Phenotypic Variation in Paediatric Inflammatory Bowel Disease by Age: A Multicentre Prospective Inception Cohort Study of the Canadian Children IBD Network.

BACKGROUND AND AIMS: Incidence of paediatric inflammatory bowel disease [IBD] in Canada is among the highest worldwide, and age of onset may be decreasing. In a multicentre nationwide inception cohort study, we examined variation in phenotype of IBD throughout the paediatric age spectrum. METHODS: Children aged ≥2 years [y] and <17y [A1 age at diagnosis], with new onset IBD, were systematically evaluated at sites of the Canadian Children IBD Network. Prospectively recorded phenotypic data were compared between age groups. RESULTS: Among 1092 children (70% Caucasian; 64% Crohn's disease [CD], 36% ulcerative colitis/inflammatory bowel disease unclassified [UC/IBD-U]; median age 13 y, interquartile range [IQR] 11-15 y), 210 [19%] were diagnosed before the age of age 10 y [Paris A1a] and 43 [4%] before age 6 y (very-early-onset [VEO-IBD]). CD was less common in younger children [42%, 56%, 66%, respectively, of VEO-IBD, A1a; A1b]. Colon-only IBD [UC/IBDU or CD-colon] was present in 81% of VEO-IBD and 65% of A1a; ileal disease increased progressively, reaching plateau at age 10 y. CD location was ileocolonic [L3] in 53% overall. Ileitis [L1] increased with age [6% of VEO-IBD; 13% of A1a; 21% of A1b], as did stricturing/penetrating CD [4% of A1a; 11% of A1b]. At all ages UC was extensive [E3/E4] in >85%, and disease activity moderate to severe according to Physician's Global Assessment [PGA] and weighted Paediatric Crohn's Disease Activity Index/Paediatric Ulcerative Colitis Activity Index [wPCDAI/PUCAI] in >70%. Heights were modestly reduced in CD [mean height z score -0.30 ± 1.23], but normal in UC/IBD-U. CONCLUSIONS: Paris classification of age at diagnosis is supported by age-related increases in ileal disease until age 10 years. Other phenotypic features, including severity, are similar across all ages. Linear growth is less impaired in CD than in historical cohorts, reflecting earlier diagnosis.

Gastral antral biopsy in the differentiation of pediatric colitides.

OBJECTIVES: Differentiation of Crohn's disease (CD) from ulcerative colitis (UC) is problematic, primarily when inflammation is confined to the colon. In a historical cohort study, we evaluated the usefulness of baseline gastric antral biopsies in the differentiation of pediatric chronic colitides. METHODS: During initial investigation for suspected inflammatory bowel disease, 39 children and adolescents with colitis but normal small bowel radiography underwent pretreatment upper endoscopy concurrently with colonoscopy. Two reviewers assigned a colonoscopic diagnosis (colonic CD, UC, or indeterminate colitis) based on the macroscopic and microscopic appearances of the colonic mucosa. Antral histological findings were compared between groups using Fisher's exact test. RESULTS: Five (14%) of colonoscopic diagnoses (four indeterminate, one UC) were changed to CD by the finding of granulomatous inflammation in antral biopsies. Nonspecific antral gastritis was found in similar proportions of children and adolescents with Crohn's colitis and UC (92% vs 75%). Focal antral gastritis was more common in patients with Crohn's colitis than UC (52% vs 8%). CONCLUSIONS: Nonspecific antral gastritis is common in all forms of chronic colitis. Nevertheless, upper gastrointestinal endoscopy with biopsy is useful in the differentiation of inflammatory bowel disease confined to the colon, particularly when colonoscopic findings are indeterminate.

Pediatric Crohn Disease Activity Index: responsive to short-term change.

BACKGROUND/AIMS: Despite documented feasibility, reliability, and validity, the Pediatric Crohn's Disease Activity Index (PCDAI) has yet to be demonstrated to be sensitive to change in the time frame of acute treatment trials. We evaluated short-term responsiveness and determined the minimal change in PCDAI score associated with a clinically meaningful improvement in disease activity. METHODS: Standardized effect size (SES) and standardized response mean (SRM) were calculated as measures of responsiveness among pediatric patients being treated for acute exacerbations of Crohn disease 1) in a regular clinical practice setting and 2) as part of a multicenter, randomized controlled trial (RCT). Receiver operating characteristic (ROC) curves were constructed to determine the minimal PCDAI score change associated with significant clinical improvement used as the gold standard in 1) physician global assessment of change and in 2) change in adult Crohn disease activity index (CDAI). RESULTS: Among responders, the SES and SRM of the PCDAI were 1.78 and 1.41 (95% CI: 0.89-1.92) and 2.10 and 1.95 (95% CI: 1.70-2.20) in the clinical practice setting and RCT setting, respectively. The optimal minimal PCDAI change score associated with clinically significant change in physician global assessment was determined to be -12.5 (sensitivity 83.3%, specificity 92.3%). In the RCT setting a change in PCDAI of -10 corresponded to a change in CDAI of not greater-than-or-equal 70 points. CONCLUSIONS: The PCDAI is responsive to improvement in disease activity in Crohn disease patients over a short interval. As such, the PCDAI is an appropriate instrument to use in pediatric acute treatment trials.