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Background Transmural healing (TH) is associated with better long-term outcomes in Crohn disease (CD), whereas pretreatment ileal gene signatures encoding myeloid inflammatory responses and extracellular matrix production are associated with stricturing. We aimed to develop a predictive model for ileal TH and to identify ileal genes and microbes associated with baseline luminal narrowing (LN), a precursor to strictures. Materials and Methods Baseline small bowel imaging obtained in the RISK pediatric CD cohort study was graded for LN. Ileal gene expression was determined by RNASeq, and the ileal microbial community composition was characterized using 16S rRNA amplicon sequencing. Clinical, demographic, radiologic, and genomic variables were tested for association with baseline LN and future TH. Results After controlling for ileal location, baseline ileal LN (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.1-0.8), increasing serum albumin (OR, 4; 95% CI, 1.3-12.3), and anti-Saccharomyces cerevisiae antibodies IgG serology (OR, 0.97; 95% CI, 0.95-1) were associated with subsequent TH. A multivariable regression model including these factors had excellent discriminant power for TH (area under the curve, 0.86; positive predictive value, 80%; negative predictive value, 87%). Patients with baseline LN exhibited increased Enterobacteriaceae and inflammatory and extracellular matrix gene signatures, coupled with reduced levels of butyrate-producing commensals and a respiratory electron transport gene signature. Taxa including Lachnospiraceae and the genus Roseburia were associated with increased respiratory and decreased inflammatory gene signatures, and Aggregatibacter and Blautia bacteria were associated with reduced extracellular matrix gene expression. Conclusions Pediatric patients with CD with LN at diagnosis are less likely to achieve TH. The association between specific microbiota, wound healing gene programs, and LN may suggest future therapeutic targets.

Environmental factors play an important role in the pathogenesis of Crohn's Disease (CD). In particular, by virtue of the instability of the microbiome and development of immunologic tolerance, early life factors may exert the strongest influence on disease risk and phenotype.We used data from 1119 CD subjects recruited from RISK inception cohort to examine the impact of early life environment on disease progression. Our primary exposures of interest were breastfeeding in infancy and exposure to maternal, active, or passive smoke. Our primary outcomes were development of complicated (stricturing or penetrating) disease, and need for CD-related hospitalization, and surgery. Multivariable logistic regression models were used to define independent associations, adjusting for relevant covariates.Our study cohort included 1119 patients with CD among whom 15% had stricturing (B2) or penetrating disease (B3) by 3 years. 331 patients (35%) and 95 patients (10.6%) required CD-related hospitalizations and surgery respectively. 74.5% were breastfed in infancy and 31% were exposed to smoking among whom 7% were exposed to maternal smoke. On multivariable analysis, a history of breastfeeding was inversely associated with complicated (B2/B3 disease) 0.65, CI 95% 0.44-96; P = 0.03) in pediatric CD. Maternal smoking during pregnancy was associated with increased risk of hospitalization during the 3-year follow-up period (OR 1.75, CI 95% 1.05-2.89; P = 0.03).Early life environmental factors influence the eventual phenotypes and disease course in CD.

Author(s): Denson, Lee A; Jurickova, Ingrid; Karns, Rebekah; Shaw, Kelly A; Cutler, David J; Okou, David; Valencia, C Alexander; Dodd, Anne; Mondal, Kajari; Aronow, Bruce J; Haberman, Yael; Linn, Aaron; Price, Adam; Bezold, Ramona; Lake, Kathleen; Jackson, Kimberly; Walters, Thomas D; Griffiths, Anne; Baldassano, Robert N; Noe, Joshua D; Hyams, Jeffrey S; Crandall, Wallace V; Kirschner, Barbara S; Heyman, Melvin B; Snapper, Scott; Guthery, Stephen L; Dubinsky, Marla C; Leleiko, Neal S; Otley, Anthony R; Xavier, Ramnik J; Stevens, Christine; Daly, Mark J; Zwick, Michael E; Kugathasan, Subra | Abstract: BACKGROUND:Granulocyte-macrophage colony-stimulating factor auto-antibodies (GMAbs) suppress neutrophil-extrinsic GM-CSF signaling and increase risk for stricturing behavior in Crohn's disease (CD). We aimed to define clinical, genomic, and functional associations with neutrophil-intrinsic GM-CSF signaling. METHODS:Missense mutations in CSF2RA, CSF2RB, JAK2, STAT5A, and STAT5B were identified using whole-exome sequencing in 543 pediatric inflammatory bowel disease (IBD) patients. Neutrophil-intrinsic GM-CSF signaling was defined using the GM-CSF-induced STAT5 stimulation index (GMSI) in 180 pediatric IBD patients and 26 non-IBD controls. Reduced GM-CSF signaling (GMSI-Lo) was defined as the 20th percentile within the control group. Variation in neutrophil phospho-protein abundance, bacterial killing, and the global pattern of gene expression with the GMSI was determined. RESULTS:We validated 18 potentially damaging missense mutations in CSF2RA and CSF2RB. CSF2RA A17G carriage increased from 10% in those with intact neutrophil GMSI to 32% in those with low GMSI (P = 0.02). The frequency of reduced Staphylococcus aureus killing increased from 17% in those with intact neutrophil GMSI to 35% in GMSI-Lo neutrophils (P = 0.043). Crohn's disease neutrophils with low GMSI exhibited specific alterations in phospho-protein networks and genes regulating cytokine production, wound healing, and cell survival and proliferation. Stricturing behavior increased from 7% in patients with both low GMAb and intact GMSI to 64% in patients with both elevated GMAb and low GMSI (P l 0.0001). CONCLUSIONS:Low/normal neutrophil-intrinsic GM-CSF signaling is associated with CSF2RA missense mutations, alterations in gene expression networks, and higher rates of disease complications in pediatric CD.

