Increased immune reactivity predicts aggressive complicating Crohn's disease in children

Priming lymphocyte responsiveness and differential T cell signaling in pediatric IBD patients with Cannabis use

The prevalence of inflammatory bowel disease (IBD) has increased dramatically in recent years, particularly in pediatric populations. Successful remission with current therapies is limited and often transient, leading patients to seek alternative therapies for symptom relief, including the use of medical marijuana (Cannabis sativa). However, chronic cannabis use among IBD patients is associated with increased risk for surgical interventions. Therefore, determining the direct impact of cannabis use on immune modulation in IBD patients is of critical importance. Peripheral blood mononuclear cells of cannabis using and non-using pediatric IBD patients were phenotyped by flow cytometry and functionally assessed for their cytokine production profile. A phospho-kinase array was also performed to better understand changes in immune responses. Results were then compared with serum phytocannabinoid profiles of each patient to identify cannabinoid-correlated changes in immune responses. Results demonstrated elevated levels of a myriad of pro-inflammatory cytokines in users versus non-users. Differences in signaling cascades of activated T cells between users and non-users were also observed. A number of anti-inflammatory cytokines were inversely correlated with serum phytocannabinoids. These results suggest that cannabis exposure, which can desensitize cannabinoid receptors, may prime pro-inflammatory pathways in pediatric IBD patients.

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.

Precision medicine in inflammatory bowel disease

Inflammatory bowel disease (IBD) is an incurable disease characterized by remission-relapse cycles throughout its course. Both Crohn's disease (CD) and ulcerative colitis (UC), the two main forms of IBD, exhibit tendency to develop complications and substantial heterogeneity in terms of frequency and severity of relapse, thus posing great challenges to the clinical management for IBD. Current treatment strategies are effective in different ways in induction and maintenance therapies for IBD. Recent advances in studies of genetics, pharmacogenetics, proteomics and microbiome provide a strong driving force for identifying molecular markers of prognosis and treatment response, which should help clinicians manage IBD patients more effectively, and then, improve clinical outcomes and reduce treatment costs of patients. In this review, we summarize and discuss precision medicine in IBD, focusing on predictive markers of disease course and treatment response, and monitoring indices during therapeutic drug monitoring.

Inflammation in the peripheral blood system of Crohn's Disease

Crohn's disease (CD) is an inflammatory bowel disease that is characterized by chronic inflammation of digestive system and has a nickname "green cancer" because of its sustained alternation of periods of flares and remissions. Here, we investigated the inflammation changes in peripheral blood system of CD patients, which are less reported in China. Peripheral blood samples of 167 CD patients and 30 healthy people, as well as their clinical information, were collected at the Second Affiliated Hospital of Soochow University. Flow cytometry was performed to analyze the ratio of CD4 T cells to CD8 T cells. Cytometric Bead Array kit was used to detect the cytokines in peripheral blood in CD patients. Moreover, the expression of inflammasomes was also detected by RT-PCR. The percentage and cell number of lymphocytes in CD patients' peripheral blood system decreased significantly, while monocytes increased remarkably. Interestingly, there was an inversion of the CD4 T cells/CD8 T cells ratio in peripheral blood of CD patients. The levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) increased significantly in CD patients' peripheral blood, and lipopolysaccharide (LPS) stimulation aggravate inflammatory response. In addition, the expression of nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 1 (NLRP1) and NLRP3 in peripheral blood mononuclear cells (PBMC) of CD patients increased significantly after LPS stimulation. The inflammation in peripheral blood of CD patients had significant changes, including PBMC, cytokines and inflammasomes. These results are helpful to get a deeper understanding of CD and improve the efficiency of diagnosis and treatment in China.

Precision medicine and drug optimization in adult inflammatory bowel disease patients

Inflammatory bowel diseases (IBD) encompass two main entities including ulcerative colitis and Crohn's disease. Although having a common global pathophysiological mechanism, IBD patients are characterized by a significant interindividual heterogeneity and may differ by their disease type, disease locations, disease behaviours, disease manifestations, disease course as well as treatment needs. Indeed, although the therapeutic armamentarium for these diseases has expanded rapidly in recent years, a proportion of patients remains with a suboptimal response to medical treatment due to primary non-response, secondary loss of response or intolerance to currently available drugs. Identifying, prior to treatment initiation, which patients are likely to respond to a specific drug would improve the disease management, avoid unnecessary side effects and reduce the healthcare expenses. Precision medicine classifies individuals into subpopulations according to clinical and molecular characteristics with the objective to tailor preventative and therapeutic interventions to the characteristics of each patient. Interventions would thus be performed only on those who will benefit, sparing side effects and expense for those who will not. This review aims to summarize clinical factors, biomarkers (genetic, transcriptomic, proteomic, metabolic, radiomic or from the microbiota) and tools that could predict disease progression to guide towards a step-up or top-down strategy. Predictive factors of response or non-response to treatment will then be reviewed, followed by a discussion about the optimal dose of drug required for patients. The time at which these treatments should be administered (or rather can be stopped in case of a deep remission or in the aftermath of a surgery) will also be addressed. IBD remain biologically complex, with multifactorial etiopathology, clinical heterogeneity as well as temporal and therapeutic variabilities, which makes precision medicine especially challenging in this area. Although applied for many years in oncology, it remains an unmet medical need in IBD.

Advances in the Comprehensive Management of Postoperative Crohn's Disease

Patients with postoperative Crohn's disease are difficult to manage because of their risk of experiencing a more severe course, multiple symptom confounders, and poor sensitivity of symptomatic remission to rule out intestinal inflammation. In this group, data are lacking on biologic therapeutic efficacy, and recommendations are lacking for those with multiple medication failures. Novel noninvasive testing can simultaneously exclude alternate causes of symptoms (serum C4, fecal fat, small intestinal bowel overgrowth breath testing) and assess intestinal inflammation (fecal calprotectin, endoscopic healing index). In addition, endoscopy-based disease activity assessment and management are required. Endoscopy should be performed within 6 months of surgery, and aggressive disease activity monitoring can be considered with colonoscopy every 1-2 years subsequently to ensure late recurrence is detected. Patients with multiple resections should be screened for short bowel syndrome. Predictive biomarkers are needed to guide medication selection in this high-risk population. Postoperative prophylactic biologic therapy is prudent for patients with preoperative biologic failure. However, there are no high-quality data to guide which agent should be selected. Selecting biologics with an alternative mechanism of action in those who had failed a biologic with adequate drug concentrations and selection of different agents in those with previous intolerance are reasonable. Significantly more study is required to assess the efficacy of therapies in this setting.

Biomarkers for the Prediction and Diagnosis of Fibrostenosing Crohn's Disease: A Systematic Review

BACKGROUND AND AIMS

Intestinal strictures are a common complication of Crohn's disease (CD). Biomarkers of intestinal strictures would assist in their prediction, diagnosis, and monitoring. Herein we provide a comprehensive systematic review of studies assessing biomarkers that may predict or diagnose CD-associated strictures.

METHODS

We performed a systematic review of PubMed, EMBASE, ISI Web of Science, Cochrane Library, and Scopus to identify citations pertaining to biomarkers of intestinal fibrosis through July 6, 2020, that used a reference standard of full-thickness histopathology or cross-sectional imaging or endoscopy. Studies were categorized based on the type of biomarker they evaluated (serum, genetic, histopathologic, or fecal).

RESULTS

Thirty-five distinct biomarkers from 3 major groups were identified: serum (20 markers), genetic (9 markers), and histopathology (6 markers). Promising markers include cartilage oligomeric matrix protein, hepatocyte growth factor activator, and lower levels of microRNA-19-3p (area under the curves were 0.805, 0.738, and 0.67, respectively), and multiple anti-flagellin antibodies (A4-Fla2 [odds ratio, 3.41], anti Fla-X [odds ratio, 2.95], and anti-CBir1 [multiple]). Substantial heterogeneity was observed and none of the markers had undergone formal validation. Specific limitations to acceptance of these markers included failure to use a standardized definition of stricturing disease, lack of specificity, and insufficient relevance to the pathogenesis of intestinal strictures or incomplete knowledge regarding their operating properties.

