Background: The influence of familial IBD on phenotype and course of disease in patients with CD and UC has not been studied in population-based cohorts.
Aim: To compare phenotype and course of disease between IBD patients with a first-degree relative with IBD and sporadic cases in a population-based cohort followed prospectively for 5 yr.
Methods: Family history of IBD was registered at diagnosis and after 1 and 5 yr. Phenotype and course of disease were compared between sporadic and familial cases.
Results: Data for 200 patients with CD and 454 with UC were sufficient for analysis. A first-degree relative with IBD was registered in 14.5% of CD patients and 10.1% of UC patients. The concordance for type of disease was 82% and 70% for CD and UC, respectively. No differences between familial and sporadic cases as regards localization and behavior of disease in CD patients or disease extent in UC patients were observed. In CD patients with colonic involvement, those in the familial group were significantly younger at diagnosis than the sporadic cases. No difference in disease severity in CD patients was observed between the familial and sporadic groups. In UC patients relapse was more frequent in familial cases, but no difference was observed in the need for surgery or medical treatment.
Conclusions: A family history of IBD does not seem to influence phenotype or to be an important prognostic factor for disease course in IBD patients.