Gene Expression Changes Associated with Resistance to Intravenous Corticosteroid Therapy in Children with Severe Ulcerative Colitis

Microarray analysis of RNA expression allows gross examination of pathways operative in inflammation. We aimed to determine whether genes expressed in whole blood early following initiation of intravenous corticosteroid treatment can be associated with response.From a prospectively accrued cohort of 128 pediatric patients hospitalized for intravenous corticosteroid treatment of severe UC, we selected for analysis 20 corticosteroid responsive (hospital discharge or PUCAI ≤45 by day 5) and 20 corticosteroid resistant patients (need for second line medical therapy or colectomy, or PUCAI >45 by day 5). Total RNA was extracted from blood samples collected on day 3 of intravenous corticosteroid therapy. The eluted transcriptomes were quantified on Affymetrix Human Gene 1.0 ST arrays. The data was analysed by the local-pooled error method for discovery of differential gene expression and false discovery rate correction was applied to adjust for multiple comparisons.A total of 41 genes differentially expressed between responders and non-responders were detected with statistical significance. Two of these genes, CEACAM1 and MMP8, possibly inhibited by methylprednisolone through IL8, were both found to be over-expressed in non-responsive patients. ABCC4 (MRP4) as a member of the multi-drug resistance superfamily was a novel candidate gene for corticosteroid resistance. The expression pattern of a cluster of 10 genes selected from the 41 significant hits were able to classify the patients with 80% sensitivity and 80% specificity.Elevated expression of several genes involved in inflammatory pathways was associated with resistance to intravenous corticosteroid therapy early in the course of treatment. Gene expression profiles may be useful to classify resistance to intravenous corticosteroids in children with severe UC and assist with clinical management decisions

Serologic, but Not Genetic, Markers Are Associated With Impaired Anthropometrics at Diagnosis of Pediatric Crohn's Disease

Objectives: Children with Crohn's disease may present with malnutrition and linear growth impairment, which can be secondary to insufficient caloric intake, chronic inflammation, malabsorption, and suppression of growth-promoting hormones. We evaluated clinical, serologic, and genetic data to determine risk factors for impaired anthropometrics in Crohn's disease at diagnosis. Methods: Our study evaluated 772 children newly diagnosed with Crohn's disease, inflammatory phenotype, enrolled in the RISK Stratification Project to determine the factors associated with anthropometric impairment. Data were collected on demographics, growth parameters, disease location, serologic and immunologic markers, and disease severity. We performed a genome-wide association study of genetic polymorphisms associated with inflammatory bowel disease. Regression analysis determined associations between anthropometrics and clinical, serologic, and genetic variables. Results: There were 59 (7%) children with height z score <−2, 126 (14%) with a weight z score <−2, and 156 (17%) with a body mass index z score <−2. Linear growth impairment was associated with hypoalbuminemia (P = 0.0052), elevated granulocyte-macrophage colony stimulating factor autoantibodies (P = 0.0110), and elevated CBir antibodies against flagellin (P = 0.0117). Poor weight gain was associated with female sex (P = 0.0401), hypoalbuminemia (P = 0.0162), and thrombocytosis (P = 0.0081). Malnutrition was associated with hypoalbuminemia (P = 0.0061) and thrombocytosis (P = 0.0011). Children with moderate or severe disease had lower weight (P = 0.02 and P = 1.16×10−6, respectively) and body mass index z scores (P = 2.7 × 10−3 and P = 1.01 × 10−6, respectively) than children with quiescent and mild disease. There was no association between age of diagnosis, Tanner stage, or disease location and having impaired anthropometrics. There was no genome-wide association between the genetic polymorphisms and the serologic variables and anthropometric measurements. Conclusions: This is the largest study evaluating growth in treatment-naïve children with Crohn's disease, inflammatory phenotype. It is the first study to use genome-wide sequencing to assess for genetic determinants of growth impairment. Granulocyte-macrophage colony stimulating factor autoantibodies and CBir antibodies are more likely to be elevated in children with growth impairment. Future investigations should evaluate the relationship between genetic polymorphisms, pathologic immune responses, and the biological pathways regulating growth

Long-Term Efficacy and Safety of Adalimumab in Pediatric Patients with Crohn's Disease

