Growth After Menarche in Pediatric Inflammatory Bowel Disease.

OBJECTIVES: Growth impairment in pediatric patients with pediatric onset inflammatory bowel disease (IBD) is multifactorial. Reports on the effect of age at menarche on adult stature in this population are limited. This study investigated the impact of age at menarche, disease-associated factors, and mid-parental height on growth from menarche to final height (FHt) in pediatric patients with Crohn disease (CD) and ulcerative colitis (UC) and IBD unclassified (IBD-U). METHODS: Subjects were enrolled from a prospectively maintained pediatric IBD database when IBD preceded menarche and dates of menarche and FHt measurements were recorded. RESULTS: One hundred forty-six patients: CD 112 and UC 30/IBD-U 4. Mean age (years) at diagnosis (10.9 vs 10.1), menarche (14.4 vs 14.0), and FHt (19.6 vs 19.7). CD and UC/IBD-U patients showed significant association between Chronological age (CA) at menarche and FHt (cm, P < 0.001) but not FHt z score (FHt-Z) < -1.0 (P = 0.42). FHt-Z < -2.0 occurred in only 5 patients. Growth impairment (FHt-Z < -1.0) was associated with surgery before menarche (P = 0.03), jejunal disease (P = 0.003), low mid-parental height z score (MPH-Z) (P < 0.001), hospitalization for CD (P = 0.03) but not UC, recurrent corticosteroid, or anti-tumor necrosis factor alpha (anti-TNFα) therapy. CONCLUSIONS: Early age of menarche was associated with greater potential for linear growth to FHt but not FHt-Z (P < 0.05). Surgery before menarche, jejunal disease, hospitalization for CD, low MPH, and weight z score were associated with FHt-Z < -1.0.

Genetic variants and pathways implicated in a pediatric inflammatory bowel disease cohort.

In the United States, approximately 5% of individuals with inflammatory bowel disease (IBD) are younger than 20 years old. Studies of pediatric cohorts can provide unique insights into genetic architecture of IBD, which includes Crohn's disease (CD) and ulcerative colitis (UC). Large genome-wide association studies have found more than 200 IBD-associated loci but explain a minority of disease variance for CD and UC. We sought to characterize the contribution of rare variants to disease development, comparing exome sequencing of 368 pediatric IBD patients to publicly available exome sequencing (dbGaP) and aggregate frequency data (ExAC). Using dbGaP data, we performed logistic regression for common variants and optimal unified association tests (SKAT-O) for rare, likely-deleterious variants. We further compared rare variants to ExAC counts with Fisher's exact tests. We did pathway enrichment analysis on the most significant genes from each comparison. Many variants overlapped with known IBD-associated genes (e.g. NOD2). Rare variants were enriched in CD-associated loci (p = 0.009) and showed suggestive enrichment in neutrophil function genes (p = 0.05). Pathway enrichment implicated immune-related pathways, especially cell killing and apoptosis. Variants in extracellular matrix genes also emerged as an important theme in our analysis.

Clinical and Genomic Correlates of Neutrophil Reactive Oxygen Species Production in Pediatric Patients With Crohn's Disease.

BACKGROUND & AIMS: Individuals 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. METHODS: We 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. RESULTS: We 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 with CD 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. CONCLUSIONS: We 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.

Change in Prevalence of Family History During Long-term Follow-up of Patients With Pediatric-onset Inflammatory Bowel Disease.

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 < 0.001). Non-Jewish Caucasians had significantly lower risk of a FH+ compared to Jewish Caucasians (P = 0.002), but similar risk to African Americans (P = 0.55). FH+ at diagnosis was not associated with disease type (P = 0.33) or age at diagnosis (P = 0.24). CONCLUSIONS: This prospective study documents changes in family history of IBD in pediatric-onset IBD patients over time. Prevalence of FH+ increased for first-degree and all relatives at 20 years by 12.9% and 13.7%, respectively. FH+ at diagnosis was associated with a 2-fold greater likelihood of subsequent FH+ at 20 years.

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

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.

Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease.

