Allergenic relationships of two different antigens of Kentucky bluegrass pollen

Two purified allergens, allergen C and KBG-1, isolated from Kentucky bluegrass (KBG) pollen, were found to be antigenically distinct with respect to rabbit precipitating antisera produced separately to each allergen. On the other hand, allergen C and KBG-1 appeared to be allergenically identical in terms of the specificities evaluated with murine reaginic antisera produced to each of these allergens; whereas they appeared to be only partially identical when evaluated with respect to the IgE antibodies present in a pool of human sera from individuals allergic to KBG pollen. Therefore, not all of the allergenic determinants recognized by the human IgE antibodies were detected by the murine reaginic antisera. This study serves to emphasize that for a meaningful evaluation of allergenic specificities any antisera prepared in animals and intended for the standardization of allergens must recognize allergenic specificities which are similar or identical to those to which the human IgE antibodies are directed.