Canadian Association of Gastroenterology Clinical Practice Guideline for the Medical Management of Pediatric Luminal Crohn's Disease

Severe myelosuppression and alopecia after thiopurine initiation in a patient with NUDT15 deficiency

Thiopurines are a class of immunosuppressant and antineoplastic agents. They are widely used in the treatment of inflammatory bowel disease, haematological malignancies and autoimmune diseases, but can cause significant toxicity. Inherited gene mutations are now recognized as independent risk factors for severe adverse drug reactions to thiopurines even at 10-fold dose reductions. We present a case of thiopurine toxicity resulting in severe myelosuppression, hepatotoxicity and alopecia in an individual with homozygous *3/*3 loss-of-function alleles in the NUDT15 gene. Our case highlights important differences in gene mutation frequencies between races that can help guide pharmacogenomic testing.

Neutrophil-to-Lymphocyte Ratio at Diagnosis Predicts Colonoscopic Activity in Pediatric Inflammatory Bowel Diseases

INTRODUCTION

Neutrophil-to-lymphocyte ratio (NLR) is a novel biomarker studied in several autoimmune diseases including inflammatory bowel disease (IBD) in adults but poorly characterized in pediatric IBD (pIBD). We aimed to primarily investigate the relationship between NLR and pIBD endoscopic disease severity. We also examined whether NLR predicted hospitalization, surgery, and therapy response by 52 weeks.

METHODS

We used the Canadian Children IBD Network prospective inception cohort including patients < 18 years old with baseline data from 2013 to 2022. We excluded patients with concurrent diseases affecting NLR. Both Mayo endoscopic score (MES) and simple endoscopic scale for Crohn's disease (SES-CD) were dichotomized as low activity (quiescent-mild) and high activity (moderate-severe). For therapy responses, we examined year-1 steroid- and biologic-free remission. We used logistic regression for binary outcomes.

RESULTS

A total of 580 patients with ulcerative colitis and 1,081 patients with CD were included. High NLR was associated with high-activity MES and SES-CD in both univariate and multivariable analyses (odds ratio = 1.45, 95% CI = 1.07-1.97, P value = 0.016; and odds ratio = 1.42, 95% CI = 1.04-1.94, P value = 0.026, respectively). We also calculated the best NLR cutoff point to predict MES (1.90, sensitivity = 68%, specificity = 67%, area under the curve [AUC] = 0.67, AUC 95% CI = 0.59-0.74) and SES-CD (2.50, sensitivity = 63%, specificity = 69%, AUC = 0.66, AUC 95% CI = 0.59-0.75) high activity. NLR did not predict therapy response in either ulcerative colitis or CD.

DISCUSSION

Patients with pIBD with high baseline NLR are more probable to have worse endoscopic disease at diagnosis. This highlights NLR potential as a reliable noninvasive biomarker of disease activity. The predictive power of NLR is based mostly on neutrophils and the balance between neutrophils and lymphocytes.

Landscape of TPMT and NUDT15 Pharmacogenetic Variation in a Cohort of Canadian Pediatric Inflammatory Bowel Disease Patients

BACKGROUND

Patients with inflammatory bowel disease (IBD) exhibit considerable interindividual variability in medication response, highlighting the need for precision medicine approaches to optimize and tailor treatment. Pharmacogenetics (PGx) offers the ability to individualize dosing by examining genetic factors underlying the metabolism of medications such as thiopurines. Pharmacogenetic testing can identify individuals who may be at risk for thiopurine dose-dependent adverse reactions including myelosuppression. We aimed to evaluate PGx variation in genes supported by clinical guidelines that inform dosing of thiopurines and characterize differences in the distribution of actionable PGx variation among diverse ancestral groups.

METHODS

Pharmacogenetic variation in TPMT and NUDT15 was captured by genome-wide genotyping of 1083 pediatric IBD patients from a diverse Canadian cohort. Genetic ancestry was inferred using principal component analysis. The proportion of PGx variation and associated metabolizer status phenotypes was compared across 5 genetic ancestral groups within the cohort (Admixed American, African, East Asian, European, and South Asian) and to prior global estimates from corresponding populations.

