IgE reactivity and cross-reactivity of Japanese monkeys (Macaca fuscata) to Japanese cedar (Cryptomeria japonica) and cypress (Chamaecyparis obtusa) pollen allergens

Background The natural occurrence of Japanese cedar (Cryptomeria japonica, CJ) pollinosis has been reported in Japanese monkeys (Macaca fuscata). However, the reactivity to Japanese cypress (Chamaecyparis obtusa, CO) pollen allergens in these monkeys has not yet been reported. Objectives The present study was designed to investigate the reactivity to CO pollen allergens in monkeys sensitized to CJ pollen allergens. Methods Serum samples from 40 monkeys naturally sensitized to CJ pollen allergens were collected from four troops. We measured the specific IgE to CO pollen allergens and examined the reactivity to the allergens by intradermal test. Cross-reactivity between CJ and CO pollen allergens was examined by ELISA inhibition method. Furthermore, we examined the sensitivity to the allergens by histamine release assay from leucocytes. Results All 40 monkeys had specific IgE to crude and purified major allergens (Cha o 1) of CO pollen. The monkeys showed a positive reaction to CO pollen allergens in the intradermal test. Allergenic cross-reactivity between Cha o 1 and Cry j 1 (a major allergen in CJ pollen) was also observed. Specific histamine release to both the major allergens was noted in two monkeys with CJ pollinosis. Conclusion Japanese monkeys sensitized to Japanese cedar pollen allergens also demonstrate reactivity to Japanese cypress pollen allergens.