Background & aimsIndividuals with monogenic disorders of phagocyte function develop chronic colitis that resembles Crohn's disease (CD). We tested for associations between mutations in genes encoding reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, neutrophil function, and phenotypes of CD in pediatric patients.MethodsWe performed whole-exome sequence analysis to identify mutations in genes encoding NADPH oxidases (such as CYBA, CYBB, NCF1, NCF2, NCF4, RAC1, and RAC2) using DNA from 543 pediatric patients with inflammatory bowel diseases. Blood samples were collected from an additional 129 pediatric patients with CD and 26 children without IBD (controls); we performed assays for neutrophil activation, reactive oxygen species (ROS) production, and bacteria uptake and killing. Whole-exome sequence analysis was performed using DNA from 46 of the children with CD to examine associations with NADPH gene mutations; RNA sequence analyses were performed using blood cells from 46 children with CD to test for variations in neutrophil gene expression associated with ROS production.ResultsWe identified 26 missense mutations in CYBA, CYBB, NCF1, NCF2, and NCF4. Patients with CD who carried mutations in these genes were 3-fold more likely to have perianal disease (P= .0008) and stricturing complications (P= .002) than children with CD without these mutations. Among patients withCD with none of these mutations, 9% had undergone abdominal surgery; among patients with mutations in these NADPH oxidase genes, 31% had undergone abdominal surgery (P=.0004). A higher proportion of neutrophils from children with CD had low ROS production (47%) than from controls (15%) among the 129 patients tested for ROS (P= .002). Minor alleles of the NADPH genes were detected in 7% of children with CD whose neutrophils produced normal levels of ROS vs 38% of children whose neutrophils produced low levels of ROS (P= .009). Neutrophils that produced low levels of ROS had specific alterations in genes that regulate glucose metabolism and antimicrobial responses.ConclusionsWe identified missense mutations in genes that encode NADPH oxidases in children with CD; these were associated with a more aggressive disease course and reduced ROS production by neutrophils from the patients.

Background Predicting Crohn’s disease (CD) phenotype development has proven challenging due to difficulties in biopsy image interpretation of histologically similar yet biologically distinct phenotypes. At initial diagnosis, mostly CD patients are classified as B1 (inflammatory behavior), they typically either retain B1 phenotype or develop more complicated B2 (stricturing), B3 (internal penetrating), or B2/B3 phenotypes (defined by Montreal Classification). Prediction of phenotype development based on baseline biopsies can radically improve our clinical care by altering disease management. Biopsy-based image analysis via Convolutional Neural Networks (CNNs) has been successful in cancer detection, but investigation into its utility for CD phenotypes is lacking. We applied a machine learning CNN model to classify CD phenotypes and histologically normal ileal controls. Methods Baseline hematoxylin & eosin (H&E) stained ileal biopsy slides were obtained from the Cincinnati Children’s Hospital Medical Center’s RISK validation sub cohort. At University of Virginia, biopsy slides were digitized, and a ResNet101 CNN model was trained. High resolution images were patched into 1000x1000 pixels with a 50% overlap and then resized to 256x256 pixels for training (80-20 split was kept between training and testing sets to ensure same patient patches were not mixed). Gradient Weighted Activating Mappings (GradCAMs) were used to visualize the model’s decision making process. Results We initially trained the model for CD vs. controls where it achieved 97% accuracy in detecting controls. We further trained it for classifying CD phenotypes (n=16 B1, n=16 B2, n=4 B3, n=13 B2/B3; phenotype decision at 5 year). It displayed a higher accuracy in detecting B2 (85%) while there were overlaps in the detection of other phenotypes (Figure 1). For B2, Grad-CAM heatmaps highlighted central pink areas within the lamina propria as the model’s regions of interests which were present when other phenotypes were misclassified as B2 (Figure 2). Conclusions: Here we highlight the potential utility of a machine learning image analysis model for describing CD phenotypes using H&E stained biopsies. Previous studies have shown B2 to be associated with increased activation for extracellular matrix genes (connective tissue component). Our GradCAM results support this finding as the pink central areas utilized by the model for classifying B2 could be connective tissue. Further confirmation via molecular phenotyping including Sirius Red immunohistochemistry is underway. Our work supports prediction of CD phenotypes using baseline biopsies at diagnosis and has potential to influence individualized care for children with CD.

