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The Phenotypic Spectrum of New-onset IBD in Canadian Children of South Asian Ethnicity: A Prospective Multi-Centre
J Dhaliwal1,2, M W Carroll3, J C deBruyn4
1SickKids Hospital, University of Toronto, Toronto, ON, Canada.
Insights
South Asian children in Canada develop inflammatory bowel disease (IBD) with distinct features compared to Caucasian children. However, treatment responses and clinical outcomes are similar across ethnic groups within similar IBD subtypes.
Area of Science:
- Pediatric Gastroenterology
- Inflammatory Bowel Disease Research
- Ethnic Disparities in Health
Background:
- Canadian-born South Asian (SA) children exhibit similar incidence rates of inflammatory bowel disease (IBD) as Caucasian children.
- This study investigates variations in the phenotypic spectrum of IBD between SA and Caucasian children within a Canadian national pediatric inception cohort.
Purpose of the Study:
- To compare the demographic and phenotypic characteristics of new-onset IBD in South Asian versus Caucasian children.
- To evaluate longitudinal IBD outcomes in these ethnic groups over an 18-month follow-up period.
Main Methods:
- Analysis of a Canadian nationwide inception cohort of pediatric IBD patients (<17 years).
- Comparison of baseline demographic and IBD phenotypic features between SA and Caucasian children.
- Propensity score matching was used to compare longitudinal outcomes at 18 months.
Main Results:
- South Asian children presented with IBD at a younger age and more frequently with ulcerative colitis/IBD-unclassified (UC/IBD-U) compared to Caucasians.
- Colonic-only disease was more prevalent in SA children with IBD, and perianal fistulizing disease was numerically more common.
- Despite phenotypic differences, anti-tumour necrosis factor (TNF) exposure and time to treatment initiation were similar, with two-thirds achieving corticosteroid-free remission at 18 months.
Conclusions:
- The phenotypic presentation of new-onset IBD in South Asian pediatric patients differs from that in Caucasian patients.
- Treatment approaches and clinical courses are comparable within similar phenotypic subgroups, irrespective of ethnicity.
Background:
Canadian-born children of South Asian [SA] ethnicity develop inflammatory bowel disease [IBD] at similar rates to those among Caucasian children. We evaluated the variation in phenotypic spectrum of IBD in SA and Caucasian children in a national paediatric inception cohort of new-onset IBD.
Methods:
Patients aged <17 years, enrolled in a Canadian nationwide inception cohort study, were included. Baseline demographic and IBD phenotypic features were compared between SA and Caucasian children. Longitudinal outcomes through 18 months of follow-up were compared matched by propensity scores.
Results:
Of 1156 children enrolled over 2014 to 2019, 623 were Caucasian [98% and 88% parents Canadian born] and 114 SA [79% Canadian born, 87% parents SA born]. Fewer SAs have a first-degree relative with IBD, 6% vs 19% in Caucasians, p = 0.002. SAs present at a younger age, median age 11.4 years (interquartile range [IQR] 9.2-14.3) vs 13 years [IQR 10.9-15 years], p = 0.03 and more commonly with a UC/IBD-U [ulcerative colitis/IBD-unclassified] subtype [ratio of UC/IBD-U to CD 1.2:1 vs 1:1.8 for Caucasians, p <0.001]. Additionally, a greater proportion of SA CD patients present with colonic-only disease [colonic-only CD/UC/IBD-U in SAs 67% vs 57% for Caucasians, p = 0.001], and among those with CD, colonic CD in SAs 31% vs 23% in Caucasians, p = 0.20]. Perianal fistulising disease was also numerically more common in SAs (14 [27%] vs 64 [18%], p = 0.06]. Adjusting for differences in phenotypic presentation, anti-tumour necrosis factor [TNF] exposure, and time to initiation was similar, and two-thirds of children, whether anti-TNF exposed or naïve, were in corticosteroid-free clinical remission at 18 months irrespective of ethnicity.
Conclusions:
The phenotypic spectrum of new-onset IBD in SA children differs from that of Caucasian children, but treatment and clinical course are similar within phenotypic subgroups.
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