CONCLUSIONS

There is a lack of well-defined studies on biomarkers of intestinal stricture. Development of reliable and accurate biomarkers of stricture is a research priority. Biomarkers can support the clinical management of CD patients and aid in the stratification and monitoring of patients during clinical trials of future antifibrotic drug candidates.

The Molecular Mechanisms of Intestinal Inflammation and Fibrosis in Crohn’s Disease

Crohn’s disease (CD) is an inflammatory bowel disease (IBD) with repeated remissions and relapses. As the disease progresses, fibrosis and narrowing of the intestine occur, leading to severe complications such as intestinal obstruction. Endoscopic balloon dilatation, surgical stricture plasty, and bowel resection have been performed to treat intestinal stenosis. The clinical issue is that some patients with CD have a recurrence of intestinal stenosis even after the medical treatments. On the other hand, there exist no established medical therapies to prevent stenosis. With the progressive intestinal inflammation, cytokines and growth factors, including transforming growth factor (TGF-β), stimulate intestinal myofibroblasts, contributing to fibrosis of the intestine, smooth muscle hypertrophy, and mesenteric fat hypertrophy. Therefore, chronically sustained inflammation has long been considered a cause of intestinal fibrosis and stenosis. Still, even after the advent of biologics and tighter control of inflammation, intestinal fibrosis’s surgical rate has not necessarily decreased. It is essential to elucidate the mechanisms involved in intestinal fibrosis in CD from a molecular biological level to overcome clinical issues. Recently, much attention has been paid to several key molecules of intestinal fibrosis: peroxisome proliferator-activating receptor gamma (PPARγ), toll-like receptor 4 (TLR4), adherent-invasive Escherichia coli (AIEC), Th17 immune response, and plasminogen activator inhibitor 1 (PAI-1). As a major problem in the treatment of CD, the pathophysiology of patients with CD is not the same and varies depending on each patient. It is necessary to integrate these key molecules for a better understanding of the mechanism of intestinal inflammation and fibrosis.

Precision Medicine in Pediatric Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) describes a heterogenous group of diseases characterized by chronic inflammation of the intestinal tract. The IBD subtypes, Crohn's disease, ulcerative colitis, and IBD-Unspecified, each have characteristic features, but heterogeneity remains even among the subtypes. There has been an explosion of new knowledge on the possible pathogenesis of IBD over the last 2 decades mirroring innovation and refinement in technology, particularly the generation of large scale - "-omic" data. This knowledge has fostered a veritable renaissance of novel diagnostics, prognostics, and therapeutics, with patients with IBD seeing hope bloom in the increasingly large armamentarium of IBD therapies. However, while there are increased numbers of therapies and more pathways being targeted, the number of medications for IBD is still finite and the efficacy has reached a plateau. Precision medicine (PM) is much needed to rationally select and optimize IBD therapies in the new reality of wider but still limited choice with a concurrent, increasingly fine resolution on the significance and utility of clinical, genetic, microbial, and proteomic characteristics that define individual patients. PM is a rapidly changing art, but this review will strive to detail the current state and future directions of PM in pediatric IBD.

Anti-Microbial Antibody Response is Associated With Future Onset of Crohn's Disease Independent of Biomarkers of Altered Gut Barrier Function, Subclinical Inflammation, and Genetic Risk

BACKGROUND AND AIMS

Altered host immune reactivity to microbial antigens is hypothesized to trigger the onset of Crohn's disease (CD). We aimed to assess whether increased serum anti-microbial antibody response in asymptomatic first-degree relatives (FDRs) of CD patients is an independent risk factor for future CD development.

METHODS

We measured host serum antibody response to 6 microbial antigens at enrollment (Prometheus enzyme-linked immunosorbent assay test: anti-Saccharomyces cerevisiae antibodies immunoglobulin A/immunoglobulin G, anti-OmpC, anti-A4-Fla2, anti-FlaX, anti-CBir1) and derived the sum of positive antibodies (AS). We used samples at enrollment of prospectively followed healthy FDRs from a nested case-control cohort of the Crohn's and Colitis Canada Genetics Environment Microbial Project. Those who later developed CD (n = 77) were matched 1:4 by age, sex, follow-up duration, and geographic location with control FDRs remaining healthy (n = 307). To address our research aims, we fitted a multivariable conditional logistic regression model and performed causal mediation analysis.

RESULTS

High baseline AS (≥2) (43% of cases, 11% of controls) was associated with higher risk of developing CD (adjusted odds ratio, 6.5; 95% confidence interval, 3.4-12.7; P < .001). Importantly, this association remained significant when adjusted for markers of gut barrier function, fecal calprotectin, C-reactive protein, and CD-polygenic risk score, and in subjects recruited more than 3 years before diagnosis. Causal mediation analysis showed that the effect of high AS on future CD development is partially mediated (42%) via preclinical gut inflammation.

CONCLUSIONS

Our results suggest that increased anti-microbial antibody responses are associated with risk of future development of CD, independent of biomarkers of abnormal gut barrier function, subclinical inflammation, and CD-related genetic risks. This suggests that anti-microbial antibody responses are an early predisease event in the development of CD.

Association of Baseline Luminal Narrowing With Ileal Microbial Shifts and Gene Expression Programs and Subsequent Transmural Healing in Pediatric Crohn Disease

BACKGROUND

Transmural healing (TH) is associated with better long-term outcomes in Crohn disease (CD), whereas pretreatment ileal gene signatures encoding myeloid inflammatory responses and extracellular matrix production are associated with stricturing. We aimed to develop a predictive model for ileal TH and to identify ileal genes and microbes associated with baseline luminal narrowing (LN), a precursor to strictures.

MATERIALS AND METHODS

Baseline small bowel imaging obtained in the RISK pediatric CD cohort study was graded for LN. Ileal gene expression was determined by RNASeq, and the ileal microbial community composition was characterized using 16S rRNA amplicon sequencing. Clinical, demographic, radiologic, and genomic variables were tested for association with baseline LN and future TH.

RESULTS

After controlling for ileal location, baseline ileal LN (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.1-0.8), increasing serum albumin (OR, 4; 95% CI, 1.3-12.3), and anti-Saccharomyces cerevisiae antibodies IgG serology (OR, 0.97; 95% CI, 0.95-1) were associated with subsequent TH. A multivariable regression model including these factors had excellent discriminant power for TH (area under the curve, 0.86; positive predictive value, 80%; negative predictive value, 87%). Patients with baseline LN exhibited increased Enterobacteriaceae and inflammatory and extracellular matrix gene signatures, coupled with reduced levels of butyrate-producing commensals and a respiratory electron transport gene signature. Taxa including Lachnospiraceae and the genus Roseburia were associated with increased respiratory and decreased inflammatory gene signatures, and Aggregatibacter and Blautia bacteria were associated with reduced extracellular matrix gene expression.

CONCLUSIONS

Pediatric patients with CD with LN at diagnosis are less likely to achieve TH. The association between specific microbiota, wound healing gene programs, and LN may suggest future therapeutic targets.

ECCO Topical Review: Refractory Inflammatory Bowel Disease

Inflammatory bowel disease is a chronic disease with variable degrees of extent, severity, and activity. A proportion of patients will have disease that is refractory to licensed therapies, resulting in significant impairment in quality of life. The treatment of these patients involves a systematic approach by the entire multidisciplinary team, with particular consideration given to medical options including unlicensed therapies, surgical interventions, and dietetic and psychological support. The purpose of this review is to guide clinicians through this process and provide an accurate summary of the available evidence for different strategies.

