Structural changes to airway smooth muscle in cystic fibrosis.
BACKGROUND
Chronic airway obstruction is characteristic of cystic fibrosis (CF) but there are few studies of airway smooth muscle remodelling in CF.


METHODS
Airway smooth muscle content and mean airway smooth muscle cell size were measured by applying design-based stereology to bronchoscopic biopsy specimens obtained from seven subjects with CF and 15 healthy controls.


RESULTS
The smooth muscle content increased by 63% in subjects with CF (mean (SD) 0.173 (0.08) v 0.106 (0.042) mm(3) smooth muscle/mm(3) submucosa, mean difference -0.067; 95% CI -0.12 to -0.013, p = 0.017) but there was no increase in mean cell size (2705 (351) v 2654 (757) microm(3), mean difference -51; 95% CI -687 to 585, p = 0.87).


CONCLUSIONS
These findings indicate hyperplasia of airway smooth muscle cells without hypertrophy and suggest that accumulation of airway smooth muscle cells may contribute to airway narrowing and bronchial hyperresponsiveness in CF.
Hays
S R
SR
Moffitt Hospital, 505 Parnassus Ave, San Francisco, CA 94143, USA.
Ferrando
R E
RE
Carter
R
R
Wong
H H
HH
Woodruff
P G
PG
D000328:Adult; D000402:Airway Obstruction / Q000473:pathology; D001706:Biopsy / Q000379:methods; D016535:Bronchial Hyperreactivity / Q000473:pathology; D001999:Bronchoscopy; D016022:Case-Control Studies; D003550:Cystic Fibrosis / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D009130:Muscle, Smooth / Q000473:pathology*; D009135:Muscular Diseases / Q000473:pathology*; D012132:Respiratory Muscles / Q000473:pathology*
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