Functional Gastrointestinal Symptoms Are Associated with Higher Serum Total IgE Levels, but Less Atopic Sensitization.

Background: The relation of gastrointestinal (GI) complaints to IgE-mediated allergy is not well understood. Increased numbers of "IgE-armed" mast cells have been observed in duodenal mucosa of patients with functional GI complaints.

Aims: To explore whether total IgE and atopic sensitization were associated with functional GI complaints.

Methods: Levels of serum total and specific IgE and GI complaints were measured in 161 patients and in a general population sample of 478 persons. Standard inhalant allergens were measured in the patient group, and selected inhalant allergens in the general population. GI complaints were assessed by two standardized questionnaires. The associations between GI complaints and total IgE were analyzed in multiple regression models.

Results: GI complaints were positively associated with higher total IgE levels (all: b = 0.028, p = 0.012; patient group: b = 0.038, p = 0.072; general population: b = 0.038, p = 0.005), but negatively associated with atopic sensitization (all: b = -11.256, p = 0.181; patient group: b = -85.667, p < 0.001; general population: b = -14.394, p = 0.083). The relationship between total IgE and GI complaints was consistent among sensitized and non-sensitized persons, among men and women, and across age groups.

Conclusion: Serum total IgE was positively associated with GI complaints, while atopic sensitization was inversely associated with GI complaints. This suggests that IgE-mediated immunology plays a role in the pathophysiology of functional GI complaints. The biological mechanisms reflected in higher total IgE levels, but less atopic sensitization, warrant further studies.