Japanese cypress

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Code: t24
Latin name: Chamaecyparis obtusa
Family: Cupressaceae
Common names: Japanese cypress, Hinoki cypress, False cypress, Hinoki Falsecypress, White cedar, Finuchi (Japanese)
Closely related species:
  • C. taiwanensis
  • C. pisifera
  • C. formosensis
  • C. formosana
A tree species producing large amounts of pollen, which may induce hayfever, asthma and conjunctivitis in sensitised individuals.
Available only for the Japanese market!

Allergen Exposure

Geographical distribution
Japanese cypress is an evergreen tree native to Japan and found most frequently in Southern Japan and in Taiwan (though it has been exported to many other temperate regions). It is a narrow, loosely conical tree with foliage that ranges from deep blue to bright golden-yellow.
It grows to 40m high and 3m in diameter, with a straight trunk and reddish-brown fibrous bark, fissured into thin strips, and pendulous branches. The tree has a narrow pyramidal crown. The branchlets are slender, closely arranged in a horizontal plane. The closely pressed, scale-like leaves are of 2 sizes and shapes. They have white X-shaped markings underneath. The cones are small and 8-scaled. The yellow-flowered tree is monoecious (having separate male and female reproductive organs on the same plant). It is in flower in May and June.
This cypress, rare in natural forests, is in extensive landscape use in Japan and Taiwan. It is found both in mass plantings and in gardens, where dwarf forms are popular. It can be used as a specimen plant, an accent in a border planting, and a "bonsai" tree.
The timber is prized and has often been used in traditional Japanese architecture, in temples and baths as well as homes. It is often the material of furniture and implements.
The following allergens from this plant have been characterised.
  • Cha o 1, pectate lyase (1-2)
  • Cha o 2, a 46 kDa protein, a poly galacturonase (3-5)
Cha o 1 was shown to be composed of 4 components. Molecular masses ranged between 48.5 kDa and 52 kDa. Cry j 1 from Cryptomeria japonica has pectate lyase enzyme activity, suggesting that Cha o 1 may have the same enzyme activity as Cry j 1 (1).
Of patients with pollinosis caused by Japanese cypress tree, 82.5% produced IgE antibodies that were shown to react with purified Cha o 2 (3).

Potential Cross-Reactivity

An extensive cross-reactivity among the different individual species of the genus could be expected but in fact does not occur frequently (6).
Recombinant Cup a 1, the major allergen of Cupressus arizonica pollen, was shown to be highly homologous with the major allergens of Mountain cedar (Jun a 1), Japanese cypress (Cha o 1) and Japanese cedar (Cry j 1). As expected, the high degree of homology with Cha o 1, Jun a 1 and Cry j 1 explains the cross-reactivity of conifer pollens. Different IgE reactivity with the glycosylated and non-glycosylated protein suggests the importance of carbohydrate moieties in the IgE binding site (7, 8). In a mouse model, the common antigenicity at the T-cell level between Japanese cedar and cypress pollen allergens was demonstrated to be caused by the existence of an identitical-cell epitope in Cry j 1 and Cha o 1 (9). These studies also indicated that Cry j 1 and Cha o 1 share their B-cell epitope but not their T-cell epitope (10).
A major allergen of Juniperus ashei (Mountain cedar) pollen, Jun a 2, was shown to be highly homologous to Cry j 2 and Cha o 2, the second major allergens of Cryptomeria japonica (Japanese cedar) and Chamaecyparis obtusa (Japanese cypress) pollen, respectively. Mountain cedar and Japanese cypress are members of the same family. The amino acid sequence of Jun a 2 shows 70.7 and 82.0% identity with those of Cry j 2 and Cha o 2, respectively. IgE antibodies in sera of Japanese pollinosis patients were shown to bind not only to Cry j 2 and Cha o 2 but also to Jun a 2, which strongly suggested that allergenic epitopes of the 3 allergens were similar (11).
The second major allergen from Japanese cypress, Cha o 2, was shown to display a high homology with Cry j 2, the second major allergen of Cryptomeria japonica (Japanese cedar) pollen. The deduced amino acid sequence of Cha o 2 shows 74.3% identity with that of Cry j 2. Cha o 2 shows significant identity with the polygalacturonases of Avocado, Tomato, and Maize as well as Cry j 2 (3, 4).
Because of cross-allergenicity between Cryptomeria japonica (Japanese cedar) and Chamaecyparis obtusa (Japanese cypress) pollen, many Japanese cedar pollinosis patients have symptoms during the cypress pollination season.
Immunotherapy (IT), specific for Japanese cedar pollinosis, reduced the daily symptoms not only in the cedar but also in the cypress pollination season, but not significantly. However, after the season, the mean symptom scores in the IT group tended to be lower than in the non-IT group (12).