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 < 5.0 × 10-8 in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance. 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 < 1.6 × 10-6): 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 Effect of Early-Life Environmental Exposures on Disease Phenotype and Clinical Course of Crohn's Disease in Children.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: Early life environmental factors influence the eventual phenotypes and disease course in CD.

Characterization of genetic loci that affect susceptibility to inflammatory bowel diseases in African Americans.

BACKGROUND & AIMS: Inflammatory bowel disease (IBD) has familial aggregation in African Americans (AAs), but little is known about the molecular genetic susceptibility. Mapping studies using the Immunochip genotyping array expand the number of susceptibility loci for IBD in Caucasians to 163, but the contribution of the 163 loci and European admixture to IBD risk in AAs is unclear. We performed a genetic mapping study using the Immunochip to determine whether IBD susceptibility loci in Caucasians also affect risk in AAs and identify new associated loci. METHODS: We recruited AAs with IBD and without IBD (controls) from 34 IBD centers in the United States; additional controls were collected from 4 other Immunochip studies. Association and admixture loci were mapped for 1088 patients with Crohn's disease, 361 with ulcerative colitis, 62 with IBD type unknown, and 1797 controls; 130,241 autosomal single-nucleotide polymorphisms (SNPs) were analyzed. RESULTS: The strongest associations were observed between ulcerative colitis and HLA rs9271366 (P = 7.5 × 10(-6)), Crohn's disease and 5p13.1 rs4286721 (P = 3.5 × 10(-6)), and IBD and KAT2A rs730086 (P = 2.3 × 10(-6)). Additional suggestive associations (P < 4.2 × 10(-5)) were observed between Crohn's disease and IBD and African-specific SNPs in STAT5A and STAT3; between IBD and SNPs in IL23R, IL12B, and C2orf43; and between ulcerative colitis and SNPs near HDAC11 and near LINC00994. The latter 3 loci have not been previously associated with IBD, but require replication. Established Caucasian associations were replicated in AAs (P < 3.1 × 10(-4)) at NOD2, IL23R, 5p15.3, and IKZF3. Significant admixture (P < 3.9 × 10(-4)) was observed for 17q12-17q21.31 (IZKF3 through STAT3), 10q11.23-10q21.2, 15q22.2-15q23, and 16p12.2-16p12.1. Network analyses showed significant enrichment (false discovery rate <1 × 10(-5)) in genes that encode members of the JAK-STAT, cytokine, and chemokine signaling pathways, as well those involved in pathogenesis of measles. CONCLUSIONS: In a genetic analysis of 3308 AA IBD cases and controls, we found that many variants associated with IBD in Caucasians also showed association evidence with these diseases in AAs; we also found evidence for variants and loci not previously associated with IBD. The complex genetic factors that determine risk for or protection against IBD in different populations require further study.

Thalidomide use and outcomes in pediatric patients with Crohn disease refractory to infliximab and adalimumab.

OBJECTIVE: The aim of the study was to evaluate thalidomide as rescue therapy for pediatric patients with severe refractory Crohn disease (CD) who failed to respond to antitumor necrosis factor (TNF) biologic agents. PATIENTS AND METHODS: A computerized database was used to identify children with CD who had failed conventional immunosuppression therapy and received thalidomide rescue therapy. Twelve patients, mean age at diagnosis 10 years, were identified. Eight children had disease localized to the ileum and colon and 4 to the gastroduodenal area and colon. Five cases were complicated by strictures and 7 by fistulae. Previous drug therapy included azathioprine/6-mercaptopurine (11/12), methotrexate (7/12), and anti-TNF biologics (12/12). Outcome measures were Harvey-Bradshaw Index, change in prednisone dose, hospitalizations, bowel resections, and incision and drainage procedures. Laboratory evaluations were calculated before and after 1 to 6 months of thalidomide. RESULTS: Mean Harvey-Bradshaw Index score improved from 11.8 to 3.9 (P = 0.0004), mean prednisone dose decreased from 13.9 to 2.3  mg/day (P = 0.001), mean number of hospitalizations decreased from 6.3 to 1.3 (P = 0.002), and erythrocyte sedimentation rate decreased from 35 to 14  mm/h (P = 0.02). The surgery rate pre-thalidomide was 0.031 and on thalidomide was 0.004. Of the 7 patients with fistulae, 5 had complete fistula closure, 1 had partial closure, and 1 showed no improvement. Adverse reactions that resulted in discontinuation of thalidomide are as follows: 42% peripheral neuropathy, 17% worsening of the CD, 8% dizziness, and 8% allergic reaction. All 5 patients who developed peripheral neuropathy had clinical resolution of the neurologic symptoms within 2 to 3 months after stopping thalidomide. CONCLUSIONS: Thalidomide is a potentially effective rescue therapy for severe refractory CD in children who fail to respond to anti-TNF medications.

