level when resistance was absent or low. When corrected survival was >0.3, mean Bt pyramid root injury tracked more closely in a positive linear fashion with mean non-rootworm Bt root injury (rootworm density x level of resistance interaction). Similar trends were obtained for adult emergence but not yield. Mean Bt pyramid root injury rating was <0.75 in most populations with Bt resistance, which contributed to no significant yield differences among categories. Results are discussed within the context of IPM:IRM tradeoffs and the need to reduce WCR densities in this system to decrease the impact of the density x resistance interaction to bridge use of current pyramids with new technologies introduced over the next decade.

Outcomes Following Acute Severe Colitis at Initial Presentation: A Multi-centre, Prospective, Paediatric Cohort Study

AIM

To assess contemporary outcomes in children with acute severe ulcerative colitis [ASUC] at initial presentation.

METHODS

Between April 2014 and January 2019, children aged <17 years, with new onset ASUC (Paediatric Ulcerative Colitis Activity Index [PUCAI ≥65) were prospectively followed in a Canadian inception cohort study. 16S rRNA amplicon sequencing captured microbial composition of baseline faecal samples. Primary endpoint was corticosteroid-free clinical remission with intact colon at 1 year [PUCAI <10, no steroids ≥4 weeks].

RESULTS

Of 379 children with new onset UC/IBD-unclassified, 105 [28%] presented with ASUC (42% male; median [interquartile range; [IQR]) age 14 [11-16] years; extensive colitis in all). Compared with mild UC, gut microbiome of ASUC patients had lower α-diversity, decreased beneficial anaerobes, and increased aerobes; 54 [51%] children were steroid-refractory and given infliximab [87% intensified regimen]. Corticosteroid-free remission at 1 year was achieved by 62 [61%] ASUC cohort (by 34 [63%] steroid-refractory patients, all on biologics; by 28 [55%] steroid responders,13 [25%] on 5- aminosalicylic acid [5-ASA], 5 [10%] on thiopurines, 10 [20%] on biologics). By 1 year, 78 [74%] escalated to infliximab including 24 [47%] steroid-responders failed by 5-ASA and/or thiopurines. In multivariable analysis, clinical predictors for commencing infliximab included hypoalbuminaemia, greater PUCAI, higher age, and male sex. Over 18 months, repeat corticosteroid course[s] and repeat hospitalisation were less likely among steroid-refractory versus -responsive but -dependent patients (adjusted odds ratio [aOR] 0.71 [95% CI 0.57-0.89] and 0.54 [95% CI 0.45-0.66], respectively).

CONCLUSION

The majority of children presenting with ASUC escalate therapy to biologics. Predictors of need for advanced therapy may guide selection of optimal maintenance therapy.

Health Services Utilization and Specialist Care in Pediatric Inflammatory Bowel Disease: A Multiprovince Population-Based Cohort Study

BACKGROUND

Patterns of health services utilization among children with inflammatory bowel disease (IBD) are important to understand as the number of children with IBD continues to increase. We compared health services utilization and surgery among children diagnosed <10 years of age (Paris classification: A1a) and between 10 and <16 years of age (A1b).

METHODS

Incident cases of IBD diagnosed <16 years of age were identified using validated algorithms from deterministically linked health administrative data in 5 Canadian provinces (Alberta, Manitoba, Nova Scotia, Ontario, Quebec) to conduct a retrospective cohort study. We compared the frequency of IBD-specific outpatient visits, emergency department visits, and hospitalizations across age groups (A1a vs A1b [reference]) using negative binomial regression. The risk of surgery was compared across age groups using Cox proportional hazards models. Models were adjusted for sex, rural/urban residence location, and mean neighborhood income quintile. Province-specific estimates were pooled using random-effects meta-analysis.

RESULTS

Among the 1165 (65.7% Crohn's) children with IBD included in our study, there were no age differences in the frequency of hospitalizations (rate ratio [RR], 0.88; 95% confidence interval [CI], 0.74-1.06) or outpatient visits (RR, 0.95; 95% CI, 0.78-1.16). A1a children had fewer emergency department visits (RR, 0.70; 95% CI, 0.50-0.97) and were less likely to require a Crohn's-related surgery (hazard ratio, 0.49; 95% CI, 0.26-0.92). The risk of colectomy was similar among children with ulcerative colitis in both age groups (hazard ratio, 0.71; 95% CI, 0.49-1.01).

CONCLUSIONS

Patterns of health services utilization are generally similar when comparing children diagnosed across age groups.

Variation in the Care of Children with Inflammatory Bowel Disease Within and Across Canadian Provinces: A Multi-Province Population-Based Cohort Study

Purpose

The incidence of childhood-onset inflammatory bowel disease (IBD) is rising. We described variation in health services utilization and need for surgery among children with IBD between six and 60 months following IBD diagnosis across Canadian pediatric centers and evaluated the associations between care provided at diagnosis at each center and the variation in these outcomes.

Patients and Methods

Using population-based deterministically-linked health administrative data from four Canadian provinces (Alberta, Manitoba, Nova Scotia, Ontario) we identified children diagnosed with IBD <16 years of age using validated algorithms. Children were assigned to a pediatric center of care using a hierarchical approach based on where they received their initial care. Outcomes included IBD-related hospitalizations, emergency department (ED) visits, and IBD-related abdominal surgery occurring between 6 and sixty months after diagnosis. Mixed-effects meta-analysis was used to pool results and examine the association between center-level care provision and outcomes.

Results

We identified 3784 incident cases of pediatric IBD, of whom 2937 (77.6%) were treated at pediatric centers. Almost a third (31.4%) of children had ≥1 IBD-related hospitalization and there were 0.66 hospitalizations per person during follow-up. More than half (55.8%) of children had ≥1 ED visit and there were 1.64 ED visits per person. Between-center heterogeneity was high for both outcomes; centers where more children visited the ED at diagnosis had more IBD-related hospitalizations and more ED visits during follow-up. Between-center heterogeneity was high for intestinal resection in Crohn's disease but not colectomy in ulcerative colitis.

Conclusion

There is variation in health services utilization among children with IBD and risk of undergoing intestinal resection in those with Crohn's disease, but not colectomy among children with ulcerative colitis, across Canadian pediatric tertiary-care centers. Improvements in clinical care pathways are needed to ensure all children have equitable and timely access to high quality care.

Inflammatory Bowel Disease Among Canadian Children: Comparison Between Children of Non-European Descent and Children of European Descent

BACKGROUND

Inflammatory bowel disease (IBD) phenotypes may differ between countries and ancestral groups. The study aim was to examine ancestry and subtype variations of children newly diagnosed with IBD.

METHODS

Children newly diagnosed with IBD enrolled into the Canadian Children Inflammatory Bowel Disease Network inception cohort study were categorized into 8 ancestral groups. Prospectively collected data at diagnosis and follow-up were compared between ancestral groups.

RESULTS

Among 1447 children (63.2% Crohn's disease, 30.7% ulcerative colitis), 67.8% were European, 9.4% were South Asian, 3.8% were West Central Asian and Middle Eastern, 2.3% were African, 2.2% were East/South East Asian, 2.0% were Caribbean/Latin/Central/South American, 9.9% were mixed, and 2.6% were other. Children of African descent with ulcerative colitis had an older age of diagnosis compared with children of European descent (median 15.6 years vs 13.3 years; P = .02). Children of European descent had a higher proportion of positive family history with IBD (19.3% vs 12.1%; P = .001) compared with children of non-European descent. Children of European descent also had a lower proportion of immigrants and children of immigrants compared with children of non-European descent (9.8% vs 35.9%; P < .0001; and 3.6% vs 27.2%; P < .0001, respectively) .

CONCLUSIONS

Important differences exist between different ancestral groups in pediatric patients with IBD with regard to age of diagnosis, family history, and immigrant status. Our study adds to the knowledge of the impact of ancestry on IBD pathogenesis.

ADALIMUMAB VERSUS INFLIXIMAB IN LUMINAL PEDIATRIC CROHN'S DISEASE: COMPARABLE OUTCOMES IN A PROSPECTIVE MULTICENTER COHORT STUDY

BACKGROUND

This study compared real-world effectiveness between adalimumab (ADA) and infliximab (IFX) in children with Crohn's disease (CD).

METHODS

Children enrolled into the prospective Canadian Children Inflammatory Bowel Disease Network (CIDsCaNN) National Inception Cohort between 2014 and 2020 who commenced ADA or IFX as first anti-tumor necrosis factor (antiTNF) agent for luminal CD were included. Multivariate logistic regression modelled the propensity of commencing ADA; propensity score matching was used to match IFX-treated children to ADA-treated children. The primary outcome at one year was steroid-free clinical remission (SFCR). Secondary outcomes at one year were I) combined SFCR and c-reactive protein (CRP) remission; II) treatment intensification; and III) antiTNF durability. Odds ratios (aOR) and hazard ratio (aHR) adjusted for concomitant immunomodulator use with 95% confidence interval (CI) are reported.

RESULTS

In the propensity score matched cohort of 147 ADA-treated and 147 IFX-treated children, 92 (63%) ADA- and 87 (59%) IFX-treated children achieved SFCR at one year (aOR: 1.4, 95% CI 0.9-2.4); 75 of 140 (54%) ADA- and 85 of 144 (59%) IFX-treated children achieved combined SFCR and CRP remission (aOR: 1.0, 95% CI 0.6-1.6). ADA-treated children less frequently underwent treatment intensification (21 [14%]) compared to IFX-treated children (69 [47%]) (P<0.0001). Discontinuation of antiTNF occurred in 18 (12%) ADA-treated and 15 (10%) IFX-treated children (aHR: 1.2, 95% CI 0.6-2.2).

CONCLUSION

Children with Crohn's disease achieved favourable outcomes at one year with either ADA or IFX as first antiTNF agents. Those receiving IFX did not have significantly superior outcomes compared to clinically similar children receiving ADA.

The 2023 Impact of Inflammatory Bowel Disease in Canada: Special Populations-Children and Adolescents with IBD

Rates of inflammatory bowel disease (IBD) in Canadian children and adolescents are among the highest in the world, and the incidence is rising most rapidly in children under five years of age. These young children may have either a typical form of IBD with multi-factorial aetiology, or they may have a monogenic form. Despite the growing number of children in Canada living with this important chronic disease, there are few available medical therapies approved by Health Canada due to the omission of children from most clinical trials of newly developed biologics. As a result, off-label use of medications is common, and physicians have learned to use existing therapies more effectively. In addition, most Canadian children are treated in multidisciplinary, specialty clinics by physicians with extra training or experience in IBD, as well as specialist nurses, dietitians, mental health care providers and other allied health professionals. This specialized clinic approach has facilitated cutting edge research, led by Canadian clinicians and scientists, to understand the causes of IBD, the optimal use of therapies, and the best ways to treat children from a biopsychosocial perspective. Canadians are engaged in work to understand the monogenic causes of IBD; the interaction between genes, the environment, and the microbiome; and how to address the mental health concerns and medical needs of adolescents and young adults transitioning from paediatric to adult care.

