Cell-bound IgE on human mast cells and basophilic granulocytes in atopic and nonatopic subjects

In previous studies basophil-bound IgE was measured by means of quantitative immunofluorescence miscroscopy. But mast cells are of particular importance in local atopic reactions, we thought it necessary to investigate the IgE-load on both cell types. The amount of mast cell-bound IgE can be estimated in a semiquantitative way by end point titration with a fluoresceinated sheep antihuman IgE (FlaIgE). The amount of mast cell-bound IgE was estimated this way in tonsils, adenoids, bronchial and tracheal tissues, and was compared with the amount of IgE on the basophils. A correlation was found between the IgE-load on mast cells and on basophils. Atopic patients had a higher mast cell fluorescence titer (MCFT) than nonatopic controls. It was demonstrated that, as on basophils, the IgE level of the serum contributes to this difference.