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.

OBJECTIVES The aim of the study was to prospectively study changes in prevalence of positive family history (FH+) in pediatric-onset inflammatory bowel disease (IBD) in contrast to previously published cross-sectional data. METHODS An observational cohort study was performed using a prospective pediatric-onset IBD database including 485 patients with disease duration ≥10 years as of December 2016. Proband characteristics and FH+ were obtained at diagnosis and subsequently from the database, medical records, and follow-up telephone interviews in 2006 and 2016. RESULTS Updated 2016 information was obtained from 322 (66%) patients and included in analysis with median follow-up of 18 years (interquartile range 14, 26). Prevalence of FH+ increased from 13.7% at diagnosis to 26.6% at 20 years for first-degree relatives and from 38.5% to 52.2% for all relatives. At 20-year follow-up, an additional 10.0% of probands had a sibling, 6.1% had a parent, 1.9% had a grandparent, and 4.5% had a cousin diagnosed with IBD. FH+ at diagnosis was associated with greater risk for additional FH+ at 20 years (43% vs 22%, P

Chronic inflammatory disorders are thought to arise due to an interplay between predisposing host genetics and environmental factors. For example, the onset of inflammatory bowel disease is associated with enteric proteobacterial infection, yet the mechanistic basis for this association is unclear. We have shown previously that genetic defiency in TLR1 promotes acute enteric infection by the proteobacteria Yersinia enterocolitica. Examining that model further, we uncovered an altered cellular immune response that promotes the recruitment of neutrophils which in turn increases metabolism of the respiratory electron acceptor tetrathionate by Yersinia. These events drive permanent alterations in anti-commensal immunity, microbiota composition, and chronic inflammation, which persist long after Yersinia clearence. Deletion of the bacterial genes involved in tetrathionate respiration or treatment using targeted probiotics could prevent microbiota alterations and inflammation. Thus, acute infection can drive long term immune and microbiota alterations leading to chronic inflammatory disease in genetically predisposed individuals.

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-1β 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-1β 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.

Summary Background 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. Methods We did a prospective inception cohort study of paediatric patients with newly diagnosed Crohn's disease at 28 sites in the USA and Canada. Genotypes, antimicrobial serologies, ileal gene expression, and ileal, rectal, and faecal microbiota were assessed. A competing-risk model for disease complications was derived and validated in independent groups. Propensity-score matching tested the effect of anti-tumour necrosis factor α (TNFα) therapy exposure within 90 days of diagnosis on complication risk. Findings Between Nov 1, 2008, and June 30, 2012, we enrolled 913 patients, 78 (9%) of whom experienced Crohn's disease complications. The validated competing-risk model included age, race, disease location, and antimicrobial serologies and provided a sensitivity of 66% (95% CI 51–82) and specificity of 63% (55–71), with a negative predictive value of 95% (94–97). Patients who received early anti-TNFα therapy were less likely to have penetrating complications (hazard ratio [HR] 0·30, 95% CI 0·10–0·89; p=0·0296) but not stricturing complication (1·13, 0·51–2·51; 0·76) than were those who did not receive early anti-TNFα therapy. Ruminococcus was implicated in stricturing complications and Veillonella in penetrating complications. Ileal genes controlling extracellular matrix production were upregulated at diagnosis, and this gene signature was associated with stricturing in the risk model (HR 1·70, 95% CI 1·12–2·57; p=0·0120). When this gene signature was included, the model's specificity improved to 71%. Interpretation Our findings support the usefulness of risk stratification of paediatric patients with Crohn's disease at diagnosis, and selection of anti-TNFα therapy. Funding Crohn's and Colitis Foundation of America, Cincinnati Children's Hospital Research Foundation Digestive Health Center.