Transition Readiness in Youth with Inflammatory Bowel Disease

OBJECTIVES

To examine readiness of adolescents and young adults (AYAs) with inflammatory bowel disease (IBD) to transition to adult care.

STUDY DESIGN

A cross-sectional multicenter study evaluating transition readiness in individuals with IBD 16-19 years old prospectively recruited from 8 Canadian IBD centers using the validated ON Taking Responsibility for Adolescent to Adult Care (ON TRAC) questionnaire. Secondary aims included (1) screening for depression and anxiety using the 8-item Personal Health Questionnaire Depression Scale and The Screen for Child Anxiety Related Emotional Disorders questionnaires, respectively; (2) evaluating the association between depression and anxiety with readiness and disease activity; and (3) subjectively evaluating AYA readiness based on physician and parent assessments.

RESULTS

In total, 186 participants (139 adolescent, 47 young adult) were enrolled, mean age 17.4 years (SD, 0.87). ON TRAC scores determined that 26.6% of AYAs at pediatric and 40.4% at adult centers reached the threshold of readiness. On multivariable linear regression analysis age was positively (P = .001) and disease remission negatively (P = .03) associated with ON TRAC scores. No statistically significant differences were determined across centers. A significant percentage of AYAs reported moderate-to-severe depression (21.7%) and generalized anxiety (36%); however, neither were significantly associated with ON TRAC scores. Notably, physician and parental assessment of AYA readiness correlated poorly with ON TRAC scores (⍴ = 0.11, ⍴ = 0.24, respectively).

CONCLUSIONS

Assessment of transition readiness in AYAs with IBD highlighted that a large proportion do not have adequate knowledge or behavior skills needed for transition to adult care. This study infers that readiness assessment tools are essential during transition to identify deficits in knowledge and behavior skills that could be specifically targeted by the youth, caregivers, and multidisciplinary team.

Characterization of western corn rootworm (Coleoptera: Chrysomelidae) susceptibility to foliar insecticides in northeast Nebraska

Foliar-applied insecticides are commonly used for adult western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), control in Nebraska but little efficacy data is available. Anecdotal reports of reduced efficacy in areas of northeast Nebraska led to the conduct of this study. Objectives were to (i) evaluate the efficacy of commercial applications of commonly used formulated insecticides (bifenthrin, lambda-cyhalothrin, chlorpyrifos, or tank mixes) for WCR control in 7 northeast Nebraska counties during 2019 and 2020 and (ii) conduct adult WCR concentration-response vial bioassays with bifenthrin, chlorpyrifos, and dimethoate active ingredients on a subset of field populations. Whole plant counts (WPC) were used to measure WCR densities in insecticide-treated and untreated maize fields before and after insecticide application. Field control was excellent with organophosphate/pyrethroid tank mixes as proportional change in mean WPC of treated fields was significantly reduced (>0.90) versus untreated fields where little change in WPC occurred. The exception was one treated Boone County field where proportional reduction in WPC was ≤0.78. Bioassays revealed LC50s and resistance ratios of most populations exposed to bifenthrin and dimethoate were not significantly different than the susceptible control. Most populations exhibited a low level of chlorpyrifos resistance when compared to the susceptible control. Field and lab data suggest the local onset of practical WCR field-evolved resistance to bifenthrin in Boone County and chlorpyrifos in Boone and Colfax counties. Results of this study will increase our understanding of WCR resistance evolution, serve as a comprehensive baseline for future research, and inform WCR management programs.

A183 VARIATION IN HEALTH SERVICES UTILIZATION AND RISK OF SURGERY ACROSS CHILDREN WITH INFLAMMATORY BOWEL DISEASE: A MULTIPROVINCE COHORT STUDY

Background

Marked variation in access to care and health services utilization is a marker of variation in quality of care. With the rising incidence of pediatric inflammatory bowel disease (IBD), we must understand variation in access to and outcomes of care to improve quality.

Purpose

Describe variation in care for pediatric IBD treated in 4 Canadian provinces.

Method

Incident cases of IBD diagnosed in children <16y were identified from health administrative data in Alberta (AB), Manitoba, Nova Scotia, and Ontario (ON) using validated algorithms. Children were assigned to one of 8 centres of care using a hierarchical assessment of health services use within 6 months of diagnosis. Children treated by adult gastroenterologists or community-based pediatric gastroenterologists were excluded due to small sample size. Outcomes included IBD-related hospitalizations, emergency department (ED) visits (AB/ON only), and IBD-related abdominal surgery. Hospitalizations and ED visits were counted cumulatively from 6-60 months after diagnosis. The risk of first surgery was defined during the same 6-60 month period. Mixed-effects meta-analysis was used to pool results across centres. Heterogeneity among centres was quantified using I² (variation in pooled event rates between centres) and τ (standard deviation of the true event rates). R² quantified the residual heterogeneity in outcomes not attributable to among-province variation.

Result(s)

We identified 3777 incident cases of pediatric IBD, 2936 (78%) of which were treated at 8 pediatric centres. The number of hospitalizations was 0.67 (95% CI 0.56-0.79) per person with high between-centre heterogeneity (I² 84%, τ 0.1556). Provincial differences accounted for 93% of heterogeneity across centres (residual heterogeneity: I² 29%, τ 0.0412). Hospitalizations were less frequent in AB than other provinces (0.43 vs. 0.72-0.78). Children averaged 1.94 IBD-related ED visits, with significant heterogeneity (I² 99%, τ 1.33) with 99.7% of heterogeneity attributable to among-province differences (residual heterogeneity: I² 32%; τ 0.074). Mean ED visits were 1.1 visits in ON (I² 39%) and 3.7 in AB (I² 0%). Intestinal resection was required by 12% (95% CI 0.08-0.15) of Crohn’s patients with high among-centre heterogeneity (I² 81%, τ 0.042), and low (19%) heterogeneity due to provincial differences (residual heterogeneity: I² 76%; τ 0.039). Colectomy was required by 12% (95% CI 10-14) of children with ulcerative colitis (UC) with no between-centre heterogeneity (I² 0%, τ 0).

Conclusion(s)

There is a high degree of between-province (but not between-centre, within province) variability in health services utilization among children with IBD. There was significant between-centre variability in surgery rates for Crohn’s, but not colectomy for UC. Differences in patient characteristics or provincial health systems may be more important predictors of variation in care. Surgery for Crohn’s disease may be a target for inter-centre quality improvement efforts.

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Disclosure of Interest

None Declared

A189 EMERGENCY DEPARTMENT UTILIZATION AND RISK OF INTESTINAL RESECTION IS LOWER AMONG CHILDREN DIAGNOSED WITH INFLAMMATORY BOWEL DISEASE BEFORE 10 YEARS OF AGE: A MULTIPROVINCE POPULATION-BASED COHORT STUDY

Background

In Canada, the incidence of inflammatory bowel disease (IBD) is increasing faster among those <10 years (y) of age than in any other age group. Understanding the health services burden of IBD in this population is important for health system planning.

Purpose

To compare healthcare utilization and risk of surgery among children diagnosed with IBD across age groups defined by the Paris Classification (A1a: <10y; A1b: 10 to <16y) across 5 Canadian provinces.

Method

Children diagnosed with IBD <16 years of age were identified from health administrative data using validated algorithms in Alberta, Manitoba, Nova Scotia, Ontario, and Québec. Negative binomial regression models were used to compare (1) the pre-diagnosis frequency of health services utilization (outpatient, emergency department (ED), and hospitalization) using diagnostic codes suggestive of future IBD and (2) the annual post-diagnosis frequency of IBD-specific and IBD-related (signs, symptoms, and extra-intestinal manifestations of IBD) visits among children diagnosed <10y (A1a) and 10 to <16y (A1b). Cox proportional hazard models compared the risk of surgery (identified with validated procedure codes) across age groups. All regression models were adjusted for sex, rural/urban residence, and mean neighbourhood income quintile. Province-specific event counts (all ages combined) and models (comparing age groups; reference: A1b [10 to <16y]) were pooled using random-effects meta-analysis.

Result(s)

Among 5124 children with IBD (1165 [23%] were <10y at diagnosis), the mean number of pre-diagnosis healthcare encounters was 1.0 (95% CI 0.38 to 1.68, I²=99.6%). The mean annual post-diagnosis number of IBD-specific outpatient visits was 3.2 (95% CI 1.9-4.4, I²=99.6%); hospitalizations, 0.19 (95% CI 0.17-0.21, I²=74%); ED visits, 0.17 (95% CI 0.19-0.39, I²=99%). The mean annual post-diagnosis number of IBD-related outpatient visits was 3.9 (95% CI 2.3-5.5, I²=99.7%); hospitalizations, 0.21 (95% CI 0.19-0.23, I²=79%); ED visits, 0.29 (95% CI 0.19-0.39, I²=97%). Intestinal resection or colectomy within 5y of diagnosis occurred in 13% (95%CI 8-22, I²=93%) with Crohn’s disease (CD) and 16% (95% CI 14-18, I²=40%) with ulcerative colitis. IBD-specific ED visits (RR 0.70, 95% CI 0.50-0.97, I²=80) and the risk of intestinal resection in CD (HR 0.49, 95% CI 0.26-0.92, I²=40%) were significantly lower among children diagnosed <10y. There were no age-related differences in pre-diagnosis health services utilization or other post-diagnosis outcomes, including frequency of outpatient visits to a gastroenterologist.

Conclusion(s)

Health services utilization was generally similar for children diagnosed with IBD at <10y and between 10 and <16y, except for lower rates of IBD-specific ED visits and intestinal resection in children with CD. Further exploration of between-province differences, represented by the high statistical heterogeneity (I²) in the meta-analyses, is needed to understand sources of variation in care.

