Analysis of cross-reactivity between sunflower pollen and other pollens of the Compositae family.

The sera of 20 patients with Compositae pollen allergy were investigated for the presence of IgE antibodies reacting against sunflower pollen by means of RAST and immunoblotting studies. Thirteen IgE-binding bands were detected with molecular weights ranging from 14.4 to 94 kd. Two of these bands, with molecular weights of 24 and 25 kd, contained major allergens that reacted strongly with 100% (24 kd) and 95% (25 kd) of the sera, respectively. Cross-reactivity between sunflower and other Compositae pollens (mugwort, marguerite, dandelion, golden rod, and short ragweed) was revealed by RAST and immunoblotting inhibition experiments. Mugwort pollen exhibited the greatest degree of allergenic homology (cross-reactivity) with sunflower pollen, whereas at the other end of the spectrum, short ragweed showed less cross-reactive epitopes.