RESULTS

Collectively, 11% of the cohort was categorized as intermediate or poor metabolizers of thiopurines, which would warrant a significant dose reduction or selection of alternate therapy. Clinically actionable variation in TPMT was more prevalent in participants of European and Admixed American/Latino ancestry (8.7% and 7.5%, respectively), whereas variation in NUDT15 was more prevalent in participants of East Asian and Admixed American/Latino ancestry (16% and 15% respectively).

CONCLUSIONS

These findings demonstrate the considerable interpopulation variability in PGx variation underlying thiopurine metabolism, which should be factored into testing diverse patient populations.

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.

Efficacy of Combined Initial Treatment of Methotrexate with Infliximab in Pediatric Crohn's Disease: A Pilot Study

BACKGROUND

The combination of antitumor necrosis factor-alpha (TNF-α) agents with immunomodulators (IMMs) is a common treatment for pediatric Crohn's disease (CD). Although methotrexate (MTX) can be a first-line medication as an IMM, most clinicians in real-life practice, especially in South Korea, are more familiar with thiopurines. This study aimed to compare the efficacy and immunogenicity of MTX and azathioprine (AZA) as concurrent therapies for pediatric CD.

METHODS

In this pilot study, 29 newly diagnosed pediatric patients with moderate-to-severe CD were randomized to receive either MTX (n = 15) (15 mg/body surface area (BSA) per week) or oral AZA (n = 14) (0.5 mg/kg per day) in combination with Infliximab (IFX). The primary outcomes were the proportion of patients in endoscopic, biochemical, and transmural remission after 14 and 54 weeks of IFX therapy. The trough levels (TLs) of IFX and anti-drug antibody (ADA) levels were also compared.

RESULTS

Among the 29 patients, there were no significant differences in the biochemical (p = 1.0 at week 14, p = 0.45 at week 54), endoscopic (p = 0.968 at week 14, p = 0.05 at week 54), or transmural (p = 0.103 at week 54) remission rates between the two medications during the concurrent therapy. Additionally, the trends in the IFX trough and ADA levels over time during the treatments were similar for both medications, with no significant differences (p = 0.686, p = 0.389, respectively).

CONCLUSION

The MTX showed comparable efficacy to the AZA in pediatric CD patients with moderate-to-severe disease. This effectively maintained adequate IFX levels and reduced ADA production. Therefore, although additional large-scale clinical trials are needed, this study demonstrated that either MTX or AZA can be selected as IMMs in the concurrent treatment of pediatric CD, depending on individual medical institutions' circumstances.

A comparison of the Child Health Utility 9D and the Health Utilities Index for estimating health utilities in pediatric inflammatory bowel disease

PURPOSE

Health utilities are challenging to ascertain in children and have not been studied in pediatric Crohn's disease (CD) and ulcerative colitis (UC). The objective was to assess discriminative validity by comparing utilities elicited using the Child Health Utility-9 Dimension (CHU9D) to the Health Utilities Index (HUI) across multiple disease activity scales in pediatric UC and CD.

METHODS

Preference-based instruments were administered to 188 children with CD and 83 children with UC aged 6 to 18 years. Utilities were calculated using CHU9D adult and youth tariffs, and HUI2 and HUI3 algorithms in children with inactive (quiescent) and active (mild, moderate, and severe) disease. Differences between instruments, tariff sets and disease activity categories and were tested statistically.

RESULTS

In CD and UC, all instruments detected significantly higher utilities for inactive compared to active disease (p < 0.05). Mean utilities for quiescent disease ranged from 0.810 (SD 0.169) to 0.916 (SD 0.121) in CD and from 0.766 (SD 0.208) to 0.871 (SD 0.186) in UC across instruments. Active disease mean utilities ranged from 0.694 (SD 0.212) to 0.837 (SD 0.168) in CD and from 0.654 (SD 0.226) to 0.800 (SD 0.128) in UC.

