Search

Objectives: Therapeutic drug monitoring (TDM) and dose optimization have been shown to improve clinical outcomes with antitumor necrosis factor and recent studies in adults suggest an exposure-response relationship with drug levels associated with improved clinical outcomes. However, these levels are not universally recognized as therapeutic targets for vedolizumab dosing. We aimed to assess the impact of a TDM quality improvement (QI) initiative on 52-week clinical outcomes and describe proactively obtained vedolizumab levels during the induction period in children with inflammatory bowel disease (IBD)., Methods: A QI initiative to proactively obtain TDM levels at Week 6 was implemented in 2019. A retrospective review of pediatric patients with IBD treated with vedolizumab from 2018 to 2022 was performed. Baseline demographic data, medication dosing details, disease characteristics, lab results, and 12-month clinical outcomes were recorded. For this study, we defined therapeutic target levels (>20 μg/mL at Week 6 and >12 μg/mL during maintenance) based on existing data correlating these levels with improved clinical outcomes., Results: Fifty-nine patients (31 Crohn disease [CD], 28 ulcerative colitis [UC]/indeterminate colitis [IC]) were included in the study. In total, 68% (40/59) of patients had vedolizumab levels at Week 6 and 90% (53/59) had levels drawn at Week 6 or 14. Thirty-five percent of Week 6 trough levels were below our defined target of 20 μg/mL. Fifty-two of 59 patients had available data at 52 weeks. Over 80% (42/52) of patients remained on vedolizumab 52 weeks after initiation (CD 79% [23/29], UC/IC 83% [19/23]). Sixty-two percent (26/42) of patients that remained on vedolizumab at 52 weeks were treated with an intensified dosing interval of <8 weeks. Thirty-one of these 42 (74%) were in clinical remission (CR) rate at 52 weeks with 29/42 (69%) in corticosteroid-free remission. The CR rate for the entire cohort including those who discontinued therapy due to a lack of efficacy before 52 weeks was 60% (31/52)., Conclusion: Proactive TDM and early dose optimization with vedolizumab may improve drug durability and clinical outcomes in pediatric patients with IBD., (© 2024 European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Understanding the role of the microbiome in inflammatory diseases requires the identification of microbial effector molecules. We established an approach to link disease-associated microbes to microbial metabolites by integrating paired metagenomics, stool and plasma metabolomics, and culturomics. We identified host-microbial interactions correlated with disease activity, inflammation, and the clinical course of ulcerative colitis (UC) in the Predicting Response to Standardized Colitis Therapy (PROTECT) pediatric inception cohort. In severe disease, metabolite changes included increased dipeptides and tauro-conjugated bile acids (BAs) and decreased amino-acid-conjugated BAs in stool, whereas in plasma polyamines (N-acetylputrescine and N1-acetylspermidine) increased. Using patient samples and Veillonella parvula as a model, we uncovered nitrate- and lactate-dependent metabolic pathways, experimentally linking V. parvula expansion to immunomodulatory tryptophan metabolite production. Additionally, V. parvula metabolizes immunosuppressive thiopurine drugs through xdhA xanthine dehydrogenase, potentially impairing the therapeutic response. Our findings demonstrate that the microbiome contributes to disease-associated metabolite changes, underscoring the importance of these interactions in disease pathology and treatment., Competing Interests: Declaration of interests R.J.X. is a co-founder of Celsius Therapeutics and Jnana Therapeutics, board director at MoonLake Immunotherapeutics, and consultant to Nestlé. D.R.M. is a co-founder of MedBiome Inc., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Ulcerative colitis (UC), Crohn's disease (CD), and celiac disease are prevalent intestinal inflammatory disorders with nonsatisfactory therapeutic interventions. Analyzing patient data-driven cohorts can highlight disease pathways and new targets for interventions. Long noncoding RNAs (lncRNAs) are attractive candidates, since they are readily targetable by RNA therapeutics, show relative cell-specific expression, and play key cellular functions. Uniformly analyzing gut mucosal transcriptomics from 696 subjects, we have highlighted lncRNA expression along the gastrointestinal (GI) tract, demonstrating that, in control samples, lncRNAs have a more location-specific expression in comparison with protein-coding genes. We defined dysregulation of lncRNAs in treatment-naive UC, CD, and celiac diseases using independent test and validation cohorts. Using the Predicting Response to Standardized Pediatric Colitis Therapy (PROTECT) inception UC cohort, we defined and prioritized lncRNA linked with UC severity and prospective outcomes, and we highlighted lncRNAs linked with gut microbes previously implicated in mucosal homeostasis. HNF1A-AS1 lncRNA was reduced in all 3 conditions and was further reduced in more severe UC form. Similarly, the reduction of HNF1A-AS1 ortholog in mice gut epithelia showed higher sensitivity to dextran sodium sulfate-induced colitis, which was coupled with alteration in the gut microbial community. These analyses highlight prioritized dysregulated lncRNAs that can guide future preclinical studies for testing them as potential targets.