Background: IMAgINE 1 assessed 52-week efficacy and safety of adalimumab in children with moderate to severe Crohn's disease. Long-Term efficacy and safety of adalimumab for patients who entered the IMAgINE 2 extension are reported. Methods: Patients who completed IMAgINE 1 could enroll in IMAgINE 2. Endpoints assessed from weeks 0 to 240 of IMAgINE 2 were Pediatric Crohn's Disease Activity Index remission (Pediatric Crohn's Disease Activity Index ≤ 10) and response (Pediatric Crohn's Disease Activity Index decrease ≥15 from IMAgINE 1 baseline) using observed analysis and hybrid nonresponder imputation (hNRI). For hNRI, discontinued patients were imputed as failures unless they transitioned to commercial adalimumab (with study site closure) or adult care, where last observation was carried forward. Corticosteroid-free remission in patients receiving corticosteroids at IMAgINE 1 baseline, discontinuation of immunomodulators (IMMs) in patients receiving IMMs at IMAgINE 2 baseline, and linear growth improvement were reported as observed. Adverse events were assessed for patients receiving ≥1 adalimumab dose in IMAgINE 1 and 2 through January 2015. Results: Of 100 patients enrolled in IMAgINE 2, 41% and 48% achieved remission and response (hNRI) at IMAgINE 2 week 240. Remission rates were maintained by 45% (30/67, hNRI) of patients who entered IMAgINE 2 in remission. At IMAgINE 2 week 240, 63% (12/19) of patients receiving corticosteroids at IMAgINE 1 baseline achieved corticosteroid-free remission and 30% (6/20) of patients receiving IMMs at IMAgINE 2 baseline discontinued IMMs. Adalimumab treatment led to growth velocity normalization. No new safety signals were identified. Conclusions: Efficacy and safety profiles of prolonged adalimumab treatment in children with Crohn's disease were consistent with IMAgINE 1 and adult Crohn's disease adalimumab trials

Designing clinical trials in paediatric inflammatory bowel diseases:a PIBDnet commentary

Introduction: The optimal trial design for assessing novel therapies in paediatric IBD (PIBD) is a subject of intense ongoing global discussions and debate among the different stakeholders. However, there is a consensus that the current situation in which most medications used in children with IBD are prescribed as off-label without sufficient paediatric data is unacceptable. Shortening the time lag between adult and paediatric approval of drugs is of the upmost importance. In this position paper we aimed to provide guidance from the global clinical research network (Pediatric Inflammatory Bowel Disease Network, PIBDnet) for designing clinical trials in PIBD in order to facilitate drug approval for children. Methods: A writing group has been established by PIBDnet and topics were assigned to different members. After an iterative process of revisions among the writing group and one face-to-face meeting, all statements have reached consensus of &gt;80% as defined a priori. Next, all core members of PIBDnet voted on the statements, reaching consensus of &gt;80% on all statements. Comments from the members were incorporated in the text. Results: The commentary includes 18 statements for guiding data extrapolation from adults, eligibility criteria to PIBD trials, use of placebo, dosing, endpoints and recommendations for feasible trials. Controversial issues have been highlighted in the text. Conclusion: The viewpoints expressed in this paper could assist planning clinical trials in PIBD which are both of high quality and ethical, while remaining pragmatic

Magnetic Resonance Enterography Cannot Replace Upper Endoscopy in Pediatric Crohn Disease: An Imagekids Sub-study

Objectives: Although magnetic resonance enterography (MRE) can accurately reflect ileal inflammation in pediatric Crohn disease (CD), there are no pediatric data on the accuracy of MRE to detect upper gastrointestinal tract (UGI) lesions. We aimed to compare MRE and esophagogastroduodenoscopy (EGD) in detecting the spectrum and severity of UGI disease in children. Methods: This is an ancillary study of the prospective multi-center ImageKids study focusing on pediatric MRE. EGD was performed within 2 weeks of MRE (at disease onset or thereafter) and explicitly scored by SES-CD modified for the UGI and physician global assessment. Local and central radiologists scored the UGI region of the MRE blinded to the EGD. Accuracy of MRE compared with EGD was examined using correlational coefficients (r) and area under receiver operating characteristic curves (AUC). Results: One hundred and eighty-eight patients were reviewed (mean age 14 +/- 1 years, 103 [55%] boys);66 of 188 (35%) children had macroscopic ulcerations on EGD (esophagus, 13 [7%];stomach, 34 [18%];duodenum, 45 [24%]). Most children had aphthous ulcers, but 10 (5%) had larger ulcers (stomach, 2 [1%];duodenum, 8 [4%]). There was no agreement between local and central radiologists on the presence or absence of UGI inflammation on MRE (Kappa=0.02, P - 0.71). EGD findings were not accurately detected by MRE, read locally or centrally (r=-0.03 to 0.11, P = 0.18-0.88;AUC - 0.47-0.55, P = 0.53-1.00).No fistulae or narrowings were identified on either EGD or MRE. Conclusions: MRE cannot reliably assess the UGI in pediatric CD and cannot replace EGD for this purpose

