IN-VITRO INVESTIGATION OF CROSS-REACTIVITY BETWEEN BIRCH AND ASH POLLEN ALLERGEN EXTRACTS

Allergenic cross-reactivity between members of the Fagales family (bir ch, alder, hazel, and beech) and between members of the Oleaceae famil y (ash, olive, lilac, and privet) is well known, but little is known a bout possible cross-reactivity between these two groups of trees, in p articular between birch and ash, both of which flower in the spring. V arious immunochemical methods including RAST inhibition, Western blot, and Western blot inhibition have been used in this study to show that there is partial cross-reactivity between birch and ash pollens. Enzy me allergosorbent test measurements were performed on sera from 35 pat ients with hay fever in spring by using birch and ash pollen allergen disks. The major allergen of birch, Bet v 1, was readily detectable in the birch pollen extract, but a homologous allergen in the ash pollen extract was barely detectable. Common allergens could be determined i n the high molecular weight region. Ash pollen should be included in d iagnostic procedures for spring pollinosis and should be considered fo r use in specific immunotherapy.