[Methods] It is a retrospective study using medical records of infants (from 6 months to 6 years old) who presented to our hospital for evaluation of allergy. We classified the groups according to the results of physical examinations with or without allergic symptom (eczema, wheezing, food allergy). In addition, we investigated the white blood cell counts (eosinophils and basophils) and the serum levels of total IgE, antigen-specific IgE, total IgA, sIgA, antigen-specific IgA.
[Results] Children who were low levels in sIgA have past histories of atopic dermatitis, and their serum levels of antigen-specific IgE was significantly higher (p=0.008) but their serum IgA level was significantly lower (p=0.021) compared with children who does not have allergic symptoms. And serum levels of antigen-specific IgA were significantly lower (p=0.038) in allergic children. Especially, ovomucoid specific IgA levels were low in children who has ovalbumin allergy.
[Conclusions] Secretory IgA levels are important to the onset of allergic reactions, and antigen-specific IgA might be played an important role in allergic reactions. IgE antibody contributes to immediate type allergic reactions, and the presence of the specific antibody can be an evidence of the diagnosis of allergic reactions. Moreover, we suggested that measurement of sIgA and antigen-specific IgA can be also useful in prediction of allergic reactions.