CONCLUSION

CHU9D and HUI discriminated between levels of disease activity in CD and UC regardless of the clinical scale used, with the CHU9D youth tariff most often displaying the lowest utilities for worse health states. Distinct utilities for different IBD disease activity states can be used in health state transition models evaluating the cost-effectiveness of treatments for pediatric CD and UC.

Inflammatory Bowel Disease: Clinical Diagnosis and Pharmaceutical Management

Inflammatory bowel disease has an enormous impact on public health, medical systems, economies, and social conditions. Biologic therapy has ameliorated the treatment and clinical course of patients with inflammatory bowel disease. The efficacy and safety profiles of currently available therapies are still less that optimal in numerous ways, highlighting the requirement for new therapeutic targets. A bunch of new drug studies are underway in inflammatory bowel disease with promising results. This is an outlined guideline of clinical diagnosis and pharmaceutical therapy of inflammatory bowel disease. Outline delineates the overall recommendations on the modern principles of desirable practice to bolster the adoption of best implementations and exploration as well as inflammatory bowel disease patient, gastroenterologist, and other healthcare provider education. Inflammatory bowel disease encompasses Crohn's disease and ulcerative colitis, the two unsolved medical inflammatory bowel disease-subtypes condition with no drug for cure. The signs and symptoms on first presentation relate to the anatomical localization and severity of the disease and less with the resulting diagnosis that can clinically and histologically be non-definitive to interpret and establish criteria, specifically in colonic inflammatory bowel disease when the establishment is inconclusive is classified as indeterminate colitis. Conservative pharmaceuticals and accessible avenues do not depend on the disease phenotype. The first line management is to manage symptoms and stabilize active disease; at the same time maintenance therapy is indicated. Nutrition and diet do not play a primary therapeutic role but is warranted as supportive care. There is need of special guideline that explore solution of groundwork gap in terms of access limitations to inflammatory bowel disease care, particularly in developing countries and the irregular representation of socioeconomic stratification with a strategic plan, for the unanswered questions and perspective for the future, especially during the surfaced global COVID-19 pandemic caused by coronavirus SARS-CoV2 impacting on both the patient's psychological functioning and endoscopy services. Establishment of a global registry system and accumulated experiences have led to consensus for inflammatory bowel disease management under the COVID-19 pandemic. Painstakingly, the pandemic has influenced medical care systems for these patients. I briefly herein viewpoint summarize among other updates the telemedicine roles during the pandemic and how operationally inflammatory bowel disease centers managed patients and ensured quality of care. In conclusion: inflammatory bowel disease has become a global emergent disease. Serious medical errors are public health problem observed in developing nations i.e., to distinguish inflammatory bowel disease and infectious and parasitic diseases. Refractory inflammatory bowel disease is a still significant challenge in the management of patients with Crohn's disease and ulcerative colitis. There are gaps in knowledge and future research directions on the recent newly registered pharmaceuticals. The main clinical outcomes for inflammatory bowel disease were maintained during the COVID-19 pandemic period.

Medical Management of Pediatric Inflammatory Bowel Disease (PIBD) in the Asia Pacific Region: A Position Paper by the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology, and Nutrition (APPSPGHAN) PIBD Working Group

Pediatric inflammatory bowel disease (PIBD) is rising rapidly in many industrialised and affluent areas in the Asia Pacific region. Current available guidelines, mainly from Europe and North America, may not be completely applicable to clinicians caring for children with PIBD in this region due to differences in disease characteristics and regional resources constraints. This position paper is an initiative from the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology and Nutrition (APPSPGHAN) with the aim of providing an up-to-date, evidence-based approach to PIBD in the Asia Pacific region, taking into consideration the unique disease characteristics and financial resources available in this region. A group of pediatric gastroenterologists with special interest in PIBD performed an extensive literature search covering epidemiology, disease characteristics and natural history, management and monitoring. Gastrointestinal infections, including tuberculosis, need to be excluded before diagnosing IBD. In some populations in Asia, the Nudix Hydrolase 15 (NUD15) gene is a better predictor of leukopenia induced by azathioprine than thiopurine-S-methyltransferase (TPMT). The main considerations in the use of biologics in the Asia Pacific region are high cost, ease of access, and potential infectious risk, especially tuberculosis. Conclusion: This position paper provides a useful guide to clinicians in the medical management of children with PIBD in the Asia Pacific region.