Background & Aims Standard therapy for children newly diagnosed with Crohn's disease (CD) includes early administration of immunomodulators after initial treatment with corticosteroids. We compared the effectiveness of early (≤3 mo after diagnosis) treatment with an anti-tumor necrosis factor (TNF)α with that of an immunomodulator in attaining clinical remission and facilitating growth of pediatric patients. Methods We analyzed data from the RISK study, an observational research program that enrolled patients younger than age 17 diagnosed with inflammatory (nonpenetrating, nonstricturing) CD from 2008 through 2012 at 28 pediatric gastroenterology centers in North America. Patients were managed by physician dictate. From 552 children (median age, 11.8 y; 61% male; 63% with pediatric CD activity index scores >30; and median C-reactive protein level 5.6-fold the upper limit of normal), we used propensity score methodology to identify 68 triads of patients matched for baseline characteristics who were treated with early anti-TNFα therapy, early immunomodulator, or no early immunotherapy. We evaluated relationships among therapies, corticosteroid and surgery-free remission (pediatric CD activity index scores, ≤10), and growth at 1 year for 204 children. Treatment after 3 months was a covariate. Results Early treatment with anti-TNFα was superior to early treatment with an immunomodulator (85.3% vs 60.3% in remission; relative risk, 1.41; 95% confidence interval [CI], 1.14-1.75; P = .0017), whereas early immunomodulator therapy was no different than no early immunotherapy (60.3% vs 54.4% in remission; relative risk, 1.11; 95% CI, 0.83-1.48; P = .49) in achieving remission at 1 year. Accounting for therapy after 3 months, early treatment with anti-TNFα remained superior to early treatment with an immunomodulator (relative risk, 1.51; 95% CI, 1.20-1.89; P = .0004), whereas early immunomodulator therapy was no different than no early immunotherapy (relative risk, 1.00; 95% CI, 0.75-1.34; P = .99). The mean height z-score increased compared with baseline only in the early anti-TNFα group. Conclusions In children newly diagnosed with comparably severe CD, early monotherapy with anti-TNFα produced better overall clinical and growth outcomes at 1 year than early monotherapy with an immunomodulator. Further data will be required to best identify children most likely to benefit from early treatment with anti-TNFα therapy.

Background & Aims The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities. Methods We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P −8 in meta-analysis with a nominal evidence ( P Results We detected SNPs at HLA-DRB1 , and African-specific SNPs at ZNF649 and LSAMP , with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication ( P −6 ): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B, PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2 ) for CD; and KCNQ2 (near TNFRSF6B ) for UC. Several of these genes, such as TNC (near TNFSF15 ), CXCR6 , and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles. Conclusions We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry.

The development of disease complications is poorly characterized in pediatric patients with Crohn's disease (CD).We retrospectively determined the cumulative incidence of stricturing and penetrating complications of CD prior to first surgery utilizing data from 989 consecutively enrolled CD patients (age 0-17 years at diagnosis) collected between January 2000 and November 2003 and stored in the Pediatric IBD Consortium Registry.Mean age at diagnosis was 11.5 +/- 3.8 (standard deviation) years. Median follow-up time was 2.8 years. Prior to first surgery, the cumulative incidence of stricturing or penetrating complications was 27% at 5 years and 38% at 10 years from the diagnosis of inflammatory bowel disease. The cumulative incidence of complicated disease was lowest in isolated colonic disease (P = 0.009). Penetrating complications that followed stricturing complications prior to first surgery occurred within 2 years of stricturing complications (cumulative incidence was 13% at 2 years from diagnosis of stricturing disease). Stricturing complications that followed penetrating complications prior to first surgery occurred within 8 years of penetrating complications (cumulative incidence was 26% at 8 years from diagnosis of penetrating complications).Strictures, abscesses, and fistulas are common in pediatric CD. Earlier aggressive management may be indicated. Prospective study is required to identify genetic and serologic markers that predict a patient's risk for the development of complicated disease and to determine optimal treatment regimens.

The relationship between the age at diagnosis and disease course is poorly defined in children with Crohn's disease (CD). We examined the presentation and course of disease in patients 0-5 compared to 6-17 yr of age at diagnosis.We analyzed uniform data from 989 consecutive CD patients collected between January 2000 and November 2003, and stored in the Pediatric IBD Consortium Registry. The statistical tests account for the length of follow-up of each patient.In total, 98 patients (9.9%) were of 0-5 yr of age at diagnosis. The mean follow-up time was 5.6 +/- 5.0 yr in the younger group and 3.3 +/- 2.8 yr in the older group (P0.001). Race/ethnicity differed by the age group (P= 0.015); a larger proportion of the younger group was Asian/Pacific Islander or Hispanic, and a larger proportion of the older group was African American. The initial classification as ulcerative colitis or indeterminate colitis was more common among the 0-5 yr of age group (P0.001). The 6-17 yr of age patients presented with more abdominal pain (P0.001), weight loss (P= 0.001), or fever (P= 0.07), while the 0-5 yr of age patients presented with more rectal bleeding (P= 0.008). The 6-17 yr of age patients were more likely to be treated with antibiotics (P0.001), 6-mercaptopurine/azathioprine (P0.001), infliximab (P= 0.001), or corticosteroids (P= 0.0006). The 6-17 yr of age patients had a higher cumulative incidence of treatment with 5-aminosalicylates (P= 0.009) or methotrexate (P= 0.04). The risk for developing an abscess (P= 0.001), a fistula (P= 0.02), a stricture (P= 0.05), or a perianal fissure (P= 0.06) was greater in the 6-17 yr of age patients.The 6-17 yr of age patients with CD appear to have a more complicated disease course compared to 0-5 yr of age children. The 0-5 yr of age group may represent a unique disease phenotype and benefit from different approaches to management. Long-term prospective studies are required to validate these findings.

