IgE reactivity and cross-reactivity to Japanese cedar (Cryptomeria japonica) and cypress (Chamaecyparis obtusa) pollen allergens in dogs with atopic dermatitis

The natural occurrence of Japanese cedar (Cryptomeria japonica) pollinosis has been reported in dogs with atopic dermatitis. However, the reactivity t o Japanese cypress (Chamaecyparis obtusa) pollen allergens in these dogs ha s not been reported. The present study was designed to investigate the reac tivity to Japanese cypress pollen allergens in dogs sensitized to Japanese cedar pollen allergens. In 19 dogs with specific IgE to C. japonica pollen allergen, we measured the specific IgE to C. obtusa pollen allergen and exa mined the reactivity to the allergen by intradermal test. Of the 19 dogs, 1 8 had specific IgE to crude and purified major allergens (Cha o 1) of C. ob tusa pollen. Most of the dogs showed a positive reaction to C obtusa pollen allergens in the intradermal test. Allergenic cross-reactivity between Cha o 1 and Cry j 1 (a major allergen in C. japonica pollen) was observed by t he ELISA inhibition method. Dogs sensitized to Japanese cedar pollen allerg ens demonstrate reactivity to Japanese cypress pollen allergens. (C) 2001 E lsevier Science B.V. All rights reserved.