Background & Aims: We aimed to model infliximab (IFX) pharmacokinetics (PK) in pediatric acute severe ulcerative colitis (ASUC) and assess the association between PK parameters, including drug exposure, and clinical response., Methods: We studied a multicenter prospective cohort of hospitalized children initiating IFX for ASUC or IBD-unclassified. Serial IFX serum concentrations over 26 weeks were used to develop a PK model. We tested the association of PK parameter estimates with day 7 clinical response, week 8 clinical remission, week 26 corticosteroid-free clinical remission (CSF-CR) (using the Pediatric Ulcerative Colitis Activity Index), and colectomy-free survival., Results: Thirty-eight participants received IFX (median initial dose, 9.9 mg/kg). Day 7 clinical response, week 8 clinical remission, and week 26 CSF-CR occurred in 71%, 55%, and 43%, respectively. Albumin, C-reactive protein, white blood cell count, platelets, weight, and antibodies to IFX were significant covariates incorporated into a PK model. Week 26 non-remitters exhibited faster IFX clearance than remitters (P = .013). However, cumulative IFX exposure did not differ between clinical response groups. One (2.7%) and 4 (10.8%) participants underwent colectomy by week 26 and 2 years, respectively. Day 3 IFX clearance >0.02 L/h was associated with colectomy (hazard ratio, 58.2; 95% confidence interval, 6.0-568.6; P < .001)., Conclusions: At median higher-than-label IFX dosing for pediatric ASUC, baseline faster IFX CL was associated with colectomy and at week 26 with lack of CSF-CR. IFX exposure was not predictive of clinical outcomes. Higher IFX dosing may sufficiently optimize early outcomes in pediatric ASUC. Larger studies are warranted to determine whether sustained intensification can overcome rapid clearance and improve later outcomes., Clinicaltrials: gov identifier: NCT02799615., (Copyright © 2023 AGA Institute. All rights reserved.)

Objectives: Iron deficiency (ID) with and without anemia is prevalent in children and adults diagnosed with inflammatory bowel disease (IBD), but often goes unrecognized. We hypothesized, quality improvement (QI) methodology could increase the screening for and treatment of ID in children newly diagnosed with IBD., Methods: We developed and implemented an easy-to-follow algorithm to facilitate screening for and treatment of ID for patients diagnosed with IBD. Through a series of Plan-Do-Study-Act cycles, the approach was modified to increase screening and treatment of ID. Data between January 2019 and July 2021 were assessed using statistical process control., Results: Among patients newly diagnosed with IBD, 298 patients were included (67% Crohn disease, 29% ulcerative colitis, 4% indeterminate colitis, and 56% males). Rates of ID screening increased significantly from a baseline of 20% to >90%. Of the 232 patients screened for ID during the improvement period, 205 (88%) met criteria for either iron deficiency anemia (IDA) or ID at diagnosis, specifically, 151 (65%) met criteria for IDA and 54 (23%) met criteria for ID., Conclusions: Use of QI methodology to standardize screening assessments for ID among children newly diagnosed with IBD improved screening rates from a baseline of 20% to >90%, with 88% of patients found to have IDA or ID., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by European Society for European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Background: Vedolizumab for inflammatory bowel disease (IBD) is often intensified based on distinct pharmacokinetics in children. Prior adult-specific population pharmacokinetic models have identified limited covariates of drug clearance., Aims: To establish a population pharmacokinetic model for children and young adults to identify novel covariates of drug clearance to better account for paediatric-specific inter-patient variability in vedolizumab pharmacokinetics; a key secondary exploratory aim was to identify microbial signatures of pharmacokinetic outcomes in a subset of patients., Methods: The study included data from 463 observed vedolizumab concentrations (59 peaks and 404 troughs) from 74 patients with IBD (52 with Crohn's disease and 22 with ulcerative colitis or unclassified IBD, median age 16 years). Pharmacokinetic analysis was conducted with non-linear mixed effects modelling. For the evaluation of the exposure-response relationship, clinical outcomes were evaluated by trough levels, clearance and vedolizumab exposure. Whole-genome metagenomic sequencing was conducted at baseline and week 2., Results: A two-compartment population pharmacokinetic model was identified with a clear correlation between CL and weight, erythrocyte sedimentation rate, and hypoalbuminemia. Trough concentrations before infusion 3 (37 μg/ml) and before infusion 4 (20 μg/ml) best predicted steroid-free clinical remission at infusion 4. Using faecal metagenomics, we identified an early (baseline and week 2) abundance of butyrate-producing species and pathways that were associated with an infusion 4 trough concentration >20 μg/ml., Conclusions: This novel paediatric vedolizumab pharmacokinetic model could inform precision dosing. While additional studies are needed, an abundance of faecal butyrate producers is associated with early response to vedolizumab, suggesting that microbial analysis may be beneficial to biological selection., (© 2022 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.)