Objectives To determine whether long-term low-dose prednisone (LTLDP) therapy has a decelerating effect on growth velocity and whether this therapy is effective in the maintenance of remission in the subgroup of pediatric patients with Crohn disease (CD) who had previously experienced flares on more than 1 occasion when prednisone was discontinued. Patients and methods A retrospective chart review of patients was done. Our sample consisted of patients 6 to 17 years of age with CD who had received uninterrupted prednisone at an average daily dose of 0.1 to 0.4 mg x kg(-1) x day(-1) for at least 8 weeks. Their heights were plotted on sex-appropriate growth charts at 4 time points: 1 year before LTLDP, at therapy onset, at therapy discontinuation, and 1 year after therapy was discontinued. The height velocities (HVs) were compared with the normal HV established by Tanner. The disease activities of 2 groups were compared: LTLDP plus azathioprine/6-mercaptopurine (AZA/6-MP) and LTLDP alone. Results One hundred two patients were included. The mean age of our sample was 13.7 +/- 2.7 years (standard deviation). The mean dose of prednisone dose was 0.18 +/- 0.07 mg x kg(-1) x day(-1)), for a mean duration of therapy of 14.4 +/- 7.2 months. Throughout the study, 78% of patients had normal HV. Growth deceleration was seen in 19% of patients with prior normal growth. Of this group, 31% had "catch-up" growth 1 year after prednisone was discontinued; the remaining 69% did not. Catch-up growth was more likely in patients who had reached the expected age peak HV, which is defined as 12.5 years for girls and 13.5 years for boys (P = 0.04). In addition, 6 patients reached the peak HV after LTLDP discontinuation; 13 did not. We found no difference in the maintenance of remission rate between the compared groups. Conclusions A minority of our study population had growth deceleration. Age was an important factor for subsequent catch-up growth. LTLDP efficacy to maintain remission was not different from that of LTLDP plus AZA/6-MP; differences in concomitant therapies (eg, antibiotics, infliximab) between the 2 groups were not statistically significant.

BACKGROUND Rare variants (

The majority of patients with chronic inflammatory bowel disease (IBD) are diagnosed with either ulcerative colitis (UC) or Crohn’s disease (CD) on the basis of established clinical, endoscopic, histologic, and radiologic criteria. However, in 5–23 % of patients with chronic colitis, a definitive diagnosis of UC or CD cannot be established because the initial macroscopic appearance (either during ileocolonoscopy or following colectomy) and histologic features overlap between UC and CD. While most of these patients eventually evolve into patterns consistent with UC or CD, approximately 20–60 % retain the diagnosis of indeterminate colitis (IC) over periods as long as 5–10 years post diagnosis. This latter observation suggests that IC may constitute a separate category within the spectrum of IBD. This chapter reviews the histologic and clinical features of IC in pediatric patients and contains updated information explaining why some patients continue to be diagnosed with IC (new proposed terminology of IBD-unclassified (IBD-U).For the present, IC and IBD-U refer to chronic colitis due to idiopathic IBD for which the features of CD and UC are absent. It has been suggested that the term IC should be the preferred term after histologic evaluation of the resected colon and IBD-U used after review of biopsy specimens.

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.

The cumulative incidence of surgery ranges from 40%-70% at 10 years from the time of diagnosis of Crohn's disease in adults. We retrospectively determined the cumulative incidence of and risk factors for surgery (intestinal resection) in pediatric patients with Crohn's disease.Uniform data from 989 consecutive Crohn's disease patients (age 0-17 years at diagnosis), collected from 6 different pediatric centers between January 2000 and November 2003 and stored in the Pediatric IBD Consortium Registry, were analyzed.Median follow-up time was 2.8 years (range, 1 day to 16.7 years). One hundred twenty-eight patients underwent surgery. Kaplan-Meier survival estimates of the cumulative incidence of surgery were 17% at 5 years and 28% at 10 years from the diagnosis of inflammatory bowel disease. Univariate Cox proportional hazards models showed leukocytosis (2.85 [hazard ratio]; P = .02), hypoalbuminemia (3.41; P = .05), and anti-Saccharomyces cerevisiae antibody (ASCA) positivity (3.43; P = .05) were associated with increased risk for surgery. Multivariate Cox models showed female gender (1.49; P = .03), initial diagnosis of ulcerative colitis (3.63; P.0001), poor growth at presentation (2.16; P = .007), and abscess (1.90; P = .009), fistula (2.30; P = .0005), or stricture (3.41; P.0001) development were associated with increased risk for surgery. Age 3-5 years (0.26; P = .01) or 6-12 years (0.62; P = .01) at diagnosis, fever at presentation (0.50; P = .03), and treatment with infliximab (0.36; P = .0005) or 5-aminosalicylic acid (0.44; P.0001) were associated with decreased risk for surgery.Risk stratification during the course of Crohn's disease in pediatric patients will help to guide therapy that may improve the natural history of disease and decrease the need for surgery.

