The distribution of IgE in canine skin was studied by immunofluorescence. The antibody was found to be associated exclusively with mast cells and to be largely cytoplasmically located. No other recognized immunoglobulin had a similar association. Immunofluorescent localization of Ascaris-binding antibodies gave parallel results to the IgE system. The amounts of IgE and of Ascaris-binding antibody in the skin of eight dogs were assessed semiquantitatively and showed a positive correlation with the results of intradermal skin tests with Ascaris extract and with anti-IgE (reversed cutaneous anaphylaxis). There was a poorer correlation between the amount of cutaneous IgE and the levels in the sera of the same eight dogs.
This work was supported by a grant from the Wellcome Trust, of which the author is a Research Fellow.