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Pollen is routinely monitored, but it is unknown whether pollen counts represent allergen exposure. We therefore simultaneously determined olive pollen and Ole e 1 in ambient air in Córdoba, Spain, and Évora, Portugal, using Hirst-type traps for pollen and high-volume cascade impactors for allergen. Pollen from different days released 12-fold different amounts of Ole e 1 per pollen (both locations P40% of Ole e 1 exposure in Évora was explained by high-potency pollen originating from the south of Spain. Thus, olive pollen can vary substantially in allergen release, even though they are morphologically identical.

In order to study allergic people responding to daily changes in pollen concentrations, we compared personal diary data on allergic symptoms and the use of allergy medicines to daily pollen counts during the two unequal alder and birch pollen seasons of 2009 and 2010. Almost 90% of the 61 subjects with physician-diagnosed birch pollinosis developed conjunctival, nasal or other symptoms during the peak birch pollination. Most subjects (95%) also reported symptoms during the alder pollination. Despite a delay between the most severe symptoms and the pollen peaks and the increased risk of allergy symptoms between the alder and birch pollen peaks at much lower pollen concentrations, the number of subjects with allergy symptoms correlated with the daily pollen concentrations in both years (r 09 = 0.35, r 10 = 0.36, p

Relationships between temporal variations in the North Atlantic Oscillation (NAO) and grass pollen counts at 13 sites in Europe, ranging from Cordoba in the south-west and Turku in the north-east, were studied in order to determine spatial differences in the amount of influence exerted by the NAO on the timing and magnitude of grass pollen seasons. There were a number of significant (P < 0.05) relationships between the NAO and start dates of the grass pollen season at the 13 pollen-monitoring sites. The strongest associations were generally recorded near to the Atlantic coast. Several significant correlations also existed between winter averages of the NAO and grass pollen season severity. Traditional methods for predicting the start or magnitude of grass pollen seasons have centred on the use of local meteorological observations, but this study has shown the importance of considering large-scale patterns of climate variability like the NAO.

Although the number of studies of pollen concentrations inside and outside buildings is increasing, little is known about the efficiency of penetration of pollen from outdoor to indoor air, and further. We studied indoor and outdoor pollen concentrations in the town of Lappeenranta and in the municipality of Rautjarvi in SE Finland from May 3–23, 2004, i.e. throughout the Betula pollen season, and assessed the risk of exposure to pollen grains. Pollen concentrations were measured inside and outside a block of flats, a detached house, and the regional central hospital, using rotorod-type samplers; in the town of Joutseno data were compared with Burkard counts. Outdoor concentrations of Betula pollen grains ranged between low and abundant (0–855 grains m−3). The corresponding indoor concentrations near the main front doors varied from low to moderate (0–17 grains m−3) in the central hospital and were low (

Resume Cette etude se propose, dans la perspective du rechauffement climatique, d’etudier la relation entre la temperature et la date de debut de pollinisation (DDP) du bouleau, un arbre a pollen allergisant particulierement important pour les allergiques dans le nord-ouest de l’Europe. Elle a permis de faire des projections pour les prochaines annees afin d’estimer, en fonction de l’evolution prevue des temperatures du printemps, l’evolution de la DDP du bouleau. L’etude a porte sur dix sites europeens, Kevo et Turku (Finlande), Londres (Royaume-Uni), Paris et Lyon (France), Bruxelles (Belgique), Zurich (Suisse), Vienne (Autriche), Poznan et Cracovie (Pologne). La periode d’etude couvrait une duree de six a 28 ans selon le site. Les pollens ont ete recueillis quotidiennement a l’aide de capteurs volumetriques de type Hirst, et les donnees comparees aux temperatures mensuelles de janvier a mai au moyen de correlations et de regressions multiples. Les resultats ont montre qu’en dehors de Kevo ou la tendance va vers des printemps plus froids et des DDP plus tardives, dans les autres sites on constate un rechauffement printanier associe a des DDP plus precoce : cette tendance est tres nette a Turku, Zurich, Londres, Vienne et Bruxelles, moins marquee en France et absente en Pologne. Les resultats de ce travail devront conduire a une mise a jour des calendriers polliniques et des modeles de prediction de la DDP, dans les sites ou se dessine une tendance nette.

