Association between peripheral airway function and neutrophilic inflammation in asthma

Respirology ◽  
2015 ◽  
Vol 20 (6) ◽  
pp. 975-981 ◽  
Author(s):  
Claude S. Farah ◽  
Laurien A.B. Keulers ◽  
Kate M. Hardaker ◽  
Matthew J. Peters ◽  
Norbert Berend ◽  
...  
Author(s):  
Joanne L. Van Der Velden ◽  
Donna Barker ◽  
Garry Barcham ◽  
Emmanuel Koumoundouros ◽  
Stuart Hirst ◽  
...  

2017 ◽  
Vol 123 (5) ◽  
pp. 1188-1194 ◽  
Author(s):  
Catherine E. Farrow ◽  
Cheryl M. Salome ◽  
Benjamin E. Harris ◽  
Dale L. Bailey ◽  
Norbert Berend ◽  
...  

In asthma, bronchoconstriction causes topographically heterogeneous airway narrowing, as measured by three-dimensional ventilation imaging. Computation modeling suggests that peripheral airway dysfunction is a potential determinant of acute airway narrowing measured by imaging. We hypothesized that the development of low-ventilation regions measured topographically by three-dimensional imaging after bronchoconstriction is predicted by peripheral airway function. Fourteen asthmatic subjects underwent ventilation single-photon-emission computed tomography/computed tomography scan imaging before and after methacholine challenge. One-liter breaths of Technegas were inhaled from functional residual capacity in upright posture before supine scanning. The lung regions with the lowest ventilation (Ventlow) were calculated using a thresholding method and expressed as a percentage of total ventilation (Venttotal). Multiple-breath nitrogen washout was used to measure diffusion-dependent and convection-dependent ventilation heterogeneity (Sacin and Scond, respectively) and lung clearance index (LCI), before and after challenge. Forced expiratory volume in 1 s (FEV1) was 87.6 ± 15.8% predicted, and seven subjects had airway hyperresponsiveness. Ventlow at baseline was unrelated to spirometry or multiple-breath nitrogen washout indices. Methacholine challenge decreased FEV1 by 23 ± 5% of baseline while Ventlow increased from 21.5 ± 2.3%Venttotal to 26.3 ± 6.7%Venttotal ( P = 0.03). The change in Ventlow was predicted by baseline Sacin ( rs = 0.60, P = 0.03) and by LCI ( rs = 0.70, P = 0.006) but not by Scond ( rs = 0.30, P = 0.30). The development of low-ventilation lung units in three-dimensional ventilation imaging is predicted by ventilation heterogeneity in diffusion-dependent airways. This relationship suggests that acinar ventilation heterogeneity in asthma may be of mechanistic importance in terms of bronchoconstriction and airway narrowing. NEW & NOTEWORTHY Using ventilation SPECT/CT imaging in asthmatics, we show induced bronchoconstriction leads to the development of areas of low ventilation. Furthermore, the relative volume of the low-ventilation regions was predicted by ventilation heterogeneity in diffusion-dependent acinar airways. This suggests that the pattern of regional airway narrowing in asthma is determined by acinar airway function.


Author(s):  
Rathnini Jayasuriya ◽  
Greg King ◽  
Hiran Selvadurai ◽  
Melissa Gabriel ◽  
Per Gustaffson ◽  
...  

2005 ◽  
Vol 148 (1-2) ◽  
pp. 179-194 ◽  
Author(s):  
Michael D. Goldman ◽  
Constantine Saadeh ◽  
David Ross

Author(s):  
Christopher Htun ◽  
Samir Lahzami ◽  
Darren Luo ◽  
Robin Schoeffel ◽  
Gregory King

Lung ◽  
1979 ◽  
Vol 156 (1) ◽  
pp. 205-215 ◽  
Author(s):  
G. N. Harrison ◽  
J. L. Mohler ◽  
L. A. Lewis ◽  
W. A. Speir

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