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., (© The Author(s) 2022. Published by Oxford University Press on behalf of European Crohn’s and Colitis Organisation. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: Evidence about specific carbohydrate diet (SCD) for inflammatory bowel disease (IBD) is limited. We conducted 54 single-subject, double-crossover N-of-1 trials comparing SCD with a modified SCD (MSCD) and comparing each with the participant's baseline, usual diet (UD)., Methods: Across 19 sites, we recruited patients aged 7-18 years with IBD and active inflammation. Following a 2-week baseline (UD), patients were randomized to 1 of 2 sequences of 4 alternating 8-week SCD and MSCD periods. Outcomes included fecal calprotectin and patient-reported symptoms. We report posterior probabilities from Bayesian models comparing diets., Results: Twenty-one (39%) participants completed the trial, 9 (17%) completed a single crossover, and 24 (44%) withdrew. Withdrawal or early completion occurred commonly (lack of response [n = 11], adverse events [n = 11], and not desiring to continue [n = 6]). SCD and MSCD performed similarly for most individuals. On average, there was <1% probability of a clinically meaningful difference in IBD symptoms between SCD and MSCD. The average treatment difference was -0.3 (95% credible interval -1.2, 0.75). There was no significant difference in the ratio of fecal calprotectin geometric means comparing SCD and MSCD (0.77, 95% credible interval 0.51, 1.10). Some individuals had improvement in symptoms and fecal calprotectin compared with their UD, whereas others did not., Discussion: SCD and MSCD did not consistently improve symptoms or inflammation, although some individuals may have benefited. However, there are inherent difficulties in examining dietary changes that complicate study design and ultimately conclusions regarding effectiveness., (Copyright © 2022 by The American College of Gastroenterology.)

Background: Develop a clinical and biological predictive model for colectomy risk in children newly diagnosed with ulcerative colitis (UC)., Methods: This was a multicenter inception cohort study of children (ages 4-17 years) newly diagnosed with UC treated with standardized initial regimens of mesalamine or corticosteroids (CS) depending upon initial disease severity. Therapy escalation to immunomodulators or infliximab was based on predetermined criteria. Patients were phenotyped by clinical activity per the Pediatric Ulcerative Colitis Activity Index (PUCAI), disease extent, endoscopic/histologic severity, and laboratory markers. In addition, RNA sequencing defined pretreatment rectal gene expression and high density DNA genotyping by the Affymetrix UK Biobank Axiom Array. Coprimary outcomes were colectomy over 3 years and time to colectomy. Generalized linear models, Cox proportional hazards multivariate regression modeling, and Kaplan-Meier plots were used., Results: Four hundred twenty-eight patients (mean age 13 years) started initial theapy with mesalamine (n = 136), oral CS (n = 144), or intravenous CS (n = 148). Twenty-five (6%) underwent colectomy at ≤1 year, 33 (9%) at ≤2 years, and 35 (13%) at ≤3 years. Further, 32/35 patients who had colectomy failed infliximab. An initial PUCAI ≥ 65 was highly associated with colectomy (P = 0.0001). A logistic regression model predicting colectomy using the PUCAI, hemoglobin, and erythrocyte sedimentation rate had a receiver operating characteristic area under the curve of 0.78 (95% confidence interval [0.73, 0.84]). Addition of a pretreatment rectal gene expression panel reflecting activation of the innate immune system and response to external stimuli and bacteria to the clinical model improved the receiver operating characteristic area under the curve to 0.87 (95% confidence interval [0.82, 0.91])., Conclusions: A small group of children newly diagnosed with severe UC still require colectomy despite current therapies. Our gene signature observations suggest additional targets for management of those patients not responding to current medical therapies., (© 2021 Crohn’s & Colitis Foundation. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

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., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