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Disclosure of Interest

E. Kuenzig: None Declared, H. Singh Consultant of: Amgen Canada, Bristol-Myers Squibb Canada, Sandoz Canada, Roche Canada, Takeda Canada and Guardant Health, A. Bitton: None Declared, G. Kaplan Grant / Research support from: Ferring, Consultant of: AbbVie, Janssen, Pfizer, Amgen, Sandoz, Pendophram, and Takeda, Speakers bureau of: AbbVie, Janssen, Pfizer, Amgen, Sandoz, Pendophram, and Takeda, M. Carroll: None Declared, A. Otley Grant / Research support from: Research support: AbbVie Global. Research site: AbbVie, Pfizer, Eli-Lily, Janssen, Consultant of: AbbVie Canada, T. Stukel: None Declared, S. Spruin: None Declared, A. Griffiths Grant / Research support from: Abbvie, Consultant of: Abbvie, Amgen, BristolMyersSquibb, Janssen, Lilly, Takeda, Speakers bureau of: Abbvie, Janssen, Takeda, D. Mack: None Declared, K. Jacobson Grant / Research support from: Abbvie Canada and Janssen Canada, Consultant of: Abbvie Canada, Janssen Canada, Merck Canada and Mylan Pharmaceuticals, Speakers bureau of: Abbvie Canada and Janssen Canada, G. Nguyen: None Declared, L. Targownik Grant / Research support from: Janssen Canada, Consultant of: AbbVie Canada, Sandoz Canada, Takeda Canada, Merck Canada, Pfizer Canada, Janssen Canada, and Roche Canada, W. El-Matary Consultant of: Abbvie and MERCK, Speakers bureau of: Abbvie and MERCK, E. Benchimol Consultant of: McKesson Canada, Dairy Farmers of Ontario (unrelated to medications used to treat inflammatory bowel disease)

Unfermented β-fructan Fibers Fuel Inflammation in Select Inflammatory Bowel Disease Patients

BACKGROUND & AIMS

Inflammatory bowel diseases (IBD) are affected by dietary factors, including nondigestible carbohydrates (fibers), which are fermented by colonic microbes. Fibers are overall beneficial, but not all fibers are alike, and some patients with IBD report intolerance to fiber consumption. Given reproducible evidence of reduced fiber-fermenting microbes in patients with IBD, we hypothesized that fibers remain intact in select patients with reduced fiber-fermenting microbes and can then bind host cell receptors, subsequently promoting gut inflammation.

METHODS

Colonic biopsies cultured ex vivo and cell lines in vitro were incubated with oligofructose (5 g/L), or fermentation supernatants (24-hour anaerobic fermentation) and immune responses (cytokine secretion [enzyme-linked immunosorbent assay/meso scale discovery] and expression [quantitative polymerase chain reaction]) were assessed. Influence of microbiota in mediating host response was examined and taxonomic classification of microbiota was conducted with Kraken2 and metabolic profiling by HUMAnN2, using R software.

RESULTS

Unfermented dietary β-fructan fibers induced proinflammatory cytokines in a subset of IBD intestinal biopsies cultured ex vivo, and immune cells (including peripheral blood mononuclear cells). Results were validated in an adult IBD randomized controlled trial examining β-fructan supplementation. The proinflammatory response to intact β-fructan required activation of the NLRP3 and TLR2 pathways. Fermentation of β-fructans by human gut whole microbiota cultures reduced the proinflammatory response, but only when microbes were collected from patients without IBD or patients with inactive IBD. Fiber-induced immune responses correlated with microbe functions, luminal metabolites, and dietary fiber avoidance.

CONCLUSION

Although fibers are typically beneficial in individuals with normal microbial fermentative potential, some dietary fibers have detrimental effects in select patients with active IBD who lack fermentative microbe activities. The study is publicly accessible at the U.S. National Institutes of Health database (clinicaltrials.gov identification number NCT02865707).

Pediatric Patient and Caregiver Satisfaction With the Use of Transabdominal Bowel Ultrasound in the Assessment of Inflammatory Bowel Diseases

OBJECTIVES

Transabdominal bowel ultrasound (TABUS) is emerging as an attractive, noninvasive tool in inflammatory bowel disease (IBD). Patient and caregiver experience with TABUS is not well described. We aimed to determine pediatric patient and caregiver satisfaction with TABUS and the impact of IBD severity, gender, age, and a history of anxiety on satisfaction.

METHODS

Pediatric patients (0-18 years old) with suspected IBD prospectively underwent baseline TABUS, magnetic resonance enterography (MRE), blood work, stool studies, and endoscopy. Patients and their caregiver each completed a cross-sectional satisfaction questionnaire (5-point Likert scale) after the baseline investigations.

RESULTS

There were 54 patients included (67% male). The majority were completely satisfied and strongly agree TABUS was better tolerated than other investigations, regardless of disease severity ( P > 0.05). Patients with higher Simple Endoscopic Score for Crohn Disease (SES-CD) scores felt that TABUS increased their understanding of their IBD ( P < 0.05) and disease location ( P < 0.05). Patients with Crohn disease had similar responses to those with ulcerative colitis, but more strongly agreed that TABUS was better than MRE and endoscopy ( P < 0.05). Those with anxiety did not have an increased level of worry about potential ultrasound findings ( P > 0.05).

CONCLUSIONS

Pediatric patients and their caregivers were highly satisfied with TABUS, preferring it to other modalities. It did not lead to increased worry, and was particularly important in those with severe IBD. These findings support wider implementation of this well tolerated and preferred monitoring tool in pediatrics.

Declining Corticosteroid Use for Inflammatory Bowel Disease Across Alberta: A Population-Based Cohort Study

BACKGROUND AND AIMS

Corticosteroid-free remission is a primary treatment goal in IBD which may be achieved with greater use of anti-TNF therapy. We defined temporal trends of corticosteroid use, anti-TNF use, hospitalization and surgery in a prevalent IBD cohort within the province of Alberta, Canada.

METHODS

Health administrative data were used to identify medication dispensing, hospitalizations and surgery in individuals with IBD from 2010 to 2015. Temporal trends were calculated using log-binomial regression for medications and log-linear models for hospitalizations and surgery rates. Analyses were stratified based on geographic location.

RESULTS

Of 28890 individuals with IBD, 50.3% had Crohn's disease. One in six individuals (15.45%) were dispensed a corticosteroid. Corticosteroid use decreased in both metropolitan areas (AAPC -20.08%, 95% CI: -21.78 to -18.04) and non-metropolitan areas (AAPC -18.14%, 95% CI: -20.78 to -18.04) with a similar pattern for corticosteroid dependence. Corticosteroid dependence was more prevalent in UC vs. CD (P < 0.05), and in the pediatric IBD cohort (13.45) compared to the adult (8.89) and elderly (7.54) cohorts (per 100 prevalent population, P < 0.001). The proportion of individuals dispensed an anti-TNF increased over the study period (AAPC 12.58%, 95% CI: 11.56 to 13.61). Significantly more non-metropolitan versus metropolitan residing individuals were hospitalized for any reason, for an IBD-related, or IBD-specific indication (all P < 0.001) though the proportion requiring IBD surgery was similar between groups.

CONCLUSIONS

An increase in anti-TNF use corresponded to a decline in corticosteroid use and dependence in those with IBD. Inequities in IBD care still exist based on location and age.

Hospitalization With Clostridioides difficile in Pediatric Inflammatory Bowel Disease: a Population-Based Study

OBJECTIVES

Several studies have demonstrated higher rates of Clostridioides difficile infection (CDI) in adults with inflammatory bowel disease (IBD). We conducted a population-based study comparing the risk of hospitalization with CDI in children with and without IBD.

METHODS

Using health administrative data and validated algorithms, we identified all children (<16 years) diagnosed with IBD in 5 Canadian provinces, then age and sex matched to 5 children without IBD. Province-specific 5-year incidence rates of hospitalization with CDI were pooled and generalized linear mixed-effects models were used to estimate the crude incidence rate ratio (IRR) comparing (1) children with and without IBD and (2) children with Crohn disease and ulcerative colitis. Hazard ratios (HR) from Cox proportional hazards models adjusting for age, sex, rural/urban household, and income were pooled using fixed-effects models.

RESULTS

The incidence rate of CDI identified during hospitalization was 49.06 [95% confidence interval (CI), 39.40-61.08] per 10,000 person-years (PY) in 3593 children with IBD compared to 0.39 (95% CI, 0.13-1.21) per 10,000 PY in 16,284 children without IBD (crude IRR, 133.4, 95% CI, 42.1-422.7; adjusted HR, 68.2, 95% CI, 24.4-190.4). CDI was identified less often in children with Crohn disease than ulcerative colitis (crude IRR, 0.51, 95% CI, 0.32-0.82; adjusted HR, 0.69, 95% CI, 0.46-1.05).

CONCLUSIONS

Children with IBD have a markedly higher incidence of CDI identified during a hospitalization relative to children without IBD. Consequently, symptomatic children with IBD who are hospitalized should be screened for CDI.

A47 MICROBIAL FUNCTIONS AS BIOMARKERS OF PRO-INFLAMMATORY RESPONSE TO SELECT DIETARY FIBERS IN IBD

Background

Dietary fibers are not digested in the bowel; they are fermented by microbes, typically promoting gut health. However, IBD patients experience sensitivity to consumption of fibers. Our previous findings offered the first mechanistic evidence demonstrating that unfermented dietary β-fructans (inulin and FOS) can induce pro-inflammatory cytokines in a subset of pediatric IBD colonic biopsies cultured ex vivo, and in the SYNERGY-1 (β-fructan) clinical study of adult remission UC patients. Incubating FOS with whole-microbiota intestinal washes from non-IBD or remission IBD patients improved fermentation and reduced pro-inflammatory responses, but not from patients with active disease. Fibre-induced immune responses correlated with microbe functions, luminal metabolites, and fibre avoidance.

Aims

Here we aimed to expand on our findings and define the role of microbial functions in mediating host response to β-fructans.

Methods

Colonic biopsies cultured ex vivo and cell lines in vitro were incubated with FOS (5g/L), or fermentation supernatants (24hr anaerobic fermentation). Immune responses (cytokine secretion [ELISA/MSD] and expression [qPCR]) were assessed. Taxonomic classification of microbial fermentation cultures was conducted with Kraken2 and metabolic profiling by HUMAnN2. HPLC and gas chromatography volatile fatty acid (CG-VFA) analysis were used to identify concentrations of remaining fibre and SCFAs following anaerobic fermentation.

Results

7 microbial enzymes were identified to be predictive of cytokine (IL-1β, IL23, IL-5, IL-8, MIP-1α) secretion in ex vivo colonic biopsies from pediatric Crohn disease (CD; n=38), ulcerative colitis (UC; n=20), and non-IBD (n=21) patients, in response to β-fructans; their use as biomarkers of response was determined in patient stool from the SYNERGY-1 clinical study cohort. Fermentation of FOS by whole-microbe intestinal washes from only non-IBD or remission IBD patients reduced cytokine secretion, and our findings demonstrate that this was due to a combination of reduction of β-fructan present and production of a precise combination of anti-inflammatory SCFAs.

Conclusions

Our findings suggest that intolerance and avoidance of fibers in select IBD patients is associated with the inability to ferment these fibers, mediated by altered microbial functions (enzymes), leading to worsened inflammation. Data indicate that gut microbial function, not composition, predicts patient pro-inflammatory response to β-fructans, supporting our hypothesis that overall community function impacts fibre fermentation and affects associated pro-inflammatory effects. Our work highlights select disease state scenarios in which administration of fermentable fibers should be avoided and tailored dietary interventions considered.