Meta-analysis: efficacy of exclusive enteral nutrition as induction therapy on disease activity index, inflammation and growth factors in paediatric Crohn's disease

BACKGROUND

There is evidence of inconsistency in sequelae of exclusive enteral nutrition (EEN) as induction therapy in paediatric patients with Crohn's disease (CD).

AIM

To investigate the potential effects of EEN on paediatric Crohn's disease activity index (PCDAI), inflammation and biochemical parameters in paediatric patients with CD.

METHODS

We performed a comprehensive systematic search of PubMed/MEDLINE, Web of Science, SCOPUS and Embase until 8 January 2022 regardless of the time of publication or language. Random-effects model was applied to combine the datasets. The main outcomes were analysed through mean difference (MD) and its 95% confidence interval (CI).

RESULTS

Forty six studies met eligibility criteria and were included in the meta-analysis. Pooled findings indicated that PCDAI score (MD of -27.24; 95% CI -31.84 to -22.64), calprotectin (MD of -842.83 mg/kg; CI -1018.24 to -667.42), CRP (pooled MD of -2.36 mg/dl; CI -2.68 to -2.03), and ESR (MD of -21.09 mm/h; CI -23.79 to -18.38), albumin (MD of 0.65 g/dl; CI 0.58 to 0.72), haemoglobin (MD of 1.12 g/dl; CI 0.87 to 1.37), weight (MD of 4.30 kg; CI 3.39 to 5.22), and height (MD of 0.98 cm; CI 0.35 to 1.62) improved significantly with EEN.

CONCLUSIONS

Adherence to EEN can have significant, beneficial effects as induction therapy in paediatric patients with CD.

Manipulation of Gut Microbiota as a Key Target for Crohn's Disease

Crohn's disease (CD) is an inflammatory bowel disease (IBD) sub-type characterized by transmural chronic inflammation of the gastrointestinal tract. Research indicates a complex CD etiology involving genetic predisposition and immune dysregulation in response to environmental triggers. The chronic mucosal inflammation has been associated with a dysregulated state, or dysbiosis, of the gut microbiome (bacteria), mycobiome (fungi), virome (bacteriophages and viruses), and archeaome (archaea) further affecting the interkingdom syntrophic relationships and host metabolism. Microbiota dysbiosis in CD is largely described by an increase in facultative anaerobic pathobionts at the expense of strict anaerobic Firmicutes, such as Faecalibacterium prausnitzii. In the mycobiome, reduced fungal diversity and fungal-bacteria interactions, along with a significantly increased abundance of Candida spp. and a decrease in Saccharomyces cerevisiae are well documented. Virome analysis also indicates a significant decrease in phage diversity, but an overall increase in phages infecting bacterial groups associated with intestinal inflammation. Finally, an increase in methanogenic archaea such as Methanosphaera stadtmanae exhibits high immunogenic potential and is associated with CD etiology. Common anti-inflammatory medications used in CD management (amino-salicylates, immunomodulators, and biologics) could also directly or indirectly affect the gut microbiome in CD. Other medications often used concomitantly in IBD, such as antibiotics, antidepressants, oral contraceptives, opioids, and proton pump inhibitors, have shown to alter the gut microbiota and account for increased susceptibility to disease onset or worsening of disease progression. In contrast, some environmental modifications through alternative therapies including fecal microbiota transplant (FMT), diet and dietary supplements with prebiotics, probiotics, and synbiotics have shown potential protective effects by reversing microbiota dysbiosis or by directly promoting beneficial microbes, together with minimal long-term adverse effects. In this review, we discuss the different approaches to modulating the global consortium of bacteria, fungi, viruses, and archaea in patients with CD through therapies that include antibiotics, probiotics, prebiotics, synbiotics, personalized diets, and FMT. We hope to provide evidence to encourage clinicians and researchers to incorporate these therapies into CD treatment options, along with making them aware of the limitations of these therapies, and indicate where more research is needed.