BACKGROUND: Allergies to grass pollen are the number one cause of outdoor hay fever. The human immune system reacts with symptoms to allergen from pollen. OBJECTIVE: We investigated the natural variability in release of the major group 5 allergen from grass pollen across Europe. METHODS: Airborne pollen and allergens were simultaneously collected daily with a volumetric spore trap and a high-volume cascade impactor at 10 sites across Europe for 3 consecutive years. Group 5 allergen levels were determined with a Phl p 5-specific ELISA in 2 fractions of ambient air: particulate matter of greater than 10μm in diameter and particulate matter greater than 2.5μm and less than 10μm in diameter. Mediator release by ambient air was determined in FcεRI-humanized basophils. The origin of pollen was modeled and condensed to pollen potency maps. RESULTS: On average, grass pollen released 2.3 pg of Phl p 5 per pollen. Allergen release per pollen (potency) varied substantially, ranging from less than 1 to 9 pg of Phl p 5 per pollen (5% to 95% percentile). The main variation was locally day to day. Average potency maps across Europe varied between years. Mediator release from basophilic granulocytes correlated better with allergen levels per cubic meter (r(2)=0.80, P&nbsp

Summary Background During specific pollen immunotherapy (SIT) there is a local mucosal shift from Th2- to Th1- type cytokine predominance, with IL-12 having a major role in this shift. IL-10-induced tolerance is supposed to be a key phenomenon in venom immunotherapy (VIT). However, the role of Th1-promoting cytokines, on the one hand, and the role of regulatory cytokines, on the other hand, have not been studied in parallel during SIT. Objective This study was undertaken to analyse the allergen-induced in vitro mRNA expression of Th1-type effector cytokine IL-18 and regulatory cytokines IL-10 and TGF-β during SIT in peripheral blood mononuclear cells (PBMC) of allergic rhinitis (AR) patients. Methods Thirty patients with AR undergoing pollen SIT and 10 patients with AR who were not treated with SIT were included in the study. The symptoms and medications were registered post-seasonally before the beginning of SIT and after 1 year of therapy. PBMC samples were collected and stimulated with pollen allergen extract prior to the treatment, at the maintenance phase in 12 patients and after 1 year of the treatment. The cytokine mRNA expression was assessed using kinetic real-time RT-PCR (TaqMan®). Results There was a clear increase in the treated AR patients, in comparison with untreated AR patients, in the expression of both IL-10 (mean change from baseline (SEM): 3.1 (0.8) vs. −0.3 (0.3), P

Early symptoms of pollen allergies arefrequently reported before pollination periodof allergenic plant starts. At northernlatitudes the main concern is Betulaceae-trees(alders, hazel, birches). Pollen allergeninformation, based on the analysis of actualairborne allergen concentrations, beside thetraditional pollen reports, based on pollencounts, has been given in SW Finland since1998. 1–2 weeks before the onset of floweringpollen allergens are detected airborne inquantities high enough to provoke symptoms.Information is given on radio and in localnewspapers. During the first season of the newservice (1998) we carried out a questionnairestudy. The results showed that new informationservice, though not as frequently used as wehad hoped for, was useful to allergic personsfor starting their medication in time. Theyalso received explanation for their earlierinexplicable symptoms. We recommend bothinformation services to be run concurrently togive the best information to the public.

Geographical and temporal variations in the start dates of grass pollen seasons are described for selected sites of the European Pollen Information Service. Daily average grass pollen counts are derived from Network sites in Finland, the Netherlands, Denmark, United Kingdom, Austria, Italy and Spain, giving a broad longitudinal transect over Western Europe. The study is part of a larger project that also examines annual and regional variations in the severity, timing of the peak and duration of the grass pollen seasons. For several sites, data are available for over twenty years enabling long term trends to be discerned. The analyses show notable contrasts in the progression of the seasons annually with differing lag times occurring between southern and northern sites in various years depending on the weather conditions. The patterns identified provide some insight into geographical differences and temporal trends in the incidence of pollinosis. The paper discusses the main difficulties involved in this type of analysis and notes possibilities for using data from the European Pollen Information service to construct pan European predictive models for pollen seasons.

