Figure 1. Histamine release assay.

Basophils in leukocyte suspension were stripped off the bound IgE. Stripped basophils were sensitized with sera of kidney bean hypersensitive patients. The sensitized basophils were stimulated with kidney bean extract. The Histamine released from 30 patients varied from 16% to 54% while in controls it is less than 6% (A). Scatter plot of the correlation analysis between % histamine release vs SPT (mm²) (B), % histamine release vs sIgE (C) and % histamine release vs total IgE (D) among 30 kidney bean sensitive individuals. Basophil histamine release has been found to be very well correlated with SPT (r = 0.83, p<0.0001) and sIgE (r = 0.99, p<0.0001) but not with total IgE (r =  −0.13, p = 0.4942).