Plasma of normal, but not atopic persons reducing basophil degranulation induced by anti-IgE.

The response to anti-IgE serum of basophils from allergic and normal persons in the presence of whole plasma or as washed cells in Tyrode solution was examined to detect any inhibiting activity of human plasma. A factor reducing the potential of anti-IgE serum to degranulate basophils was present in plasma of normal but not of allergic persons. It is considered that this property of plasma could contribute to homeostatic control in immediate hypersensitivity.