Role of immunoglobulin G antibodies in diagnosis of food allergy

This paper presents current views on the role of immunoglobulin G (IgG) antibodies in the reactions with food antigens in the digestive tract and their role in the diagnosis of food allergy based on the assays of specific IgG class antibodies, with a special focus on contemporary practice guidelines. In the light of current scientific knowledge, the IgG-specific antibody-mediated reactions are a body's natural and normal defensive reactions to infiltrating food antigens, which are considered as pathogens. On the other hand, specific IgG antibodies against food allergens play a crucial role in the induction and maintaining of immunological tolerance to food antigens. The statements of many scientific societies stress that sIgG are of no significant importance in the diagnosis of food allergy since their presence is associated with a normal immune response to food allergens and attests to a protracted exposure to food antigens.