Adalimumab in Pediatric Inflammatory Bowel Disease

The introduction of biological agents with strong anti-inflammatory action, such as antitumor necrosis factor (TNF) agents, has changed inflammatory bowel disease (IBD) treatment strategy and goals, and has contributed significantly to improve the long-term prognosis of patients. Moreover, several biological agents are being used or researched in pediatric populations. However, only two biological agents, infliximab (IFX) and adalimumab (ADL), are currently approved for children and adolescents. In pediatric IBD, there are limitations and burdens associated with facilitating mucosal healing (MH) when utilizing these two biological agents. ADL is effective in both naïve patients and those with previous experience with biologics. Beyond clinical remission, this drug is also effective for MH and histological remission. The use of therapeutic drug monitoring to further enhance the effectiveness of ADL treatment can be expected to reduce treatment failure of ADL and pave the way for appropriate treatment in the treat-to-target era. This review paper focuses on ADL, examine studies conducted in children, and determine the role this agent plays against pediatric inflammatory bowel disease.

Risk Factors of Clinical Relapses in Pediatric Luminal Crohn's Disease: A Retrospective Cohort Study

INTRODUCTION

There is currently little knowledge on factors associated with the relapse of Crohn's disease (CD) in children. The aims of this study were to describe the risk factors associated with relapse in pediatric CD and the changes in the relapse rate over the past decade.

METHODS

Patients younger than 18 years and diagnosed between 2009 and 2019 were included in this retrospective cohort study. Clinical, endoscopic, histological, and laboratory data, as well as induction and maintenance treatments, were collected from the medical records. Survival analyses and Cox regression models were used to assess the impact of these risk factors on relapse.

RESULTS

Six hundred thirty-nine patients were included. There was a decrease in the clinical relapse rate over the past decade: 70.9% of the patients diagnosed between 2009 and 2014 relapsed as compared with 49.1% of the patients diagnosed between 2015 and 2019 (P < 0.0001). The following variables were associated with clinical relapse: female sex (adjusted hazard ratio [aHR] = 1.52, P = 0.0007), exposure to oral 5-ASA (aHR = 1.44, P = 0.04), use of immunomodulatory agents compared with tumor necrosis factor-alpha inhibitors (methotrexate aHR = 1.73, P = 0.003; thiopurines aHR = 1.63, P = 0.002), presence of granulomas (aHR = 1.34, P = 0.02) and increased eosinophils on intestinal biopsies (aHR = 1.36, P = 0.02), high levels of C-reactive protein (aHR = 1.01, P < 0.0001) and fecal calprotectin (aHR = 1.08, P < 0.0001), and low serum infliximab levels (aHR = 2.32, P = 0.001).

DISCUSSION

Relapse of pediatric CD has decreased in the past decade. The risk of relapse is significantly associated with clinical, endoscopic, histological, and laboratory variables and treatment strategies.

Clinical and Laboratory Characteristics Are Associated With Biologic Therapy Use in Pediatric Inflammatory Bowel Disease: A Retrospective Cohort Study

Background

Biologic agents are a highly useful class of medications for treating inflammatory bowel disease (IBD). Limited evidence exists to guide initiation of biologic therapy, especially in pediatric patients. It is unclear if disease severity is connected to biologic response. We hypothesized that the clinical, biochemical and radiographic characteristics of pediatric IBD at diagnosis were associated with subsequent initiation of biologic therapy.

Methods

We performed a retrospective analysis of the charts of all pediatric patients diagnosed with IBD at our centre over 14 years. Kaplan–Meier curves evaluated patient characteristics at diagnosis with time to initiation of biologic therapy. A Cox proportional hazards model was used for multivariate characteristic analysis.

