Canadian study shows ethnicity is important factor in paediatric inflammatory bowel disease

Inflammatory bowel disease (IBD) includes Crohn's disease and ulcerative colitis and is characterized by chronic inflammation of the gastrointestinal tract. High rates of IBD among Canadian children, paired with the multicultural fabric of our population, provides a unique opportunity for researchers to study the role of ethnicity in IBD.

“IBD has traditionally been known as a disease of industrialized countries, with the highest rates in regions such as Canada, Australia and Northern Europe,” explains Dr. Jennifer deBruyn, MD.

“However, recent studies of adult groups show increasing incidence of IBD in other places, like Asia, Africa and South America. With increasing global incidence of IBD, population-based studies suggest that how IBD presents and how individuals respond to treatment may differ between countries and ancestry groups.”

This study, conducted by the Canadian Children Inflammatory Bowel Disease Network (CIDsCaNN), is published in the IBD Journal. The aim of the study is to identify differences in disease presentation between different ancestral groups. The researchers used data collected at 13 major paediatric hospitals across Canada from children newly diagnosed with IBD, including the Alberta Children’s Hospital.

“We identified important differences between children of European and non-European descent who develop IBD in Canada,” says senior author and co-chair of CIDsCaNN, deBruyn. “These include differences in age, where the disease occurs in the gastrointestinal tract, family history of IBD, and immigrant status.”

For example, researchers found that children of African descent with ulcerative colitis were older at diagnosis compared to European children and that children of East/Southeast Asian descent with Crohn’s disease more often had perianal fistula (tunnel that develops between the inside of the anus and the outside skin around the anus), compared to European children.

Researchers also found that European children in Canada with IBD were less likely to be immigrants compared to non-European children with IBD. These findings are in line with other research studies, suggesting that, while environmental exposure likely increases risk of developing IBD in some immigrant groups, other factors such as genetic predisposition also determine susceptibility to developing IBD.

The researchers reviewed data collected in their inception cohort study from more than 1,400 children and adolescents with new-onset IBD. While previous studies evaluated three or four ancestral groups, this study encompassed eight distinct ancestral groups.

The findings of this research will be used as a building block for future studies aimed at achieving more personalized diagnostic evaluation and treatment plans for Canadian children with IBD.