Funding Agencies

CIHRWeston Foundation, Mitacs

Crohn's and Colitis Canada's 2021 Impact of COVID-19 and Inflammatory Bowel Disease in Canada: Children and Expectant Mothers With Inflammatory Bowel Disease

Coronavirus disease 2019 (COVID-19) in children with inflammatory bowel disease (IBD) typically results in a mild infection, similar to those without IBD. Children and adolescents have less severe manifestations of COVID-19 compared to older people, whether or not they have IBD. However, some IBD medications (in particular, corticosteroids) are associated with more severe COVID-19. During the first year of the global pandemic, more IBD care was provided with online technology, necessitated by efforts to reduce hospital and clinic visits. Additionally, non-endoscopic monitoring of inflammation has been required due to the cancellation of non-urgent procedures, resulting in longer endoscopy wait-times. In contrast, pregnant people (with and without IBD) who contract COVID-19 are at increased risk of severe manifestations, death and preterm delivery, making them a priority for severe acute respiratory syndrome coronavirus 2 protective measures and vaccination. Few studies have examined effect of COVID-19 on IBD-related disease activity in pregnant people with IBD. The pandemic has significantly affected the mental health and sense of well-being of children and their families, as well as pregnant people with IBD. These groups were much more likely to experience anxiety and depression compared with prior to the pandemic, even while concern has mostly abated regarding the effect of IBD medications and COVID-19 severity. Unfortunately, the availability of mental health care providers who specialize in people with IBD has not kept pace with the increasing demand.

Crohn's and Colitis Canada's 2021 Impact of COVID-19 and Inflammatory Bowel Disease in Canada: Executive Summary

Persons with inflammatory bowel disease (IBD) make up more than 0.75% of the Canadian population in 2021. Early in the COVID-19 pandemic, individuals with IBD, particularly those on immunosuppressive therapies, were concerned that their health status may place them at higher risk of contracting COVID-19 or experiencing more severe disease course if infected with SARS-CoV-2. In response, Crohn’s and Colitis Canada developed the COVID-19 and IBD Taskforce in March 2020 to rapidly synthesize the evolving knowledge of COVID-19 as relevant to Canadians with IBD. The Taskforce communicated expert information directly to the Canadian IBD community through online tools and a webinar series. In order to understand the full impact of COVID-19 on the IBD community, Crohn’s and Colitis Canada commissioned a policy report that was informed through a systematic literature review and synthesized across working groups along the following domains: Epidemiology, Children and Expectant Mothers with IBD, Seniors with IBD, Mental Health, Risk Factors and Medications, Vaccines, and Healthcare Delivery during the Pandemic and the Future Model of IBD Care. This report from Canadian physicians, researchers, and IBD community representatives highlights the physical, mental, and health systems impact of COVID-19 on the entire spectrum of the IBD community, including children, adolescents, adults, seniors, and pregnant people with IBD. This executive summary provides an overview of the crucial information from each of the chapters of the policy report, supplemented with additional information made available through Crohn’s and Colitis Canada’s webinar-based knowledge translation platform.

Canadian Association of Gastroenterology Clinical Practice Guideline for Immunizations in Patients With Inflammatory Bowel Disease (IBD)-Part 2: Inactivated Vaccines

Background and Aims

The effectiveness and safety of vaccinations can be altered by immunosuppressive therapies, and perhaps by inflammatory bowel disease (IBD) itself. These recommendations developed by the Canadian Association of Gastroenterology and endorsed by the American Gastroenterological Association, aim to provide guidance on immunizations in adult and pediatric patients with IBD. This publication focused on inactivated vaccines.

Methods

Systematic reviews evaluating the efficacy, effectiveness, and safety of vaccines in patients with IBD, other immune-mediated inflammatory diseases, and the general population were performed. Critical outcomes included mortality, vaccine-preventable diseases, and serious adverse events. Immunogenicity was considered a surrogate outcome for vaccine efficacy. Certainty of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. Key questions were developed through an iterative online platform, and voted on by a multidisciplinary group. Recommendations were formulated using the Evidence-to-Decision framework. Strong recommendation means that most patients should receive the recommended course of action, whereas a conditional recommendation means that different choices will be appropriate for different patients.

Results

Consensus was reached on 15 of 20 questions. Recommendations address the following vaccines: Haemophilus influenzae type b, recombinant zoster, hepatitis B, influenza, pneumococcus, meningococcus, tetanus-diphtheria-pertussis, and human papillomavirus. Most of the recommendations for patients with IBD are congruent with the current Centers for Disease Control and Prevention and Canada’s National Advisory Committee on Immunization recommendations for the general population, with the following exceptions. In patients with IBD, the panel suggested Haemophilus influenzae type b vaccine for patients older than 5 years of age, recombinant zoster vaccine for adults younger than 50 year of age, and hepatitis B vaccine for adults without a risk factor. Consensus was not reached, and recommendations were not made for 5 statements, due largely to lack of evidence, including double-dose hepatitis B vaccine, timing of influenza immunization in patients on biologics, pneumococcal and meningococcal vaccines in adult patients without risk factors, and human papillomavirus vaccine in patients aged 27–45 years.

Conclusions

Patients with IBD may be at increased risk of some vaccine-preventable diseases. Therefore, maintaining appropriate vaccination status in these patients is critical to optimize patient outcomes. In general, IBD is not a contraindication to the use of inactivated vaccines, but immunosuppressive therapy may reduce vaccine responses.

Canadian Association of Gastroenterology Clinical Practice Guideline for Immunizations in Patients With Inflammatory Bowel Disease (IBD)-Part 1: Live Vaccines

Background & Aims

Patients with inflammatory bowel disease (IBD) may be at increased risk of some vaccine-preventable diseases. The effectiveness and safety of vaccinations may be altered by immunosuppressive therapies or IBD itself. These recommendations, developed by the Canadian Association of Gastroenterology and endorsed by the American Gastroenterological Association, aim to provide guidance on immunizations in patients with inflammatory bowel disease. This publication focused on live vaccines.

Methods

Systematic reviews evaluating the efficacy, effectiveness, and safety of vaccines in patients with IBD, other immune-mediated inflammatory diseases, and the general population were performed. Critical outcomes included mortality, vaccine-preventable diseases, and serious adverse events. Immunogenicity was considered a surrogate outcome for vaccine efficacy. Certainty of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. Key questions were developed through an iterative process and voted on by a multidisciplinary panel. Recommendations were formulated using the Evidence-to-Decision framework. Strong recommendation means that most patients should receive the recommended course of action, whereas a conditional recommendation means that different choices will be appropriate for different patients.

Results

Three good practice statements included reviewing a patient’s vaccination status at diagnosis and at regular intervals, giving appropriate vaccinations as soon as possible, and not delaying urgently needed immunosuppressive therapy to provide vaccinations. There are 4 recommendations on the use of live vaccines. Measles, mumps, rubella vaccine is recommended for both adult and pediatric patients with IBD not on immunosuppressive therapy, but not for those using immunosuppressive medications (conditional). Varicella vaccine is recommended for pediatric patients with IBD not on immunosuppressive therapy, but not for those using immunosuppressive medications (conditional). For adults, recommendations are conditionally in favor of varicella vaccine for those not on immunosuppressive therapy, and against for those on therapy. No recommendation was made regarding the use of live vaccines in infants born to mothers using biologics because the desirable and undesirable effects were closely balanced and the evidence was insufficient.

Conclusions

Maintaining appropriate vaccination status in patients with IBD is critical to optimize patient outcomes. In general, live vaccines are recommended in patients not on immunosuppressive therapy, but not for those using immunosuppressive medications. Additional studies are needed to evaluate the safety and efficacy of live vaccines in patients on immunosuppressive therapy.

The Phenotypic Spectrum of New-onset IBD in Canadian Children of South Asian Ethnicity: A Prospective Multi-Centre Comparative Study

BACKGROUND

Canadian-born children of South Asian [SA] ethnicity develop inflammatory bowel disease [IBD] at similar rates to those among Caucasian children. We evaluated the variation in phenotypic spectrum of IBD in SA and Caucasian children in a national paediatric inception cohort of new-onset IBD.

METHODS

Patients aged <17 years, enrolled in a Canadian nationwide inception cohort study, were included. Baseline demographic and IBD phenotypic features were compared between SA and Caucasian children. Longitudinal outcomes through 18 months of follow-up were compared matched by propensity scores.

RESULTS

Of 1156 children enrolled over 2014 to 2019, 623 were Caucasian [98% and 88% parents Canadian born] and 114 SA [79% Canadian born, 87% parents SA born]. Fewer SAs have a first-degree relative with IBD, 6% vs 19% in Caucasians, p = 0.002. SAs present at a younger age, median age 11.4 years (interquartile range [IQR] 9.2-14.3) vs 13 years [IQR 10.9-15 years], p = 0.03 and more commonly with a UC/IBD-U [ulcerative colitis/IBD-unclassified] subtype [ratio of UC/IBD-U to CD 1.2:1 vs 1:1.8 for Caucasians, p <0.001]. Additionally, a greater proportion of SA CD patients present with colonic-only disease [colonic-only CD/UC/IBD-U in SAs 67% vs 57% for Caucasians, p = 0.001], and among those with CD, colonic CD in SAs 31% vs 23% in Caucasians, p = 0.20]. Perianal fistulising disease was also numerically more common in SAs (14 [27%] vs 64 [18%], p = 0.06]. Adjusting for differences in phenotypic presentation, anti-tumour necrosis factor [TNF] exposure, and time to initiation was similar, and two-thirds of children, whether anti-TNF exposed or naïve, were in corticosteroid-free clinical remission at 18 months irrespective of ethnicity.

CONCLUSIONS

The phenotypic spectrum of new-onset IBD in SA children differs from that of Caucasian children, but treatment and clinical course are similar within phenotypic subgroups.

Canadian Association of Gastroenterology Clinical Practice Guideline for Immunizations in Patients With Inflammatory Bowel Disease (IBD)-Part 1: Live Vaccines

BACKGROUND & AIMS

Patients with inflammatory bowel disease (IBD) may be at increased risk of some vaccine-preventable diseases. The effectiveness and safety of vaccinations may be altered by immunosuppressive therapies or IBD itself. These recommendations developed by the Canadian Association of Gastroenterology and endorsed by the American Gastroenterological Association, aim to provide guidance on immunizations in adult and pediatric patients with IBD. This publication focused on live vaccines.

METHODS

Systematic reviews evaluating the efficacy, effectiveness, and safety of vaccines in patients with IBD, other immune-mediated inflammatory diseases, and the general population were performed. Critical outcomes included mortality, vaccine-preventable diseases, and serious adverse events. Immunogenicity was considered a surrogate outcome for vaccine efficacy. Certainty of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. Key questions were developed through an iterative process and voted on by a multidisciplinary panel. Recommendations were formulated using the Evidence-to-Decision framework. Strong recommendation means that most patients should receive the recommended course of action, whereas a conditional recommendation means that different choices will be appropriate for different patients.

