Immunocytochemical mapping of IgE/IgG binding sites within the birch pollen grain using serum from a patient undergoing hyposensitization therapy. Comparison with biochemically determined data.
Serum from an atopic patient undergoing a hyposensitization therapy to birch pollen allergens was used to carry out immunocytochemical mapping of specific IgE/IgG binding sites within ultrathin sections of birch pollen grains. There was a distinct rise in the density of specific IgG labelling in the course of therapy, whereas the density of IgE labelling remained fairly constant. However, the patterns of IgG and IgE binding in the pollen grain did not completely coincide since there was only IgE binding to certain pollen structures such as the apertural region. If the widely accepted concept of specific antibodies as 'blocking antibodies' is taken as a basis, the success of therapy must be questioned in this case because no IgG antibodies were formed to some of the allergens localized in the pollen grain and relevant to this patient. Very probably this result must be attributed to an incomplete pollen extract used in hyposensitization therapy. The results of the biochemical measurements (RAST, ELISA) agreed well with the immunocytochemical observations.