CROSS-REACTIVITY TO OLIVE TREE POLLEN AND ORCHARD GRASS-POLLEN IN PATIENTS WITH POLLINOSIS

We studied 92 patients with allergic rhinitis in Syodoshima, Japan, du ring the pollen season between April and June to evaluate the crossrea ctivity to different antigens, including pollen from the olive tree (O lea europaea) and orchard grass (Dactylis glomerata). Olive tree polle n was present in the atmosphere for 23 days, from May 19 to June 12, 1 994. Specific IgE antibodies for olive tree pollen antigen were presen t in 21 (26.9%) of the 78 patients with allergic rhinitis. Nine (24.3% ) of the 37 patients with allergic rhinitis exhibited positive skin re activity to an extract of olive tree pollen. Fifteen (88.2%) of the 17 patients who had IgE reactivity in their sera to olive tree pollen an tigen demonstrated allergic reactions to an extract of olive tree poll en. Specific IgE antibodies for orchard grass pollen antigen were pres ent in 43 (48.3%) of the 89 patients with allergic rhinitis and 20 (95 .2%) of the 21 patients who had IgE reactivity in their sera to olive tree pollen antigen. The inhibition test using the CAP System revealed that the reactivity of the IgE antibody specific for olive tree polle n antigen was inhibited dose-dependently by an extract of orchard gras s pollen. These findings show that there is a reaction in some patient s with grass (Gramineae) pollinosis that might be induced by olive tre e pollen.