In vivo and in vitro tests showing sensitization to Japanese cedar (Cryptomeria japonica) pollen allergen in atopic dogs.

Using both in vivo and in vitro tests, dogs with atopic dermatitis were examined for sensitization with Japanese cedar (Cryptomeria japonica, CJ) pollen allergen. Ten dogs with clinical manifestation of atopic dermatitis were shown to be sensitized to CJ pollen based on the results of intradermal skin test and serum antigen-specific IgE test. In vitro lymphocyte stimulation test showed blastogenic response after stimulation with crude antigen of CJ pollen in all of the 5 cases examined. The peripheral leukocytes showed increased histamine release after stimulation with crude antigen of CJ pollen in 2 cases examined. These data indicate that a proportion of dogs with atopic dermatitis is sensitized to CJ pollen in a cell-mediated manner and show immediate phase reaction of type I hypersensitivity.