There is some controversy regarding the prevalence of tonsillectomy and appendectomy among patients with Crohn's disease (CD) and a lower rate of appendectomy among patients with ulcerative colitis (UC). However, some environmental and familial factors that could alter those figures have not been studied.
Objective: To explore the prevalence of MALTectomy (appendectomy and tonsillectomy) among patients with IBD, stressing those factors that may be significantly associated to it.
Method: Age-and-sex matched case-control study in patients with IBD, their relatives and the general population. Two hundred and eighty seven cases were IBD patients (153 UC, and 134 CD), the "family control" group included 203 siblings and the population-based control group included 570 individuals. Potential confounding factors, such as smoking, educational level, oral contraceptive use, place of birth and residence up to the age of 15 years, were ruled out.
Results: Appendectomy and UC: 7% of UC patients had undergone appendectomy versus 20% (OR: 0.23; 95% CI: 0.11-0.5; p < 0.0001) of controls. Appendectomy rates in families with at least one case of UC were 17/153 (6.3%) and 61/306 (20%) in the control group (p < 0.001). Appendectomy and CD: Twelve per cent of CD patients had undergone appendectomy six months before the onset of the disease versus 17% among the control population (OR: 0.43; 95% CI: 0.29-0.95; p < 0.01). The frequency of appendectomy in families with at least one case of CD was 22/221 (10%), which was significantly lower (p < 0.05) than among the control group 45/264 (17%). No differences were found between IBD patients and familial controls. Tonsillectomy and CD: Forty six per cent of CD patients had undergone tonsillectomy versus 39% of control patients (OR: 1.77; 95% CI: 0.92-2.05; p = ns). Tonsillectomy and UC: Twenty eight per cent of UC patients had undergone tonsillectomy versus 39% of the population control group (OR: 1.07; 95 CI: 0.57-1.25: p = ns). In fact, no differences were found regarding the prevalence of tonsillectomies within families with IBD cases as compared to population controls.
Conclusions: Appendectomy is not only less frequent among CD and UC patients, but also among their relatives, thus suggesting the existence of environmental and genetic factors with opposed etiological roles in IBD and appendicitis.