Results of the Seventh Scientific Workshop of ECCO: Precision Medicine in IBD-Disease Outcome and Response to Therapy

Inflammatory bowel diseases [IBD] are a heterogeneous spectrum with two extreme phenotypes, Crohn's disease [CD] and ulcerative colitis [UC], which both represent numerous phenotypical variations. Hence, we should no longer approach all IBD patients similarly, but rather aim to rethink clinical classifications and modify treatment algorithms to usher in a new era of precision medicine in IBD. This scientific ECCO workshop aims to provide a state-of-the-art overview on prognostic and predictive markers, shed light on key questions in biomarker development, propose best practices in IBD biomarker development [including trial design], and discuss the potential for multi-omic data integration to help drive further advances to make precision medicine a reality in IBD.

Prognostic biomarkers to identify patients likely to develop severe Crohn's disease: a systematic review

BACKGROUND

Identification of biomarkers that predict severe Crohn's disease is an urgent unmet research need, but existing research is piecemeal and haphazard.

OBJECTIVE

To identify biomarkers that are potentially able to predict the development of subsequent severe Crohn's disease.

DESIGN

This was a prognostic systematic review with meta-analysis reserved for those potential predictors with sufficient existing research (defined as five or more primary studies).

DATA SOURCES

PubMed and EMBASE searched from inception to 1 January 2016, updated to 1 January 2018.

REVIEW METHODS

Eligible studies were studies that compared biomarkers in patients who did or did not subsequently develop severe Crohn's disease. We excluded biomarkers that had insufficient research evidence. A clinician and two statisticians independently extracted data relating to predictors, severe disease definitions, event numbers and outcomes, including odds/hazard ratios. We assessed risk of bias. We searched for associations with subsequent severe disease rather than precise estimates of strength. A random-effects meta-analysis was performed separately for odds ratios.

RESULTS

In total, 29,950 abstracts yielded just 71 individual studies, reporting 56 non-overlapping cohorts. Five clinical biomarkers (Montreal behaviour, age, disease duration, disease location and smoking), two serological biomarkers (anti-Saccharomyces cerevisiae antibodies and anti-flagellin antibodies) and one genetic biomarker (nucleotide-binding oligomerisation domain-containing protein 2) displayed statistically significant prognostic potential. Overall, the strongest association with subsequent severe disease was identified for Montreal B2 and B3 categories (odds ratio 4.09 and 6.25, respectively).

LIMITATIONS

Definitions of severe disease varied widely, and some studies confounded diagnosis and prognosis. Risk of bias was rated as 'high' in 92% of studies overall. Some biomarkers that are used regularly in daily practice, for example C-reactive protein, were studied too infrequently for meta-analysis.

CONCLUSIONS

Research for individual biomarkers to predict severe Crohn's disease is scant, heterogeneous and at a high risk of bias. Despite a large amount of potential research, we encountered relatively few biomarkers with data sufficient for meta-analysis, identifying only eight biomarkers with potential predictive capability.

FUTURE WORK

We will use existing data sets to develop and then validate a predictive model based on the potential predictors identified by this systematic review. Contingent on the outcome of that research, a prospective external validation may prove clinically desirable.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016029363.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 45. See the NIHR Journals Library website for further project information.

Therapeutic strategies for stricturing Crohn’s disease in childhood: a systematic review

PURPOSE

Childhood stricturing Crohn's disease (CD) has significant morbidity. Interventions including resection, stricturoplasty and endoscopic balloon dilatation (EBD) are often required. Optimal intervention modality and timing, and use of adjuvant medical therapies, remains unclear. We aim to review the therapies used in paediatric stricturing CD.

METHODS

A systematic review in accordance with PRISMA was performed (PROSPERO: CRD42020164464). Demographics, stricture features, interventions and outcomes were extracted.

RESULTS

Fourteen studies were selected, including 177 patients (183 strictures). Strictures presented at 40.6 months (range 14-108) following CD diagnosis. Medical therapy was used in 142 patients for an average of 20.4 months (2-36), with a complete response in 11 (8%). Interventions were undertaken in 138 patients: 53 (38%) resections, 39 (28%) stricturoplasties, and 17 (12%) EBD. Complications occurred in 11% of resections, versus 15% stricturoplasties, versus 6% EBD (p = 0.223). At a median follow-up of 1.9 years (interquartile range 1.2-2.4) pooled stricture recurrence was 22%. Resection had 9% recurrence, versus 38% stricturoplasty, versus 47% EBD (p < 0.001).

CONCLUSIONS

Resection is associated with a low incidence of recurrence and complications. There remains a paucity of evidence regarding adjuvant medical therapy and the role of EBD. We propose a minimum reported dataset for interventions in paediatric stricturing CD.

Risk Factors for Disease Behavior Evolution and Efficacy of Biologics in Reducing Progression in Pediatric Patients with Nonstricturing, Nonpenetrating Crohn's Disease at Diagnosis: A Single-Center Experience in Korea

Background/Aims

Recently, the treatment of Crohn’s disease (CD) has changed to a treat-to-target strategy, in which disease progression is prevented with early intervention. We analyzed the long-term evolution of nonstricturing, nonpenetrating (B1) disease at diagnosis and factors related to disease evolution in pediatric CD.

Methods

We retrospectively analyzed 402 patients between 2000 and 2013 who were younger than 18 years and had B1 disease at CD diagnosis. The median follow-up was 6.1 years (range, 1 to 13 years). The cumulative probabilities of developing stricturing (B2) or penetrating (B3) disease and associations between risk factors and disease behavior evolution were evaluated.

Results

Among the 402 patients, 75 (18.7%) had B2 or B3 disease by the final follow-up. The cumulative probabilities of disease behavior evolution were 18.3%, 34.3%, and 50.9% at 5, 10, and 13 years, respectively. Patients whose disease progressed had an increased risk of intestinal resection (hazard ratio [HR], 3.61; 95% confidence interval [CI], 2.25 to 6.03; p<0.001). First-degree family history of inflammatory bowel disease (HR, 2.38; 95% CI, 1.07 to 5.28; p=0.032), isolated ileal involvement at diagnosis (HR, 7.55; 95% CI, 1.04 to 15.57; p=0.045), and positive anti-Saccharomyces cerevisiae antibody titers (HR, 2.10; 95% CI, 1.03 to 4.25; p=0.040) were associated with disease behavior evolution. Early treatment with biologics significantly reduced disease progression (HR, 0.46; 95% CI, 0.79 to 3.39; p=0.042).

Conclusions

This study suggests that early aggressive therapy should be considered in B1 behavior pediatric CD patients with risk factors of disease evolution to improve long-term outcomes.

Fibrotic Strictures in Crohn's Disease: Mechanisms and Predictive Factors

Fibrotic strictures are one of the most severe complications of Crohn's Disease (CD). They occur in about 50% of patients at five years and in 70% at ten years of the diagnosis. The only treatment available for symptomatic fibrotic strictures is surgical resection and endoscopic dilation. Both strategies are associated with a high rate of recurrence, and with multiple surgical resections, which pose the threat of surgical morbidity and short bowel syndrome. Therefore, it is crucial to identify, early, the patients more prone to develop intestinal fibrosis to intensify follow-ups, switch to more aggressive treatments, and suggest lifestyle modifications. Scarce data are available concerning biomarkers and genetic determinants to predict which patient will develop intestinal fibrosis. Biologic or clinical markers would be useful to determine this subgroup of CD patients and to predict the onset of intestinal fibrosis and, ideally, its severity. Furthermore, the identification of environmental risk factors may suggest lifestyle changes aimed at modifying the natural course, thus decreasing the risk of complicated CD. In this review, we will critically revise clinical, environmental, genetic, and serologic factors that have been associated with a complicated CD course with a particular focus on the fibrostenosing phenotype and their possible implications as predictive factors of intestinal fibrosis.

Machine learning identifies novel blood protein predictors of penetrating and stricturing complications in newly diagnosed paediatric Crohn's disease

BACKGROUND

There is a need for improved risk stratification in Crohn's disease.