Sensitive pollen-allergic patients have been reported to show allergic symptoms not only during the pollen release of allergenic plants but also both before and after the pollen season. Symptoms before the season are evidently provoked by small-sized particles originating partly from developing pollen grains, partly from other plant parts. After the pollen season, antigenic material settles on various surfaces, which thus form a new source of allergenic material. Measuring the allergen concentrations in indoor and outdoor environments demands an effective sampling method and a rapid and sensitive immunochemical analysis, especially for particles of small-sized fractions which are not detected in microscopic analyses. The efficiency of an ELISA and an immunochemical staining method was tested with monoclonal IgG against Phl p 5, the main grass allergen. The Burkard trap and MPC impactor (Marple personal cascade impactor with six-stage particle size fractionation) were compared. The sampling was carried out in southwestern Finland in the summer of 1994. The number of grass-pollen antigen spots greatly exceeded the simultaneous pollen count, indicating considerable antigen activity outside the pollen grains. The counts were especially high in small-sized fractions after the pollen season, when hardly any airborne pollen was found. Spots and pollen divided according to size were highly intercorrelated, indicating that the threshold values used were appropriate.

Pollen of mugwort (Artemisia vulgaris L.) is the most important allergenic pollen in urban areas of south and central Finland in late summer. The purpose of this study was to investigate, experimentally, whether the cutting of mugwort stands affects its airborne pollen concentrations. Experimental plots were either cut (4 plots) or uncut (4 plots) in 2 previous seasons: 4 of them were small (less than 0.5 hectare) and 4 large (greater than 5 hectares). Finally, the plots were divided randomly into 2 groups according to a third variable, cutting in the study season, 1989. Samples were taken on 2 rainless mornings at the peak mugwort flowering time. Two rotorod type samplers were used at heights of 1 and 2 m from ground level, simulating the inhalation heights of children and adults, respectively. The results indicate that cutting mugwort stands significantly reduces airborne pollen concentrations, but the treated areas have to be large, since in the town area there are plenty of mugwort pollen sources. The pollen concentrations at the 2 heights tested did not differ significantly.

Concentrations of birch-pollen antigens were measured in 10 homes in southwestern Finland, four in urban and six in rural areas. Dust samples were collected once a week with a vacuum cleaner equipped with a special collection device (ALK, Copenhagen) combined with an exchangeable glass microfiber filter in a filter dish. Control samples were taken from horizontal surfaces outdoors. All samples were analyzed by a modification of the IgG-ELISA procedure. The birch-pollen antigenic activity in indoor settled dust was lower than that in dust outdoors. The mean concentration of antigenic activity indoors peaked 3 weeks later than outdoors. The lag indicates that the most important means whereby antigens are carried indoors is via footwear and clothes, rather than, for instance, ventilation. Antigenic activity was still detected 2 months after the peak pollen period. As a source of antigens, both indoor and outdoor dust may be an important cause of pollen-allergy symptoms after the season.

It is no longer enough that aerobiologists identify pollen grains and fugal spores under the microscope. They are expected to serve as well allergologists, who want to known about the concentrations of various allergens in the air samples, as meteorologists, who need to know about the frequency of primary biological aerosols, which may act in radiative forcing of the atmosphere. Methods utilized by the aerobiologists vary from immunochemical analyses, culture and germination to infecting host plants with certain pathogens. Difficulties to separate between short, medium and long range transport of airborne particles on the basis of their viability are discussed.