RESULTS

Three good practice statements included reviewing a patient's vaccination status at diagnosis and at regular intervals, giving appropriate vaccinations as soon as possible, and not delaying urgently needed immunosuppressive therapy to provide vaccinations. There are 4 recommendations on the use of live vaccines. Measles, mumps, rubella vaccine is recommended for both adult and pediatric patients with IBD not on immunosuppressive therapy, but not for those using immunosuppressive medications (conditional). Varicella vaccine is recommended for pediatric patients with IBD not on immunosuppressive therapy, but not for those using immunosuppressive medications (conditional). For adults, recommendations are conditionally in favor of varicella vaccine for those not on immunosuppressive therapy, and against for those on therapy. No recommendation was made regarding the use of live vaccines in infants born to mothers using biologics because the desirable and undesirable effects were closely balanced and the evidence was insufficient.

CONCLUSIONS

Maintaining appropriate vaccination status in patients with IBD is critical to optimize patient outcomes. In general, live vaccines are recommended in patients not on immunosuppressive therapy, but not for those using immunosuppressive medications. Additional studies are needed to evaluate the safety and efficacy of live vaccines in patients on immunosuppressive therapy.

Canadian Association of Gastroenterology Clinical Practice Guideline for Immunizations in Patients With Inflammatory Bowel Disease (IBD)-Part 2: Inactivated Vaccines

BACKGROUND AND AIMS

The effectiveness and safety of vaccinations can be altered by immunosuppressive therapies, and perhaps by inflammatory bowel disease (IBD) itself. These recommendations developed by the Canadian Association of Gastroenterology and endorsed by the American Gastroenterological Association, aim to provide guidance on immunizations in adult and pediatric patients with IBD. This publication focused on inactivated vaccines.

METHODS

Systematic reviews evaluating the efficacy, effectiveness, and safety of vaccines in patients with IBD, other immune-mediated inflammatory diseases, and the general population were performed. Critical outcomes included mortality, vaccine-preventable diseases, and serious adverse events. Immunogenicity was considered a surrogate outcome for vaccine efficacy. Certainty of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. Key questions were developed through an iterative online platform, and voted on by a multidisciplinary group. Recommendations were formulated using the Evidence-to-Decision framework. Strong recommendation means that most patients should receive the recommended course of action, whereas a conditional recommendation means that different choices will be appropriate for different patients.

RESULTS

Consensus was reached on 15 of 20 questions. Recommendations address the following vaccines: Haemophilus influenzae type b, recombinant zoster, hepatitis B, influenza, pneumococcus, meningococcus, tetanus-diphtheria-pertussis, and human papillomavirus. Most of the recommendations for patients with IBD are congruent with the current Centers for Disease Control and Prevention and Canada's National Advisory Committee on Immunization recommendations for the general population, with the following exceptions. In patients with IBD, the panel suggested Haemophilus influenzae type b vaccine for patients older than 5 years of age, recombinant zoster vaccine for adults younger than 50 year of age, and hepatitis B vaccine for adults without a risk factor. Consensus was not reached, and recommendations were not made for 5 statements, due largely to lack of evidence, including double-dose hepatitis B vaccine, timing of influenza immunization in patients on biologics, pneumococcal and meningococcal vaccines in adult patients without risk factors, and human papillomavirus vaccine in patients aged 27-45 years.

CONCLUSIONS

Patients with IBD may be at increased risk of some vaccine-preventable diseases. Therefore, maintaining appropriate vaccination status in these patients is critical to optimize patient outcomes. In general, IBD is not a contraindication to the use of inactivated vaccines, but immunosuppressive therapy may reduce vaccine responses.

Inflammatory Bowel Disease Increases the Risk of Venous Thromboembolism in Children: A Population-Based Matched Cohort Study

BACKGROUND AND AIMS

Although venous thromboembolism [VTE] is a well-known complication of inflammatory bowel disease [IBD] in adults, limited data exist on the risk in children. We report the incidence of VTE among children with and without IBD.

METHODS

We conducted a matched cohort study within a distributed network of population-based Canadian provincial health administrative databases. Children <16 years diagnosed with IBD were identified using validated algorithms from administrative data in Alberta, Manitoba, Nova Scotia, Ontario and Québec and compared to age- and sex-matched children without IBD. Hospitalizations for VTE within 5 years of IBD diagnosis were identified. Generalized linear mixed-effects models were used to pool province-specific incidence rates and incidence rate ratios [IRR] with 95% confidence intervals [CI]. Hazard ratios [HR] from Cox proportional hazards models were pooled with fixed-effects meta-analysis.

RESULTS

The 5-year incidence of VTE among 3593 children with IBD was 31.2 [95% CI 23.7-41.0] per 10 000 person-years [PY] compared to 0.8 [95% CI 0.4-1.7] per 10 000 PY among 16 289 children without IBD [unadjusted IRR 38.84, 95% CI 16.59-90.83; adjusted HR 22.91, 95% CI 11.50-45.63]. VTE was less common in Crohn's disease than ulcerative colitis [unadjusted IRR 0.47, 95% CI 0.27-0.83; adjusted HR 0.52, 95% CI 0.29-0.94]. The findings were similar for deep vein thrombosis and pulmonary embolism when comparing children with and without IBD.

CONCLUSIONS

The risk of VTE is much higher in children with IBD than controls without IBD. While the absolute risk is low, we found a higher incidence rate than previously described in the pediatric literature.Conference Presentation: An abstract based on the data included in this paper was presented at Canadian Digestive Diseases Week [Montréal, Canada] in March 2020.

A33 MEALTIME SUPPORT: A PILOT COHORT STUDY OF AN EFFECTIVE, COST-SAVING OUTPATIENT HUNGER-BASED FEEDING PROGRAM FOR TUBE DEPENDENCY

Background

Tube dependency is an under recognized complication of long-term enteral feeding in young children. Many children struggle to progress to full oral feeds even with sufficient oral motor skills and swallowing ability. Tube dependency greatly impacts the quality of life of children and families and is a significant burden to the health care system. Economic challenges, increased burden of care and psychosocial issues all reinforce the need for timely tube removal.

Aims

We aimed to examine the efficacy of a multidisciplinary child-led, hunger-based approach called “Mealtime Support” at the Stollery Children’s Hospital in Edmonton. Nutritional outcomes, parental satisfaction and cost implications were evaluated. As a secondary aim we sought to determine the rates of gastrostomy tube insertions in the pediatric age range across Canada as a potential indicator of increasing need for long term tube feeding, hence the need for cost effective tube weaning programs to be developed in Canada.

Methods

The ambulatory program was delivered 2–3 times a day, for 2 weeks, by an occupational therapist and dietitian, under medical supervision. Hunger was promoted by reducing tube fed calories by 80% prior to commencement. Top-up tube feeds were given immediately after feeding sessions if needed. Caregivers completed 12-question subjective surveys pre and post intervention. Micro-costing methods compared costs between the program and ongoing tube feeding. The number of pediatric hospital admissions and gastrostomy tube insertions from 2008–2019, per province, was collected from the Canadian Institute for Health Information (CIHI).

Results

From 2016 - 2017, 6 children who had been tube fed from 7 to 21 months in total were enrolled and 5 completed the program. At 1-month post intervention, 4/5 of the children were 100% orally fed. Parents reported improvement in mealtime struggles (p-value = 0.005), reduction in worry about their child’s eating (p-value = 0.005) and improvement in their child’s appetite/variety foods eaten (p-value = 0.004). Over a year the potential cost savings were estimated at $42,471.24. By 6-months, all feeding tubes were removed. Based on the CIHI data, the number of gastrostomy tubes inserted per 100,000 children varied significantly between provinces, but highest in Nova Scotia, Saskatchewan and Alberta with increases seen from 2008–2018.

Conclusions

The transition from tube feeding to oral feeding is difficult for children who are tube dependent and poses several economic and psychosocial challenges. Mealtime Support was safe and successful in reducing tube dependency and cost-effective compared to no intervention or hospital based programs. There is a need to develop and fund Canadian outpatient feeding programs.

Funding Agencies

The Stollery Children’s Foundation

A41 LINKING THE APPENDIX MICROBIOME WITH INFLAMMATORY BOWEL DISEASES

Background

The appendix has been shown to be associated with the pathogenesis and health outcomes in inflammatory bowel diseases (IBD). Specifically, post appendectomy patients are found to be protective for development of ulcerative colitis (UC); however, mechanisms of appendix involvement remain unclear.

Aims

Our aim is to examine the microbes associated with the appendix of IBD patients by identifying changes in microbe abundance and interactions with the host in patient cecum luminal washes, collected from close to the neck of the appendix during colonoscopy. We hypothesize that microbes originating in the appendix of IBD patients, through interactions with host-cells in a disrupted microenvironment in the appendix, could contribute to the pathogenesis of UC.

Methods

Shotgun metagenomics was performed on cecum luminal washes of IBD patients and non-IBD controls. Guided by the metagenomic results, we performed gentamicin protection assays to determine virulence of microbes of interest using Caco2 intestinal epithelial cells. Co-culturing them with human host cells in vitro will identify relevant disease-related factors secreted by microbes and/or host cells using disease models and multiomic approaches.

Results

Shotgun metagenomics results showed that among numerous microbes, several bacterial taxa demonstrated differences in abundance between IBD and non-IBD patients: Flavonifractor, Bacteroide fragilis, and Alistipes represented 8%, 10%, and 21% abundance respectively in non-IBD patients, while in IBD patients they were present below 0.1%. In contrast, Bacteroide vulgatus and Escherichia coli were about 9% and 69% respectively, in IBD patients, whilst they were present at 1.7% and 1.2% in non-IBD patients, respectively. Following our recent method for validating pathobionts (Armstrong, 2019), we used the gentamicin protection assays to assess the ability of these bacteria to invade Caco2 cells, demonstrating a correlation between invasive potential of these microbes and cecal abundance. Mechanistic experiments, aimed at identifying factors impacting invasion, are in progress.

Conclusions

These results provide preliminary, but promising findings suggesting mechanisms by which microbiota possibly originating in the appendix may show altered virulence, which may be related to changes in the appendix microenvironment in IBD. With plans in place to increase our patient cohort we will validate these findings. Identifying and profiling these microbes in IBD patients can help improve the understanding of mechanisms underlying microenvironment changes within the appendix and the gut, which could shed light on the role of the appendix in IBD pathogenesis and clarify how microbes drive inflammation in IBD.

Funding Agencies

CIHR

A31 COMPLEX ROLE OF DIETARY FIBERS IN IBD: MICROBES MEDIATE FIBER-INDUCED INFLAMMATION

Background

Dietary fibers pass through the bowel undigested and are fermented within the intestine by microbes, typically promoting gut health. However, many IBD patients describe experiencing sensitivity to fibers. β-glucan, found on the surface of fungal cells during fungal infection, has been shown to bind to fiber receptors, such as Dectin-1, on host immune cells, resulting in a pro-inflammatory response. These fungal fibres share properties with dietary fibers.

