Cypress pollen allergy. Identification of allergens and crossreactivity between divergent species.

Studies employing sera from 34 subjects allergic to white cypress pine (Callitris glaucophylla) pollen identified 18 IgE antibody-binding components in the pollen of this species, five of which (MWs approximately 94, 68, 64, 43 and 34 kDa) were recognized by all of the sera. Protein blotting and quantitative inhibition studies revealed clear cross-reactivity between C. glaucophylla and Cupressus sempervirens pollen proteins and striking similarities in the IgE recognition band patterns of the two pollens. Inhibition experiments with other pollen extracts revealed that sera from C. glaucophylla pollen-allergic subjects can be divided into two groups--those inhibited only by extracts from the two Cupressaceae pollens and those inhibited both by these pollen proteins and by pollen extracts from other species. Most of the crossreactions in the latter group cannot be explained on the basis of taxonomic relationships or separate sensitizations. As with previous studies on birch and olive pollens, we conclude that pollen allergenic crossreactivity is much more wide-ranging than generally believed.