High birch pollen antigenic activities in outdoor air samples were found in all particle sizes studied (> 7.2, 2.4-7.2, < 2.4 microns and molecular size class, with an ELISA modification). Sampling was done with a low-volume, size-selective bioaerosol sampler (SSBAS) simulating the human respiratory tract in both volume and fractionation. Airborne birch pollen counts for comparisons were obtained from a Burkard trap. No correlations were obtained between antigen concentrations in any particle size fraction and airborne pollen counts. The meteorologic factors studied differed clearly in their effect on antigenicity, depending on the size class studied. Likewise, the effect of meteorologic factors differed among the three study periods (period I, 4 weeks before the peak pollen season; period II, during the season; and period III, 4 weeks after the season). During the peak pollen period, temperature and relative humidity were the most important meteorologic factors. Before the season, large and very small particles predominated, medium-sized particles being totally absent. The largest size class studied (containing all intact pollen grains) clearly reacted to changes in meteorologic factors; for smaller size classes, these factors were found to be less important, a fact which may make the forecasting of antigen concentrations in the air on the basis of meteorologic data impossible.

Pollen and spore counts from Burkard traps for routine pollen and spore sampling placed at 15 m above ground and at ground level were compared. Daily counts of most pollen types were higher on the ground than at roof level, but the counts were significantly correlated. The ratios of pollen frequencies at high and low levels varied between 1.0 and 11.5. The most prominent differences were recorded for herbaceous pollen (e.g. Artemisia counts 11.5 and Poaccae counts 4.4 times higher at ground level) and in Botrytis and Ustilaginales spores. Tree pollen grains and basidiomycetous spores were more equally distributed. Wind speed did not affect the variation of pollen frequencies at either height. Large spores are not so unevenly distributed as previously supposed. Artemisia and grass pollen was detected 1 to 2 weeks earlier at ground level than on the roof. It is therefore concluded that especially the beginning of flowering should be monitored at a low level.

Most inviable spore counts of outdoor air in Europe are based on Burkard spore trap results. For viable counts different kinds of slit samplers and Andersen sampler are used. Results of viable and inviable sampling methods are not completely comparable, but the results complete each other. Spore frequencies in outdoor air are almost equal in different Nordic countries. Cladosporium is the most important spore type everywhere. In South Finland it accounts for ca. 85% of viable and ca. 50% inviable spore counts. The frequencies are lower in the country than in town. Cladosporium frequencies decrease northwards so that in Lapland the percentage is only ca. 5 and the maxima are 1/4-1/5 of those in South Finland. The frequencies of Alternaria spores are 4-5 times lower in Nordic countries than in Middle Europe. E.g. in Turku weekly maxima have been ca. 250 spores X m-3, in the country even lower. Penicillium accounts for ca. 4% of all colonies in viable counts in South Finland, Botrytis 2%, and yeasts also ca. 2%. The most important yeasts are Cryptococcus albidus, Cr. laurentii, Sporobolomyces roseus and Rhodotorula species. Actinomycetes very seldom occur on culture plates, only 0.02% of all.

The penetration of Cladosporium spores and spore aggregates into human airways was studied using three different spore sampling methods: 1) a Burkard spore trap for determining the aggregation degree of Cladosporium; two samplers, simulating the human respiratory system, 2) a 6-stage Andersen 2000 sampler, and 3) a new size-selective bioaerosol sampler (SSBAS), designed specifically for immunochemical and chemical analyses. The aggregation degree of Cladosporium spores varied between 1.0 and 1.3 spores per dispersal unit. Grouping seems to be of little if any importance to the penetration ability of Cladosporium spores into the respiratory tract. The distribution of spores in the Andersen and SSBAS differed significantly in the largest size class (spores greater than 7 microns in diameter); with the Andersen sampler only 10.8% of the spores were detected in stage 1, compared with 43% with the SSBAS. On the Andersen culture plates 95% of all colonies were detected in stages 1-4, where particles greater than 2.1 microns in diameter are trapped. In the SSBAS altogether 99.4% of spores were found in the first two filter stages (cutoff point approx. 2.5 microns in diameter). Conclusions regarding the penetration of spores to the lungs on the basis of aerobiological results should always be based on the use of properly calibrated spore traps.