IgE-sensitization to food and inhalant allergens in IBD patients compared with normal blood donors at Oslo University Hospital, Norway.

Objectives: Crohn's disease (CD) and ulcerative colitis (UC) have been regarded as autoimmune Th-1/Th-17- and Th-2-associated conditions, respectively. The aim of the study was to examine possible differences in allergen sensitization between these diseases and relative to normal blood donors (BD). Materials and methods: Plasma from 29 UC and 37 CD patients with moderate disease activity and 100 healthy age- and gender-matched BD, were analyzed for specific IgE to 22 food- and 28 inhalation allergens using EUROLINE atopy screen. Results: There was significantly higher proportion of allergen sensitized patients in UC compared to BD. Corresponding mean percentages for UC, CD and BD were 8.5, 8.9 (p = .2) and 5.9 (p = .04). There was no intergroup difference in sensitization to food allergens. Most prominent result was the double level of sensitization to inhalants in CD (15%) compared to BD (8%) (p = .03). Overall highest levels of sensitization to inhalants were for grass pollens. Interestingly, the number of allergens (n = 50) the subjects were sensitized to, was significantly lower among UC (n = 20; 40%) (p = .0005) than CD (n = 31; 62%) and BD (n = 38; 76%). Conclusions: The percentage of individuals sensitized to inhalants in CD and to inhalants and foods in UC, were higher than corresponding results in BD. However, whereas allergen positive reactions in CD were comparable to those in BD, they were reduced in UC because of the few UC reactions to food allergens. This contrasts previous data and the study also points to sensitization to inhalants as a potential factor in the complex pathogenesis of IBD.