Identification of allergen fractions of wheat flour responsible for anaphylactic reactions to wheat products in infants and young children.

Wheat is a food allergen which occasionally causes anaphylactic reactions exclusively in young children. There is very little knowledge of the clinical outcome in cases of food-related anaphylaxis and the differences in the allergenic protein components of food involved, comparing individuals who have suffered from an anaphylactic reaction with other individuals. The objectives of the present study were to examine the clinical features of 7 young children who had experienced anaphylactic reactions after ingesting wheat flour-containing products, and to analyze the allergens in wheat flour responsible for the anaphylactic symptoms. We measured the total IgE levels and the levels of IgE antibodies specific to wheat flour and performed IgE immunoblotting, comparing the sera from these children with sera from patients with atopic dermatitis. All sera from children who had experienced anaphylactic reactions were found to be positive for IgE specific to wheat. IgE immunoblotting revealed that 3 of these 7 children had sera showing reactivity to components of the salt-soluble protein fraction (16, 35--67 and 94 kD) and salt-insoluble protein-containing fraction (16, 38 and 70 kD) and 4 had no sera showing reactivity to components of the salt-soluble fraction. Patients with atopic dermatitis showed similar staining patterns. Various proteins in wheat flour could be allergens responsible for anaphylaxis and atopic dermatitis in infants or young children. Our findings suggest that these two clinically diverse allergic diseases do not necessarily represent responses to different allergenic proteins of wheat.