Clinical Experience

IgE-mediated reactions
Japanese cypress may commonly induce symptoms of asthma, allergic rhinitis and allergic conjunctivitis in countries where this tree is common, e.g., Japan (13). The prevalence of sensitisation to Japanese cypress and Japanese cedar in 267 patients was reported to be 50.1% and 74.7%, respectively (14). RAST inhibition assays indicated cross-allergenicity between these two pollens and species-specific allergens, which may contribute to the high prevalence of sensitisation to these pollens.
Further studies of sensitisation to Japanese cypress have also reported high levels of sensitisation. Of 934 patients born and raised in an area of Matsusaka, Japan, with nose and/or throat allergies, 35.2% demonstrated specific IgE to Japanese cedar pollen in their serum, and 23.2% for cypress pollen (15). In 232 ENT patients in Tokyo, positive serum-specific IgE for Japanese cypress was demonstrated in 64.7% (16). In 267 patients with allergic rhinitis, serum-specific IgE determination demonstrated raised specific IgE to Japanese cypress in 50.6% (17).
Compiled by Dr Harris Steinman, harris@zingsolutions.com


  1. Aceituno E, Del Pozo V, Minguez A, Arrieta I, Cortegano I, et al. Molecular cloning of major allergen from Cupressus arizonica pollen: Cup a 1. Clin Exp Allergy 2000;30(12):1750-1758
  2. Suzuki M, Komiyama N, Itoh M, Itoh H, Sone T, Kino K, Takagi I, Ohta N. Purification, characterization and molecular cloning of Cha o 1, a major allergen of Chamaecyparis obtusa (Japanese cypress) pollen. Mol Immunol 1996;33(4-5):451-60
  3. Mori T, Yokoyama M, Komiyama N, Okano M, Kino K. Purification, identification, and cDNA cloning of Cha o 2, the second major allergen of Japanese cypress pollen. Biochem Biophys Res Commun 1999;263(1):166-71
  4. Yasueda H, Saito A, Sakaguchi M, Ide T, Saito S, Taniguchi Y, Akiyama K, Inouye S. Identification and characterization of a group 2 conifer pollen allergen from Chamaecyparis obtusa, a homologue of Cry j 2 from Cryptomeria japonica. Clin Exp Allergy 2000;30(4):546-50
  5. Mari A. Recombinant cypress allergens. Allerg Immunol 2000;32(3):98-100
  6. Yman L. Botanical relations and immunological cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09
  7. Aceituno E, Del Pozo V, Minguez A, Arrieta I, Cortegano I, Cardaba B, Gallardo S, Rojo M, Palomino P, Lahoz C. Molecular cloning of major allergen from Cupressus arizonica pollen: Cup a 1. Clin Exp Allergy 2000;30(12):1750-8
  8. Midoro-Horiuti T, Goldblum RM, Kurosky A, Wood TG, Schein CH, Brooks EG. Molecular cloning of the mountain cedar (Juniperus ashei) pollen major allergen, Jun a 1. J Allergy Clin Immunol 1999;104(3 Pt 1):613-7
  9. Ohno N, Ide T, Sakaguchi M, Inouye S, Saito S. Common antigenicity between Japanese cedar (Cryptomeria japonica) pollen and Japanese cypress (Chamaecyparis obtusa) pollen, II. Determination of the cross-reacting T-cell epitope of cry j 1 and cha o 1 in mice. Immunology 2000;99(4):630-4
  10. Kingetsu I, Ohno N, Hayashi N, Sakaguchi M, Inouye S, Saito S. Common antigenicity between Japanese cedar (Cryptomeria japonica) pollen and Japanese cypress (Chamaecyparis obtusa) pollen, I. H-2 complex affects cross responsiveness to Cry j 1 and Cha o 1 at the T- and B-cell level in mice. Immunology 2000;99(4):625-9
  11. Yokoyama M, Miyahara M, Shimizu K, Kino K, Tsunoo H. Purification, identification, and cDNA cloning of Jun a 2, the second major allergen of mountain cedar pollen. Biochem Biophys Res Commun 2000;275(1):195-202
  12. Ito Y, Takahashi Y, Fujita T, Fukuyama S. Clinical effects of immunotherapy on Japanese cedar pollinosis in the season of cedar and cypress pollination. Auris Nasus Larynx 1997;24(2):163-70
  13. Seno S, Dake Y, Sakoda T, Saito Y, Ikeda H, Kitano H, Kitajima K, Enomoto T. 2001 survey of pollen in Wakayama City with a real-time pollen counter. [Japanese] Nippon Jibiinkoka Gakkai Kaiho 2002;105(3):232-9
  14. Ito H, Nishimura J, Suzuki M, Mamiya S, Sato K, Takagi I, Baba S. Specific IgE to Japanese cypress (Chamaecyparis obtusa) in patients with nasal allergy. Ann Allergy Asthma Immunol 1995;74(4):299-303
  15. Yamagiwa M, Hattori R, Ito Y, Yamamoto S, Kanba M, Tasaki T, Ueda K, Nishizumi T. Birch-pollen sensitization in an area without atmospheric birch pollens. Auris Nasus Larynx 2002;29(3):261-6
  16. Nishihata S, Saito Y. Medical consultation dynamics in Japanese cedar pollinosis patients at an office building clinic in central Tokyo. [Japanese] Nippon Jibiinkoka Gakkai Kaiho 2002;105(6):751-8
  17. Suzuki M, Itoh H, Sugiyama K, Takagi I, Nishimura J, Kato K, Mamiya S, Baba S, Ohya Y, Itoh H, et al. Causative allergens of allergic rhinitis in Japan with special reference to silkworm moth allergen. Allergy 1995;50(1):23-7


As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.