Clinical and biological predictors of response to standardised paediatric colitis therapy (PROTECT): a multicentre inception cohort study.

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.

Biologics Delay Progression of Crohn's Disease, but Not Early Surgery, in Children.

BACKGROUND & AIMS: Up to 30% of patients with Crohn's disease (CD) require surgery within the first 5 years from diagnosis. We investigated the recent risk of bowel surgery in an inception cohort of pediatric patients with CD and whether early use of biologics (tumor necrosis factor antagonists) alters later disease course. METHODS: We collected data from the Pediatric Inflammatory Bowel Disease Collaborative Research Group registry on 1442 children (age, ≤16 y) diagnosed with CD from January 2002 through December 2014. Data were collected at diagnosis, 30 days following diagnosis, and then quarterly and during hospitalizations for up to 12 years. Our primary aim was to determine the 10-year risk for surgery in children with CD. Our secondary aim was to determine whether early use of biologics (<3 mo of diagnosis) affected risk of disease progression. RESULTS: The 10-year risk of first bowel surgery was 26%. The 5-year risk of bowel surgery did not change from 2002 through 2014, and remained between 13% and 14%. Most surgeries occurred within 3 years from diagnosis. The only predictor of surgery was disease behavior at diagnosis. CD with inflammatory behavior had the lowest risk of surgery compared to stricturing disease, penetrating disease, or both. We associated slowing of disease progression to stricturing or penetrating disease (but not surgery) with early use of biologics, but this effect only became evident after 5 years of disease. Our results indicate that biologics slow disease progression over time (hazard ratio, 0.85; 95% CI, 0.76-0.95). CONCLUSIONS: In an analysis of data from a registry of pediatric patients with CD, we found that among those with significant and progressing disease at or shortly after presentation, early surgery is difficult to prevent, even with early use of biologics. Early use of biologics (<3 mo of diagnosis) can delay later disease progression to stricturing and/or penetrating disease, but this affect could become evident only years after initial management decisions are made.

Predictors of depression in youth with Crohn disease.

OBJECTIVE: The aim of the study was to determine whether infliximab use and other potential predictors are associated with decreased prevalence and severity of depression in pediatric patients with Crohn disease (CD). METHODS: A total of 550 (n = 550) youth ages 9 to 17 years with biopsy-confirmed CD were consecutively recruited as part of a multicenter randomized controlled trial. Out of the 550, 499 patients met study criteria and were included in the analysis. At recruitment, each subject and a parent completed the Children's Depression Inventory (CDI). A child or parent CDI score ≥  12 was used to denote clinically significant depressive symptoms (CSDS). Child and parent CDI scores were summed to form total CDI (CDIT). Infliximab use, demographic information, steroid use, laboratory values, and Pediatric Crohn's Disease Activity Index (PCDAI) were collected as the potential predictors of depression. Univariate regression models were constructed to determine the relations among predictors, CSDS, and CDIT. Stepwise multivariate regression models were constructed to predict the relation between infliximab use and depression while controlling for other predictors of depression. RESULTS: Infliximab use was not associated with a decreased proportion of CSDS and CDIT after adjusting for multiple comparisons. CSDS and CDIT were positively associated with PCDAI, erythrocyte sedimentation rate, and steroid dose (P < 0.01) and negatively associated with socioeconomic status (SES) (P < 0.001). In multivariate models, PCDAI and SES were the strongest predictors of depression. CONCLUSIONS: Disease activity and SES are significant predictors of depression in youth with Crohn disease.

Depression subtypes in pediatric inflammatory bowel disease.

OBJECTIVE: The association between inflammatory bowel disease (IBD) and depression provides a unique opportunity to understand the relation between systemic inflammation and depressive symptom profiles. METHODS: Youth (n = 226) ages 9 to 17 years with comorbid IBD and depression underwent psychiatric assessment and evaluation of IBD activity. Latent profile analysis (LPA) identified depressive subgroups based on similar responses to the Children's Depression Rating Scale-Revised. Demographic factors, depression severity, anxiety, IBD activity, inflammatory markers, IBD-related medications, and illness perception were evaluated as predictors of profile membership. RESULTS: Mean age was 14.3 years; 75% had Crohn disease; 31% were taking systemic corticosteroids. Mean depressive severity was moderate, whereas IBD activity, which reflects inflammation, was mild. LPA identified 3 subgroups: Profile-1 (mild, 75%) had diverse low-grade depressive symptoms and highest quality of life; Profile-2 (somatic, 19%) had severe fatigue, appetite change, anhedonia, decreased motor activity, and depressed mood with concurrent high-dose steroid therapy and the highest IBD activity; and Profile-3 (cognitive, 6%) had the highest rates of self-reported depressive symptoms, ostomy placements, and anxiety with IBD symptoms in the relative absence of inflammation. CONCLUSIONS: Evidence was found for 3 depression profiles in youth with IBD and depression. Our analyses determined that patients with predominantly somatic or cognitive symptoms of depression comprised 25% of our cohort. These findings may be used to design subgroup-specific interventions for depression in adolescents with IBD and other physical illnesses associated with systemic inflammation.