AIM

To identify novel blood protein biomarkers associated with future Crohn's disease complications METHODS: We performed a case-cohort study utilising a paediatric inception cohort, the Risk Stratification and Identification of Immunogenetic and Microbial Markers of Rapid Disease Progression in Children with Crohn's disease (RISK) study. All patients had inflammatory disease (B1) at baseline. Outcomes were development of stricturing (B2) or penetrating (B3) complications. We assayed 92 inflammation-related proteins in baseline plasma using a proximity extension assay (Olink Proteomics). An ensemble machine learning technique, random survival forests (RSF), selected variables predicting B2 and B3 complications. Selected analytes were compared to clinical variables and serology only models. We examined selected proteins in a single-cell sequencing cohort to analyse differential cell expression in blood and ileum.

RESULTS

We included 265 patients with mean age 11.6 years (standard deviation [SD] 3.2). Seventy-three and 34 patients, respectively, had B2 and B3 complications within mean 1123 (SD 477) days for B2 and 1251 (442) for B3. A model with 5 protein markers predicted B3 complications with an area under the curve (AUC) of 0.79 (95% confidence interval [CI] 0.76-0.82) compared to 0.69 (95% CI 0.66-0.72) for serologies and 0.74 (95% CI 0.71-0.77) for clinical variables. A model with 4 protein markers predicted B2 complications with an AUC of 0.68 (95% CI 0.65-0.71) compared to 0.62 (95% CI 0.59-0.65) for serologies and 0.52 (95% CI 0.50-0.55) for clinical variables. B2 analytes were highly expressed in ileal stromal cells while B3 analytes were prominent in peripheral blood and ileal T cells.

CONCLUSIONS

We identified novel blood proteomic markers, distinct for B2 and B3, associated with progression of paediatric Crohn's disease.

Predicting Outcomes in Pediatric Crohn's Disease for Management Optimization: Systematic Review and Consensus Statements From the Pediatric Inflammatory Bowel Disease-Ahead Program

BACKGROUND & AIMS

A better understanding of prognostic factors within the heterogeneous spectrum of pediatric Crohn's disease (CD) should improve patient management and reduce complications. We aimed to identify evidence-based predictors of outcomes with the goal of optimizing individual patient management.

METHODS

A survey of 202 experts in pediatric CD identified and prioritized adverse outcomes to be avoided. A systematic review of the literature with meta-analysis, when possible, was performed to identify clinical studies that investigated predictors of these outcomes. Multiple national and international face-to-face meetings were held to draft consensus statements based on the published evidence.

RESULTS

Consensus was reached on 27 statements regarding prognostic factors for surgery, complications, chronically active pediatric CD, and hospitalization. Prognostic factors for surgery included CD diagnosis during adolescence, growth impairment, NOD2/CARD15 polymorphisms, disease behavior, and positive anti-Saccharomyces cerevisiae antibody status. Isolated colonic disease was associated with fewer surgeries. Older age at presentation, small bowel disease, serology (anti-Saccharomyces cerevisiae antibody, antiflagellin, and OmpC), NOD2/CARD15 polymorphisms, perianal disease, and ethnicity were risk factors for penetrating (B3) and/or stenotic disease (B2). Male sex, young age at onset, small bowel disease, more active disease, and diagnostic delay may be associated with growth impairment. Malnutrition and higher disease activity were associated with reduced bone density.

CONCLUSIONS

These evidence-based consensus statements offer insight into predictors of poor outcomes in pediatric CD and are valuable when developing treatment algorithms and planning future studies. Targeted longitudinal studies are needed to further characterize prognostic factors in pediatric CD and to evaluate the impact of treatment algorithms tailored to individual patient risk.

First United Arab Emirates consensus on diagnosis and management of inflammatory bowel diseases: A 2020 Delphi consensus

Ulcerative colitis and Crohn's disease are the main entities of inflammatory bowel disease characterized by chronic remittent inflammation of the gastrointestinal tract. The incidence and prevalence are on the rise worldwide, and the heterogeneity between patients and within individuals over time is striking. The progressive advance in our understanding of the etiopathogenesis coupled with an unprecedented increase in therapeutic options have changed the management towards evidence-based interventions by clinicians with patients. This guideline was stimulated and supported by the Emirates Gastroenterology and Hepatology Society following a systematic review and a Delphi consensus process that provided evidence- and expert opinion-based recommendations. Comprehensive up-to-date guidance is provided regarding diagnosis, evaluation of disease severity, appropriate and timely use of different investigations, choice of appropriate therapy for induction and remission phase according to disease severity, and management of main complications.

The Medical Management of Paediatric Crohn's Disease: an ECCO-ESPGHAN Guideline Update

OBJECTIVE

We aimed to provide an evidence-supported update of the ECCO-ESPGHAN guideline on the medical management of paediatric Crohn's disease [CD].

METHODS

We formed 10 working groups and formulated 17 PICO-structured clinical questions [Patients, Intervention, Comparator, and Outcome]. A systematic literature search from January 1, 1991 to March 19, 2019 was conducted by a medical librarian using MEDLINE, EMBASE, and Cochrane Central databases. A shortlist of 30 provisional statements were further refined during a consensus meeting in Barcelona in October 2019 and subjected to a vote. In total 22 statements reached ≥ 80% agreement and were retained.

RESULTS

We established that it was key to identify patients at high risk of a complicated disease course at the earliest opportunity, to reduce bowel damage. Patients with perianal disease, stricturing or penetrating behaviour, or severe growth retardation should be considered for up-front anti-tumour necrosis factor [TNF] agents in combination with an immunomodulator. Therapeutic drug monitoring to guide treatment changes is recommended over empirically escalating anti-TNF dose or switching therapies. Patients with low-risk luminal CD should be induced with exclusive enteral nutrition [EEN], or with corticosteroids when EEN is not an option, and require immunomodulator-based maintenance therapy. Favourable outcomes rely on close monitoring of treatment response, with timely adjustments in therapy when treatment targets are not met. Serial faecal calprotectin measurements or small bowel imaging [ultrasound or magnetic resonance enterography] are more reliable markers of treatment response than clinical scores alone.

CONCLUSIONS

We present state-of-the-art guidance on the medical treatment and long-term management of children and adolescents with CD.

Mucosal Inflammatory and Wound Healing Gene Programs Reveal Targets for Stricturing Behavior in Pediatric Crohn's Disease

BACKGROUND AND AIMS

Ileal strictures are the major indication for resective surgery in Crohn's disease (CD). We aimed to define ileal gene programs present at diagnosis linked with future stricturing behavior during five year follow-up, and to identify potential small molecules to reverse these gene signatures.

METHODS

Antimicrobial serologies and pre-treatment ileal gene expression were assessed in a representative subset of 249 CD patients within the RISK multicenter pediatric CD inception cohort study, including 113 that are unique to this report. These data were used to define genes associated with stricturing behavior and for model testing to predict stricturing behavior. A bioinformatics approach to define small molecules which may reverse the stricturing gene signature was applied.

RESULTS

19 of the 249 patients developed isolated B2 stricturing behavior during follow-up, while 218 remained B1 inflammatory. Using deeper RNA sequencing than in our prior report, we have now defined an inflammatory gene signature including an oncostatin M co-expression signature, tightly associated with extra-cellular matrix (ECM) gene expression in those who developed stricturing complications. We further computationally prioritize small molecules targeting macrophage and fibroblast activation and angiogenesis which may reverse the stricturing gene signature. A model containing ASCA and CBir1 serologies and a refined eight ECM gene set was significantly associated with stricturing development by year five after diagnosis (AUC (95th CI) = 0.82 (0.7-0.94)).

CONCLUSION

An ileal gene program for macrophage and fibroblast activation is linked to stricturing complications in treatment naïve pediatric CD, and may inform novel small molecule therapeutic approaches.

