Pediatric Inflammatory Bowel Disease Among South Asians Living in British Columbia, Canada: A Distinct Clinical Phenotype.

BACKGROUND: Inflammatory bowel disease (IBD) incidence is increasing among low-risk populations. This study examined a cohort of Canadian South Asian (SA) children with IBD to determine if their disease course differed from non-SA (NSA) children.
METHODS: Children of SA ethnicity diagnosed with IBD between 1997 and 2012 were identified and compared with NSA children. Data on duration and the type of presenting symptoms, disease phenotype, corticosteroid exposure (CS), exclusive enteral nutrition use, time to commencement of immunomodulator (IM), biologic therapy, and surgical intervention were extracted.
RESULTS: Overall, 160 SA children were identified and compared with 783 NSA patients (Crohn's disease [CD]: 44% versus 72%; ulcerative colitis [UC]: 43% versus 21%; IBD-Unclassified: 13% versus 7%; P < 0.001). SA patients were predominantly second-generation Canadians (92%) and had shorter symptom duration (2 versus 4 months; P < 0.001). SA CD patients were less likely to have a parent with IBD (1% versus 14%; P = 0.003). SA patients had more extensive colonic disease (CD: 55% versus 35%; P = 0.005; UC: 77% versus 58%; P = 0.006); SA CD patients presented with more complicated disease (B2/B3: 39% versus 27%; P = 0.006) and UC patients presented with more severe disease (49% versus 23%; P < 0.001). In SA CD patients, CS use was higher (70% versus 58%; P = 0.045), and IM and biologic therapy were commenced earlier (P = 0.027; P = 0.047). SA UC patients were more likely to need CS and IM (P = 0.024; P < 0.001).
CONCLUSIONS: These data describe an ethnically unique clinical phenotype, where SA children have a higher proportion of UC, shorter symptom duration, more extensive colonic disease, and are more likely to require earlier escalation of therapy.