CagA-positive Helicobacter pylori infection may increase the risk of food allergy development

The aim of this study was to test whether patients with symptomatic food al lergy and significant levels of immunoglobulin E (IgE) to alimentary antige ns were more likely infected by H. pylori, especially by strains expressing the CagA protein, with respect to controls. A group of 38 patients with sy mptomatic food allergy and 53 age-matched controls were examined serologica lly for H. pylori infectious status, and for CagA seropositivity. IgE to al imentary allergens were measured by a commercial kit. The prevalence of H. pylori infection in patients with food allergy and controls was similar (42 .1%, and 48.3%, respectively). However, anti-CagA antibodies in H. pylori-i nfected persons were detected in 62.5% of patients with food allergy, and 2 8% of controls (P = 0.030, odds ratio = 4.29). The mean level of IgE to the most common alimentary antigens in serum samples from infected patients wi th anti-CagA antibodies was significantly higher than in CagA-negative infe cted patients: 3.28 kU/L (SD 3.93), vs. 1.99 kU/L (SD 1.53), P = 0.002, 95% confidence interval 0.61 to 2.53). Infection by CagA-positive H. pylori in creases the risk of developing food allergy.