Liver enzyme elevations within 3 months of diagnosis of inflammatory bowel disease and likelihood of liver disease.

BACKGROUND: Inflammatory bowel disease-associated liver diseases (IBD-LDs) include autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC), and an overlap syndrome. Prospective unbiased multicenter data regarding the frequency of IBD-LD in patients with pediatric inflammatory bowel disease (IBD) are lacking. We examined early alanine aminotransferase (ALT) and γ-glutamyl transpeptidase (GGT) elevations in children diagnosed as having IBD and assessed the likelihood of IBD-LD. METHODS: Data collected from the prospective observational Pediatric Inflammatory Bowel Disease Collaborative Research Group Registry enrolling children of age <16 years within 30 days of diagnosis. AIH, PSC, and overlap syndrome were diagnosed using local institutional criteria. RESULTS: A total of 1569 subjects had liver enzymes available. Of the total, 757 had both ALT and GGT, 800 had ALT only (no GGT), and 12 had GGT only (no ALT). Overall, 29 of 1569 patients (1.8%) had IBD-LD. IBD-LD was diagnosed in 1 of 661 (0.15%) of patients with both ALT and GGT ≤ 50 IU/L compared with 21 of 42 (50%) of patients with both ALT and GGT > 50 (odds ratio 660, P < 0.0001). Of the 29 patients with IBD-LD, 21 had PSC, 2 had AIH, and 6 had overlap syndrome. IBD-LD was more common in patients with ulcerative colitis and IBD-unclassified (indeterminate colitis) than in those with Crohn disease (4% vs 0.8%, respectively, P < 0.001). CONCLUSIONS: Elevation of both ALT and GGT within 90 days after the diagnosis of IBD is associated with a markedly increased likelihood of IBD-LD. Both ALT and GGT levels should be measured in all of the pediatric patients newly diagnosed as having IBD.

Characterization of relations among sleep, inflammation, and psychiatric dysfunction in depressed youth with Crohn disease.

OBJECTIVES: Recent reports demonstrate a link between inflammatory bowel disease (IBD) and sleep disturbance. Increased psychiatric dysfunction is consistently reported in patients with IBD. Our objective is to examine relations among sleep disturbance, inflammation, and psychiatric dysfunction in a pediatric population with Crohn disease (CD) and depression. METHODS: Pediatric patients with CD with depression (n = 96) and healthy controls (n = 19) completed measures of sleep (Pittsburgh Sleep Quality Index [PSQI]), depression, anxiety, and abdominal pain, and provided blood for inflammatory markers. CD activity was determined by the Pediatric Crohn's Disease Activity Index. Factor analysis was performed on subscales of the PSQI to derive measures of sleep disturbance. Univariate and multivariate regression analyses assessed relations between sleep disturbance, psychosocial, and biological measures of CD and psychiatric dysfunction. RESULTS: Sleep disturbance in depressed youth with CD was significantly greater than healthy controls, and was significantly related to measures of abdominal pain, depression, and anxiety, but not biomarkers of inflammation. Factor analysis of the PSQI demonstrated a 2-factor solution. The first factor, termed "Qualitative," included Subjective Sleep Quality, Daytime Dysfunction, Sleep Disturbance, and Sleep Latency, whereas the second factor, "Quantitative," consisted of Habitual Sleep Efficiency and Sleep Duration. This factor showed a significant relation to inflammatory markers. Multivariate modeling suggested that qualitative sleep disturbance was predicted by disease activity, pain, and anxiety, whereas quantitative sleep disturbance was predicted by disease activity. CONCLUSIONS: These results indicate that sleep disturbance in depressed youth with CD differs depending upon illness activity. Patients may require different interventions depending upon the sleep disturbance exhibited.

Impact of inflammatory bowel disease and high-dose steroid exposure on pupillary responses to negative information in pediatric depression.

