Appendicitis, not appendectomy, is protective against ulcerative colitis, both in the general population and first-degree relatives of patients with IBD.

摘要

Concordant case-control studies reported in the 1990s have suggested a negative relationship between appendectomy and the subsequent risk of ulcerative colitis (UC). This was confirmed in 2001 through the publication of the Swedish cohort pivotal study by Andersson et al. The authors also demonstrated that the protective effect of appendectomy was restricted to appendectomy performed under the age of 20 years for appendicitis or lymphadenitis, but not for nonspecific abdominal pain without objective inflammatory condition. Around the same time the results of a Danish cohort exploring the same issue failed to reach statistical significance, probably because of a lack of power. In the work published online first in the British Medical Journal, data from the Swedish and Danish cohorts were pooled in order to confirm the previously published results and to bring new insights to the topic by exploring the protective effect of appendectomy in the subgroup of patients with at least 1 first-degree relative affected by inflammatory bowel disease (IBD).