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., Competing Interests: Declaration of interests J.S.H. has served on an advisory board for Janssen and is acting as a consultant for AbbVie, Takeda, Lilly, Boehringer-Ingelheim, Allergan, Pfizer, Receptos, and AstraZeneca. S.D.T. has been a member of an independent data monitoring committee for Lycera Corporation. A.M.G. has received research support from AbbVie; been a consultant for AbbVie, Celgene, Janssen, Lilly, Pfizer, and Takeda; and been a speaker for AbbVie, Janssen, and Shire. N.S.L. has been a consultant for AbbVie. C.G.S. has been a consultant for AbbVie. J.M. has been a consultant for Janssen, Celgene, and Lilly. J.R.R. has been a consultant for AbbVie, Celgene, Janssen, Luitpold, and Pfizer and received grant funding from Janssen and AbbVie. A.S.P. has participated in speakers bureaus for AbbVie and Janssen. M.B.H. has received research grants from Genentech, AbbVie, Shire, Takeda, Mallinkrodt, Janssen, and Gilead. P.A.R. has been a consultant for Shire and Leutpold; been a speaker for AbbVie; and received research support from TechLab. S.K. has been a consultant for Janssen and UCB. L.A.D. has received grant support from AbbVie and Janssen. D.P.B.M. and T.H. are faculty members at Cedars-Sinai Medical Center. E.M. is an employee at Cedars-Sinai. Cedars-Sinai has financial interests in Prometheus Biosciences, a company that has access to the data and specimens in Cedars-Sinai’s MIRIAD Biobank. Prometheus Biosciences seeks to develop commercial products. D.M. is a paid consultant and shareholder of Prometheus Biosciences. D.M. has consulted for Pfizer, Gilead, Palatin Technologies, Bridge Biotherapeutics, and Takeda. All other authors declare no competing interests., (Copyright © 2021. Published by Elsevier Inc.)

Background: Cessation of statural growth occurs with radiographic closure of the growth plates, radiographically defined as bone age (BA) 15 years in females and 17 in males., Methods: We determined the frequency of continued growth and compared the total height gain beyond the time of expected growth plate closure and the chronological age at achievement of final adult height in Crohn's disease (CD) vs ulcerative colitis (UC) and described height velocity curves in inflammatory bowel disease (IBD) compared with children in the National Health and Nutrition Examination Survey (NHANES). We identified all females older than chronological age (CA) 15 years and males older than CA 17 years with CD or UC in the ImproveCareNow registry who had height documented at ≥3 visits ≥6 months apart., Results: Three thousand seven patients (48% female; 76% CD) qualified. Of these patients, 80% manifested continued growth, more commonly in CD (81%) than UC (75%; P = 0.0002) and in females with CD (83%) than males with CD (79%; P = 0.012). Median height gain was greater in males with CD (1.6 cm) than in males with UC (1.3 cm; P = 0.0004), and in females with CD (1.8 cm) than in females with UC (1.5 cm; P = 0.025). Height velocity curves were shifted to the right in patients with IBD vs NHANES., Conclusions: Pediatric patients with IBD frequently continue to grow beyond the time of expected growth plate closure. Unexpectedly, a high proportion of patients with UC exhibited continued growth, indicating delayed BA is also common in UC. Growth, a dynamic marker of disease status, requires continued monitoring even after patients transition from pediatric to adult care., (© 2020 Crohn’s & Colitis Foundation. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: The aim of this study was to assess common laboratory tests in identifying severe ulcerative colitis in children at diagnosis., Methods: A cohort of 427 children 4 to 17 years of age newly diagnosed with ulcerative colitis (UC) was prospectively enrolled. Boosted classification trees were used to characterize predictive ability of disease attributes based on clinical disease severity using Pediatric Ulcerative Colitis Activity Index (PUCAI), severe (65+) versus not severe (<65) and total Mayo score, severe (10-12) versus not severe (<10); mucosal disease by Mayo endoscopic subscore, severe (3) versus not severe (<3); and extensive disease versus not extensive (left-sided and proctosigmoiditis)., Results: Mean age was 12.7 years; 49.6% (n = 212) were girls, and 83% (n = 351) were Caucasian. Severe total Mayo score was present in 28% (n = 120), mean PUCAI score was 49.8 ± 20.1, and 33% (n = 142) had severe mucosal disease with extensive involvement in 82% (n = 353). Classification and regression trees identified white blood cell count, erythrocyte sedimentation rate, and platelet count (PLT) as the set of 3 best blood laboratory tests to predict disease extent and severity. For mucosal severity, albumin (Alb) replaced PLT. Classification models for PUCAI and total Mayo provided sensitivity of at least 0.65 using standard clinical cut-points with misclassification rates of approximately 30%., Conclusions: A combination of the white blood cell count, erythrocyte sedimentation rate, and either PLT or albumin is the best predictive subset of standard laboratory tests to identify severe from nonsevere clinical or mucosal disease at diagnosis in relation to objective clinical scores.

