Baseline Clinical Factors Are Associated With Risk of Complications in Crohn's Disease: Appraisal of the American Gastroenterological Association Clinical Care Pathway.

INTRODUCTION: The American Gastroenterological Association (AGA) has compiled risk factors that may be predictive of disease complications in Crohn's disease (CD) and ulcerative colitis (UC). The aim of this study was to evaluate the performance of the AGA risk factors for risk stratification in UC and CD. METHODS: We included participants of 2 cohorts: the Ocean State Crohn's and Colitis Area Registry cohort and the Mayo Clinic cohort. Baseline clinical risk factors were extracted according to the AGA pathway. Our primary end point was defined as follows: (i) any inflammatory bowel disease related-hospitalization, (ii) any inflammatory bowel disease-related bowel surgery, or (iii) any progression of disease. We analyzed the association of the number of AGA risk factors with our end point. Statistical multivariable modeling was performed with Cox proportional hazards model. RESULTS: A total of 412 patients with CD were included. Comparing ≥3 risk factors with 0-1 risk factor, we found a significantly increased risk of complications in both the Ocean State Crohn's and Colitis Area Registry cohort (hazard ratio [HR] 2.75, 95% confidence interval 1.71-4.41) and Mayo Clinic cohort (HR 2.07, 95% confidence interval 1.11-3.84). Diagnosis at younger age (HR 2.07), perianal disease (HR 1.99), and B2/B3 behavior (HR 1.92) were significantly associated with disease complications. We did not observe a consistent association between number of risk factors nor any specific individual risk factors and risk of disease complications in the 265 patients with UC included. DISCUSSION: We found a significant association between the number of AGA risk factors and the risk of disease complication in CD; this association was not significant in UC. The presence of ≥ 3 risk factors in CD leads to the highest risk of complications. The AGA care pathway is a useful tool to stratify patients who are at higher risk of disease complications in patients with CD.

Safety and Durability of Accelerated Infliximab Dosing Strategies in Pediatric IBD: A Single Center, Retrospective Study.

OBJECTIVES: Infliximab (IFX) is commonly used to treat children with inflammatory bowel disease (IBD). We previously reported that patients with extensive disease started on IFX at a dose of 10 mg/kg had greater treatment durability at year one. The aim of this follow-up study is to assess the long-term safety and durability of this dosing strategy in pediatric IBD. METHODS: We performed a retrospective single-center study of pediatric IBD patients started on IFX over a 10-year period. RESULTS: Two hundred ninety-one patients were included (mean age = 12.61, 38% female) with a follow-up range of 0.1-9.7 years from IFX induction. One hundred fifty-five (53%) were started at a dose of 10 mg/kg. Only 35 patients (12%) discontinued IFX. The median duration of treatment was 2.9 years. Patients with ulcerative colitis ( P ≤ 0.01) and patients with extensive disease ( P = 0.01) had lower durability, despite a higher starting dose of IFX ( P = 0.03). Adverse events (AEs) were observed to occur at a rate of 234 per 1000 patient-years. Patients with a higher serum IFX trough level (≥20 µg/mL) had a higher rate of AEs ( P = 0.01). Use of combination therapy had no impact on risk of AEs ( P = 0.78). CONCLUSIONS: We observed an excellent IFX treatment durability, with only 12% of patients discontinuing therapy over the observed timeframe. The overall rate of AEs was low, the majority being infusion reactions and dermatologic conditions. Higher IFX dose and serum trough level> 20 µg/mL were associated with higher risk of AEs, the majority being mild and not resulting in cessation of therapy.

Targeted Assessment of Mucosal Immune Gene Expression Predicts Clinical Outcomes in Children with Ulcerative Colitis.

