Family: Cupressaceae.
Mountain juniper is a large, many-stemmed shrub or a small tree, up to about 6 metres. In contrast to other members of the large conifer family, Cupressaceae, noted for their attractive foliage in shades of green, yellow and blue-grey, it grows at a snail's pace. It has persistent, aromatic leaves and its reddish brown wood makes for long-lasting exteriors. It occurs in rocky soils in canyons, ravines, around rim-rocks and breaks and can live as long as 2 000 years.

The genus Juniperus is widely distributed in the northern hemisphere. Mountain juniper is native in south-western North America, and is particularly common in Texas. It colonises grasslands and becomes a pest.

In the USA, Mountain cedar is a major cause of seasonal allergy in the South-West and Texas. In Europe, this species is present only in the Balkan peninsula and Crimean mountains. (Hrabina 2003 ref.8294 7)

Mountain juniper flowers in winter (December and January). Male pollens and female flowers occur on different trees. Most species of Juniper produce copious amounts of pollen that can be carried long distances by the wind. Juniper is the most significant allergenic offender in the Cypress family.

Mountain juniper tree, Italian funeral cypress tree and Arizona cypress tree belong to the same botanical family of Cupressaceae.

While Italian Funeral Cypress tree and Arizona Cypress are commonly encountered in Mediterranean regions, Mountain cedar is only present in Europe in the Balkans, and is a major cause of allergy in the USA. (Andre 2000 ref.4491 4)

Juniperus ashei (mountain cedar) is the leading cause of respiratory allergy in South Texas. (Schwietz 2000 ref.4701 3)

Allergens/Function:

Allergens:
Jun a 1, the major allergen, a pectate lyase (Midoro-Horiuti 1999 ref.4702 3) (Mari 2000 ref.4890 6) (Gross 1978 ref.5181 8) (Ford 1991 ref.3936 6)
Jun a 2, a 43 kDa protein, a major allergen (Yokoyama 2000 ref.4489 3)
Jun a 3, a 30 kDa protein, a Thaumatin-like protein (Soman 2000 ref.4889 6) (Mari 2000 ref.4890 6)


The 42 kDa allergen, corresponding to Jun a 1, has 7 isoforms. (Hrabina 2003 ref.8294 7)

Of 91 sera from Cypress-allergic patients, 81% contained IgE specific fo the 42 kDa allergen. Among them, 46.7% only recognized only this single 42 kDa band. (Ford 1991 ref.3936 6)

Adverse Reactions:

IGE AND IMMUNE:
Cypress pollen allergy is a major cause of rhinoconjunctivitis and asthma in the Mediterranean area. (Hrabina 2003 ref.8294 7) Increased planting of cypress trees for ornamental purposes has probably contributed to the increased prevalence of sensitisation to cypress pollen which is the third most sensitising allergen source after mites and grass pollens in South-East France. (Charpin 2000 ref.3752 2)

The role of cypress pollen allergy in upper respiratory tract diseases has often been underestimated because of winter pollination of cypress trees (and the lack of efficacy of nonstandardized extracts for diagnosis. (Hrabina 2003 ref.8294 7)

Cedar pollen causes asthma, allergic rhinitis and allergic conjunctivitis. (Ramirez 2000 ref.4492 6)

A high degree of cross-reactivity could be expected among the different species of the family Cupressaceae. In Europe, juniper (J. communis) seldom causes sensitisation in atopics.

The flowering season of mountain juniper is closely related to the serious type of winter hay fever especially pronounced in Texas, USA. It has been suggested that J. sabinoides causes allergic reactions in patients with no other sensitivities because of its chemical composition.

During the winter months, pollen from the mountain cedar causes severe respiratory tract allergy in central Texas, where 34 % of allergic patients were found to be allergic only to mountain juniper and 66% were allergic to mountain juniper and other aeroallergens. Sensitised individuals appear to require much longer exposure to juniper pollen before developing mountain juniper pollinosis, and they develop allergic disease at a later age (39 yr) when compared to patients with multiple allergies. These results suggest that the mountain juniper pollen may be unique in causing allergic rhinitis in patients who have no other sensitivities. A possible explanation may lie in the carbohydrate nature of the main allergen of the mountain juniper pollen, which may facilitate allergen transport through the respiratory tract mucosa and subsequent sensitization. (Ramirez 2000 ref.4492 6)

NON IMMUNE:
Unknown or Nil