Aims

As an altered gut microbial composition has been associated with IBD, we hypothesized that the loss of fiber-fermenting microbes populating the gut in IBD could lead to dietary fibers not being efficiently broken down into their beneficial biproducts (e.g. short chain fatty acids; SCFA), resulting in binding of intact fibers to pro-inflammatory host cell receptors.

Methods

Immune and epithelial cell lines and colonic biopsies cultured ex vivo were incubated with oligofructose or inulin (5g/L), or pre-fermented fibers (24hr anaerobic fermentation). Immune responses were measured by cytokine secretion (ELISA), and expression (qPCR). Barrier integrity was measured by transepithelial resistance (TEER). Food frequency questionnaire (FFQ) data of patient fiber consumption were correlated with gut microbes (shotgun sequencing) and immune responses to fiber in patient biopsies.

Results

Unfermented oligofructose induced IL-1β secretion in leukocytes (macrophage, T cell, neutrophil) and in colon biopsies from pediatric Crohn disease (CD; n=38) and ulcerative colitis (UC; n=20) patients cultured ex vivo, but not in non-IBD patients (n=21). IL-1β secretion was greater in patients with more severe disease. Pre-fermentation of oligofructose by whole-microbe intestinal washes from non-IBD patients or remission patients reduced secretion of IL-1β, while whole microbe intestinal washes from severe IBD patients were unable to ferment oligofructose or reduce cytokine secretion. Fiber effects on IL-1β secretion in biopsies positively correlated with effects on barrier integrity in T84 cells. Fiber-associated immune responses in patient biopsies cultured ex vivo (ELISA) correlated with fiber avoidance (FFQ) and gut microbiome (sequencing) in matching patient samples.

Conclusions

Our findings demonstrate that intolerance and avoidance of prebiotic fibers in select IBD patients is associated with the inability to ferment these fibers, leading to pro-inflammatory immune responses and intestinal barrier disruption. This highlights select disease state scenarios, in which administration of fermentable fibers should be avoided and tailored dietary interventions should be considered in IBD patients.

Funding Agencies

CIHRWeston Foundation

Characterisation of the T-cell response to Ebola virus glycoprotein amongst survivors of the 2013-16 West Africa epidemic

Zaire ebolavirus (EBOV) is a highly pathogenic filovirus which can result in Ebola virus disease (EVD); a serious medical condition that presents as flu like symptoms but then often leads to more serious or fatal outcomes. The 2013-16 West Africa epidemic saw an unparalleled number of cases. Here we show characterisation and identification of T cell epitopes in surviving patients from Guinea to the EBOV glycoprotein. We perform interferon gamma (IFNγ) ELISpot using a glycoprotein peptide library to identify T cell epitopes and determine the CD4+ or CD8+ T cell component response. Additionally, we generate data on the T cell phenotype and measure polyfunctional cytokine secretion by these antigen specific cells. We show candidate peptides able to elicit a T cell response in EBOV survivors and provide inferred human leukocyte antigen (HLA) allele restriction. This data informs on the long-term T cell response to Ebola virus disease and highlights potentially important immunodominant peptides.

Comparing Health Administrative and Clinical Registry Data: Trends in Incidence and Prevalence of Pediatric Inflammatory Bowel Disease in British Columbia

Purpose

Canada maintains robust health administrative databases and British Columbia Children's Hospital (BCCH), as the only tertiary care pediatric hospital in British Columbia (BC), maintains a comprehensive clinical inflammatory bowel disease (IBD) registry. To evaluate the strengths and weaknesses of utilizing health administrative and clinical registry data to study the epidemiology of IBD in BC, we conducted a population-based retrospective cohort study of all children <18 years of age who were diagnosed with IBD between 1996 and 2008 in BC.

Methods

IBD cases from health administrative data were identified using a combination of IBD-coded physician encounters and hospitalizations while a separate IBD cohort was identified from the BCCH clinical registry data. Age and gender standardized incidence and prevalence rates were fitted to Poisson regression models.

Results

The overall incidence of pediatric IBD identified in health administrative data increased from 7.1 (95% CI 5.5-9.2) in 1996 to 10.3 (95% CI 8.2-12.7) per 100,000 children in 2008. Similarly, the incidence of the BCCH cohort increased from 4.3 (95% CI 3.0-6.0) to 9.7 (95% CI 7.6-12.1) per 100,000. Children aged 10-17 had the highest rise in incidence in both data sources; however, the administrative data identified significantly more 10-17-year-olds and significantly less 6-9-year-olds (p<0.05) compared to clinical registry data.

Conclusion

While the application of both health administrative and clinical registry data demonstrates that the incidence of IBD is increasing in BC, we identify strengths and limitations to both and suggest that the utilization of either data source requires unique considerations that mitigate misclassification biases.

FODMAP intake in children with coeliac disease influences diet quality and health-related quality of life and has no impact on gastrointestinal symptoms

Children with coeliac disease (CD) following the gluten-free diet may experience ongoing gastrointestinal symptoms despite strict adherence. The study objective was to evaluate the association between foods high in fermentable oligo/di/monosaccharides, and polyols (FODMAP) and gastrointestinal symptoms, and the potential implications to diet quality and health-related quality of life in CD children. Dietary intake was studied in age-sex matched children 5-18 years (CD, n = 46; non-coeliac mild chronic gastrointestinal complaints [GIC], n = 46; healthy controls [HC], n = 46). CD children consumed fewer foods high in FODMAPs compared to GIC and HC (p < .0001). FODMAP intake was not related to gastrointestinal symptoms in CD children (p > 0.05) but was positively associated with child health-related quality of life (p < 0.05). FODMAP intake from fruits and vegetables was positively associated with diet adequacy and total diet quality in CD children (p < 0.05). FODMAP intake may influence diet quality and health-related quality of life but has no impact on gastrointestinal symptoms in CD children.

Early Serum Infliximab Levels in Pediatric Ulcerative Colitis

Background: Data on serum infliximab concentrations during induction in pediatric ulcerative colitis are limited. The study aim is to evaluate the relationship between serum infliximab concentrations during induction and short-term clinical remission in children with ulcerative colitis. Methods: We carried out a prospective, multi-center cohort study in pediatric patients with ulcerative colitis. Serum infliximab concentrations were collected at peak dose #1, week 1, trough pre-dose #2, and trough pre-dose #3. Infliximab dosing was left to investigator discretion. Clinical remission was defined by pediatric ulcerative colitis activity index <10 at week 8. Results: Twenty-four of thirty-four subjects (71%) achieved clinical remission at week 8. The median infliximab concentrations were 33.0 μg/mL (interquartile range: 26.5-52.1 μg/mL) pre-dose #2 and 22.5 μg/mL (interquartile range:15.9-32.3 μg/mL) pre-dose #3. Trough pre-dose #2 infliximab concentration yielded area under receiver operator characteristic curve 0.7, 95% CI: 0.5-0.9 in predicting week 8 clinical remission; a cut-off of 33.0 μg/mL yielded 62.5% sensitivity, 66.7% specificity. Trough pre-dose #3 infliximab concentrations were lower for subjects <10 years compared to ≥ 10 years [median 15.9 μg/mL, interquartile range (IQR) 8.5-21.8 μg/mL vs. 27.7 μg/mL, IQR 17.2-46.7 μg/mL, p = 0.01] and correlated with baseline weight (Spearman's rank correlation coefficient 0.45, p = 0.01). The median half-life following first IFX dose was 6.04 days (IQR 5.3-7.9 days). Conclusions: Infliximab concentrations ≥33 μg/mL prior to the second dose were associated with week 8 clinical remission. As young age and low body weight impact infliximab concentration, prospective studies with proactive adjustment in pediatric patients with ulcerative colitis should be carried out. Clinicians caring for children with UC should diligently adjust and monitor infliximab to optimize response.

Diagnostic Delay Is Associated With Complicated Disease and Growth Impairment in Paediatric Crohn's Disease

BACKGROUND

Paediatric data on the association between diagnostic delay and inflammatory bowel disease [IBD] complications are lacking. We aimed to determine the effect of diagnostic delay on stricturing/fistulising complications, surgery, and growth impairment in a large paediatric cohort, and to identify predictors of diagnostic delay.

METHODS

We conducted a national, prospective, multicentre IBD inception cohort study including 1399 children. Diagnostic delay was defined as time from symptom onset to diagnosis >75th percentile. Multivariable proportional hazards [PH] regression was used to examine the association between diagnostic delay and stricturing/fistulising complications and surgery, and multivariable linear regression to examine the association between diagnostic delay and growth. Predictors of diagnostic delay were identified using Cox PH regression.

RESULTS

Overall (64% Crohn's disease [CD]; 36% ulcerative colitis/IBD unclassified [UC/IBD-U]; 57% male]), median time to diagnosis was 4.2 (interquartile range [IQR] 2.0-9.2) months. For the overall cohort, diagnostic delay was >9.2 months; in CD, >10.8 months and in UC/IBD-U, >6.6 months. In CD, diagnostic delay was associated with a 2.5-fold higher rate of strictures/internal fistulae (hazard ratio [HR] 2.53, 95% confidence interval [CI] 1.41-4.56). Every additional month of diagnostic delay was associated with a decrease in height-for-age z-score of 0.013 standard deviations [95% CI 0.005-0.021]. Associations persisted after adjusting for disease location and therapy. No independent association was observed between diagnostic delay and surgery in CD or UC/IBD-U. Diagnostic delay was more common in CD, particularly small bowel CD. Abdominal pain, including isolated abdominal pain in CD, was associated with diagnostic delay.

CONCLUSIONS

Diagnostic delay represents a risk factor for stricturing/internal fistulising complications and growth impairment in paediatric CD.

PODCAST

This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.

A26 PEDIATRIC-ONSET INFLAMMATORY BOWEL DISEASE INCREASES THE RISK OF VENOUS THROMBOEMBOLISM: A CANGIEC POPULATION-BASED STUDY

Background

Inflammatory bowel disease (IBD) increases the risk of venous thromboembolism (VTE) in patients of all ages but the risk of VTE among Canadian children with IBD has not previously been investigated.

Aims

Report the incidence of VTE and subtypes pulmonary embolism (PE) and deep vein thrombosis (DVT) in children with and without IBD.

Methods

Children diagnosed with IBD &lt;16y were identified from health administrative data in Ontario (2002–2014), Alberta (2007–2015), and Nova Scotia (2002–2012) using validated algorithms and matched by age and sex to children without IBD (1:5 ratio). Validated ICD-10 codes identified hospitalizations for incident VTE (DVT, PE, and sinovenous thrombosis). Province-specific 5-year cumulative incidence per 1000 person-years (PY) of VTEs were pooled using fixed-effects generalized linear mixed models with a Freeman-Tukey double arcsine transformation. Incidence rate ratios (IRR) within 5 years of diagnosis were pooled using fixed-effects generalized linear mixed models to compare children with and without IBD, and children with Crohn’s disease (CD) and ulcerative colitis (UC).