Primary Humoral Immune Deficiencies: Overlooked Mimickers of Chronic Immune-Mediated Gastrointestinal Diseases in Adults

In recent years, the incidence of immune-mediated gastrointestinal disorders, including celiac disease (CeD) and inflammatory bowel disease (IBD), is increasingly growing worldwide. This generates a need to elucidate the conditions that may compromise the diagnosis and treatment of such gastrointestinal disorders. It is well established that primary immunodeficiencies (PIDs) exhibit gastrointestinal manifestations and mimic other diseases, including CeD and IBD. PIDs are often considered pediatric ailments, whereas between 25 and 45% of PIDs are diagnosed in adults. The most common PIDs in adults are the selective immunoglobulin A deficiency (SIgAD) and the common variable immunodeficiency (CVID). A trend to autoimmunity occurs, while gastrointestinal disorders are common in both diseases. Besides, the occurrence of CeD and IBD in SIgAD/CVID patients is significantly higher than in the general population. However, some differences concerning diagnostics and management between enteropathy/colitis in PIDs, as compared to idiopathic forms of CeD/IBD, have been described. There is an ongoing discussion whether CeD and IBD in CVID patients should be considered a true CeD and IBD or just CeD-like and IBD-like diseases. This review addresses the current state of the art of the most common primary immunodeficiencies in adults and co-occurring CeD and IBD.

Serum biomarkers of fibrostenotic Crohn's disease: Where are we now?

Intestinal fibrosis and subsequent stricture formation are major clinical challenges in inflammatory bowel disease, resulting in an increased rate of operation and poor prognosis compared with those without. With the changing perception that intestinal fibrosis is irreversible to the point of view that it is reversible in recent years, various candidate serum biomarkers have been studied over the past decades, which may stratify patients based on their risks of developing stenosis and enable the detection of early stages of fibrosis. However, reliable and accurate biomarkers are still unavailable due to conflicting results and the lack of high-quality evidence. In this review we summarized the serum biomarkers that have been proposed for intestinal fibrosis in recent years, which includes gene polymorphisms or variants, epigenetic markers, extracellular matrix components, growth factors, and antibodies, aiming to provide clues for future research.

The Role of Immunomodulators and Biologics in the Medical Management of Stricturing Crohn's Disease

Crohn's disease is a progressive and disabling inflammatory disease involving the gastrointestinal tract. It usually produces inflammatory lesions in the ileocolonic region, but up to half of patients will also develop complications such as strictures in the long term. Indeed, a proportion of patients have progression of the disease with the development of stricturing lesions because there are no drugs that effectively prevent or reverse established fibrosis, and hence these patients are usually treated with surgery or endoscopic balloon dilation. Fibrotic lesions are always associated with some degree of inflammatory changes, but there is little evidence supporting the use of medical therapy in this context. Here, we discuss the most important findings on the possible use of immunomodulators or biologics in the prevention and treatment of intestinal strictures in Crohn's disease patients. Recent evidence demonstrates that these drugs may also be effective in treating lesions with high levels of collagen deposition, and thus might, at least in some patients, reduce the progression of the disease and bowel damage, and further avoid the need for surgery and a disabling course in the long term.

New-Onset of Crohn's Disease Is Associated with Antistreptolysin O Positive Titers

Objective

Different infectious agents have been presumed to be candidates acting as an etiologic factor or trigger of Crohn’s disease (CD). Group A Streptococcus (GAS) is a common human infection agent that can also trigger post-infectious immune-mediated conditions. The current study aimed to examine whether the immunogenic activity induced by GAS may trigger new-onset of CD.

Methods

Data for antistreptolysin O (ASO) level, throat culture for GAS, and history of streptococcal infection were collected from 91 patients with CD that were divided into three groups including; new-onset CD, CD in remission and active CD. The data were compared with the control group.

Results

All participants had negative results of throat culture for GAS and had no history of documented streptococcal infection in the past year. Our results indicate that new-onset CD, but not CD in remission or active CD, is associated with significantly increased positive ASO compared to controls. Half of the patients in the new-onset CD group were ASO positive, which was significantly higher compared to the control group in a univariant (OR: 4.00; 95% CI 1.27–12.58; P=0.02) and multivariant analysis (OR: 4.41; 95% CI 1.35–14.37; P=0.014).

Conclusion

Our study is the first to focus on ASO levels in patients with CD and to demonstrate a significant association between ASO and new-onset of CD. Large prospective randomized controlled studies are needed to confirm the validity of this data and to further clarify the clinical significance of our findings.

Identifying Patients With Inflammatory Bowel Diseases at High vs Low Risk of Complications

People with Crohn's disease and ulcerative colitis have varying presentations and clinical consequences of their disease. Patients commonly ask about their prognosis, and what this diagnosis means for them. They are asking their clinicians to predict the future. The importance of predicting the course of any disease is to guide patient expectations and to guide treatment decisions. In the past decade the strategy of inflammatory bowel disease (IBD) treatment has shifted to treat patients earlier in the course of their disease, before irreversible damage occurs. Treatment approaches for disease categorized as mild, moderate or severe has most often been based on a current assessment of symptoms or disease activity without including a longitudinal assessment of a patient's disease course including past disease complications and surgeries. While a patient's current disease activity most typically drives these treatment decisions, optimally, treatment decisions would be made accounting for past disease activity and complications and the predicted future disease course. When developing a treatment plan for an individual patient, the immediate goal is to treat the current disease activity for relief of symptoms, and the long-term goal is to prevent progression of their disease due to complications. Since not all patients will progress to a complicated disease course, it is important to be able to select the right patients for the right therapy. Therefore, developing methods of stratifying patients into low-risk versus high-risk of complications will be an important aspect of treating IBD now and in the future.

Changing Global Epidemiology of Inflammatory Bowel Diseases: Sustaining Health Care Delivery Into the 21st Century

Crohn's disease and ulcerative colitis have emerged as global diseases. They affect over 2 million individuals in the North America, 3.2 million in Europe, and millions more worldwide. The recent decades have been characterized by several important changes in the epidemiology of these diseases, in particularly an increasing incidence rates in newly industrialized countries experiencing a westernization of lifestyle. While rates of surgery have experienced a temporal decline attributable in part to increasing availability of medical treatments, earlier initiation of effective therapy, and changes in clinical practice, the healthcare costs associated with these diseases have continued to increase, in part due to costly therapies. Robust epidemiologic and experimental studies have defined the role of the external environment and microbiome on disease pathogenesis and have offered opportunities for disease prevention by modifying such factors. We propose several important steps that are necessary to provide globally sustainable inflammatory bowel disease care in the 21st century.

Labordiagnostik bei chronisch‑entzündlichen Darmerkrankungen

Die Labordiagnostik hat sowohl im empfohlenen initialen „work up“ bei Verdacht auf eine chronisch entzündliche Darmerkrankung (CED) wie auch für das Monitoring des Krankheitsverlaufs und des Therapieansprechens einen klar umrissenen Stellenwert: Mithilfe der „Basislaborparameter“ wie z. B. Blutkörperchensenkungsgeschwindigkeit (BSG) können krankheitsspezifische Aktivitätsindizes erstellt werden, und neue serologische Marker (u. a. ANCA [„antineutrophil cytoplasmic antibodies“], ASCA [„anti-saccharomyces cerevisiaeantibodies“]) dienen der ergänzenden Differenzierung der CED-Entitäten. Derzeit dürfte das Stuhl-Calprotectin – als am weitreichendsten untersuchter fäkaler Inflammationsmarker – v. a. aufgrund der hohen Sensitivität initial und zur Einschätzung der Krankheitsaktivität der relativ beste Surrogatmarker sein. Nach wie vor ist aber die endoskopisch-histopathologische Evaluierung nicht nur für die Diagnose unabdingbar, sondern auch bezüglich des erklärten Therapieziels des „mucosal healing“, also im Rahmen der präzisen Verlaufsdokumentation. Der Entwicklung weniger invasiver „Biomarker“, die möglichst gut mit dem Schleimhautbefund korrelieren, kommt besondere Bedeutung zu, um die derzeit oft noch notwendige invasive Reevaluierung verringern zu helfen. Wie die Wertigkeit sowohl in der Routine etablierter, aber auch neuer, teils experimentell angewandter serologischer, fäkaler und funktioneller Laborparameter bzw. -tests einzuschätzen ist, und welche diagnostischen Methoden in Erprobung sind, wird im vorliegenden Beitrag erläutert.