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 car

Natural History of Very Early Onset Inflammatory Bowel Disease in North America: A Retrospective Cohort Study

Background: The incidence of very early onset inflammatory bowel disease (VEOIBD) is increasing, yet the phenotype and natural history of VEOIBD are not well described. Methods: We performed a retrospective cohort study of patients diagnosed with VEOIBD (6 years of age and younger) between 2008 and 2013 at 25 North American centers. Eligible patients at each center were randomly selected for chart review. We abstracted data at diagnosis and at 1, 3, and 5 years after diagnosis. We compared the clinical features and outcomes with VEOIBD diagnosed younger than 3 years of age with children diagnosed with VEOIBD at age 3 to 6 years. Results: The study population included 269 children (105 [39%] Crohn\u27s disease, 106 [39%] ulcerative colitis, and 58 [22%] IBD unclassified). The median age of diagnosis was 4.2 years (interquartile range 2.9-5.2). Most (94%) Crohn\u27s disease patients had inflammatory disease behavior (B1). Isolated colitis (L2) was the most common disease location (70% of children diagnosed younger than 3 years vs 43% of children diagnosed 3 years and older; P = 0.10). By the end of follow-up, stricturing/penetrating occurred in 7 (6.6%) children. The risk of any bowel surgery in Crohn\u27s disease was 3% by 1 year, 12% by 3 years, and 15% by 5 years and did not differ by age at diagnosis. Most ulcerative colitis patients had pancolitis (57% of children diagnosed younger than 3 years vs 45% of children diagnosed 3 years and older; P = 0.18). The risk of colectomy in ulcerative colitis/IBD unclassified was 0% by 1 year, 3% by 3 years, and 14% by 5 years and did not differ by age of diagnosis. Conclusions: Very early onset inflammatory bowel disease has a distinct phenotype with predominantly colonic involvement and infrequent stricturing/penetrating disease. The cumulative risk of bowel surgery in children with VEOIBD was approximately 14%-15% by 5 years. These data can be used to provide anticipatory guidance in this emerging patient population

Prediction of complicated disease course for children newly diagnosed with Crohn's disease: a multicentre inception cohort study

Stricturing and penetrating complications account for substantial morbidity and health-care costs in paediatric and adult onset Crohn’s disease. Validated models to predict risk for complications are not available, and the effect of treatment on risk is unknown

Analysis of Using the Total White Blood Cell Count to Define Severe New-onset Ulcerative Colitis in Children

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

Cloning and variation of ground state intestinal stem cells

Stem cells of the gastrointestinal tract, pancreas, liver, and other columnar epithelia collectively resist cloning in their elemental states. Here we demonstrate the cloning and propagation of highly clonogenic, “ground state” stem cells of the human intestine and colon. We show that derived stem cell pedigrees sustain limited copy number and sequence variation despite extensive serial passaging and display exquisitely precise, cell-autonomous commitment to epithelial differentiation consistent with their origins along the intestinal tract. This developmentally patterned and epigenetically maintained commitment of stem cells likely enforces the functional specificity of the adult intestinal tract. Using clonally-derived colonic epithelia, we show that toxins A or B of the enteric pathogen C. difficile recapitulate the salient features of pseudomembranous colitis. The stability of the epigenetic commitment programs of these stem cells, coupled with their unlimited replicative expansion and maintained clonogenicity, suggests certain advantages for their use in disease modeling and regenerative medicine