Agrawal M¹, Burisch J², Colombel JF¹, Shah SC³. J Crohns Colitis. 2019 Jul 30. pii: jjz139. doi: 10.1093/ecco-jcc/jjz139. [Epub ahead of print]

Author information

1 Dr. Henry D. Janowitz Division of Gastroenterology, Icahn School of Medicine at Mount Sinai, New York NY.

2 Gastrounit, Medical Division, Hvidovre Hospital, Copenhagen, Denmark.

3 Division of Gastroenterology, Vanderbilt University, Nashville TN.

Abstract

The inflammatory bowel diseases (IBD), inclusive of Crohn's disease (CD) and ulcerative colitis (UC), are chronic, progressive immune-mediated diseases associated with high morbidity and substantial economic impact. The pathogenesis implicates a complex interaction between environmental determinants and genetic susceptibility. Of concern, the incidence and prevalence of IBD are increasing globally, with the highest relative increase observed in developing and recently developed countries. One high-risk yet underappreciated population is immigrants from countries of low- to high-IBD incidence, as evidenced by epidemiologic studies demonstrating higher risk of IBD among second- versus first-generation and younger versus older immigrants from low- to high-incidence countries (LTHIC). The reasons underlying these emerging patterns among immigrants are incompletely understood and provide enormous opportunities to better define the pathophysiology of IBD and move toward disease prevention or at least earlier diagnosis. The rapidity of this epidemiologic shift in the demographic profile of IBD, which was traditionally a disease of Caucasians in industrialized countries, strongly implicates nongenetic factors and gene-environment interactions in the pathophysiology of IBD among immigrants from LTHIC. The primary objectives of this Viewpoint are to 1) provide a focused overview of IBD epidemiology among immigrants from countries at differential IBD risk; 2) emphasize the potential to advance our understanding of IBD pathogenesis via targeted research efforts to delineate risk and protective determinants in this cohort; and 3) highlight disparities and barriers in IBD care, as well as the economic implications of the rising, yet underappreciated, diseaseburden among immigrants from LTHIC.