BACKGROUND AND AIMS: We aimed to determine whether a targeted gene expression panel could predict clinical outcomes in paediatric ulcerative colitis [UC] and investigated putative pathogenic roles of predictive genes. METHODS: In total, 313 rectal RNA samples from a cohort of newly diagnosed paediatric UC patients (PROTECT) were analysed by a real-time PCR microfluidic array for expression of type 1, 2 and 17 inflammation genes. Associations between expression and clinical outcomes were assessed by logistic regression. Identified prognostic markers were further analysed using existing RNA sequencing (RNA-seq) data sets and tissue immunostaining. RESULTS: IL13RA2 was associated with a lower likelihood of corticosteroid-free remission (CSFR) on mesalamine at week 52 (p = .002). A model including IL13RA2 and only baseline clinical parameters was as accurate as an established clinical model, which requires week 4 remission status. RORC was associated with a lower likelihood of colectomy by week 52. A model including RORC and PUCAI predicted colectomy by 52 weeks (area under the receiver operating characteristic curve 0.71). Bulk RNA-seq identified IL13RA2 and RORC as hub genes within UC outcome-associated expression networks related to extracellular matrix and innate immune response, and lipid metabolism and microvillus assembly, respectively. Adult UC single-cell RNA-seq data revealed IL13RA2 and RORC co-expressed genes were localized to inflammatory fibroblasts and undifferentiated epithelial cells, respectively, which was supported by protein immunostaining. CONCLUSION: Targeted assessment of rectal mucosal immune gene expression predicts 52-week CSFR in treatment-naïve paediatric UC patients. Further exploration of IL-13Rɑ2 as a therapeutic target in UC and future studies of the epithelial-specific role of RORC in UC pathogenesis are warranted.

Emulsifiers and Intestinal Health: An Introduction.

ABSTRACT: Food additives in general, and emulsifiers in particular, are considered to be important dietary components with a potential to harm the intestine, in part by promoting intestinal inflammation. There is inadequate objective information about the specific nature and the magnitude of the problem.The Food and Drug Administration (FDA) has recognized approximately 450 items added to our foods as being generally regarded as safe and has placed them on a generally regarded as safe (GRAS) list. Additionally, it has also approved approximately 3000 "food additives." There is a general lack of transparency as to how either of these selections were and continue to be made. Once items are officially designated by the FDA as "food additives" or placed on the GRAS list, there is no regulatory mechanism for the ongoing monitoring of their safety.The most widely used emulsifier is "lecithin," which is biochemically identified as phosphatidylcholine (PC). Regulatory guidelines allow manufacturers to use the label "lecithin" to be applied to emulsifiers that contain PC plus other phospholipids in a variety of unspecified concentrations. The PC used in experiments cited in the literature, is unlikely to be the same thing as the "lecithin" in our diets.The objective of this introduction to emulsifiers is to raise awareness of the current state of food additives in the USA and to encourage thoughtful approaches to the study of all additives found in our diets. The overriding goal should be to assure the safety of what we eat. As examples we discuss eight widely distributed food additives; four "natural" emulsifiers that are classified as GRAS as well as an additional emulsifier-associated food additive that is also on the GRAS list, and three synthetic emulsifying agents that are FDA approved as "food additives."

Early Change in Fecal Calprotectin Predicts One-Year Outcome in Children Newly Diagnosed With Ulcerative Colitis.

INTRODUCTION: While fecal calprotectin (FC) is used to assess disease activity in ulcerative colitis (UC) there are little data concerning the role of serial FC levels at diagnosis in predicting clinical course. We sought to determine whether FC at diagnosis or early change following therapy predicts clinical outcomes in pediatric UC.Methods: Children with newly diagnosed UC were treated with standardized regimens of mesalamine or corticosteroids (CS). CS tapering and escalation to additional therapy or colectomy were by protocol. Patients with baseline or week 4 or week 12 FC levels were included in the analysis. Our primary outcome was CS-free remission on mesalamine at week 52. We compared the prognostic value of a baseline FC as well as a change in FC by week 4 or week 12 in predicting clinical outcomes. RESULTS: The study included 352 children (113 initial mesalamine, 239 initial CS, mean age 12.6 years) with UC. At Week 52, 135 (38.3%), 84 (23.8%), and 19 (5.4%) children achieved CS-free remission, needed anti-tumor necrosis factor therapy or had colectomy respectively. Baseline FC was not associated with CS-free remission at week 52. However, both week 4 (odds ratio [OR] 0.95, 95% confidence interval [CI] 0.901.00) and week 12 FC levels (OR 0.91, 95% CI 0.87-0.96) were associated with outcomes, with the latter having a stronger association with CS-free remission. Patients with a >75% decrease by 12 weeks, had a 3-fold increased likelihood of CS-free remission at 1 year. DISCUSSION: Longitudinal changes in FC may predict 1 year outcomes better than values at diagnosis in children with a new diagnosis of UC.