Results

A total of 198 patients were included, 57.6% had Crohn’s disease, 27.8% had ulcerative colitis and 14.6% had IBD type unclassified. Mean follow-up time was 47.8 months. About 55.5% of the patients received a biologic medication, the mean time to biologic initiation was 21.5 months. Earlier initiation of biologic therapy was frequently associated with older age, higher disease activity index and lower serum albumin.

Conclusions

Older pediatric patients with more severely active disease and lower serum albumin levels at the time of IBD diagnosis were more likely to initiate biologic therapy when considering biologic initiation, even many years after diagnosis. Identification of these characteristics may help inform decisions to initiate biologic therapy earlier in the IBD disease course.

Reduced Systemic Corticosteroid Use among Pediatric Patients With Inflammatory Bowel Disease in a Large Learning Health System

OBJECTIVES

Corticosteroids have long been used to treat inflammatory bowel disease. However, cumulative corticosteroid exposure is associated with adverse effects, particularly in growing children. Professional guidelines recommend steroid-sparing strategies. It remains unknown whether corticosteroid use has decreased in children with inflammatory bowel disease.

METHODS

We performed retrospective cohort study using data from 2007 to 2018 from the international multi-center ImproveCareNow Network, a pediatric inflammatory bowel disease quality improvement collaborative. Pediatric patients diagnosed with inflammatory bowel disease were included. Patients with missing diagnosis or corticosteroid use data were excluded. We performed serial cross-sectional analyses of period prevalence and used multivariate regression models.

RESULTS

27,321 patients were included (65% Crohn disease, 28% ulcerative colitis, 7% indeterminate colitis). Corticosteroids were used in 10,206 (37%). Corticosteroid use decreased from 28% (2007) to 12% (2018). Black patients received corticosteroids more commonly than white patients. This disparity improved as corticosteroid use decreased in both groups. Most corticosteroid use occurred <120 days after diagnosis. Corticosteroid or 5-aminosalicylate use <120 days after diagnosis predicted later corticosteroid use. Anti-tumor necrosis factor-alpha medication use <120 days after diagnosis was associated with a reduction in corticosteroid use. As corticosteroid use decreased, steroid-sparing therapy use increased and height and weight z scores improved, particularly among children with Crohn disease. Despite improvement across the network, variation in corticosteroid usage remains.

CONCLUSIONS

Corticosteroid use among pediatric patients with inflammatory bowel disease in the ImproveCareNow Network has decreased over time. Racial disparities in corticosteroid use were found, but gradually improved.

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.

Imputing missing patient-level data and propensity score matching in cost-effectiveness analysis in Crohn's disease

Objectives: The effect of imputing missing data followed by propensity score analysis on the incremental cost-effectiveness ratio (ICER) in a cost-effectiveness analysis is unknown. The objective was to compare alternative approaches in grouping data following imputation and prior to calculating propensity scores for use in economic evaluation.Methods: Patient-level data from an observational study of 573 children with Crohn's disease were used in a microsimulation model to determine the incremental cost of early anti-tumor necrosis factor-α treatment compared to standard care per remission week gained. Multiple imputation of a missing covariate followed by propensity score matching to create comparator groups was approached in two ways. The Within approach calculated propensity scores on each imputed dataset separately, while the Across method averaged propensity scores to create one matched population resulting in multiple sets of health state transition probabilities.Results: The incremental cost per remission week gained ranged from CAD$2,236 to CAD$12,464 (mean CAD$4,266) with Within datasets and was CAD$4,679 per remission week gained with the Across dataset.Conclusion: Imputation of missing patient-level data and propensity score analysis increases methodological uncertainty in cost-effectiveness analysis. The present study indicated that the Across approach may be less cumbersome, and slightly reduce bias and variance.

The effects of resistant starches on inflammatory bowel disease in preclinical and clinical settings: a systematic review and meta-analysis

Background

Inflammatory bowel disease (IBD) is a debilitating chronic disease with limited treatment options. Resistant starches may represent a novel treatment for IBD. However, its efficacy and safety remain unclear. Our objective was to perform a systematic review to summarize the preclinical and clinical effects of resistant starch, which may help guide future studies.

