The number and affinity of IgE receptors on dispersed human lung mast cells.

Mast cells obtained by fragmentation of human lung tissue retained the capacity to bind IgE and to respond to immunological challenge. Direct binding studies with radiolabelled IgE enabled quantification of binding parameters of the reaction between IgE and its receptor on human mast cells. The average equilibrium constant was estimated as 1.0 x 10(8) M -1 and the average number of IgE receptors per mast cell as 1.3 x 10(5).