Results

3127 children with IBD (1826 CD; 1045 UC) were matched to 15,635 children without IBD. The cumulative incidence of VTE within 5 years of IBD diagnosis was 2.8 (95% CI 2.1–3.8) per 1000 PYs compared to 0.13 (95% CI 0.07–0.24) per 1000 PYs in children without IBD (Table). The 5-year cumulative incidences of VTE, DVT, and PE were significantly higher in children with IBD than in children without IBD (VTE: IRR 21.44, 95% CI 10.73–42.82; DVT: IRR 25.15, 95% CI 11.12–56.89; PE: IRR 4.01, 95% CI 1.22–13.18). Compared to UC patients, children with CD were at lower risk of VTE (IRR 0.53, 95% CI 0.29–0.96) and numerically, but not statistically, lower risk of DVT (IRR 0.59, 95% CI 0.30–1.14).

Conclusions

Although VTEs are relatively rare among children with IBD, these children are at much greater risk than children without IBD. Gastroenterologists caring for these patients should be cognizant of VTE risk and provide appropriate prophylaxis to those at high risk of VTE.

Funding Agencies

CCC

A217 DEFINING THE RELATIONSHIP BETWEEN DIETARY FIBERS AND INFLAMMATORY RESPONSE IN PEDIATRIC INFLAMMATORY BOWEL DISEASES

Background

The incidence rates of inflammatory bowel diseases (IBD), Crohn disease (CD) and ulcerative colitis (UC) are increasing in children. Although the etiology of IBD is poorly understood, factors such as urban lifestyle, diet, increased hygiene, and reduced microbial biodiversity have been implicated as risk factors. Compositional changes and reduced microbial biodiversity have been linked to therapy failure in pediatric IBD. Non-digestible dietary carbohydrates, such as fiber, must undergo fermentation by gut microbiota within the large bowel, producing short chain fatty acids (SCFAs). Animal studies have shown that dietary fibers can inhibit IBD-associated inflammation, and clinical trials have demonstrated that SCFAs can prevent intestinal atrophy and allow for tissue recovery in IBD patients. In disease settings with altered gut microbes, fermentation of dietary fibers may be greatly affected. Unfermented fibers interact with receptors on host immune cells and can induce proinflammatory immune response, production of oxygen species and inflammation, or an inhibition of proinflammatory receptors.

Aims

Based on this rationale, we hypothesize that dysbiosis in the IBD gut leads to decreased fiber fermenting microbes, resulting in reduced SCFA production. This contributes to increased inflammatory responses both in in vitro cell lines, as well as ex vivo patient biopsies. Because intact fibers can bind to host cell receptors, this promotes inflammatory response and continued dysbiosis.

Methods

To assess effects of intact fiber on immune cells, macrophage and T-cell in vitro cultures were used to measure cytokine response to inulin (5mg/mL) and oligofructose (5mg/mL) through ELISAs/qPCR. These cell lines and ex vivo patient biopsies were treated with whole fibers and IL-1β secretion was measured. Fibers were also pre-fermented with microbes of interest or whole microbe patient intestinal washes and used to treat cell lines and patient biopsies.

Results

Whole fibers induced a pro-inflammatory response in macrophage cells but not T-cells, and this pro-inflammatory response was mitigated by pre-fermenting the fibers. Intestinal washes from severe IBD patients were unable to successfully ferment oligofructose or reduce fiber-associated inflammation in macrophage cell lines, whereas washes from remission or non-IBD samples reduced IL-1β. Oligofructose was found to increase IL-1β secretion in UC and CD patient biopsies, but not in non-IBD specimens. This increase was also correlated with disease severity.

Conclusions

These results indicate that a lack of fiber-fermenting microbes and presence of whole fibers can lead to pro-inflammatory responses, both in cell lines and patient biopsies. However, the presence of appropriate fermenting microbes can reduce fiber-associated inflammation.

Funding Agencies

CCCWCHRI, Weston Foundation

A64 HOSPITALIZATION IN INFLAMMATORY BOWEL DISEASE: A POPULATION-BASED COMPARISON OF DEFINITIONS

Background

Most administrative studies of hospitalization in inflammatory bowel disease (IBD) use two definitions: IBD in any diagnostic position (IBD-ANY), and IBD as the most responsible diagnostic (IBD-MRD). There is a third less commonly used definition: total hospitalization; this definition captures all hospitalizations of prevalent IBD patients and therefore it can give a more realistic picture of the burden of IBD.

Aims

To compare differing definitions (total, IBD-ANY, and IBD-MRD) of hospitalizations.

Methods

A previously defined population-based IBD prevalent cohort for Alberta (n=30,698) was used to pull all hospital admissions from the Discharge Administrative Database (DAD; 2002–2015). Three hospitalization definitions were used: i. Total (all hospitalizations of prevalent cohort independent of presence of code for IBD); ii. IBD-ANY (code for IBD [K50.x; K51.x] contained in any diagnosis field); and, iii. IBD-MRD (most responsible diagnosis was IBD). Age- and sex- standardized rates (2015 Canadian population) were calculated using the prevalent population. Log-linear regression was performed to calculate Average Annual Percentage Change (AAPC) with associated 95% confidence intervals (CI) of each type of hospitalization. We assessed the top five most common most-responsible diagnosis codes for hospitalizations that were contained in the total hospitalizations but not an IBD-ANY hospitalization.

Results

From 2002 to 2015, 63.5% of IBD prevalent patients in AB had ≥1 hospitalization; 44.2% had ≥1 IBD-ANY hospitalization; 28.6% had ≥1 IBD-MRD hospitalization; and, 40.6% had a hospitalization that did not contain a code for IBD. All hospitalization rates decreased significantly over time. Of the top five most common most responsible diagnosis, contained in admissions that were not IBD-ANY, three were gastroenterological: i. K52.9 (non-infective gastroenteritis); ii. A09.9 (diarrhea and gastroenteritis of presumed infectious origin); and, iii. Z43.2 (attention to ileostomy).

Conclusions

Total hospitalizations is an important measure to report since accounting for all hospitalizations of IBD patients is necessary in order to allocate healthcare resources appropriately. To be able to ensure these patients receive the care they need we need to be able to accurately assess the true burden of IBD.

Funding Agencies

CIHR

A15 MICROBES MEDIATE FIBER-INDUCED INFLAMMATION IN IBD

Background

The etiology of inflammatory bowel diseases (IBD) remains unknown, although gut microorganisms and diet have been implicated. Dietary fibers pass through the bowel undigested and are fermented within the intestine by microbes, promoting gut health. However, many IBD patients describe experiencing sensitivity to fibres. Interestingly, fiber receptors on immune cells are able to interact with fibers typically found on the surface of fungal cells (which share properties with dietary fibers), for example, resulting in a paradoxical pro-inflammatory response.

Aims

As an altered microbial composition is a hallmark of IBD, we hypothesized that the loss of fiber fermenting-microbes populating the IBD gut could lead to dietary fibers not being efficiently broken down into their beneficial biproducts, resulting in binding of intact fibers to pro-inflammatory host cell receptors. This can ultimately drive pro-inflammatory responses and a microenvironment that promotes continued dysbiosis and increased pathogenicity of select microbes, as observed in IBD.

Methods

Fiber receptor expression gut was examined using immunohistochemistry and flow cytometry and demonstrated elevated receptor expression due to increased presence of immune cells in IBD patient biopsies. Cytokine secretion, in response to fiber (5mg/mL) or pre-fermented fibers, cultured with microbes of interest, was measured by ELISAs in cell lines in vitro and biopsy tissues cultured ex vivo.

Results

Whole-fibers induced pro-inflammatory cytokine production in macrophage, monocytes, and neutrophils. Specific microbes were capable of fermenting fiber, measured by gas chromatography. Pre-fermentation of fibers by these microbes reduced inflammatory cytokine production. The fiber oligofructose increased IL-1β in pediatric CD (n=44) and UC (n=29) biopsies cultured ex vivo but not in non-IBD (n=25). The increase was greater in patients with more severe disease. Pre-fermentation of oligofructose by bacteria reduced this secretion of IL-1β. Whole-microbe intestinal washes from severe IBD patients were unable to ferment oligofructose or reduce fiber-associated inflammation in macrophage cells compared to remission or non-IBD children. Statistical analysis of food frequency questionnaire (FFQ) data on fiber consumption demonstrated that fiber-associated inflammation in patient biopsies cultured ex vivo (ELISA and qPCR) correlated with fiber avoidance (FFQ).

Conclusions

Comparing in vitro findings to our patient FFQs, intestinal washes (microbe abundance), and detailed patient history will better define the relationship between microbes, dietary fibers, and gut inflammation in IBD. This will allow for tailored dietary intervention through dietary recommendations, prebiotic, and/or probiotic therapies.

Funding Agencies

CCCWeston Foundation, WCHRI

Capsule Endoscopy Complements Magnetic Resonance Enterography and Endoscopy in Evaluating Small Bowel Crohn's Disease

Aims

Wireless capsule endoscopy (WCE) and magnetic resonance enterography (MRE) are increasingly utilized to evaluate the small bowel (SB) in Crohn's disease (CD). The primary aims were to compare the ability of WCE and MRE to detect SB inflammation in children with newly diagnosed CD, and in the terminal ileum (TI) to compare them to ileo-colonoscopy. Secondary aims were to compare diagnostic accuracy of WCE and MRE and changes in Paris classification after each study.

Methods

Patients (10 to 17 years of age) requiring ileo-colonoscopy for suspected CD were invited to participate. Only patients with endoscopic/histologic evidence of CD underwent MRE and WCE. SB inflammation and extent were documented and comparative analyses performed.

Results

Of 38 initially recruited subjects, 20 completed the study. WCE and MRE were similarly sensitive in identifying active TI inflammation (16 [80%] versus 12 [60%]) and any SB inflammation (17 [85%] versus 16 [80%]). However, WCE detected more extensive SB disease than MRE with active inflammation throughout the SB in 15 [75%] versus 1 [5%] patient (P < 0.001). Moreover, WCE was more likely to detect proximal SB disease (jejunum and ileum) compared to MRE (85% versus 50%, P = 0.04). Overall, the Paris classification changed in 65% and 85% of patients following MRE and WCE, respectively.

Conclusions

WCE is as sensitive as MRE for identifying active TI inflammation, but appears more sensitive in identifying more proximal SB inflammation. In the absence of concern regarding stricturing or extra-luminal disease WCE can be considered for the evaluation of suspected SB CD.