Predictors of proctocolectomy in children with ulcerative colitis.

OBJECTIVES: Few 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. METHODS: Children diagnosed with UC at age <18 years were identified using the Pediatric Inflammatory Bowel Disease Consortium (PediIBDC) database. Demographic and clinical variables from January 1999 to November 2003 were extracted alongside incidence and surgical staging. RESULTS: Review of the PediIBDC database identified 406 children with UC. Approximately half were girls (51%) with an average age at diagnosis of 10.6 ±â€Š4.4 years in both boys and girls. Average follow-up was 6.8 (±4.0) years. Of the 57 (14%) who underwent surgery, median time to surgery was 3.8 (interquartile range 4.9) years after initial diagnosis. Children presenting with weight loss (hazard ratio [HR] 2.55, 99% confidence interval [CI] 1.21-5.35) or serum albumin <3.5 g/dL (HR 6.05, 99% CI 2.15-17.04) at time of diagnosis and children with a first-degree relative with UC (HR 1.81, 99% CI 1.25-2.61) required earlier surgical intervention. Furthermore, children treated with cyclosporine (HR 6.11, 99% CI 3.90-9.57) or tacrolimus (HR 3.66, 99% CI 1.60-8.39) also required earlier surgical management. Other symptoms, laboratory tests, and medical therapies were not predictive for need of surgery. CONCLUSION: Children with UC presenting with hypoalbuminemia, weight loss, a family history of UC, and those treated with calcineurin inhibitors frequently require restorative proctocolectomy for definitive treatment. Early identification and recognition of these factors should be used to shape treatment goals and initiate multidisciplinary care at the time of diagnosis.

Genetic and Transcriptomic Variation Linked to Neutrophil Granulocyte-Macrophage Colony-Stimulating Factor Signaling in Pediatric Crohn's Disease.

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 < 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.

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.

Inflammatory bowel disease in African American children compared with other racial/ethnic groups in a multicenter registry.

BACKGROUND & AIMS: Few epidemiologic investigations characterize inflammatory bowel disease (IBD) in non-Caucasian children. Our study compared IBD characteristics between African Americans and non-African Americans enrolled in a multicenter pediatric IBD registry with endoscopic- and pathology-based diagnosis. METHODS: The study retrieved data entered from January 2000 to October 2003 on children 1 to 17 years old, inclusive, followed by a consortium of academic and community US pediatric gastroenterology practices. Analyses examined racial/ethnic differences by comparing the proportions of African Americans and non-African Americans in the following categories: each diagnostic disease classification (any IBD, Crohn's disease, ulcerative colitis, indeterminate colitis); age group (<6 y, 6-12 y, or >12 y) at diagnosis or symptom onset; presence of extraintestinal manifestations, Z-scores for height and weight, immunomodulatory therapy, anatomic disease location, and abnormal hemoglobin, albumin, or sedimentation rate at diagnosis. RESULTS: A total of 1406 patients had complete data, 138 (10%) of whom were African American. African Americans more often were older than 12 years of age at diagnosis (52% vs 37%; odds ratio [OR], 1.82; 95% confidence interval [95% CI], 1.28-2.59) and symptom onset (46% vs 30%; OR, 1.99; 95% CI, 1.40-2.84); had Crohn's disease (78% vs 59%; OR, 2.36; 95% CI, 1.56-3.58); and had a low hemoglobin level at diagnosis (39% vs 17%; OR, 3.15; 95% CI, 1.92-5.17). CONCLUSIONS: IBD in African American children and adolescents presents more commonly with Crohn's disease and at older ages compared with non-African Americans. Racial/ethnic differences in the epidemiology of IBD, particularly Crohn's disease, among American youths require further investigation.

