Ethnicity and the risk of development of Crohn's disease of the ileal pouch.

BACKGROUND

A system-wide, multi-ethnicity study on Crohn's disease (CD) of the pouch, including Indian American (IA) patients has not been conducted.

AIM: To compare the frequency of subsequent development of CD of the pouch for African-American (AA), Hispanic-American (HA), IA and Caucasian patients with ulcerative (UC) undergoing ileal-pouch anal anastomosis (IPAA).

METHODS

In this historical cohort study from our Pouch Registry, patients with restorative proctocolectomy and IPAA for IBD with identifiable, self-declared racial background (i.e. AA, HA, IA or Caucasian) were included. Univariable and multivariable analyses were performed to identify risk factors for CD of the pouch.

RESULTS

The study included 235 patients: AA (N=26), HA (N=37), IA (N=22) and randomly selected Caucasian (N=150) controls. Greater number of HA and Caucasians had a history of smoking than IA (27.3% and 27.0% vs. 0; p=0.007). Caucasians and HA were also more likely to have a family history of IBD than IA or AA (25% vs. 27% vs. 5% vs. 4%; p=0.016.) IA less frequently had extensive colitis before colectomy than Caucasians (71.4% vs. 94.0%; p=0.004) and more frequently required anti-TNF biologics than HA (22.7% vs. 0; p=0.016). On multivariable logistic regression analysis, AA (odds ratio [OR]=10.1, 95% confidence interval [CI]: 1.03, 1365.8, p=0.004) and Caucasians (OR=11.1, 95% CI: 1.4, 1427.2, p=0.015) had a higher risk of developing CD of the pouch than IA. However, the event-free survival was not significantly different between the groups on Cox regression analysis, presumably due to the sample size.

CONCLUSION

Racial background may be associated with different risk for the development of CD of the pouch for patients with IBD undergoing IPAA.