Objectives: The objectives of this study were to evaluate the safety, pharmacokinetics, and immunogenicity of CDP571 in pediatric patients with Crohn's disease. Methods: A single dose of CDP571, 10 mg/kg, was administered by infusion to pediatric patients (aged 6–17 years) with Crohn's disease in a 12-week open-label study. Adverse events were monitored during infusion and throughout the study. Plasma concentrations of CDP571 and standard clinical and laboratory values were assessed. Changes in disease activity were monitored using the Pediatric Crohn's Disease Activity Index (PCDAI). Results: Twenty patients were enrolled and stratified by age: 6 to 13 (n = 9) and 14 to 17 years (n = 11). Fourteen patients experienced adverse events, which were mainly mild or moderate in intensity. The plasma concentration profile was consistent with a half-life of approximately 2 weeks. At Week 4, 4 patients in the 6- to 13-year-old group and 2 patients in the 14- to 17-year-old group had detectable anti-CDP571 antibodies. By Week 2, 7 patients in the 6- to 13-year-old group and 6 patients in the 14- to 17-year-old group had responded to treatment (reduction in PCDAI score >10 points). Conclusion: In conclusion, CDP571 was well tolerated among pediatric patients with Crohn's disease.

Growth is a dynamic process that is characterized by physiological changes in an individual from infancy into adulthood. Growth should be monitored sequentially and is an important tool in the early detection of chronic disease in children. Growth occurs in three phases: infancy, childhood and puberty (adolescence). The adequacy of nutritional status can be assessed by anthropometric measurements that include height, weight and body composition as well as laboratory evaluations. Individual patients can then be compared to normative or expected values. Impaired growth and nutritional status can be seen in a variety of gastrointestinal disorders and are described in this chapter.

Crohn's disease is a chronic inflammatory disorder of the gastrointestinal tract, which is thought to result from the effect of environmental factors in a genetically predisposed host. A gene location in the pericentromeric region of chromosome 16, IBD1, that contributes to susceptibility to Crohn's disease has been established through multiple linkage studies, but the specific gene(s) has not been identified. NOD2, a gene that encodes a protein with homology to plant disease resistance gene products is located in the peak region of linkage on chromosome 16 (ref. 7). Here we show, by using the transmission disequilibium test and case-control analysis, that a frameshift mutation caused by a cytosine insertion, 3020insC, which is expected to encode a truncated NOD2 protein, is associated with Crohn's disease. Wild-type NOD2 activates nuclear factor NF-kappaB, making it responsive to bacterial lipopolysaccharides; however, this induction was deficient in mutant NOD2. These results implicate NOD2 in susceptibility to Crohn's disease, and suggest a link between an innate immune response to bacterial components and development of disease.

Background & Aims: There is evidence for the IBD1 Crohn's disease (CD) susceptibility locus on chromosome 16 in several but not all populations studied. Genetic and phenotypic heterogeneity may underlie ability to replicate IBD1 . We determined if age and severity stratification could identify a clinical subgroup at risk for IBD1 . Methods: Linkage analysis at microsatellites spanning chromosome 16 was performed in 2 groups of CD pedigrees: group 1, 57 pedigrees with at least one affected relative classified as having "severe" disease, by history of surgical resection or immunomodulator therapy, and with disease diagnosed before age 22; and group 2, 33 pedigrees with no history of early-onset, severe CD. Results: Group 1 pedigrees demonstrated genomewide significant linkage evidence for the IBD1 locus (nonparametric multipoint logarithm of the odds [Mlod], 3.84; P = 1.3 × 10 −5 ) with linkage evidence greater than all 90 pedigrees (Mlod, 2.12; P = 9.0 × 10 −4 ). Group 2 pedigrees had near zero nonparametric 2-point and Mlod scores for the IBD1 region. Heterogeneity between groups 1 and 2 was significant ( P = 0.002). Conclusions: Presence of early-onset, more severe CD identifies pedigrees at high risk for IBD1 . These pedigrees will have more power to refine the IBD1 locus and identify the causative gene. GASTROENTEROLOGY 2000;119:1483-1490

Lactobacillus GG is a safe probiotic bacterium known to transiently colonize the human intestine. It has been found to be useful in treatment of several gastrointestinal conditions characterized by increased gut permeability. In the current study, the efficacy of Lactobacillus GG was investigated in children with Crohn's disease.In this open-label pilot evaluation viewed as a necessary preliminary step for a possible subsequent randomized placebo-controlled trial, four children with mildly to moderately active Crohn's disease were given Lactobacillus GG (10(10) colony-forming units [CFU]) in enterocoated tablets twice a day for 6 months. Changes in intestinal permeability were measured by a double sugar permeability test. Clinical activity was determined by measuring the pediatric Crohn's disease activity index.There was a significant improvement in clinical activity 1 week after starting Lactobacillus GG, which was sustained throughout the study period. Median pediatric Crohn's disease activity index scores at 4 weeks were 73% lower than baseline. Intestinal permeability improved in an almost parallel fashion.Findings in this pilot study show that Lactobacillus GG may improve gut barrier function and clinical status in children with mildly to moderately active, stable Crohn's disease. Randomized, double-blind, placebo-controlled trials are warranted for a final assessment of the efficacy of Lactobacillus GG in Crohn's disease.