Value of magnetic resonance enterography in diagnosis and treatment follow up in Crohn's disease in children

PURPOSE

Crohn's disease (CD) is a chronic inflammatory disease which can affect all parts of the gastrointestinal tract. Magnetic resonance enterography (MRE) enables detection of pathologic changes in the small intestine, which are not accessible by conventional endoscopy. The aim of the study was to assess the value of MRE in imaging of small bowel lesions, their location and extent, in CD patients and its correlation with clinical and endoscopic activity.

MATERIALS AND METHODS

MRE was performed in 108 children with CD, aged 5.5 to 18 years. The diagnosis was based on the Porto criteria. Location and clinical manifestation was evaluated according to the Paris classification. Clinical CD activity was assessed with PCDAI and endoscopic activity with SES-CD. In 36 children, control MRE was performed.

RESULTS

The most common endoscopic location of the disease was the colon (41.7%), terminal ileum and colon (24.1%). Inflammation as the main clinical manifestation was dominant (81.5%). In MRE, inflammatory changes were found in 40.8% of children, strictures in 11.1%. The EIA value (activity in MRE) increased along with PCDAI score and SES-CD. MRE performed during follow up, showed transmural healing in 16.7% of patients and improvement in 55.5%.

CONCLUSIONS

MRE is an efficient diagnostic tool in proper characterization of disease location in pediatric CD. As positive correlation of the results of MRE with the endoscopic and clinical activity has been found, taking into account good tolerance and non-invasiveness of the procedure it can be recommended to be used in reassessment.

Fecal transplantation for ulcerative colitis: current evidence and future applications

Introduction: Established evidence suggests that gut microbiota plays a role in ulcerative colitis (UC). Fecal microbiota transplantation (FMT) is clearly recognized as a highly effective treatment for patients with recurrent Clostridium difficile infection and has been investigated also in patients with UC, with promising results.Areas covered: Literature review was performed to select publications concerning current evidence on the role of gut microbiota in the pathogenesis of UC, and on the effectiveness of FMT in this disorder.Expert opinion: The randomized controlled trials published investigating the use of FMT suggested a potential role for FMT in the treatment of mild to moderate UC. However, given several unanswered questions regarding donor selection, dose, route of administration and duration of therapy, this is not yet recommended as a viable therapy option. FMT has allowed for more in depth investigation with regards to the role the gut microbiota may be playing in UC. This knowledge is critical to identifying where FMT may appropriately fit in the UC treatment paradigm. As our understanding of the role the microbiome plays in this chronic disease, FMT, and then eventually defined microbes, will hopefully serve in a complementary role to conventional IBD therapies.

Protein Glycosylation as a Diagnostic and Prognostic Marker of Chronic Inflammatory Gastrointestinal and Liver Diseases

Glycans are sequences of carbohydrates that are added to proteins or lipids to modulate their structure and function. Glycans modify proteins required for regulation of immune cells, and alterations have been associated with inflammatory conditions. For example, specific glycans regulate T-cell activation, structures, and functions of immunoglobulins; interactions between microbes and immune and epithelial cells; and malignant transformation in the intestine and liver. We review the effects of protein glycosylation in regulation of gastrointestinal and liver functions, and how alterations in glycosylation serve as diagnostic or prognostic factors, or as targets for therapy.

Recent advances in understanding and managing pediatric inflammatory bowel disease

The landscape of pediatric inflammatory bowel disease is rapidly evolving. The therapeutic advances seen in the adult arena are rapidly being adopted by pediatric gastroenterologists and evaluated in both controlled trials and real-world experience. Though anti-tumor necrosis factor agents have been the primary therapy over the last decade, recently there has been an expansion of therapeutic targets and alternative mechanism of action drugs with a focus on individualized and personalized therapy. By reviewing epidemiology, pathophysiology, and goals of treatment, we hope to frame the discussion of current and novel therapeutics for the pediatric gastroenterologist. As scientific discovery continues to push the envelope in defining our understanding of pediatric inflammatory bowel disease, the current era of therapeutics gives us hope that a cure may be realized soon.

The Role of Early Biologic Therapy in Inflammatory Bowel Disease

The goals for treatment of inflammatory bowel diseases (IBDs) are changing from elimination of symptoms toward complete disease control-a process that demands both clinical and endoscopic remission. This new IBD treatment paradigm has been shifting from a conventional "step-up" approach toward a more "top-down" early intervention treatment strategy. Recent studies suggest that the use of biologic agents, specifically those targeting tumor necrosis factor alpha, earlier in the treatment course improves patient outcomes and can prevent progression to irreversible bowel damage. Although the strategy of early intervention has accumulating evidence in Crohn's disease, there is less evidence supporting its impact in ulcerative colitis.

Natural history of children with mild Crohn’s disease

BACKGROUND

There is a small and poorly studied population of patients with mild and limited Crohn’s disease (CD), who either spontaneously enter remission and can discontinue therapy, or be maintained on milder anti-inflammatory treatment.

AIM

To identify a group of children with mild CD who were not escalated to immunomodulators (azathioprine, mercaptopurine, or methotrexate) or biologics (infliximab or adalimumab) within the first two years after their Crohn’s diagnosis and outline the natural history and phenotypic features of these patients.

METHODS

In a retrospective chart review of the inflammatory bowel disease database at Boston Children’s Hospital we reviewed all the mild CD patient’s clinic visits, laboratory studies, and procedures for the duration of time they were followed at the center. Patients were included if they had clear diagnosis of Crohn’s disease, and they were not escalated to immunosuppressive therapies for at least 2 years after the date of diagnosis. These mild CD patients were compared to controls diagnosed at a similar time, that were treated with immunomodulators or biologics. Data that was abstracted included: Age at diagnosis, sex, disease location utilizing the Paris classification, medical treatment, surgical treatment, endoscopic findings, histology, and hospitalizations. We also analyzed differences in the phenotypic features between those with mild CD and those with moderate to severe disease.

RESULTS

Out of 1205 patients with CD diagnosed between 1990 and 2013, we identified 29 patients that met the inclusion criteria, and they were matched with 58 controls. There were no significant differences between the disease behaviors at presentation, with approximately 90% of patients in each group having inflammatory disease. However, patients with mild disease were more likely to have disease limited to the colon (31% vs 12%, P = 0.03). In contrast, patients with moderate to severe disease (aka control group) were more likely to have ileocolonic disease (70% vs 45% in the mild group, P = 0.02). Of the 29 patients, only 8 required medication escalation to immunomodulators during the period of follow-up. The primary indication for escalation to immune suppressive therapies was corticosteroid dependence. We also found that patients treated without immunomodulators or biologics for mild CD continue to exhibit histologic intestinal inflammation. Of the 29 patients, three developed significant complications of ileal disease, though only one required surgical intervention during the period of follow-up.

CONCLUSION

We identified a cohort of children with mild CD, who were able to avoid the institution of immune suppressive therapies for several years, and generally had good outcomes during the period of follow-up. While a subset of these patients will eventually require either immunosuppression or surgery, the majority of them have a good quality of life despite having low-grade intestinal inflammation. Importantly, this subset of patients has managed to avoid the potential toxicities of immune suppression for several years. The majority of these patients have either colonic disease with minimal small bowel involvement or limited ileal disease.