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., (© 2019 Crohn’s & Colitis Foundation. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Lack of evidence-based outcomes data leads to uncertainty in developing treatment regimens in children who are newly diagnosed with ulcerative colitis. We hypothesised that pretreatment clinical, transcriptomic, and microbial factors predict disease course., Methods: In this inception cohort study, we recruited paediatric patients aged 4-17 years with newly diagnosed ulcerative colitis from 29 centres in the USA and Canada. Patients initially received standardised mesalazine or corticosteroids, with pre-established criteria for escalation to immunomodulators (ie, thiopurines) or anti-tumor necrosis factor-α (TNFα) therapy. We used RNA sequencing to define rectal gene expression before treatment, and 16S sequencing to characterise rectal and faecal microbiota. The primary outcome was week 52 corticosteroid-free remission with no therapy beyond mesalazine. We assessed factors associated with the primary outcome using logistic regression models of the per-protocol population. This study is registered with ClinicalTrials.gov, number NCT01536535., Findings: Between July 10, 2012, and April 21, 2015, of 467 patients recruited, 428 started medical therapy, of whom 400 (93%) were evaluable at 52 weeks and 386 (90%) completed the study period with no protocol violations. 150 (38%) of 400 participants achieved week 52 corticosteroid-free remission, of whom 147 (98%) were taking mesalazine and three (2%) were taking no medication. 74 (19%) of 400 were escalated to immunomodulators alone, 123 (31%) anti-TNFα therapy, and 25 (6%) colectomy. Low baseline clinical severity, high baseline haemoglobin, and week 4 clinical remission were associated with achieving week 52 corticosteroid-free remission (n=386, logistic model area under the curve [AUC] 0·70, 95% CI 0·65-0·75; specificity 77%, 95% CI 71-82). Baseline severity and remission by week 4 were validated in an independent cohort of 274 paediatric patients with newly diagnosed ulcerative colitis. After adjusting for clinical predictors, an antimicrobial peptide gene signature (odds ratio [OR] 0·57, 95% CI 0·39-0·81; p=0·002) and abundance of Ruminococcaceae (OR 1·43, 1·02-2·00; p=0·04), and Sutterella (OR 0·81, 0·65-1·00; p=0·05) were independently associated with week 52 corticosteroid-free remission., Interpretation: Our findings support the utility of initial clinical activity and treatment response by 4 weeks to predict week 52 corticosteroid-free remission with mesalazine alone in children who are newly diagnosed with ulcerative colitis. The development of personalised clinical and biological signatures holds the promise of informing ulcerative colitis therapeutic decisions., Funding: US National Institutes of Health., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Molecular mechanisms driving disease course and response to therapy in ulcerative colitis (UC) are not well understood. Here, we use RNAseq to define pre-treatment rectal gene expression, and fecal microbiota profiles, in 206 pediatric UC patients receiving standardised therapy. We validate our key findings in adult and paediatric UC cohorts of 408 participants. We observe a marked suppression of mitochondrial genes and function across cohorts in active UC, and that increasing disease severity is notable for enrichment of adenoma/adenocarcinoma and innate immune genes. A subset of severity genes improves prediction of corticosteroid-induced remission in the discovery cohort; this gene signature is also associated with response to anti-TNFα and anti-α 4 β 7 integrin in adults. The severity and therapeutic response gene signatures were in turn associated with shifts in microbes previously implicated in mucosal homeostasis. Our data provide insights into UC pathogenesis, and may prioritise future therapies for nonresponders to current approaches.

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., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: In contrast to pediatric Crohn's disease (CD), little is known in pediatric ulcerative colitis (UC) about the relationship between disease phenotype and serologic reactivity to microbial and other antigens., Aim: The aim of this study was to examine disease phenotype and serology in a well-characterized inception cohort of children newly diagnosed with UC during the PROTECT Study (Predicting Response to Standardized Pediatric Colitis Therapy)., Methods: Patients were recruited from 29 participating centers. Demographic, clinical, laboratory, and serologic (pANCA, ASCA IgA/IgG, Anti-CBir1, and Anti-OmpC) data were obtained from children 4-17 years old with UC., Results: Sixty-five percent of the patients had positive serology for pANCA, with 62% less than 12 years old and 66% 12 years old or older. Perinuclear anti-neutrophil cytoplasmic antibodies did not correspond to a specific phenotype though pANCA ≥100, found in 19%, was strongly associated with pancolitis (P = 0.003). Anti-CBir1 was positive in 19% and more common in younger children with 32% less than 12 years old as compared with 14% 12 years old or older (P < 0.001). No association was found in any age group between pANCA and Anti-CBir1. Relative rectal sparing was more common in +CBir1, 16% versus 7% (P = 0.02). Calprotectin was lower in Anti-CBir1+ (Median [IQR] 1495 mcg/g [973-3333] vs 2648 mcg/g [1343-4038]; P = 0.04). Vitamin D 25-OH sufficiency was associated with Anti-CBir1+ (P = 0.0009)., Conclusions: The frequency of pANCA in children was consistent with adult observations. High titer pANCA was associated with more extensive disease, supporting the idea that the magnitude of immune reactivity may reflect disease severity. Anti-CBir1+ was more common in younger ages, suggesting host-microbial interactions may differ by patient age.