Metagenomic sequencing at the epicenter of the Nigeria 2018 Lassa fever outbreak

The 2018 Nigerian Lassa fever season saw the largest ever recorded upsurge of cases, raising concerns over the emergence of a strain with increased transmission rate. To understand the molecular epidemiology of this upsurge, we performed, for the first time at the epicenter of an unfolding outbreak, metagenomic nanopore sequencing directly from patient samples, an approach dictated by the highly variable genome of the target pathogen. Genomic data and phylogenetic reconstructions were communicated immediately to Nigerian authorities and the World Health Organization to inform the public health response. Real-time analysis of 36 genomes and subsequent confirmation using all 120 samples sequenced in the country of origin revealed extensive diversity and phylogenetic intermingling with strains from previous years, suggesting independent zoonotic transmission events and thus allaying concerns of an emergent strain or extensive human-to-human transmission.

Host immunoglobulin G selectively identifies pathobionts in pediatric inflammatory bowel diseases

BACKGROUND

Inflammatory bowel diseases (IBD) are a group of complex and multifactorial disorders with unknown etiology. Chronic intestinal inflammation develops against resident intestinal bacteria in genetically susceptible hosts. We hypothesized that host intestinal immunoglobulin (Ig) G can be used to identify bacteria involved in IBD pathogenesis.

RESULTS

IgG-bound and -unbound microorganisms were collected from 32 pediatric terminal ileum aspirate washes during colonoscopy [non-IBD (n = 10), Crohn disease (n = 15), and ulcerative colitis (n = 7)], and composition was assessed using the Illumina MiSeq platform. In vitro analysis of invasive capacity was evaluated by fluorescence in situ hybridization and gentamicin invasion assay; immune activation was measured by qPCR. Despite considerable inter-individual variations, IgG binding favored specific and unique mucosa-associated species in pediatric IBD patients. Burkholderia cepacia, Flavonifractor plautii, and Rumminococcus sp. demonstrated increased IgG binding, while Pseudomonas ST29 demonstrated reduced IgG binding, in IBD. In vitro validation confirmed that B. cepacia, F. plautii, and Rumminococcus display invasive potential while Pseudomonas protogens did not.

CONCLUSION

Using IgG as a marker of pathobionts in larger patient cohorts to identify microbes and elucidate their role in IBD pathogenesis will potentially underpin new strategies to facilitate development of novel, targeted diagnostic, and therapeutic approaches. Interestingly, this method can be used beyond the scope of this manuscript to evaluate altered gut pathobionts in a number of diseases associated with altered microbiota including arthritis, obesity, diabetes mellitus, alcoholic liver disease, cirrhosis, metabolic syndrome, and carcinomas.

Higher Postinduction Infliximab Serum Trough Levels Are Associated With Healing of Fistulizing Perianal Crohn's Disease in Children

BACKGROUND

There is some evidence in adults that higher serum infliximab (IFX) levels are needed to adequately treat fistulizing perianal Crohn's disease (CD). However, data in children are lacking. We aimed to determine postinduction serum trough IFX levels that are associated with healing of fistulizing perianal CD (PCD) at week 24.

METHODS

In a multicenter inception cohort study, consecutive children younger than age 17 years with fistulizing perianal CD treated with IFX between April 2014 and June 2017 who had serum trough IFX titers measured before the fourth infusion were included. Area under the receiver operating characteristic curve (AUROC) was calculated to determine the best cutoff to predict fistula healing.

RESULTS

A total of 667 children with Crohn's disease were recruited, with 85 (12.7%) patients diagnosed with fistulizing PCD. There were 27 of 52 (52%) children in whom pre-fourth infusion IFX levels were measured (mean age, 12.57 ± 5.12 years). At week 24, 14 of 27 (52%) patients responded with healing/healed PCD, whereas the rest had ongoing active fistulizing disease. The median IFX pre-fourth dose level in the responders was 12.7 ug/mL, compared with 5.4 ug/mL in the active disease group (P = 0.02). There was a strong correlation between IFX levels and healing of fistulizing PCD at week 24 (r = 0.65; P < 0.001). The AUROC was 0.80 (95% confidence interval, 0.64-0.97; P = 0.007) for pre-fourth IFX level to predict response of fistulizing PCD at week 24, and a level of 12.7 ug/mL best predicted fistula healing.

CONCLUSIONS

Higher trough IFX levels are associated with healing of fistulizing perianal CD.

Rural and urban disparities in the care of Canadian patients with inflammatory bowel disease: a population-based study

BACKGROUND AND AIMS

Canada's large geographic area and low population density pose challenges in access to specialized health care for remote and rural residents. We compared health services use, surgical rate, and specialist gastroenterologist care in rural and urban inflammatory bowel disease (IBD) patients in Canada.

METHODS

We used validated algorithms that were applied to population-based health administrative data to identify all people living with the following three Canadian provinces: Alberta, Manitoba, and Ontario (ON). We compared rural residents with urban residents for time to diagnosis, hospitalizations, outpatient visits, emergency department (ED) use, surgical rate, and gastroenterologist care. Multivariable regression compared the outcomes in rural/urban patients, controlling for confounders. Provincial results were meta-analyzed using random-effects models to produce overall estimates.

RESULTS

A total of 36,656 urban and 5,223 rural residents with incident IBD were included. Outpatient physician visit rate was similar in rural and urban patients. IBD-specific and IBD-related hospitalization rates were higher in rural patients (incidence rate ratio [IRR] 1.17, 95% CI 1.02-1.34, and IRR 1.27, 95% CI 1.04-1.56, respectively). The rate of ED visits in ON were similarly elevated for rural patients (IRR 1.53, 95% CI 1.42-1.65, and IRR 1.33, 95% CI 1.25-1.40). There were no differences in surgical rates or prediagnosis lag time between rural and urban patients. Rural patients had fewer IBD-specific gastroenterologist visits (IRR 0.79, 95% CI 0.73-0.84) and a smaller proportion of their IBD-specific care was provided by gastroenterologists (28.3% vs 55.2%, P<0.0001). This was less pronounced in children <10 years at diagnosis (59.3% vs 65.0%, P<0.0001), and the gap was widest in patients >65 years (33.0% vs 59.2%, P<0.0001).

CONCLUSION

There were lower rates of gastroenterologist physician visits, more hospitalizations, and greater rates of ED visits in rural IBD patients. These disparities in health services use result in costlier care for rural patients. Innovative methods of delivering gastroenterology care to rural IBD patients (such as telehealth, online support, and remote clinics) should be explored, especially for communities lacking easy access to gastroenterologists.

The Impact of Inflammatory Bowel Disease in Canada 2018: A Scientific Report from the Canadian Gastro-Intestinal Epidemiology Consortium to Crohn's and Colitis Canada

Canada has among the highest rates of IBD in the world, and the number of people living with these disorders is growing rapidly. This has placed a high burden on the health care system and on the Canadian economy—a burden that is only expected to grow in the future. It is important to understand IBD and its impact on Canadian society in order to appropriately plan for health care expenditures, reduce the burden on patients and their families, and improve the quality of life for those afflicted with IBD. In Canada, there is a lack of public awareness of the impact of Crohn’s disease and ulcerative colitis. Raising awareness is crucial to reducing the social stigma that is common with these diseases and to help individuals maximize their overall quality of life. A better public understanding of IBD can also help to raise and direct funds for research, which could lead to improved treatments and, ultimately, to a cure. This report from Canadian clinicians and researchers to Crohn’s and Colitis Canada makes recommendations aimed at the public, policy-makers, scientific funding agencies, charitable foundations and patients regarding future directions for advocacy efforts and areas to emphasize for research spending. The report also identifies gaps in knowledge in the fields of clinical, health systems and epidemiological research.

The Impact of Inflammatory Bowel Disease in Canada 2018: Children and Adolescents with IBD

Canada has among the highest rates of childhood-onset IBD in the world. Over 7000 children and youth under 18 years old are living with IBD in Canada, and 600 to 650 children under 16 years old are diagnosed annually. While the peak age of onset of IBD is highest in the second and third decades of life, over the past two decades incidence has risen most rapidly in children under 5 years old. The treatment of children with IBD presents important challenges including therapeutic choices, risk of adverse events to medications, psychosocial impact on the child and family, increased cost of health care and the implications of the transition from pediatric to adult care. Despite the unique circumstances faced by children and their families, there is a lack of research to help understand the causes of the rising incidence and the best therapies for children with IBD. Scientific evidence—and specifically clinical trials of pharmaceuticals—are too often extrapolated from adult research. Health care providers must strive to understand the unique impact of childhood-onset IBD on patients and families, while researchers must expand work to address the important needs of this growing patient population.

Highlights

Key Summary Points

Gaps in Knowledge and Future Research Directions

Tumor necrosis factor α-induced protein 3 (A20) is dysregulated in pediatric Crohn disease

PURPOSE

A significant feature of pediatric inflammatory bowel diseases (IBD), which include Crohn disease (CD), and ulcerative colitis (UC), is failure to suppress inflammation. The inability to regulate inflammation renders a major challenge toward establishing effective treatments in IBD. Nuclear factor kappa-light-chain-enhancer of activated B-cells-induced inflammation is inhibited by A20 through interactions with TAX1BP1 (Tax1-binding protein 1) and A20-binding inhibitor of NF-κβ activation (ABIN)-1 (A20 binding and inhibitor of NF-κβ) and upon phosphorylation by inhibitor of nuclear factor kappa-β kinase subunit beta (IKKβ), which stabilizes it. We hypothesized that dysregulation of A20 is an important factor in uncontrolled inflammation in pediatric IBD.

PATIENTS AND METHODS

Gene expression of A20, IKKβ, ABIN-1, TAX1BP1, A20 protein, cytokine levels, and A20 phosphorylation was analyzed in the terminal ileum (TI) of 39 patients (14 non-IBD, 15 CD, and 10 UC). A20 expression and protein in T-84 cells and ex vivo biopsies of patients were measured after treatment with Escherichia coli strains or tumor necrosis factor (TNF)-α.

RESULTS

TNF-α levels and A20 expression were increased in the TI of CD patients. A20 protein levels and ABIN-1 expression were low, TAX1BP1 expression was high, and IKKβ was unchanged. A20 expression positively correlated with biopsy TNF-α levels and inflammatory markers in CD patients. A20 phosphorylation appeared lower in CD patients. A20 expression in TI biopsies from CD patients and T84 cells was triggered with E. coli, strain LF82, while A20 protein levels remained unchanged.

CONCLUSION

We describe a potential mechanism related to failure of A20 to suppress inflammation in CD, characterized by high A20 expression and low A20 protein levels. The dysregulation of A20 is potentially due to alterations in ABIN-1, and infection with E. coli strain LF82 could affect the function and stability of A20. Our study signifies an important finding in A20 regulation in IBD, which prevents it from suppressing inflammation.