Prognosticating the Course of Inflammatory Bowel Disease

Both Crohn's disease and ulcerative colitis are inflammatory bowel diseases (IBD) that can lead to progressive irreversible bowel damage. Selecting the most appropriate therapy for patients is a challenge because not all patients diagnosed with IBD have complications, and the amount of time to develop a complication is different for individuals. Models using patient characteristics, genetics, and immune responses help identify those patients who require early aggressive therapy with a goal to modify their disease course. Future research will help identify the role that the microbiome, metagenomics, metaproteomics, and microRNAs play in a patient prognosis.

Serum Protein Biomarkers of Fibrosis Aid in Risk Stratification of Future Stricturing Complications in Pediatric Crohn's Disease

OBJECTIVES

Avoiding fibrostenotic complications is of paramount concern in the management of Crohn's disease (CD). We sought to investigate the association of candidate biomarkers of fibrosis collected at diagnosis with the future development of fibrostenotic CD.

METHODS

Using the Risk Stratification and Identification of Immunogenetic and Microbial Markers of Rapid Disease Progression in Children with Crohn's Disease cohort, a multicenter prospective observational pediatric inception cohort, subjects with an inflammatory phenotype (B1) at diagnosis who later converted to a stricturing phenotype (B2) within 3 years were compared with those who remained B1. Serum collected at diagnosis underwent both parallel reaction monitoring-targeted proteomic analysis and conventional enzyme-linked immunosorbent assay for 10 candidate biomarkers of intestinal fibrosis. Cox proportional hazard regression was used for multivariable analysis of time-dependent outcomes.

RESULTS

In 116 subjects 58 subjects with verified B1 phenotype at diagnosis who later converted to B2 disease were compared with 58 subjects who remained B1 over 3 years of follow-up. Extracellular matrix protein 1 (ECM1) levels in the upper quartile (hazard ratio [HR] 3.43, 95% confidence limit [CL] 1.33, 8.42) were associated with future fibrostenotic disease. ASCA IgA (HR 4.99, 95% CL 1.50, 16.68) and CBir levels (HR 5.19, 95% CL 1.83, 14.74) were also associated with future intestinal fibrostenosis, although ECM1 continued to demonstrate independent association with conversion to B2 even with adjustment for serologies in multivariable analysis (HR 5.33, 95% CL 1.29, 22.13).

CONCLUSIONS

ECM1 and other biomarkers of fibrosis may aid in determining the risk of uncomplicated inflammatory disease converting to B2 stricturing phenotypes in children with CD. Prospective validation studies to verify test performance and optimize clinical utilization are needed before clinical implementation.

Maneuvering Clinical Pathways for Crohn's Disease

PURPOSE OF REVIEW

Crohn's disease management has changed significantly with increasing use of biologics. We review the recent literature on the clinical management of Crohn's disease and new approaches in selecting and optimizing therapy.

RECENT FINDINGS

Recent studies have addressed the efficacy of proactive anti-TNFα trough level monitoring, the efficacy of biosimilars, and the efficacy and immunogenicity of newer biologics including anti-integrin therapy and anti-IL12/23 therapy. Optimizing anti-TNFα therapy according to trough concentrations correlates with improved remission rates. Patients can be switched from the reference drug to a biosimilar, or vice versa, without a measurable change in efficacy, safety, or immunogenicity. Immunomodulators are effective in decreasing immunogenicity and boosting anti-TNFα drug level. The anti-integrin and anti-IL12/23 therapies are effective as induction and maintenance therapy with low immunogenicity and excellent safety profiles. Patients at high risk for post-operative recurrence should be started on a biologic therapy within 4 weeks post-op. Multiple biologic therapies are currently available for treatment of Crohn's disease including anti-TNFα therapy, anti-integrin therapy, and anti-IL12/23 therapy. The choice of first-line therapy should be based on individual risk-benefit analysis, route of administration, and patient preference. Patient with inadequate response should have their trough level checked and therapy optimized. Therapeutic prophylaxis for post-operative recurrence should be based on patient's risk factors for recurrence.

Age-of-diagnosis dependent ileal immune intensification and reduced alpha-defensin in older versus younger pediatric Crohn Disease patients despite already established dysbiosis

Age-of-diagnosis associated variation in disease location and antimicrobial sero-reactivity has suggested fundamental differences in pediatric Crohn Disease (CD) pathogenesis. This variation may be related to pubertal peak incidence of ileal involvement and Peyer's patches maturation, represented by IFNγ-expressing Th1 cells. However, direct mucosal evidence is lacking. We characterize the global pattern of ileal gene expression and microbial communities in 525 treatment-naive pediatric CD patients and controls (Ctl), stratifying samples by their age-of-diagnosis. We show a robust ileal gene signature notable for higher expression of specific immune genes including GM-CSF and INFγ, and reduced expression of antimicrobial Paneth cell α-defensins, in older compared to younger patients. Reduced α-defensin expression in older patients was associated with higher IFNγ expression. By comparison, the CD-associated ileal dysbiosis, characterized by expansion of Enterobacteriaceae and contraction of Lachnospiraceae and Ruminococcaceae, was already established within the younger group and did not vary systematically with increasing age-of-diagnosis. Multivariate analysis considering individual taxa, however did demonstrate negative associations between Lachnospiraceae and IFNγ, and positive associations between Bacteroides and α-defensin expression. These data provide evidence for maturation of mucosal Th1 immune responses and loss of epithelial antimicrobial α-defensins which are associated with specific taxa with increasing age-of-diagnosis in pediatric CD.

Response to treatment is more important than disease severity at diagnosis for prediction of early relapse in new-onset paediatric Crohn's disease

BACKGROUND

Paediatric Crohn's disease is characteried by frequently relapsing disease which may lead to hospitalisations and complications.

AIM

To develop predictive models for early relapse following first remission.

METHODS

The GROWTH CD prospective inception cohort was designed to predict risk for early disease relapse and poor outcomes. Newly diagnosed children underwent endoscopies and imaging. They were phenotyped and followed at scheduled visits through 78 weeks for relapses. Twenty-eight dichotomous and continuous variables were assessed at baseline and week 12, including phenotype, inflammatory markers, disease activity (PCDAI) and other markers. Clinical relapses defined as PCDAI >10 after remission were recorded using a relapse form. Logistic regression & risk modelling was performed.

RESULTS

We enrolled 282 eligible patients of whom 178 (63.6%) patients achieved steroid free remission by week 12. Disease complications developed in 22/76(29%) of patients with relapse compared to 20/206 (9.7%) without relapse (P = 0.01). Multivariable analysis demonstrated that while variables from age/gender at diagnosis were not predictive, week 12 variables including PCDAI >5 (P = 0.02), CRP >20 mg/L (P = 0.02), and faecal calprotectin >400 µg/g (P = 0.03) as optimal cut-offs were associated with increased risk of relapse. A prediction model for patients in remission including gender, age, week 12 PCDAI, calprotectin and CRP had sensitivity 43%, specificity 92%, PPV 78%, NPV 71% for relapse.

CONCLUSIONS

Early relapses were associated with a higher risk for disease complications at followup. Relapse prediction based on week 12 disease activity or inflammation is superior to prediction using data from diagnosis.

Late-Onset Crohn's Disease Is A Subgroup Distinct in Genetic and Behavioral Risk Factors With UC-Like Characteristics

BACKGROUND

Age of onset is linked to variations in clinical phenotypes and natural history in Crohn's disease (CD). We aim to define etiologically more homogenous subgroups in CD based on ages of onset.

METHODS

We examined the distribution of CD polygenetic risk score (PRS) across ages of diagnosis in a Caucasian cohort of 2344 independent CD patients. We identified subgroups with a distinct distribution of PRS and compared those groups in genetics, demographic characteristics, clinical subphenotypes, and serological markers. The results were replicated in an independent cohort of 13,065 CD patients from the International Inflammatory Bowel Diseases Genetic Consortium (IIBDGC).