Background: The genetic contributions to pediatric onset ulcerative colitis (UC), characterized by severe disease and extensive colonic involvement, are largely unknown. In adult onset UC, Genome Wide Association Study (GWAS) has identified numerous loci, most of which have a modest susceptibility risk (OR 0.84-1.14), with the exception of the human leukocyte antigen (HLA) region on Chromosome 6 (OR 3.59)., Method: To study the genetic contribution to exclusive pediatric onset UC, a GWAS was performed on 466 cases with 2099 healthy controls using UK Biobank array. SNP2HLA was used to impute classical HLA alleles and their corresponding amino acids, and the results are compared with adult onset UC., Results: HLA explained the almost entire association signal, dominated with 191 single nucleotide polymorphisms (SNPs) (p = 5 x 10-8 to 5 x 10-10). Although very small effects, established SNPs in adult onset UC loci had similar direction and magnitude in pediatric onset UC. SNP2HLA imputation identified HLA-DRB1*0103 (odds ratio [OR] = 6.941, p = 1.92*10-13) as the most significant association for pediatric UC compared with adult onset UC (OR = 3.59). Further conditioning showed independent effects for HLA-DRB1*1301 (OR = 2.25, p = 7.92*10-9) and another SNP rs17188113 (OR = 0.48, p = 7.56*10-9). Two HLA-DRB1 causal alleles are shared with adult onset UC, while at least 2 signals are unique to pediatric UC. Subsequent stratified analyses indicated that HLA-DRB1*0103 has stronger association for extensive disease (E4: OR = 8.28, p = 4.66x10-10) and female gender (OR = 8.85, p = 4.82x10-13)., Conclusion: In pediatric onset UC, the HLA explains almost the entire genetic associations. In addition, the HLA association is approximately twice as strong in pediatric UC compared with adults, due to a combination of novel and shared effects. We speculate the paramount importance of antigenic stimulation either by infectious or noninfectious stimuli as a causal event in pediatric UC onset.

Background: Vitamin D regulates intestinal epithelial and immune functions, and vitamin D receptor deficiency increases the severity of murine colitis. Bioavailable 25-hydroxyvitamin D (25(OH)D) is available to target tissues and may be a driver of immune function. The aim is to evaluate the relationship of bioavailable 25(OH)D to the clinical expression of treatment naive pediatric ulcerative colitis (UC)., Methods: The PROTECT (Predicting Response to Standardized Pediatric Colitis Therapy) study enrolled children ≤17 years newly diagnosed with UC. Free and total 25(OH)D were directly measured and 25(OH)D fractions were compared with disease activity measures., Results: Data were available on 388 subjects, mean age 12.7 years, 49% female, 84% with extensive/pancolitis. The median (IQR) total 25(OH)D concentration was 28.5 (23.9, 34.8) ng/mL, and 57% of subjects demonstrated insufficient vitamin D status (25(OH)D < 30 ng/mL). We found no evidence of association between total 25(OH)D and disease activity. Regression models adjusted for age, sex, race, and ethnicity demonstrated that an increase from 25th to 75th percentile for bioavailable and free 25(OH)D were associated with a mean (95th CI) decrease in the Pediatric Ulcerative Colitis Activity Index (PUCAI) of -8.7 (-13.7, -3.6) and -3.1 (-5.0, -1.2), respectively. No associations were detected between 25(OH)D fractions and fecal calprotectin or Mayo endoscopy score., Conclusions: Vitamin D insufficiency is highly prevalent in children with newly diagnosed UC. We found associations of free and bioavailable, but not total 25(OH)D, with PUCAI. Bioavailable vitamin D may contribute to UC pathophysiology and clinical activity.

