Cypress Pollinosis: from Tree to Clinic

Abstract

Cypress (Cupressus sp.pl) is a genus within the Cupressaceae family. This family covers all of the Earth's continents except for Antarctica, and it includes about 160 species. The most important taxa for allergic diseases belong to five different genera: Cupressus, Hesperocyparis, Juniperus, Cryptomeria, and Chamaecyparis. Cupressaceae species share a common pollen type that can even include the genus Taxus (Taxaceae) when this plant is also present. As Juniperus oxycedrus pollinates in October, Cupressus sempervirens in January and February, Hesperocyparis arizonica (prev. Cupressus arizonica) in February and March, and Juniperus communis in April, the symptomatic period is long-lasting. Due to global warming, the pollination period tends to last longer, and there is a trend for Cupressaceae bioclimate niches to migrate north. In Mediterranean areas, C. sempervirens (Italian cypress or Mediterranean cypress) is by far the most common pollinating species. It accounts for half of the total pollination level. The group 1 major allergens belong to the pectate-lyase family, and members share 70 to 97% sequence homology within the different Cupressaceae. Group 2 allergens correspond to the polygalacturonase protein family, while group 3, a minor allergen, belongs to the family of "thaumatin-like proteins," a pathogenesis-related protein 5. Group 4 allergens are Ca-binding protein (4 EF-hands). Aside from these four groups, about 15 other allergens have been reported. Prominent among these is a basic low-molecular mass cross-reactive allergen that was identified recently, and which is suspected to be involved in pollen food syndromes which are common with peach and citrus. The prevalence of cypress allergy in the general population ranges from 0.6 to 3%, depending on the degree of exposure to the pollen. Depending on the geographic area and the studied population, 9 to 65% of outpatients consulting an allergist may have sensitization to cypress pollen. Repeated cross-sectional studies performed at different time intervals have demonstrated a threefold increase in the percentage of cypress allergy around the Mediterranean area. Risk factors include a genetic predisposition and/or a strong exposure to pollen, and the natural history of cypress allergy allows identification of a subgroup of patients as allergic rather than atopic. Concerning the clinical expression, rhinitis is the most prevalent symptom, while conjunctivitis is the most disabling. Pharmacological treatment of cypress allergies is not different from that of other seasonal allergies. Immunotherapy has been used, initially by subcutaneous injections, but currently mostly through the sublingual route. Although clinical trials have included only a limited number of patients, it has proven effective and safe. Avoidance can be implemented at the individual level, as well as at the community level, through the use of alternative plants, low-pollinating cypresses, or by trimming hedges before pollination.

Pru p 7 sensitization is a predominant cause of severe, cypress pollen‐associated peach allergy

“…Similarly, little is known about allergen(s) other than Pru p 7 potentially involved in the cypress‐peach syndrome . Teams from southern France and Spain reported an association of CP and PA in Pru p 3 sensitized patients .…”

“…Although cypress trees are typical of Mediterranean regions, Cupressaceae pollen dispersal also affects non‐Mediterranean environments, including Central Europe, North America, Mexico and Japan . GRP‐related allergy to Rosaceae and Citrus fruits was reported in conjunction with Japanese cedar pollinosis .…”

“…In south‐central United States, mountain cedar ( Juniperus ashei ) pollen is a major cause of allergic rhinoconjunctivitis . Pollinosis to Cupressaceae has been steadily increasing during the past decades, possibly as a result of extended species distribution due to climate change and ability of Cupressaceae pollen to travel over hundreds of kilometres . Individuals with Cupressaceae pollinosis who display similar sensitization profiles due to the homology of allergens from different Cupressaceae species might become exposed to previously unencountered, cross‐reacting foods, when changing residence regions, travelling overseas, or expanding their consumption of fruits and vegetables as a result of healthy living trends .…”

A new allergen family involved in pollen food-associated syndrome: Snakin/gibberellin-regulated proteins

“…1 The pollinosis can be severe including infectious complications, partly due to winter pathologies occurring within cypress pollinating period. 2 In Southern France, a pollen food-associated syndrome (PFAS) was described involving cypress pollen and peach and/or citrus sensitizations inducing mainly oral syndrome but also urticaria and angioedema.…”

“…Because Pru p 7 shares more than 80% sequence identity with snakin-1 and more than 95% with other fruit GRP allergens, BP14 should be considered as the cross-reactive allergen in the 2 documented PFAS involving peach and/or citrus. 1 Preliminary experiments showed that patients allergic to cypress pollen and citrus expressed IgE against cypress pollen BP14 cross-reactive with a cationic 12-kDa allergen from grapefruit (unpublished data Q 1 ). Therefore, snakin/GRP may represent a new diagnostic marker of PFAS in addition to other allergens such as Bet v 1-like proteins involved in the well-studied birch/apple syndrome.…”