P215 - UNDERSTANDING PHENOTYPIC DISTINCTIONS IN SUB-POPULATIONS OF VERY EARLY ONSET- INFLAMMATORY BOWEL DISEASE
(Room Poster Hall)
19 Jan 18
5:30 PM
-
7:00 PM
Background: IBD diagnosed 5 can present with a distinct and more severe phenotype than older–onset IBD. We aim to compare the clinical characteristics of infantile IBD and children who present between 2-5 years of age (VEO-IBD). In addition, in a small subset of the cohorts, using patient-derived enteroids we explored phenotypic and functional aberrations in the small intestine and colon epithelium. We hypothesize there are key differences in phenotype and disease course that can point to distinct underlying disease-causing mechanisms and impact treatment. Methods: Children diagnosed with IBD 5 and their parents were recruited. Blood samples were obtained for whole exome sequencing (WES). The EMR was queried to obtain demographic data, disease phenotype and characteristics. Intestinal biopsies were collected in a subset of the cohorts (n=8 infantile IBD, n=7 VEO-IBD) and growth efficiency was evaluated. Results: 65 patients with infantile IBD and 35 patients with VEO-IBD were included. There were similar rates of Crohn Disease, UC and Indeterminate Colitis in both groups. Monogenic defects were identified in 16.9% of infantile IBD and in 1 patient (2.9%) with VEO-IBD. There were 2 deaths in the infantile IBD cohort and none in VEO-IBD. 14% of patients with infantile IBD required surgery as compared to 4% of VEO-IBD. Analyses of enteroids showed similar poor rates of growth in the colon (29% each). However, fewer crypts from infantile VEO-IBD patients survived and grew into enteroids from ileal samples (28% vs 68%). Conclusions: The presentation and phenotype of infantile IBD is different from VEO-IBD with more refractory disease and identified monogenic defects. Additionally, enteroid growth was less robust in infantile IBD as compared to VEO-IBD. While further analysis is required, infantile IBD appears to have different genetic drivers than children who present with VEO-IBD. Ultimately these difference may inform our evaluation and therapeutic approach.