[Analysis of immune responses in buckwheat allergy]

Hypersensitivity resulting from the ingestion or inhalation of buckwheat allergen causes immediate manifestation of symptoms including urticaria, wheezing, dyspnea, anaphylactic shock, which is considered to be IgE-mediated type I hypersensitivity. Using sera of patients with buckwheat allergy the immuno-reactivity to purified buckwheat protein was investigated by enzyme-linked immunosorbent assay (ELISA) and immunoblotting method. The incidence of positive RAST value to buckwheat was 80% in the patients and 66.6% in the RAST-positive controls, whereas the RAST-negative controls showed all negative. The sera of both patients and RAST-positive controls showed significantly higher levels of specific IgG antibodies against salt-soluble and salt-insoluble fractions of buckwheat protein than the RAST-negative controls. By means of IgG-immunoblotting analysis, ten polypeptide bands of salt-soluble fraction and six polypeptides bands of salt-insoluble fraction were detected in all sera of the patients. In contrast, the patterns of IgE-immunoblots varied depending on the sera used. Taken together, the immune activation to buckwheat protein in patients with buckwheat allergy is not restricted to IgE antibody formation but extends to other immunoglobulin class. IgG, which indicating that the overall immune activation to buckwheat protein may be the basic characteristics of buckwheat allergy. Additionally, other factor is necessary for the manifestation of symptoms.