Edited by: Wytske Fokkens
The allergen Bet v 1 in fractions of ambient air deviates from birch pollen counts
Article first published online: 4 FEB 2010
© 2010 John Wiley & Sons A/S
Volume 65, Issue 7, pages 850–858, July 2010
How to Cite
Buters, J. T. M., Weichenmeier, I., Ochs, S., Pusch, G., Kreyling, W., Boere, A. J. F., Schober, W. and Behrendt, H. (2010), The allergen Bet v 1 in fractions of ambient air deviates from birch pollen counts. Allergy, 65: 850–858. doi: 10.1111/j.1398-9995.2009.02286.x
- Issue published online: 1 JUN 2010
- Article first published online: 4 FEB 2010
- Accepted for publication 26 October 2009
- Bet v 1;
To cite this article: Buters JTM, Weichenmeier I, Ochs S, Pusch G, Kreyling W, Boere AJF, Schober W, Behrendt H. The allergen Bet v 1 in fractions of ambient air deviates from birch pollen counts. Allergy 2010; 65: 850–858.
Background: Proof is lacking that pollen count is representative for allergen exposure, also because allergens were found in nonpollen-bearing fractions of ambient air.
Objective: We monitored simultaneously birch pollen and the major birch pollen allergen Bet v 1 in different size fractions of ambient air from 2004 till 2007 in Munich, Germany.
Methods: Air was sampled with a ChemVol® high-volume cascade impactor equipped with stages for particulate matter (PM)>10 μm, 10 μm>PM>2.5 μm, and 2.5 μm>PM>0.12 μm. Allergen was determined with a Bet v 1-specific ELISA. Pollen count was assessed with a Burkard pollen trap. We also measured the development of allergen in pollen during ripening.
Results: About 93 ± 3% of Bet v 1 was found in the PM > 10 μm fraction, the fraction containing birch pollen. We did not measure any Bet v 1 in 2.5 μm > PM > 0.12 μm. Either in Munich no allergen was in this fraction or the allergen was absorbed to diesel soot particles that also deposit in this fraction. Pollen released 115% more Bet v 1 in 2007 than in 2004. Also within 1 year, the release of allergen from the same amount of pollen varied more than 10-fold between different days. This difference was explained by a rapidly increasing expression of Bet v 1 in pollen in the week just before pollination. Depending on the day the pollen is released during ripening, its potency varies.
Conclusion: In general, pollen count and allergen in ambient air follow the same temporal trends. However, because a 10-fold difference can exist in allergen potency of birch pollen, symptoms might be difficult to correlate with pollen counts, but perhaps better with allergen exposure.