PT  - JOURNAL ARTICLE
AU  - Anna-Carin Olin
AU  - Emilia Viklund
AU  - Per Larsson
AU  - Ann-Charlotte Almstrand
AU  - Anna Bredberg
AU  - Ekaterina Mirgorodskaya
AU  - Björn Bake
TI  - Number of particles in exhaled air is decreased by broncho-constriction
DP  - 2013 Sep 01
TA  - European Respiratory Journal
PG  - P3552
VI  - 42
IP  - Suppl 57
4099  - http://erj.ersjournals.com/content/42/Suppl_57/P3552.short
4100  - http://erj.ersjournals.com/content/42/Suppl_57/P3552.full
SO  - Eur Respir J2013 Sep 01; 42
AB  - Background: Particles in exhaled air (PEx) are formed from the lining fluid in small airways, and is suggested a new method to monitor respiratory disease affecting small airways. To interpret PEx results it is important to know effects of potential influential factors like bronchoconstriction.Aim: To examine the effect of bronchomotor tone and pollen season on PEx.Method: 13 subjects with pollen-asthma and 12 healthy non-atopic subjects were examined before and after bronchodilation during and after pollen season. The subjects performed spirometry and sampling of PEx in 60 L of exhaled air, by an in-house developed instrument, using a breathing maneuvers allowing for airway closure and re-openingResults: The subjects with asthma had mild symptoms and low reversibility also during pollen-season (ΔFEV1 = 6.1 % predicted normal). They had lower PEx concentrations during pollen season compared to out of pollen season (3.46 v s 4.32, p=0.01). Controls showed non-significant differences between seasons, and exhaled significanly higher contentration of particles than subjects with asthma, but only during pollenseason.PEx concentrations increased after bronchodilatation in subjects with asthma (median 4.05*103 to 4.92*103, p=0.02), but not in controls. The change in PEx concentration (%) was associated with the change in FVC (%) (rp= 0.51, p=0.001) and FEV1 (rp= 0.46, p=0.003) among subjects with asthma whereas there were no significant correlations among controls.Conclusion: During pollen season airway opening is reduced despite unaffected spirometry among pollen sensitized subjects with asthma. Bronchodilatation presumably increases airway opening resulting in an increased number of exhaled particles.