Allergie et immunologie最新文献

The non-standardized Cupressus sempervirens allergen extract currently available for the diagnosis of cypress allergy has a low level of activity. The search for an active material consisted of in vitro and in vivo comparison of three Cupressaceae pollen extracts: Cupressus sempervirens (Cs), Cupressus arizonica (Ca) and Juniperus ashei (Ja) (synonyms: Juniperus sabinoides and Mountain Cedar). These 3 trees belong to the same botanical family of Cupressaceae. While Cs and Ca are commonly encountered in Mediterranean regions, Ja is only present in Europe in the Balkans, but is a major cause of allergy in the USA. In vitro, with a similar protein content, the allergenic properties of Ja extract are 20-Fold higher than those of Cs and 11-fold higher than those of Ca. IgE immunoblotting revealed 14, 42 and 70 kDa allergens common to all 3 extracts. The inhibition curves of the 3 extracts were more than 88% parallel. A significant correlation was observed between serum specific IgE titres for Ja and Cs in 23 patients (r = 0.916; p < 0.001). In vivo, in 23 patients with cypress allergy, the mean diameter of the prick test papule at 1/20 W/V of Ja (8.3 mm) was greater than that of the Cs papule (6.3 mm) (p = 0.001) and the Ca papule (6.7 mm) (p < 0.001). Correlations between cutaneous responses to Cs and Ja (r = 0.629; p = 0.002), and to Cs and Ca (r = 0.75; p = 0.001) were significant. These results demonstrate the intense cross-reactivity between Cs, Ca and Ja. The allergenic potency of the Ja extract is superior to that of Cs and Ca extracts, both in vitro and in vivo. This superiority is correlated with a high concentration of the major allergen, Jun a 1. The non-standardized The now standardized extract of in vitro ashei pollen therefore represents an effective and documented solution for identification, and probably for treatment, of Cupressaceae pollen allergy.

The two Research Institutes, the CNR (National Research Institute, Italy) and the INRA (Institut National de Recherche Agronomique, France) which have been collaborating on the problem of cypress canker from Seiridium cardinale since 1975 in the context of EU projects, have measured in the SEM the pollen size of fourteen species of cypress, determining the differences between the maximum diameter of 100 granules per species and noting differences in pollen colour. A research strategy based on the use of material previously selectively bred for canker resistance is proposed to maintain the cypress in its Mediterranean habitat with a reduced risk of pollinosis. For the success of the project it is stressed that close collaboration between Forest research institutions and the medical profession will be necessary.

The authors emphasize, thanks to their clinical data over the last 20 years: The steady increase of allergy to C. sempervirens pollen compared to other pollinosis and to atopy. The frequency of cross-reactivity between C. sempervirens and other pollens belonging to Cupressaceae and Taxodiaceae families, in order, in the absence of a very good standardization and of a purification of this pollen, to try to undertake a sound specific immunotherapy using the most cross-reactive pollen mixed with C. sempervirens extracts. As a matter of fact the partially purified extracts of C. japonica gave the higher incidence (91%) of cross-reactivity. Consequently, a mixture of C. sempervirens and C. japonica extracts was used since 1993 with good results in a double blind study.

In Italy the Cupressaceae pollen has been monitored by the Italian Aeroallergen Network (IAN) in collaboration with the Italian Research Council (CNR) since 1988. The measurements carried out over the last decade show a positive trend of the seasonal emission of the cypress pollen, whose flowering peak occurs in Italy from mid-February to mid-March. During the pollination period the cypress pollen represents 10% to 40% of the total pollen, showing a high variability of its annual production.

During the winter months, pollen from the mountain cedar (MC) (Juniperus sabinoides) causes severe respiratory tract allergy in central Texas. We have been impressed with the fact that many of our MC-allergic patients had only allergic rhinitis and were only sensitive to MC pollen. We therefore studied 234 unselected MC-allergic patients at the end of the MC season. The main criteria for inclusion into the study was a bona fide history of MC pollinosis confirmed by a positive skin test. All patients completed a detailed history questionnaire, were prick skin tested by using 1:20 w/v, extracts, and had a total IgE determined with commercially available reagents (PRIST). Thirty-four percent of patients were found to be allergic only to MC and 66% were allergic to MC and other aeroallergens. As a group, patients allergic only to MC had significantly lower total IgE levels (84 IU/ml vs. 360, p < 0.001) (normal < 180), required much longer exposure intervals to cedar pollen before developing MC pollinosis (14.4 yr vs, 5.69, p < 0.001), had less of a family history of allergic disease (43% vs. 88%, p < 0.001), had less of a history of asthma or eczema (11% vs. 39%, p < 0.001), and developed allergic disease at a later age (39 yr vs. 13, p < 0.001) when compared to patients with multiple allergies. These results suggest that the MC 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 MC pollen, which may facilitate allergen transport through the respiratory tract mucosa and subsequent sensitization.

Cypresses are part of the Israeli landscape, as well as they are over most of the Mediterranian area. Pollen dispersal starts in January and peaks in March-April. Assessment of hay-fever patients showed a prevalence of 24%-32% (depending on the region) sensitization to Cypress (Cupressus sempervirens) pollen extracts. 13% of all those who are sensitive to Cypress were monosensitized. They are symptomatic from February till April, when 70% of them have rhinitis, 30% also asthma and 18% conjunctivitis. In the monosensitized patients, anti-cypress immunotherapy was successful.