OBJECTIVE: To better understand emotional information processing in pediatric inflammatory bowel disease (IBD) and its relationship with depression. Pediatric IBD is associated with higher rates of depression than seen in other physical diseases and in community samples. In systemic inflammation, proinflammatory cytokines have been implicated in altering activity in brain regions known to affect emotion processing and emotion regulation in depression. METHODS: We examined differences in pupillary responses as a marker of brain function in response to negative emotional information in youths (ages, 8-17 years) with IBD both with (n = 8) and without (n = 15) comorbid depression and who were receiving high-dose steroid treatment. We compared their responses to each other and to depressed youths without IBD (n = 20) and healthy youths (n = 22). RESULTS: Youths with IBD demonstrated greater pupillary responses to the initial presentation of negative emotional stimuli, regardless of their depression status (p = .05). In contrast, depressed youths, regardless of their IBD status, demonstrated a greater constriction of the pupil 10 seconds to 12 seconds after exposure to negative stimuli. This constriction was associated with greater depressive severity and lower albumin levels. CONCLUSIONS: IBD may be associated with increased sensitivity to negative emotional stimuli above and beyond depression diagnosis. Depressed youths potentially demonstrate affective blunting, emotional avoidance, or a failure to regulate emotion after exposure to negative emotional information. Thus, there seem to be unique contributions of medical disease and depression to physiological indications of emotional reactivity, but these factors do not seem to interact.

Factors that determine risk for surgery in pediatric patients with Crohn's disease.

BACKGROUND & AIMS: We examined the incidence of Crohn's disease (CD)-related surgery in a multi-center, inception cohort of pediatric patients with CD. We also examined the effect of starting immunomodulator therapy within 30 days of diagnosis. METHODS: Data from 854 children with CD from the Pediatric Inflammatory Bowel Disease Collaborative Research Group who were diagnosed with CD between 2002 and 2008 were analyzed. RESULTS: Overall, 76 (9%) underwent a first CD-related surgery, 57 (7%) underwent a first bowel surgery (bowel resection, ostomy, strictureplasty, or appendectomy), and 19 (2%) underwent a first non-bowel surgery (abscess drainage or fistulotomy). The cumulative risks for bowel surgery, non-bowel surgery, and all CD-related surgeries were 3.4%, 1.4%, and 4.8%, respectively, at 1 year after diagnosis and 13.8%, 4.5%, and 17.7%, respectively, at 5 years after diagnosis. Older age at diagnosis, greater disease severity, and stricturing or penetrating disease increased the risk of bowel surgery. Disease between the transverse colon and rectum decreased the risk. Initiation of immunomodulator therapy within 30 days of diagnosis, sex, race, and family history of inflammatory bowel disease did not influence the risk of bowel surgery. CONCLUSIONS: In an analysis of pediatric patients with CD, the 5-year cumulative risk of bowel surgery was lower than that reported in recent studies of adult and pediatric patients but similar to that of a recent retrospective pediatric study. Initiation of immunomodulator therapy at diagnosis did not alter the risk of surgery within 5 years of diagnosis.

Variation in care in pediatric Crohn disease.

OBJECTIVES: Variation in medical care can be a barrier to improving clinical outcomes. We aim to describe the variation in care of Crohn disease as provided by a broad sample of pediatric gastroenterologists. METHODS: Two hundred forty-six Crohn disease patients of 93 pediatric gastroenterologists from 48 practice sites starting treatment with either thiopurine or infliximab were studied. We assessed variation in diagnostic testing that had been performed to establish the diagnosis of Crohn disease and to assess the phenotype, extent, and severity of disease. We also assessed variation in initial thiopurine and infliximab dosage and in nutritional therapy. RESULTS: Diagnostic studies in which care was uniform included complete blood count, performed in 100% of patients, erythrocyte sedimentation rate and colonoscopy in 96%, and upper endoscopy in 89%. However, imaging of the small bowel had not been performed in 19%, and a stool test for pathogens had not been performed in 29%. Thiopurine methyltransferase (TPMT) had been measured in 61% of patients before treatment with a thiopurine; in 85%, TPMT was normal. Nonetheless, even when TPMT was normal, 40% of patients received an initial dose of thiopurine that was lower than recommended. Testing for tuberculosis before initiating treatment with infliximab was not performed in 30%. In addition, 36% of severely underweight patients were not receiving a multivitamin supplement, supplemental formula, or tube feeding. CONCLUSIONS: There is variation in diagnostic and therapeutic interventions in the management of pediatric Crohn disease, and gaps exist between recommended and actual care.