Presentation and disease course in early- compared to later-onset pediatric Crohn's disease.

BACKGROUND: 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. METHODS: 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. RESULTS: 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 (P < 0.001). 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 (P < 0.001). The 6-17 yr of age patients presented with more abdominal pain (P < 0.001), 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 (P < 0.001), 6-mercaptopurine/azathioprine (P < 0.001), 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. CONCLUSIONS: 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.

Growth hormone treatment for growth failure in pediatric patients with Crohn's disease.

OBJECTIVE: To investigate the effect of human growth hormone (GH) injections on growth velocity in growth-impaired children with Crohn's disease (CD). STUDY DESIGN: Ten children and adolescents (mean age, 12.6 +/- 4.5 years; 6 males) with CD and poor height growth were treated with open-label recombinant GH, 0.043 mg/kg/day administered via subcutaneous injection, for 1 year. Patients were retrospectively matched with untreated patients (3 comparisons per case) by race, age, sex, and baseline height. Primary endpoint was height velocity; secondary endpoints were disease activity, body composition, and bone density determined by dual-energy x-ray absorptiometry scan. RESULTS: Mean height velocity increased by 5.33 +/- 3.40 (mean +/- standard deviation) cm/year in the GH-treated patients during the year of GH treatment, compared with 0.96 +/- 3.52 cm/year in the comparison group (P = .03). Height z-score increased by 0.76 +/- 0.38 in the treated group, compared with 0.16 +/- 0.40 in the comparison group (P < .01), and weight z-score increased by 0.81 +/- 0.89 in the treated group, compared with 0.00 +/- 0.57 in the comparison group (P < .01). Bone density revealed an increase of 0.31 +/- 0.33 in the lumbar spine z-score (P = .03 vs baseline). CONCLUSIONS: GH treatment increases height velocity and may enhance bone mineralization in children with CD. A randomized controlled trial in a large cohort of children is needed to evaluate the ultimate impact of GH treatment.

Measuring quality of life in pediatric patients with inflammatory bowel disease: psychometric and clinical characteristics.

OBJECTIVE: To extend development of a pediatric inflammatory bowel disease (IBD) health-related quality of life (HRQoL) measure by determining its factor structure and associations of factors with generic HRQoL measures and clinical variables. PATIENTS AND METHODS: Cross-sectional survey of children and adolescents ages 8 years to 18 years and their parents attending any of 6 US IBD centers, recruited from either existing registry of age-eligible subjects or visits to participating centers. The survey included generic (Pediatric Quality of Life Inventory) and IBD-specific (Impact Questionnaire) quality of life measures, disease activity, and other clinical indicators. We carried out factor analysis of Impact responses, comparing resulting factors with results on the generic HRQoL and the clinical measures. RESULTS: We included 220 subjects (161 with Crohn disease and 59 with ulcerative colitis). Initial confirmatory factor analysis did not support the 6 proposed Impact domains. Exploratory factor analysis indicated 4 factors with good to excellent reliability for IBD responses: general well-being and symptoms, emotional functioning, social interactions, and body image. Two items did not load well on any factor. The 4 factors correlated well with the Pediatric Quality of Life Inventory and subscales. Children with higher disease activity scores and other indicators of clinical activity reported lower HRQoL. CONCLUSIONS: This study provides further characteristics of a HRQoL measure specific to pediatric IBD and indicates ways to score the measure based on the resulting factor structure. The measure correlates appropriately with generic HRQoL measures and clinical severity indicators.

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.

Effect of long-term low-dose prednisone on height velocity and disease activity in pediatric and adolescent patients with Crohn disease.

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.

Differentiating ulcerative colitis from Crohn disease in children and young adults: report of a working group of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the Crohn's and Colitis Foundation of America.