RESULTS

We identified a late-onset (LO) subgroup in CD (age at diagnosis ≥ 55 years) with significantly lower PRS compared with the intermediate group (age at diagnosis between 5 and 55 years) in both cohorts. Smoking cessation, a risk factor for ulcerative colitis (UC) and protective factor for CD, had a higher rate in this LO subgroup in comparison with the intermediate group. We also compared the LO group with the intermediate group, and, consistent with previous reports, the LO group more often had colonic CD, had less penetrating disease behavior, and had less need for surgery. Serological analysis showed that LO CD patients were more antineutrophil cytoplasmic antibody positive and less antisaccharomyces cerevisiae antibody positive compared with the intermediate group. Variance component analysis indicated that overall genetic contribution to LO CD was lower relative to the middle group, and genetic heterogeneity testing indicated that LO CD was different from the middle group in underlying genetic architecture.

CONCLUSIONS

Late-onset CD is subgroup distinct in genetic and behavioral risk factors with UC-like characteristics. 10.1093/ibd/izy148_video1izy148.video15791413461001.

Compositional and Temporal Changes in the Gut Microbiome of Pediatric Ulcerative Colitis Patients Are Linked to Disease Course

Evaluating progression risk and determining optimal therapy for ulcerative colitis (UC) is challenging as many patients exhibit incomplete responses to treatment. As part of the PROTECT (Predicting Response to Standardized Colitis Therapy) Study, we evaluated the role of the gut microbiome in disease course for 405 pediatric, new-onset, treatment-naive UC patients. Patients were monitored for 1 year upon treatment initiation, and microbial taxonomic composition was analyzed from fecal samples and rectal biopsies. Depletion of core gut microbes and expansion of bacteria typical of the oral cavity were associated with baseline disease severity. Remission and refractory disease were linked to species-specific temporal changes that may be implicative of therapy efficacy, and a pronounced increase in microbiome variability was observed prior to colectomy. Finally, microbial associations with disease-associated serological markers suggest host-microbial interactions in UC. These insights will help improve existing treatments and develop therapeutic approaches guiding optimal medical care.

Perioperative Care of Patients with Inflammatory Bowel Disease: Focus on Nutritional Support

Patients with inflammatory bowel disease (IBD) commonly require surgery despite the availability of an increasingly large repertoire of powerful immunosuppressive medications for the treatment of IBD. Optimizing patients' care preoperatively is crucial to obtaining good surgical outcomes. This review discusses preoperative assessment and management principles including assessing disease location and activity with cross-sectional or endoscopic imaging, addressing modifiable risk factors (i.e., stopping smoking, weaning steroids, and correcting anemia), and properly managing medications. The major focus of our literature review is the evaluation for malnutrition, a common finding that affects up to 70% of patients with IBD and a well-known, independent risk factor for adverse postoperative outcomes. Our review confirms that whenever feasible, oral or enteral nutrition (EN) is the preferred method of nutritional support; parenteral nutrition (PN) should be reserved for nutritionally deficient IBD patients unable to tolerate EN. In selected patients, recent data demonstrated that the use of preoperative PN resulted in improved nutritional status, fewer postoperative complications, and reduced disease severity. Our review highlights the need for well-designed, prospective trials investigating perioperative nutritional support in patients with IBD. Future studies should perform modern nutritional assessment, standardize for diet, and include patients with UC since this subset of patients is underrepresented in existing studies. In addition, relevant outcome of interest specific to Crohn's disease (CD) patients such as length of small bowel resected, number of anastomoses, and need for an ostomy should be included as these patients may require repeated small bowel resections.

Evolution of Pediatric Inflammatory Bowel Disease Unclassified (IBD-U): Incorporated With Serological and Gene Expression Profiles

BACKGROUND

Inflammatory bowel disease (IBD) mainly consists of Crohn's disease (CD) and ulcerative colitis (UC). About 10%-15% of patients with IBD cannot be firmly diagnosed with CD or UC; hence, they are initially diagnosed as inflammatory bowel disease unclassified (IBD-U). Having a firm diagnosis is clearly preferred to guide treatment choices, and better understanding of the nature of IBD-U is required.

METHODS

We performed an analysis of a subset of pediatric subjects from an inception IBD cohort of patients initially enrolled in a prospective multicenter study (the RISK study). Initial diagnosis and 2-year follow-up data from the subjects diagnosed with IBD-U were analyzed. An expert panel verified final diagnosis using predefined criteria as a guide. Serological and disease-relevant ileal and rectal tissue gene expression profiles were investigated. The use and the time to initiate anti-TNFα treatment was analyzed among the outcome groups.

RESULTS

A total of 1411 subjects were enrolled with initial diagnosis of IBD, and among them, 136 subjects were initially diagnosed as IBD-U at enrollment. And 26% were reclassified as UC and 14% as CD within 2 years of diagnosis, while 60% remained as IBD-U. Of those who were reclassified, there was a 2:1 ratio, UC (n = 35) to CD (n = 19). The molecular and serological features of IBD-U at the end of follow-up were very similar to UC and very different from CD. There was less likelihood of receiving anti-TNFα agents if the diagnosis was IBD-U compared with CD (P < 0.0001).

CONCLUSIONS

In our cohort, 60% of the IBD-U subjects remained as unclassified at 2 years; of those subsequently classified, a higher percentage followed a course more similar to UC. Most of the IBD-U subjects at diagnosis had serological and molecular signatures that are very similar to UC. Although the atypical presentations made the clinician to make an interim diagnosis of IBD-U, results of the molecular and serological factors performed at the time of diagnosis suggests that they were very similar to UC. However, long-term studies are needed to better understand the natural history and molecular characterization of pediatric onset IBD-U. 10.1093/ibd/izy136_video1Video 1.Video 1. Watch now at https://academic.oup.com/ibd/article-lookup/doi/10.1093/ibd/izy136izy136.video15791389938001.

Serological markers and inflammatory bowel disease: Prevalence of serum markers and their diagnostic value in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic nonspecific disease of the digestive tract that is caused by genetic and environmental factors, including ulcerative colitis, Crohn's disease, and unclassified IBD. At present, the diagnosis of IBD depends mainly on clinical manifestations, imaging changes, colonoscopy, and pathological biopsy, but there exist some limitations. The advantages of serological markers in IBD diagnosis are prominent, and a large number of relevant studies have been reported. This paper reviews the diagnostic and therapeutic value of serological markers in IBD, with an aim to clarify their role in the diagnosis and treatment of IBD.

Penetrating Crohn disease: does it occur in the absence of stricturing disease?

PURPOSE

To establish the relationship between penetrating complications and bowel luminal narrowing/stricturing disease in pediatric Crohn disease (CD).

MATERIALS AND METHODS

This retrospective study was IRB-approved and HIPAA compliant with waiver of informed consent. CT and MRI examinations describing intra-abdominal penetrating complications in CD patients ≤ 18 years old between January 1, 2009 and March 31, 2016 were reviewed to document: type of complication, affected bowel segment, minimum bowel luminal diameter, maximum upstream diameter, location of penetrating complication relative to luminal narrowing, length of narrowed bowel segment, and the presence of active bowel wall inflammation. Data were summarized using descriptive statistics including means, standard deviations, as well as counts and percentages.

RESULTS

A total of 52 penetrating complications were identified in 45 patients. Mean patient age was 15.7 ± 2.2 years (range 11-18 years) with 25/45 (56%) boys. Nearly all penetrating complications (51/52, 98%) were associated with a minimum bowel luminal diameter of ≤ 2 mm, with no visible lumen in 26/52 (50%). Mean maximum upstream diameter was 2.8 ± 0.8 cm (range 1.2-5.2 cm), and 17/52 (33%) penetrating complications were associated with > 3 cm upstream diameter. The mean ratio of maximum to minimum luminal diameter was 26.2 ± 8.8 (range 3.6-52.0). Active intestinal inflammation was associated with 100% (52/52) of penetrating complications. Nearly every penetrating complication (51/52, 98%) involved the terminal or distal ileum.

CONCLUSIONS

Penetrating complications in pediatric CD nearly always occur in the setting of considerable luminal narrowing or stricture and active intestinal inflammation.