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.

Free and Bioavailable 25-Hydroxyvitamin D Concentrations are Associated With Disease Activity in Pediatric Patients With Newly Diagnosed Treatment Naïve Ulcerative Colitis.

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.

Serologic Reactivity Reflects Clinical Expression of Ulcerative Colitis in Children.

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.

Long ncRNA Landscape in the Ileum of Treatment-Naive Early-Onset Crohn Disease.

Background: Long noncoding RNAs (lncRNA) are key regulators of gene transcription and many show tissue-specific expression. We previously defined a novel inflammatory and metabolic ileal gene signature in treatment-naive pediatric Crohn disease (CD). We now extend our analyses to include potential regulatory lncRNA. Methods: Using RNAseq, we systematically profiled lncRNAs and protein-coding gene expression in 177 ileal biopsies. Co-expression analysis was used to identify functions and tissue-specific expression. RNA in situ hybridization was used to validate expression. Real-time polymerase chain reaction was used to test lncRNA regulation by IL-1ß in Caco-2 enterocytes. Results: We characterize widespread dysregulation of 459 lncRNAs in the ileum of CD patients. Using only the lncRNA in discovery and independent validation cohorts showed patient classification as accurate as the protein-coding genes, linking lncRNA to CD pathogenesis. Co-expression and functional annotation enrichment analyses across several tissues and cell types 1showed that the upregulated LINC01272 is associated with a myeloid pro-inflammatory signature, whereas the downregulated HNF4A-AS1 exhibits association with an epithelial metabolic signature. We confirmed tissue-specific expression in biopsies using in situ hybridization, and validated regulation of prioritized lncRNA upon IL-1ß exposure in differentiated Caco-2 cells. Finally, we identified significant correlations between LINC01272 and HNF4A-AS1 expression and more severe mucosal injury. Conclusions: We systematically define differentially expressed lncRNA in the ileum of newly diagnosed pediatric CD. We show lncRNA utility to correctly classify disease or healthy states and demonstrate their regulation in response to an inflammatory signal. These lncRNAs, after mechanistic exploration, may serve as potential new tissue-specific targets for RNA-based interventions.

Factors associated with early outcomes following standardised therapy in children with ulcerative colitis (PROTECT): a multicentre inception cohort study.

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.

Dissecting Allele Architecture of Early Onset IBD Using High-Density Genotyping.

BACKGROUND: The inflammatory bowel diseases (IBD) are common, complex disorders in which genetic and environmental factors are believed to interact leading to chronic inflammatory responses against the gut microbiota. Earlier genetic studies performed in mostly adult population of European descent identified 163 loci affecting IBD risk, but most have relatively modest effect sizes, and altogether explain only ~20% of the genetic susceptibility. Pediatric onset represents about 25% of overall incident cases in IBD, characterized by distinct disease physiology, course and risks. The goal of this study is to compare the allelic architecture of early onset IBD with adult onset in population of European descent. METHODS: We performed a fine mapping association study of early onset IBD using high-density Immunochip genotyping on 1008 pediatric-onset IBD cases (801 Crohn's disease; 121 ulcerative colitis and 86 IBD undetermined) and 1633 healthy controls. Of the 158 SNP genotypes obtained (out of the 163 identified in adult onset), this study replicated 4% (5 SNPs out of 136) of the SNPs identified in the Crohn's disease (CD) cases and 0.8% (1 SNP out of 128) in the ulcerative colitis (UC) cases. Replicated SNPs implicated the well known NOD2 and IL23R. The point estimate for the odds ratio (ORs) for NOD2 was above and outside the confidence intervals reported in adult onset. A polygenic liability score weakly predicted the age of onset for a larger collection of CD cases (p< 0.03, R2= 0.007), but not for the smaller number of UC cases. CONCLUSIONS: The allelic architecture of common susceptibility variants for early onset IBD is similar to that of adult onset. This immunochip genotyping study failed to identify additional common variants that may explain the distinct phenotype that characterize early onset IBD. A comprehensive dissection of genetic loci is necessary to further characterize the genetic architecture of early onset IBD.

Pediatric Crohn disease patients exhibit specific ileal transcriptome and microbiome signature.