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare disease of children characterized by aseptic inflammation of the long bones and clavicles. No infectious etiology has been identified, and CRMO has been associated with a number of autoimmune diseases (including Wegener's granulomatosis and psoriasis). The relationship between CRMO and inflammatory bowel disease is poorly described. Through an internet bulletin board subscribed to by 500 pediatric gastroenterologists, we identified six inflammatory bowel disease patients (two with ulcerative colitis, four with Crohn's colitis) with confirmed CRMO. In all cases, onset of the bony lesions preceded the onset of bowel symptoms by as much as five years. Immunosuppressive therapy for the bowel disease generally resulted in improvement of the bone inflammation. Chronic recurrent multifocal osteomyelitis should be considered in any inflammatory bowel disease patient with unexplained bone pain or areas of uptake on bone scan. CRMO may be a rare extraintestinal manifestation of inflammatory bowel disease; alternatively, certain individuals may be genetically predisposed to the development of both diseases.

Managing IBD in children and adolescents requires attention to issues unique to these age groups. The spectrum of presenting signs and symptoms is broad and often, subtle. Physician awareness of intestinal and extra-intestinal features prompts earlier diagnosis and intervention. The focus of treatment is not limited to intestinal symptoms, but also involves assessing weight and height gains, sexual maturation, extra-intestinal manifestations and psychosocial well-being. Differences in selecting drugs for pediatric versus adult patients are based on: 1. lack of prospective trials establishing effective doses for different ages; 2. inability to swallow capsules; 3. importance of nutrition in promoting growth; 4. paucity of data regarding the long-term safety of medications; 5. untoward cosmetic effects of corticosteroids, and 6. the need to develop coping mechanisms for a chronic illness. While sulfasalazine and mesalamine are useful in mild disease, corticosteroids are necessary for moderate and severe disease. Metronidazole and ciprofloxacin are effective in perianal CD. Elemental and polymeric formulas induce and maintain remission in active CD and reverse growth failure. Immunomodulatory agents (azathioprine and 6-mercaptopurine) enable physicians to reduce steroids and hospitalization. In practice, combination therapy is recommended to control symptoms and limit drug-induced side effects.

Background & Aims: Two European genome-wide screens for inflammatory bowel disease have identified two significant regions of linkage on chromosomes 16 ( IBD1 ) and 12 ( IBD2 ) and two regions with suggestive levels of significance (chromosomes 3p and 7q). The aim of this study was to determine if there was evidence for linkage to these regions in non-Jewish and Ashkenazi Jewish families multiplex for Crohn's disease from the United States. Methods: One hundred forty-eight affected relative pairs, 34% Ashkenazim, were genotyped with 10–14 highly polymorphic markers overlying each candidate region. Nonparametric multipoint and two-point linkage analyses were performed. Results: Significant evidence for replication of linkage was found only for the chromosome 16 locus, IBD1 , maximal at D16S769 (nonparametric linkage score [NPL], 2.49; P = 0.007). Analysis by ethnicity showed stronger evidence for Ashkenazim (D16S769; NPL=2.52; P = 0.007) than for non-Jewish white populations (D16S401; NPL=1.40; P = 0.082). There was no significant evidence for replication on chromosome 12 ( IBD2 ). Minimal evidence for extension of linkage evidence was observed for the chromosomes 3p and 7q regions. Conclusions: American families, particularly Ashkenazim, have significant evidence for the Crohn's disease susceptibility locus, IBD1 , on chromosome 16, but not for IBD2 on chromosome 12. GASTROENTEROLOGY 1998;115:1056-1061

Azathioprine (AZA) and 6-mercaptopurine (6-MP) are used in pediatric patients with ulcerative colitis and Crohn's disease to reduce disease activity, maintain remission, prevent relapse, and lower corticosteroid dosage, but their long-term side effects remain to be studied. The aim of this study was to analyze the safety of AZA and 6-MP and steroid reduction in this age group.The investigators' database identified 118 patients who received either drug; 23 were excluded (single visit, noncompliance, or therapy1 week), leaving 95 patients, with a mean (+/-SD) age of 14.2 +/- 4.4 years. Medical files were reviewed for adverse side effects: fever, pancreatitis, infections, gastrointestinal intolerance, aminotransferase level increase, leukopenia, and thrombocytopenia. Prednisone doses before and after immunomodulatory therapy were compared.AZA or 6-MP was tolerated in 51 of 95 patients (54%) without adverse reaction; 27 of 95 (28%) experienced side effects that responded to dose reduction (23 patients) or spontaneously (4 patients), most commonly increased aminotransferase level (13.7%). Cessation of therapy was needed in 17 of 95 patients (18%), including recurrent fever (4), pancreatitis (4), gastrointestinal intolerance (4), and recurrent infections (3). Mean prednisone dose decreased from 24.3 to 8.6 mg/day.AZA and 6-MP were well tolerated in 82% of patients; of these, prednisone reduction occurred in 87%. However, 18% required discontinuation because of hypersensitivity or infectious side effects.

