Background: The number of patients with Inflammatory Bowel Disease (IBD) from non-Caucasian descent in Western-Europe is increasing. We aimed to explore the impact of ethnicity and country of birth on IBD the phenotype.
Methods: IBD patients treated in the eight University Medical Centres in the Netherlands and enrolled in the Dutch IBD Biobank were divided into three groups 1) Caucasian patients from West- and Central-European descent (CEU) 2) patients born in the Netherlands or Western-Europe from non-Caucasian descent (non-CEU European born) and 3) non-Caucasian patients born outside Western-Europe that migrated to the Netherlands (non-CEU non-European born), and analyzed for phenotype differences (by chi-square test). Analyses were repeated in an independent Dutch IBD cohort (COIN cohort).
Results: The Dutch IBD Biobank included 2,921 CEU patients and 233 non-CEU patients. Non-CEU patients more often had upper Gastro-Intestinal disease (16% vs. 8%, p=0.001) and anal stenosis (10% vs. 4%, p=0.002). Non-CEU patients born in Europe (n=116) were diagnosed at a younger age than non-CEU patients born outside Europe (n=115) (22.7 vs. 28.9 years old, p<0.001). In the COIN cohort (2,170 Europeans and 98 non-Europeans), non-Europeans more often had fistulas or abscesses (29% vs. 13%, p<0.001), used more anti-TNF-α compounds (45% vs. 20%, p=0.001) and had a lower Health-related Quality of Life (mean IBDQ 161 vs. 177, p<0.001).
Conclusions: Non-CEU patients born in Europe are diagnosed at a younger age with IBD compared to those born outside Europe. Ethnicity and country of birth are associated with different phenotypes in IBD. In clinical IBD care, a tailored approach to the non-CEU patient is warranted.