Background: Genetic factors may play a role in determining the development of extraintestinal manifestations (EIMs) and autoimmune diseases (AD) in patients with inflammatory bowel disease (IBD). We sought to determine the association between EIMs and AD in patients with first-degree familial IBD and sporadic IBD.
Methods: All patients evaluated in the IBD Clinic at the Mayo Clinic between January and September 1999 were offered enrollment. One clinic patient who was matched on age, gender, and geographic area of residence to each case served as controls. Information regarding EIMs and AD was obtained from a questionnaire completed by all IBD patients and controls. The adjusted odds ratios (95% CIs) for EIM as a function of first-degree familial IBD compared with sporadic IBD and AD as a function of first-degree familial IBD compared with sporadic IBD were estimated with a matched one-to-one conditional logistic regression model.
Results: Two hundred forty-three patients with IBD (47 first-degree familial IBD, 196 sporadic IBD) were enrolled. Forty percent of IBD patients had one or more EIMs compared with 14% matched controls [p < 0.001; OR = 3.1 (95% CI: 1.8 to 5.2)]. A total of 259 of the 1122 IBD patients and their first-degree family members indicated one or more EIM diagnoses (23%). The association between "familial versus sporadic" status and any EIM diagnosis was not significant [p = 0.59, the odds for an individual from a familial IBD family relative to an individual from a sporadic IBD family was 1.2 (95% CI: 0.8 to 1.7)]. Ten percent of IBD patients had one or more AD diagnoses compared with 19% matched controls [p = 0.04; OR = 0.4 (95% CI: 0.1 to 0.96)]. A total of 153 of the 1122 IBD patients and their first-degree family members indicated one or more AD diagnoses (14%). The association between disease status ("familial or sporadic") versus any AD diagnosis was not significant [p = 0.68, the odds for any AD in an individual from a familial IBD family relative to an individual from a sporadic IBD family was 1.4 (95% CI: 0.9 to 2.3)].
Conclusions: There was a positive association between IBD status (patient vs control) versus EIM, but not AD. A significant positive association between disease type (familial or sporadic) versus either EIM or AD was not detected.