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2008
Journal Article
Titel
The role of pollen starch granules in bronchial inflammation
Titel Supplements
Abstract
Abstract
Background: It is somewhat unclear how pollen allergens cause lower airway inflammation because pollen grains with a diameter of 30 mm are too large to reach the lower airways. One hypothesis is that lower airway inflammation is caused by allergen containing pollen starch granules which are released from the pollen grains and can easily enter the peripheral airways due to their smaller size. However, no data are available which have investigated the contribution of pollen starch granules to nasal symptoms and lower airway inflammation. Methods: In an 2 part cross over design 30 patients with allergic rhinitis and mild intermittent asthma underwent 4 h allergen challenges on two consecutive days in the Fraunhofer Environmental Challenge Chamber with either a normal and established mixture of pollen grains (4000 pollen/ m3) plus starch granules (app. 8000 granules/m3) or only starch granules (app. 8000 granules/m3). Prior to and during the challenges, the total nasal symptom score (TNSS), spirometry, nasal secretion weight, and nasal flow measured by rhinomanometry was determined. Furthermore the exhaled NO was measured prior to challenge and 24 h after the second challenge in each part. Results: The presence of pollen grains had a significant and considerable effect on increase in TNSS and secretion weight and on decline in nasal flow. Starch granules alone only had minimal effects on nasal symptoms. Challenges with starch granules alone increased exhaled NO. Pollen had no additional effect on exhaled NO. Conclusion: Pollen grains elicit nasal symptoms and starch granules trigger lower airway inflammation. This difference is probably caused by the different sizes of pollen grains and starch granules.