Positive association between Helicobacter pylori infection and food allergy in children

BACKGROUND: In children Helicobacter pylori has been involved as a pathogenetic factor in gastritis and duodenal ulcer and as a cofactor in protein-losing enteropathy, chronic diarrhoea, short stature, and gastritis lymphoproliferative disease. A subset of an H. pylori strain possesses an antigen, CagA, as a virulence factor. In the present study we determined anti-H. pylori IgG and anti-CagA IgG titres in children with food allergy. METHODS: Ninety paediatric patients were studied: 30 with food allergy, 30 with atopic asthma, and 30 with inflammatory bowel disease. Anti-H. pylori IgG and anti-CagA IgG were determined in all children by means of a commercial enzyme immunoassay (ELISA). RESULTS: The anti-H. pylori IgG titre was significantly higher in allergic patients than in the other two groups. The anti-CagA IgG titre did not differ significantly between the patients. CONCLUSIONS: These findings show a positive association between H. pylori infection and food allergy in children. We hypothesize that virulence factors other than CagA may be involved in the pathogenesis of H. pylori infection in paediatric patients with food allergy.