Stratification of risk of progression to colectomy in ulcerative colitis via measured and predicted gene expression.

An important goal of clinical genomics is to be able to estimate the risk of adverse disease outcomes. Between 5% and 10% of individuals with ulcerative colitis (UC) require colectomy within 5 years of diagnosis, but polygenic risk scores (PRSs) utilizing findings from genome-wide association studies (GWASs) are unable to provide meaningful prediction of this adverse status. By contrast, in Crohn disease, gene expression profiling of GWAS-significant genes does provide some stratification of risk of progression to complicated disease in the form of a transcriptional risk score (TRS). Here, we demonstrate that a measured TRS based on bulk rectal gene expression in the PROTECT inception cohort study has a positive predictive value approaching 50% for colectomy. Single-cell profiling demonstrates that the genes are active in multiple diverse cell types from both the epithelial and immune compartments. Expression quantitative trait locus (QTL) analysis identifies genes with differential effects at baseline and week 52 follow-up, but for the most part, differential expression associated with colectomy risk is independent of local genetic regulation. Nevertheless, a predicted polygenic transcriptional risk score (PPTRS) derived by summation of transcriptome-wide association study (TWAS) effects identifies UC-affected individuals at 5-fold elevated risk of colectomy with data from the UK Biobank population cohort studies, independently replicated in an NIDDK-IBDGC dataset. Prediction of gene expression from relatively small transcriptome datasets can thus be used in conjunction with TWASs for stratification of risk of disease complications.

Immunoglobulin A Targets a Unique Subset of the Microbiota in Inflammatory Bowel Disease.

The immunopathogenesis of inflammatory bowel disease (IBD) has been attributed to a combination of host genetics and intestinal dysbiosis. Previous work in a small cohort of IBD patients suggested that pro-inflammatory bacterial taxa are highly coated with secretory immunoglobulin IgA. Using bacterial fluorescence-activated cell sorting coupled with 16S rRNA gene sequencing (IgA-SEQ), we profiled IgA coating of intestinal microbiota in a large cohort of IBD patients and identified bacteria associated with disease and treatment. Forty-three bacterial taxa displayed significantly higher IgA coating in IBD compared with controls, including 8 taxa exhibiting differential IgA coating but similar relative abundance. Patients treated with anti-TNF-α therapies exhibited dramatically altered microbiota-specific IgA responses compared with controls. Furthermore, increased IgA coating of Oscillospira was associated with a delay in time to surgery. These results demonstrate that investigating IgA responses to microbiota can uncover potential disease-modifying taxa and reveal improved biomarkers of clinical course in IBD.

Constipation.

Constipation in otherwise healthy infants and children is a common problem despite confusion about how to precisely define constipation and constipation-related disorders. Constipation may, rarely, be a sign or symptom of a more serious disease or a diagnosis defined only by its symptoms and without any structural or biochemical findings. In the latter case it is classified as a functional gastrointestinal disorder (FGID). FGIDs are defined as disorders that cannot be explained by structural or biochemical findings. The Rome Foundation has standardized diagnostic criteria for all FGIDs. The Rome criteria are based on the available research as well as the clinical experience of the Foundation's assembled experts. The most recent report, Rome IV, described clinical criteria and diagnostic tools and encouraged more rigorous research in the area of FGIDs. The true incidence and prevalence of constipation is difficult to know because it may be treated at home using home remedies or diagnosed at a visit to a primary care provider or to a subspecialist pediatric gastroenterologist. The most recent attempts to define the prevalence of all pediatric FGIDs have been made using the Rome IV criteria. The defined FGID entities that may be associated with the complaint of constipation are infant dyschezia, functional constipation, and nonretentive fecal incontinence. The term encopresis, omitted from Rome IV, is defined by the American Psychiatric Association (APA) in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition The 3 Rome-defined (constipation-related) entities and the APA entity of encopresis are the focus of this review.