Background: Previous retrospective studies of paediatric ulcerative colitis have had limited ability to describe disease progression and identify predictors of treatment response. In this study, we aimed to identify characteristics associated with outcomes following standardised therapy after initial diagnosis., Methods: The PROTECT multicentre inception cohort study was based at 29 centres in the USA and Canada and included paediatric patients aged 4-17 years who were newly diagnosed with ulcerative colitis. Guided by the Pediatric Ulcerative Colitis Activity Index (PUCAI), patients received initial standardised treatment with mesalazine (PUCAI 10-30) oral corticosteroids (PUCAI 35-60), or intravenous corticosteroids (PUCAI ≥65). The key outcomes for this analysis were week 12 corticosteroid-free remission, defined as PUCAI less than 10 and taking only mesalazine, and treatment escalation during the 12 study weeks to anti-tumour necrosis factor α (TNFα) agents, immunomodulators, or colectomy among those initially treated with intravenous corticosteroids. We identified independent predictors of outcome through multivariable logistic regression using a per-protocol approach. This study is registered with ClinicalTrials.gov, number NCT01536535., Findings: Patients were recruited between July 10, 2012, and April 21, 2015. 428 children initiated mesalazine (n=136), oral corticosteroids (n=144), or intravenous corticosteroids (n=148). Initial mean PUCAI was 31·1 (SD 13·3) in children initiating with mesalazine, 50·4 (13·8) in those initiating oral corticosteroids, and 66·9 (13·7) in those initiating intravenous corticosteroids (p<0·0001 for between-group comparison). Week 12 outcome data were available for 132 patients who initiated with mesalazine, 141 with oral corticosteroids, and 143 with intravenous corticosteroids. Corticosteroid-free remission with the patient receiving mesalazine treatment only at 12 weeks was achieved by 64 (48%) patients in the mesalazine group, 47 (33%) in the oral corticosteroid group, and 30 (21%) in the intravenous corticosteroid group (p<0·0001). Treatment escalation was required by nine (7%) patients in the mesalazine group, 21 (15%) in the oral corticosteroid group, and 52 (36%) in the intravenous corticosteroid group (p<0·0001). Eight patients, all of whom were initially treated with intravenous corticosteroids, underwent colectomy. Predictors of week 12 corticosteroid-free remission were baseline PUCAI less than 35 (odds ratio 2·44, 95% CI 1·41-4·22; p=0·0015), higher baseline albumin by 1 g/dL increments among children younger than 12 years (4·05, 1·90-8·64; p=0·00030), and week 4 remission (6·26, 3·79-10·35; p<0·0001). Predictors of treatment escalation by week 12 in patients initially treated with intravenous corticosteroids included baseline total Mayo score of 11 or higher (2·59, 0·93-7·21; p=0·068 [retained in model due to clinical relevance]), rectal biopsy eosinophil count less than or equal to 32 cells per high power field (4·55, 1·62-12·78; p=0·0040), rectal biopsy surface villiform changes (3·05, 1·09-8·56; p=0·034), and not achieving week 4 remission (30·28, 6·36-144·20; p<0·0001)., Interpretation: Our findings provide guidelines to assess the response of children newly diagnosed with ulcerative colitis to standardised initial therapy and identify predictors of treatment response and failure. These data suggest that additional therapeutic interventions might be warranted to improve early outcomes, especially in patients presenting with severe disease and requiring intravenous corticosteroids., Funding: National Institutes of Health., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

To characterize rectal histology in an inception cohort of children newly diagnosed with ulcerative colitis (UC) and to explore its relationship with clinical indices of disease severity. The PROTECT (Predicting Response to Standardized Pediatric Colitis Therapy) Study enrolled children 17 years of age and younger newly diagnosed with UC. Baseline rectal biopsies were evaluated for acute and chronic inflammation, eosinophilic inflammation (peak eosinophil count > 32 eosinophils/high powered field, eosinophilic cryptitis or abscesses), and architectural/nonarchitectural chronic changes. Correlation with clinical indices including Mayo endoscopy subscore and Pediatric Ulcerative Colitis Activity Index was performed. Rectal biopsies from 369 patients (mean age, 12.9±3.1 y, 50% female) were reviewed. Cryptitis was found in 89%, crypt abscesses in 25%, and eosinophilic inflammation in 58%. Crypt distortion/atrophy was present in 98% of specimens. Higher grades of acute and chronic inflammation were associated with the presence of basal plasmacytosis (P<0.0001), basal lymphoid aggregates (P<0.0001), and surface villiform changes (P<0.0001). A severe Mayo endoscopy subscore was most common among those with severe acute and chronic inflammation, although this relationship was not linear. Severe Pediatric Ulcerative Colitis Activity Index scores were associated with the absence of or only mild eosinophilic inflammation (<32 eosinophils/high powered field) (P<0.03) and the presence of surface villiform changes (P<0.005). Acute and chronic inflammation, eosinophilic inflammation and chronic changes are common in children newly diagnosed with UC. The clinical and biological implication of low to absent eosinophilic inflammation and the presence of surface villiform changes requires further study.