Methods

Medline, EMBASE, and the Cochrane Central Register were searched. Included studies investigated the use of resistant starch therapy in in vivo animal models of IBD or human patients with IBD. Articles were screened, and data extracted, independently and in duplicate. The primary outcomes were clinical remission (clinical) and bowel mucosal damage (preclinical).

Results

21 preclinical (n = 989 animals) and seven clinical (n = 164 patients) studies met eligibility. Preclinically, resistant starch was associated with a significant reduction in bowel mucosal damage compared to placebo (standardized mean difference − 1.83, 95% CI − 2.45 to − 1.20). Clinically, five studies reported data on clinical remission but clinical and methodological heterogeneity precluded pooling. In all five, a positive effect was seen in patients who consumed resistant starch supplemented diets. The majority of studies in both the preclinical and clinical settings were at a high or unclear risk of bias due to poor methodological reporting.

Conclusions

Our review demonstrates that resistant starch is associated with reduced histology damage in animal studies, and improvements in clinical remission in IBD patients. These results need to be tempered by the risk of bias of included studies. Rigorously designed preclinical and clinical studies are warranted.

Trial registration

The review protocols were registered on PROSPERO (preclinical: CRD42019130896; clinical: CRD42019129513).

Positioning Biologic Therapies in the Management of Pediatric Inflammatory Bowel Disease

The incidence and prevalence of pediatric inflammatory bowel disease (IBD) are rising worldwide, with a steep increase in children under 5 years of age. Compared to adult IBD, pediatric IBD presents with a more severe, aggressive phenotype and unique complications, notably growth impairment. Treatment goals include achieving intestinal healing, reaching growth potential, and optimizing quality of life, all while limiting drug toxicities. In the last 2 decades, the advent of anti-tumor necrosis factor (TNF) α agents has significantly increased the potential to reach these goals. However, nonresponse or loss of response to anti- TNFα agents is still encountered in approximately one-third of patients. Although the development of novel biologic therapies has offered new alternatives in recent years, the use of these therapies in the pediatric setting has been limited due to delayed approval. This article summarizes the key evidence for biologic agents currently used in the treatment of pediatric IBD and discusses challenges and barriers unique to pediatric drug development.

Bacterial Taxa and Functions Are Predictive of Sustained Remission Following Exclusive Enteral Nutrition in Pediatric Crohn's Disease

BACKGROUND

The gut microbiome is extensively involved in induction of remission in pediatric Crohn's disease (CD) patients by exclusive enteral nutrition (EEN). In this follow-up study of pediatric CD patients undergoing treatment with EEN, we employ machine learning models trained on baseline gut microbiome data to distinguish patients who achieved and sustained remission (SR) from those who did not achieve remission nor relapse (non-SR) by 24 weeks.

METHODS

A total of 139 fecal samples were obtained from 22 patients (8-15 years of age) for up to 96 weeks. Gut microbiome taxonomy was assessed by 16S rRNA gene sequencing, and functional capacity was assessed by metagenomic sequencing. We used standard metrics of diversity and taxonomy to quantify differences between SR and non-SR patients and to associate gut microbial shifts with fecal calprotectin (FCP), and disease severity as defined by weighted Pediatric Crohn's Disease Activity Index. We used microbial data sets in addition to clinical metadata in random forests (RFs) models to classify treatment response and predict FCP levels.

RESULTS

Microbial diversity did not change after EEN, but species richness was lower in low-FCP samples (<250 µg/g). An RF model using microbial abundances, species richness, and Paris disease classification was the best at classifying treatment response (area under the curve [AUC] = 0.9). KEGG Pathways also significantly classified treatment response with the addition of the same clinical data (AUC = 0.8). Top features of the RF model are consistent with previously identified IBD taxa, such as Ruminococcaceae and Ruminococcus gnavus.

CONCLUSIONS

Our machine learning approach is able to distinguish SR and non-SR samples using baseline microbiome and clinical data.