Harmonizing Nutritional Therapies for Pediatric Inflammatory Bowel Disease.

Uses of nutritional therapies for inflammatory bowel disease (IBD) are of tremendous interest to the lay and professional communities. This interest currently outweighs the scientific basis for deciding on a particular therapy for any given patient. Some nutritional therapies have credible reports, in peer-review journals, validating their use for some patients. The broad pediatric gastroenterology community in the United States has, however, been unable or unwilling to agree on the details necessary to disseminate the most effective therapies with adequate reliability and validity to implement these interventions successfully. The well-established importance of the appropriate use of nutritional interventions for the treatment of undernutrition and maintenance of optimal nutrition is not an issue. A consensus and widely applicable solution for nutrition as therapy for IBD is, however, not imminent. In the interim, we aim to help the science-based reader to evaluate manuscripts appearing in our journals and to use this information to make rational, informed therapeutic decisions. We outline the current limited evidence base and make recommendations to advance the field of nutritional therapy in IBD.

Longitudinal non-adherence predicts treatment escalation in paediatric ulcerative colitis.

BACKGROUND: Medication non-adherence in paediatric ulcerative colitis (UC) has been associated with negative health outcomes including flares in disease activity. However, no studies to date have examined longitudinal adherence to maintenance medication in a prospective controlled trial. AIMS: To determine whether objectively measured adherence to standardised mesalazine (mesalamine) therapy over time was related to remission at 52 weeks and the need for treatment escalation in newly diagnosed paediatric patients with UC METHODS: PROTECT (NCT01536535) was a prospective, inception cohort, multi-site study of paediatric patients aged 4-17 years with newly diagnosed UC followed for 52 weeks. Patients received standardised mesalazine, with pre-established criteria for escalation to thiopurines or anti-TNFα inhibitors. Patients used pill bottles with electronic caps to monitor mesalazine adherence. We tested whether longitudinal adherence to mesalazine predicted steroid-free remission at week 52 (i.e. quiescent disease on mesalazine alone with no corticosteroids ≥4 weeks prior) and need for treatment escalation (i.e. introduction of immunomodulators, calcineurin-inhibitors or anti-TNFα inhibitors). RESULTS: Among 268 patients, average mesalazine adherence trajectories did not predict week 52 steroid-free remission. Declining adherence over time strongly predicted treatment escalation (ß = -.037, P = .001). By month 6, adherence rate ≤85.7% was associated with treatment escalation. CONCLUSIONS: Non-adherence may have affected therapeutic efficacy of standardised mesalazine, thereby contributing to need for treatment escalation. Routine adherence monitoring for at least 6 months following treatment initiation and addressing adherence difficulties early in the disease course are recommended.

Characterization of Stool Virome in Children Newly Diagnosed With Moderate to Severe Ulcerative Colitis.

BACKGROUND: Viral infections have been suggested as possible triggers for the onset of ulcerative colitis (UC). METHODS: We employed VirCapSeq-Vert, a high-throughput sequencing virus capture platform, to examine the stool virome of children with newly diagnosed moderate to severe UC. We surveyed fecal samples collected at presentation, after symptom remission, and from a control group diagnosed with irritable bowel syndrome. RESULTS: Seventy subjects with UC (mean age 13 years, 45 had moderate symptoms, 25 had severe, 69 of 70 had a Mayo endoscopy subscore 2/3) were studied. We detected a wide range of animal viruses that were taxonomically classified into 12 viral families. A virus was present in 50% of fecal samples collected at presentation, 41% of samples collected after remission, and 40% of samples in our control group. The most frequently identified viruses were diet-based gyroviruses. The UC cohort had a significantly higher prevalence of anelloviruses compared with the control cohort. However, we did not identify a single virus that can be implicated in the onset of UC and did not find an association between UC disease severity and viral presence. CONCLUSION: Presence of virus in stool was not associated with the onset of pediatric UC.