BACKGROUND: Studies of pediatric inflammatory bowel disease (IBD) have varied in the criteria used to classify patients as having Crohn disease (CD), ulcerative colitis (UC), or indeterminate colitis (IC). Patients undergoing an initial evaluation for IBD will often undergo a series of diagnostic tests, including barium upper gastrointestinal series with small bowel follow-through, abdominal CT, upper endoscopy, and colonoscopy with biopsies. Other tests performed less frequently include magnetic resonance imaging scans, serological testing, and capsule endoscopy. The large amount of clinical information obtained may make a physician uncertain as to whether to label a patient as having CD or UC. Nevertheless, to facilitate the conduct of epidemiological studies in children, to allow the entry of children into clinical trials, and to allow physicians to more clearly discuss diagnosis with their patients, it is important that clinicians be able to differentiate between CD and UC. METHODS: A consensus conference regarding the diagnosis and classification of pediatric IBD was organized by the Crohn's and Colitis Foundation of America. The meeting included 10 pediatric gastroenterologists and 4 pediatric pathologists. The primary aim was to determine the utility of endoscopy and histology in establishing the diagnosis of CD and UC. Each member of the group was assigned a topic for review. Topics evaluated included differentiating inflammatory bowel disease from acute self-limited colitis, endoscopic and histological features that allow differentiation between CD and UC, upper endoscopic features seen in both CD and UC, ileal inflammation and "backwash ileitis" in UC, patchiness and rectal sparing in pediatric IBD, periappendiceal inflammation in CD and UC, and definitions of IC. RESULTS: Patients with UC may have histological features such as microscopic inflammation of the ileum, histological gastritis, periappendiceal inflammation, patchiness, and relative rectal sparing at the time of diagnosis. These findings should not prompt the clinician to change the diagnosis from UC to CD. Other endoscopic findings, such as macroscopic cobblestoning, segmental colitis, ileal stenosis and ulceration, perianal disease, and multiple granulomas in the small bowel or colon more strongly suggest a diagnosis of CD. An algorithm is provided to enable the clinician to differentiate more reliably between these 2 entities. CONCLUSIONS: The recommendations and algorithm presented here aim to assist the clinician in differentiating childhood UC from CD. We hope the recommendations in this report will reduce variability among practitioners in how they use the terms "ulcerative colitis," "Crohn disease," and "indeterminate colitis." The authors hope that progress being made in genetic, serological, and imaging studies leads to more reliable phenotyping.

IBD Serology and Disease Outcomes in African Americans With Crohn's Disease.

Backgrounds: Recent studies have identified the role of serologic markers in characterizing disease phenotype, location, complications, and severity among Northern Europeans (NE) with Crohn's disease (CD). However, very little is known about the role of serology in CD among African Americans (AA). Our study explored the relationship between serology and disease phenotype in AA with CD, while controlling for genetic ancestry. Methods: AAs with CD were enrolled as participants through multicenter collaborative efforts. Serological levels of IgA anti-Saccharomyces cervisiae antibody (ASCA), IgG ASCA, E. coli outermembrane porin C, anti-CBir1, and ANCA were measured using enzyme-linked immunosorbent assays. Genotyping was performed using Illumina immunochip technology; an admixture rate was calculated for each subject. Multiple imputation by chained equations was performed to account for data missing at random. Logistic regression was used to calculate adjusted odds ratio (OR) for associations between serological markers and both complicated disease and disease requiring surgery. Results: A total of 358 patients were included in the analysis. The majority of our patients had inflammatory, noncomplicated disease (58.4%), perianal disease (55.7%), and documented colonic inflammation (86.8%). On multivariable analysis, both IgG ASCA and OmpC were associated with complicated disease (OR, 2.67; 95% CI, 1.67-4.28; OR, 2.23; 95% CI, 1.41-3.53, respectively) and disease requiring surgery (OR, 2.51; 95% CI, 1.49-4.22; OR, 3.57; 95% CI, 2.12-6.00). NE admixture to the African genome did not have any associations or interactions in relation to clinical outcome. Conclusions: Our study comprises the largest cohort of AAs with CD. The utility of serological markers for the prognosis of CD in NE applies equally to AA populations.