The idiopathic inflammatory bowel diseases, Crohn’s disease (CD) and ulcerative colitis (UC), are chronic, frequently disabling diseases of the intestines. Segregation analyses, twin concordance, and ethnic differences in familial risks have established that CD and UC are complex, non-Mendelian, related genetic disorders. We performed a genome-wide screen using 377 autosomal markers, on 297 CD, UC, or mixed relative pairs from 174 families, 37% Ashkenazim. We observed evidence for linkage at 3q for all families (multipoint logarithm of the odds score (MLod) = 2.29, P = 5.7 × 10 −4 ), with greatest significance for non-Ashkenazim Caucasians (MLod = 3.39, P = 3.92 × 10 −5 ), and at chromosome 1p (MLod = 2.65, P = 2.4 × 10 −4 ) for all families. In a limited subset of mixed families (containing one member with CD and another with UC), evidence for linkage was observed on chromosome 4q (MLod = 2.76, P = 1.9 × 10 −4 ), especially among Ashkenazim. There was confirmatory evidence for a CD locus, overlapping IBD1 , in the pericentromeric region of chromosome 16 (MLod = 1.69, P = 2.6 × 10 −3 ), particularly among Ashkenazim (MLod = 1.51, P = 7.8 × 10 −3 ); however, positive MLod scores were observed over a very broad region of chromosome 16. Furthermore, evidence for epistasis between IBD1 and chromosome 1p was observed. Thirteen additional loci demonstrated nominal (MLod > 1.0, P < 0.016) evidence for linkage. This screen provides strong evidence that there are several major susceptibility loci contributing to the genetic risk for CD and UC.

Background & Aims: Children with inflammatory bowel disease (IBD) are at risk for osteoporosis because of undernutrition, delayed puberty, and prolonged corticosteroid use. The aim of this study was to compare bone mineral density (BMD) in children with IBD with that in normal children and to assess the effects of nutritional and hormonal factors and corticosteroid dosages on BMD. Methods: One hundred sixty-two subjects (99 with IBD and 63 healthy sibling controls) were enrolled. Patients underwent anthropometric assessment, pubertal staging, bone age radiography, and BMD assessment by dual energy x-ray absorptiometry of the lumbar spine, femoral neck, and radius. Laboratory evaluations included serum calcium, phosphate, alkaline phosphatase, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, parathyroid hormone, osteocalcin, urinary N -telopeptides, albumin, insulin-like growth factor I, and testosterone or estradiol. Cumulative corticosteroid doses were calculated. Results: BMD Z scores at the lumbar spine and femoral neck were lower in patients with IBD, and lower in those with Crohn's disease compared with those with ulcerative colitis. Low BMD persisted after correction for bone age in girls with Crohn's disease (lumbar spine, P = 0.004; femoral neck, P = 0.002). Cumulative corticosteroid dose was a significant predictor of reduced BMD. BMD did not correlate with measures of calcium homeostasis, except elevated serum phosphate and urine calcium levels in girls. Conclusions: Low BMD occurs in children with IBD (more in Crohn's disease than in ulcerative colitis), especially pubertal and postpubertal girls. Cumulative corticosteroid dose is a predictor of low BMD, but other factors in Crohn's disease remain undetermined. GASTROENTEROLOGY 1998;114:902-911

reviewed in the Pediatric Clinics of North much new information has accumulated. In particular, the areas of genetic predisposition and alteration in the mucosal immune response have gained from intense research regarding the basic pathogenetic mechanisms of these disorders. Patients have benefited from recent drug trials that have expanded the therapeutic armamentarium available for treating IBD. This article describes recent advances in the field and summarizes the clinical presentation, diagnostic evaluation, and management of children

The foregoing discussion emphasizes the broad range of problems experienced by children and adolescents with chronic IBD. Approaches to the diagnosis and treatment of UC and CD in this distinctive population were provided herein.

The term “delayed growth and sexual maturation” is cited extensively in literature describing inflammatory bowel disease (IBD) with onset during childhood and adolescence. Indeed, evidence suggests that many of the nutritional, inflammatory/immunological, and endocrine factors which result from IBD affect both growth and the onset and progression of puberty. This chapter will address how puberty can be affected in children with IBD, and how disorders in puberty can influence other aspects of health in the pediatric age population with IBD.

ObjectivesFew clinical predictors are associated with definitive proctocolectomy in children with ulcerative colitis (UC). The purpose of the present study was to identify clinical predictors associated with surgery in children with UC using a disease-specific database.MethodsChildren diagnosed with UC at age