Temporal and spatiotemporal autocorrelation of daily concentrations of Alnus, Betula, and Corylus pollen in Poland.

The aim of the study was to determine the characteristics of temporal and space-time autocorrelation of pollen counts of Alnus, Betula, and Corylus in the air of eight cities in Poland. Daily average pollen concentrations were monitored over 8 years (2001-2005 and 2009-2011) using Hirst-designed volumetric spore traps. The spatial and temporal coherence of data was investigated using the autocorrelation and cross-correlation functions. The calculation and mathematical modelling of 61 correlograms were performed for up to 25 days back. The study revealed an association between temporal variations in Alnus, Betula, and Corylus pollen counts in Poland and three main groups of factors such as: (1) air mass exchange after the passage of a single weather front (30-40 % of pollen count variation); (2) long-lasting factors (50-60 %); and (3) random factors, including diurnal variations and measurements errors (10 %). These results can help to improve the quality of forecasting models.

Geographic and temporal variations in pollen exposure across Europe.

BACKGROUND: The EC-funded EuroPrevall project examined the prevalence of food allergy across Europe. A well-established factor in the occurrence of food allergy is primary sensitization to pollen. OBJECTIVE: To analyse geographic and temporal variations in pollen exposure, allowing the investigation of how these variations influence the prevalence and incidence of food allergies across Europe. METHODS: Airborne pollen data for two decades (1990-2009) were obtained from 13 monitoring sites located as close as possible to the EuroPrevall survey centres. Start dates, intensity and duration of Betulaceae, Oleaceae, Poaceae and Asteraceae pollen seasons were examined. Mean, slope of the regression, probability level (P) and dominant taxa (%) were calculated. Trends were considered significant at P < 0.05. RESULTS: On a European scale, Betulaceae, in particular Betula, is the most dominant pollen exposure, two folds higher than to Poaceae, and greater than five folds higher than to Oleaceae and Asteraceae. Only in Reykjavik, Madrid and Derby was Poaceae the dominant pollen, as was Oleaceae in Thessaloniki. Weed pollen (Asteraceae) was never dominant, exposure accounted for >10% of total pollen exposure only in Siauliai (Artemisia) and Legnano (Ambrosia). Consistent trends towards changing intensity or duration of exposure were not observed, possibly with the exception of (not significant) decreased exposure to Artemisia and increased exposure to Ambrosia. CONCLUSIONS: This is the first comprehensive study quantifying exposure to the major allergenic pollen families Betulaceae, Oleaceae, Poaceae and Asteraceae across Europe. These data can now be used for studies into patterns of sensitization and allergy to pollen and foods.

Prevalence of allergy, patterns of allergic sensitization and allergy risk factors in rural and urban children.

BACKGROUND: We aimed to compare the prevalence of allergic diseases and sensitization in children living in urban and rural areas and to identify potential risk/protection factors associated with allergy. METHODS: School children 12-16 years old, from urban community (n = 201) and rural area (n = 203) were recruited. The data obtained by questionnaire were referred to doctors' diagnosis, skin prick tests (SPTs), and serum specific and total IgE assessment. RESULTS: The prevalence of allergic diseases in urban children was significantly higher as compared with rural children [asthma 16.42%vs 1.97% (P < 0.001) allergic rhinitis 38.81%vs 10.84% (P < 0.001)]. Positive SPTs to at least one allergen was found in 63.7% of urban and 22.7% rural children (P < 0.001). Significantly higher percentage of allergic rural than urban children were monosensitized or sensitized to 2-4 allergens, but almost a fourfold higher percentage of allergic urban children was found to be sensitized to five or more allergens (P < 0.0001). The history of frequent upper respiratory factor (URT) infections, antibiotic therapy, tonsiltectomy/adenoidectomy were positively associated with development of atopy and sensitization. CONCLUSION: Our findings confirm that residence of rural area is associated with a significant lower prevalence of allergic sensitization and symptoms in school children. Several risk and protective factors related to environment and style of life could be identified in both environments.

The release of eosinophil chemotactic activity and eosinophil chemokinesis inhibitory activity by mononuclear cells from atopic asthmatic and non-atopic subjects.

The goal of our study was to assess the chemotactic activity for eosinophils (ECA) and neutrophils (NCA) and histamine releasing activity (HRA) in crude supernatants of mononuclear cells in monosensitized atopic asthmatics and healthy controls. Chemotactic activity for ECA and neutrophils was measured in supernatants of cultured mononuclear cells with modified Boyden's chamber and HRA was assessed on healthy donor basophils. With respect to ECA generation two distinct subgroups of subjects were distinguished: releasers [ECA (+)] and non-releasers [ECA (-)]. In atopic and non-atopic ECA (+) the mean ECA index was 3.78 +/- 0.49 and 2.47 +/- 0.27 respectively (P > 0.05). Supernatants from the remaining subjects (seven of 22 atopic and five of 11 non-atopic) did not express ECA, but revealed significant inhibitory activity for chemokinesis of eosinophils (mean chemotactic index 0.25 +/- 0.16 and 0.48 +/- 0.22 for atopic and non-atopic non-releasers respectively). Stimulation with antigen of MNC from atopic and with PHA from non-atopic ECA (-) restored cells ability to release ECA. Sephadex gel chromatography revealed that supernatants of MNC contained chemotactic and chemokinesis inhibitory activity in different fractions. The spontaneous productions of NCA and HRA by mononuclear cells was similar in ECA releasers and non-releasers, although the HRA was higher following stimulation with PHA in the non-atopic ECA (+) subgroup. Our study demonstrated, for the first time, that MNC are capable of generating not only chemotactic activity but also chemokinesis inhibitory activity for eosinophils.

Nasal reactivity to capsaicin in patients with seasonal allergic rhinitis during and after the pollen season.

BACKGROUND: We aimed to study the participation of neurogenic mechanisms in nasal allergic inflammation by assessing the effect of neurogenic stimulation on the secretory and cellular responses of nasal mucosa in patients with allergic rhinitis. METHODS: A group of patients suffering from seasonal allergic rhinitis was challenged intranasally with incremental doses of capsaicin (0.3, 3, 12 microg) during and after the pollen season. Clinical symptoms after provocations were monitored, and unilateral nasal lavages were obtained. The nasal lavage fluid (NAL) was assayed for concentration of total protein, albumin, lactoferrin, and number of leukocytes, following by differential count. RESULTS: Capsaicin challenge during the pollen season produced greater congestion (P < 0.01) and rhinorrhea (P < 0.05) than after the season. The intensity of burning sensation (pain) was similar on both occasions. Capsaicin failed to increase albumin content in NAL both during and after the season. Total protein was increased only after the highest dose of capsaicin (P < 0.03) after the season. The number of eosinophils in basal lavages was higher during the season. During the season, the total number of leukocytes at least doubled in 7/12 patients and the percentage of eosinophils increased in 6/12 patients after the capsaicin challenge. CONCLUSIONS: Our study demonstrated that during the symptomatic period the nasal mucosa of allergic patients is more susceptible to neurogenic stimulation, showing enhanced secretory and inflammatory (cellular) responses.