Interactions between the host and gut microbial community likely contribute to Crohn disease (CD) pathogenesis; however, direct evidence for these interactions at the onset of disease is lacking. Here, we characterized the global pattern of ileal gene expression and the ileal microbial community in 359 treatment-naive pediatric patients with CD, patients with ulcerative colitis (UC), and control individuals. We identified core gene expression profiles and microbial communities in the affected CD ilea that are preserved in the unaffected ilea of patients with colon-only CD but not present in those with UC or control individuals; therefore, this signature is specific to CD and independent of clinical inflammation. An abnormal increase of antimicrobial dual oxidase (DUOX2) expression was detected in association with an expansion of Proteobacteria in both UC and CD, while expression of lipoprotein APOA1 gene was downregulated and associated with CD-specific alterations in Firmicutes. The increased DUOX2 and decreased APOA1 gene expression signature favored oxidative stress and Th1 polarization and was maximally altered in patients with more severe mucosal injury. A regression model that included APOA1 gene expression and microbial abundance more accurately predicted month 6 steroid-free remission than a model using clinical factors alone. These CD-specific host and microbe profiles identify the ileum as the primary inductive site for all forms of CD and may direct prognostic and therapeutic approaches.

Retrospective cohort study of methotrexate use in the treatment of pediatric Crohn's disease.

BACKGROUND: Methotrexate (MTX) use as an alternative to thiopurines in the treatment of Crohn's disease (CD) in children is increasing. This study was undertaken to assess safety and efficacy of MTX in children with CD. METHODS: Patients treated with MTX with a minimum of 1-year follow-up were identified in the Pediatric IBD Collaborative Research Group Registry, a prospective inception cohort study started in 2002. The clinical efficacy and safety of MTX were analyzed retrospectively. RESULTS: Two hundred ninety patients treated with MTX were identified. One hundred seventy-two patients received at least 3 months of MTX without thiopurine or biologicals and had ≥1 year of follow-up. Eighty-one of 172 patients (47%) received MTX as first immunomodulator (IMM), of which 22 (27%) achieved ≥12 months of sustained clinical remission without surgery, thiopurine, biologicals, or corticosteroids. Those receiving MTX as second IMM achieved similar remission rate (35%, P = not significant). Fourteen percent received MTX as first IMM in 2002 and 60% in 2010 (P = 0.005). Disease location did not affect outcomes. MTX doses were equivalent in both groups. Fifteen percent of patients developed an alanine aminotransferase >60 international units/liter and 12% developed a white blood cell <4000 cells per microliter while on MTX. Only 4% of these discontinued MTX completely. A small group of 6 centers, which contributed only about one-third of patients with CD in the registry, contributed nearly two-thirds of the patients receiving MTX (P < 0.001). CONCLUSIONS: MTX use as first choice IMM is increasing in pediatric CD. MTX provided sustained clinical remission in nearly one-third of patients with minimal toxicity. There is large center-to-center variability in its use.

The inflammatory bowel disease live interinstitutional and interdisciplinary videoconference education (IBD LIVE) series.

BACKGROUND: Managing patients with inflammatory bowel disease requires multidisciplinary coordination. Technological advances have enhanced access to care for patients and improved physician interactions. The primary aim of our project was to convene diverse institutions and specialties through a multisite virtual conferencing platform to discuss complex patient management. METHODS: The case conference is designed to include multiple institutions to exchange ideas, review evidence-based data, and provide input on the management of patients with Crohn's disease and ulcerative colitis. Technology is supplied and coordinated by an information technology specialist and Chorus Call, Inc., an international teleconferencing service provider. The Inflammatory Bowel Disease Live Interinstitutional Interdisciplinary Videoconference Education (IBD LIVE) initiative is accredited by the University of Pittsburgh Medical Center (UPMC) Center for Continuing Education in the Health Sciences for 1 AMA PRA Category 1 Credit per weekly session. RESULTS: IBD LIVE began in 2009 comprising only adult gastroenterology and pediatric gastroenterology from UPMC Presbyterian and Children's Hospitals. Participation steadily increased from 5 sites in 2010 to 11 sites in 2014. Maximum attendance for a single conference was 73 participants with a median of 48. The Continuing Medical Education scores (1 = worst to 5 = best) have a high median overall score (4.6, range 3.2-5.0) with positive responses with regard to the degree to which the conference changed practice. CONCLUSIONS: IBD LIVE has been successful and continues to grow. Implementation of the Crohn's and Colitis Foundation of America Virtual Preceptor Program using the IBD LIVE platform will provide expanded national physician access to this professional education activity.