Identification of a polygalacturonase (Cup s 2) as the major CCD-bearing allergen in Cupressus sempervirens pollen.

As IgE glyco-epitopes, also referred to as cross-reactive carbohydrate determinants (CCDs), can share significant structural homologies between different plants, they are prone to extensive cross-reactivity among allergen pollen extracts. Here, cypress pollen allergens, especially a polygalacturonase (PG), were further characterized using double one-dimensional electrophoresis (D1-DE). The presence of specific IgE directed against CCDs was investigated by bromelain IgE inhibition and concanavalin A binding assays using sera of cypress pollen-sensitized patients. Our results showed that IgE reactivity to CCDs in Cupressus sempervirens pollen extracts is mainly related to bromelain-type epitopes of a newly identified cypress PG. This glycoprotein has been further characterized through an immunoproteomic approach and officially indexed as Cup s 2 by the WHO/IUIS allergen nomenclature. Cup s 2 could thus be associated with the increased prevalence of IgE reactivity to cypress pollen extracts because of CCD interference.

Complementarity between microarray and immunoblot for the comparative evaluation of IgE repertoire of French and Italian cypress pollen allergic patients.

Cypress pollen represents the primary cause of respiratory allergies in Mediterranean areas. Patients allergic to Cupressus sempervirens pollen (Cups) (CPA) can be discriminated on the basis of the immunoglobulin E (IgE) binding to a basic 14 kDa protein (BP14) or to high-molecular-weight (HMW) glycoproteins only. Specific IgE repertoires of two differentially exposed CPA cohorts, French and Italian, were investigated using an IgE microarray system (some known major allergens from several allergenic sources) and individual IgE immunoblotting (IB) of whole Cups pollen extract separated by SDS-PAGE (all allergens from one allergenic source: cypress pollen). The prevalence of sensitization to BP14 was higher in French (37 %) than in Italian patients (17 %) and major differences were observed in IgE reactivities to lipid transfer proteins (LTPs). Thirty percent of the Italian CPA (4 % in the French group) had specific IgE against the Parietaria pollen LTP, independently of IB subgroups. Regarding peach LTP sensitization, all Pru p 3+ Italian CPA (10 %) were in the HMW+ subgroup, while Pru p 3+ French CPA (20 %) were all included in the BP14+ subgroup. BP14 sensitization is likely a marker of Cups exposure and is, in French CPA, significantly correlated to Pru p 3 sensitization. The IgE immunoblot and microarray are complementary tools that highlight differences in the subtle sensitization profile between groups of patients in comparative studies.

Seasonal allergic symptoms and their relation to pollen exposure in south-east France.

In order to evaluate the relationship between pollen exposure and prevalence of allergic respiratory symptoms, we performed a cross-sectional epidemiological study in 2 areas with contrasted exposure to cypress and grass pollens. The study population consisted of 5427 subjects 18 to 65-years-old representative of the general population. All answered an abridged version of the 1978 ATS questionnaire and a sample had a skin test evaluation including grass and cypress pollens. Prevalence of hay fever symptoms was equal to 31.5% and 14.1%, respectively, in exposed and less exposed community (P < 0.001). Prevalence of hay fever symptoms together with a positive skin test to pollen was also significantly higher in the exposed (13.6%) vs less exposed community (5.5%, P < 0.001). In contrast, overall prevalence of asthma was equal to 4.5% and 3.4%, respectively. Prevalence of asthma with positive skin tests was also not statistically significant, equal to 2.5% and 1.9%, respectively. Thus, high exposure to pollen is a risk factor for developing hay fever but not asthma.

[Spatial and temporal variations of the quantities of pollen from Cupressaceae-Taxaceae collected in Marseilles]. / Variations spatiales et temporelles des quantités de pollen de Cupressacées-Taxacées recueillies à Marseille.

Marseille has two sites (Centre and North) where airborne pollens are collected and counted. The most numerous pollens are from Cupressaceae Taxaceae. We compared the quantities collected with both pollen traps during February, March and April 1988 and 1989. Most of pollinization takes place in March. In Marseille's Centre, there were three times more trapped pollen during 1989 than in 1988. In 1989, there was 40% more pollen on northern site as compared with the other one. As indicated in 1989 with both sites, it suggests a circadian periodicity of Cupressaceae Taxaceae pollen: their highest count is usually between 9 and 11 hours a.m.

Seasonal increase of spontaneous histamine release in washed leucocytes from rhinitis patients sensitive to grass pollen.

The spontaneous histamine release (SHR) in basophils from patients sensitive to grass pollen has been studied before and during the 1987 grass pollen season. Nineteen patients were recruited on seasonal rhinitis symptoms, positivity for cutaneous tests and for serum-specific IgE with grass pollen. At the time of the biological investigations the patients were following a clinical trial of hyposensitization, including placebo, calcium phosphate and aluminium hydroxide-adsorbed grass pollen extract treatments. During the pollen season, grass pollen counts and clinical scores were checked over a 40-day period. Mean SHR was significantly higher during the pollen period than before, for the whole population of 19 patients (10.9% and 4.6%; P less than 0.005) as well as when the high SHR responders were excluded (5.5% and 3.6%; P less than 0.01). No significant correlation existed between SHR and clinical scores or treatments. SHR could be inhibited at 4 degrees C, in absence of CA++ or of oxidative metabolism and thus originated from cells actively secreting histamine.