Objectives: The prevalence of inflammatory bowel diseases (IBD) and use of complementary and alternative medicine (CAM) are both common and increasing. The definition of CAM therapy among both practitioners and patients is variable. The aim of our study was to update our understanding of how pediatric IBD patients use, perceive, and define CAM therapies., Methods: We surveyed families of patients with IBD followed in the Gastroenterology Division at Nationwide Children's Hospital in summer 2014 during a routine clinic visit. The survey included questions about the following demographic and disease information; use and side effects associated with prior conventional therapies (CT); and attitudes toward, and use of CAM., Results: The questionnaire was completed by 104 of 118 patients approached (14 ± 3 years; 43% women). Patients had previously used an average of 3 CT. CAM therapy was used by 84% of patients surveyed, although only 24% of patients/families considered themselves to be using CAM. Common CAM therapies included vitamins/supplements, stress management techniques, and/or dietary changes. Factors associated with using specific CAM therapies included self-reported prior CT-related side effects (P < 0.01) and moderate/severe disease activity (P < 0.01). Most families (77%) desired to learn more about CAM., Conclusions: Patients seen in a tertiary care center for pediatric IBD frequently integrated CAM therapies into their treatment regimen. Patients with prior side effects from CT or more severe disease were more likely to use CAM. Given the high prevalence of CAM use, pediatric gastrointestinal physicians should be knowledgeable and open to discussions about CAM therapies with their patients.

Objectives: Patients with inflammatory bowel disease (IBD) often develop elevated liver enzymes (ELE), which are frequently a benign, transient finding, but may be related to treatment or IBD-associated liver diseases. Distinguishing benign from pathologic ELE is crucial for focused diagnostic and therapeutic interventions. We sought to characterize the incidence, character, chronicity, degree, and etiology of ELE in children with IBD., Methods: Institutional review board-approved retrospective review of all of the patients with IBD (2-21 years) seen between October 2009 and October 2012 with >9 months of follow-up were included in the study. We examined body mass index, disease activity, extent, phenotype, concurrent medications, and character, chronicity, degree of enzyme elevation, and final diagnosis., Results: A total of 219 of 514 patients with IBD had ≥1 episode of ELE. Five patients were excluded for preexisting liver disease, leaving 214 patients (Crohn disease [CD]: 14.8 ± 3.5 years, 46% girls; ulcerative colitis [UC]: 14.4 ± 4.2 years, 37% girls). One hundred forty-eight patients (69%) had a hepatic, 17 (8%) cholestatic, and 49 (23%) mixed character of ELE. There were no significant differences in character, chronicity, or degree of ELE between CD and UC (P = 0.71, P = 0.58, P > 0.33). Of the 128 patients with sufficient data to determine chronicity, 98 (77%) had transient elevations, (CD: n = 66, 75% and UC: n = 32, 80%). Episodes of ELE were idiopathic in 87% of patients with IBD. A final diagnosis of idiopathic ELE was associated with a lower degree of ELE elevation (P < 0.0001)., Conclusions: Pediatric patients with IBD commonly experience transient, idiopathic ELE. Our findings suggest that higher degrees of ELE, specifically alanine aminotransferase, are associated with an etiology that requires more extensive evaluation.

Objective: To examine sex differences in medical therapy and clinical outcomes in pediatric patients with inflammatory bowel disease (IBD)., Methods: We performed a cross-sectional analysis of children with Crohn disease (CD) and ulcerative colitis (UC) using data from the ImproveCareNow Network collected between May 2007 and May 2010. Clinical remission, disease severity, body mass index (BMI) z scores, normal height velocity, and medication use were analyzed by sex and age., Results: One thousand four hundred nine patients were included (993 had CD and 416 had UC). No significant sex differences were found in disease severity, BMI, height velocity, or use of medications. Further analysis of combination therapy with infliximab + 6-mercaptopurine/azathioprine and infliximab + methotrexate also did not reveal any differences. No sex differences were found after mediation use was stratified by age (those younger than 13 years and those 13 years old or older)., Conclusions: In this sample of CD and UC pediatric patients, no significant sex differences were found in disease severity, BMI, height velocity, or medication use. Our data do not support the use of sex as a major factor in patient risk stratification for children with IBD. In addition, despite concerns for sex-specific complications of some medications, our analysis did not suggest any sex differences in medication use.