Suchergebnisse

Ambrosia artemisiifolia (ragweed) is a neophyte in Europe and Germany, which originated from the United States of America. In the USA the rate of sensitization against ragweed equals that of grass pollen, and without containment the rate of allergic sensitizations against ragweed pollen will clearly increase. Currently, the most frequent sensitizations in Germany are against grass pollen, followed by sensitizations against house dust mite and birch pollen. Ragweed pollen evokes symptoms at about 10 pollen/m3, grass pollen at about 15 pollen/m3. ese concentrations of ragweed pollen are only reached on limited occasions in Germany. Ragweed cross-reacts with mugwort (Artemisia vulgaris) and a correct diagnosis is only feasible with the ragweed specic allergen Amb a 1. Due to cross reactivity with mugwort, new sensitizations against ragweed pollen are not needed to evoke allergic symptoms. e neophyte encounters an already mugwort-sensitized population, extends the pollen season and may provoke new sensitizations. Ragweed sensitizations are characterized by an increased tendency to also aect the lower airways, which is less with mugwort sensitizations. us containment of ragweed is needed. Ragweed seeds are imported or spread by contaminated bird feed, the transport of ragweed contaminated soil (also in tyre treads) and agricultural products from infested areas. States bordering on ragweed positive areas, like Brandenburg and Bavaria, are especially at risk and invasion is already underway. Ragweed seeds survive up to 40 years in soil, and so extended timescales for eradication and observations are needed. Germany is, compared to other countries like France (Rhone-Valley), Italy (Po-Valley), Ukraine and Hungary, limited in respect to ragweed infestation. Conditions in Germany are therefore favourable for the containment of ragweed. Switzerland implemented legislation against birdseed contamination by ragweed early during the plants expansion, and obligatory ragweed registration- and eradication showed that ragweed containment is possible. Without counter measures ragweed expansion in Germany will take place, resulting in more allergic disease. Considering the increasing number of allergic individuals, even without ragweed invasion, containment of the neophyte should be actively persued. Unfortunately, time is running out.

Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network). Pollen count was assessed with Hirst type pollen traps at 10 I min(-1) at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 I min(-1) with a Chemvol (R) high-volume cascade impactor equipped with stages PM > 10 mu m, 10 mu m > PM > 2.5 mu m, and in Germany also 2.5 mu m > PM > 0.12 mu m. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an FC epsilon R1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient. Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 mu m fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration. Although Bet v 1 is a mixture of different isoforms, its fingerprint is constant across Europe. Bet v 1 was also exclusively linked to pollen. Pollen from different days varied >10-fold in allergen release. Thus exposure to allergen is inaccurately monitored by only monitoring birch pollen grains. Indeed, a humanized basophil activation test correlated much better with allergen concentrations in ambient air than with pollen count. Monitoring the allergens themselves together with pollen in ambient air might be an improvement in allergen exposure assessment. ; European Commission ; Christine Kühne - Center for Allergy Research and Education