In vitro quantitative methods for determination of antigenic release of histamine from leucocytes and stimulation of small lymphocytes to transformation into blast forms were applied to a study of immunologic responses to food proteins in allergic and non-allergic children. The allergic group was subdivided according to positive or negative reactions to intradermal injection of the food proteins.
Significant lymphocyte stimulation by proteins from foods universal in the diets, like cow's milk and eggs, occurred as frequently in non-allergic as allergic children, with or without positive skin tests to the food proteins. Furthermore, the average stimulation among the groups was not significantly different.
A soybean protein gave significantly greater stimulation of lymphocytes from allergic children, in whose diets soybean formulae are frequently substituted for cow's milk.
Antigenic release of histamine from leucocytes occurs only with leucocytes from skin-test positive persons, and in only about 25-50% of these in the case of food proteins.
Neither the procedure for lymphocyte stimulation nor for histamine release from leucocytes, as carried out in this study, will serve to determine unequivocally whether a particular food protein is causing symptoms in question.