title: Irreversible acinar airway abnormality in well controlled asthma.
abstract: BACKGROUND
  Even in stable asthma patients, acinar ventilation distribution can be abnormal, and we aimed to specifically maximize its reversibility by switching patients from a standard inhaled corticosteroid (iCS) to a fine particle iCS formulation.
  
  
  METHODS
  For this prospective double-blind double-dummy randomized study, 66 stable asthma patients under maintenance iCS (equivalent budesonide ≤ 800 μg/day) were screened for abnormal baseline acinar ventilation heterogeneity (Sacin). After a 3-week run-in period, 35 eligible patients were randomized to fine particle beclomethasone (HFA-BDP; Qvar Autohaler) or to budesonide (DPI-BUD; Pulmicort Turbohaler). Asthma Control Test (ACT) score and various lung function indices reflecting the small airways were obtained at baseline, after 6 and 12 weeks.
  
  
  RESULTS
  Thirty one patients [age:52 ± 17(SD) years; FEV1:76 ± 19(SD)%pred] completed the study (DPI-BUD:n = 16; HFA-BDP:n = 15). After 6 and 12 weeks, there were no significant changes in acinar or conductive ventilation heterogeneity, nor in mid-expiratory flow, RV/TLC, closing capacity, impulse oscillometry indices (resistance, reactance), bronchial NO production or alveolar NO, in either treatment arm. Asthma control was maintained in both arms.
  
  
  CONCLUSIONS
  In stable asthma patients with small airways dysfunction under maintenance therapy, there is a residual functional abnormality in the lung periphery which is probably not eosinophilic in origin and cannot be normalized with the iCS formulations under study. ISRCTN17195095.
authors.affiliation: Respiratory Division, Universitair Ziekenhuis Brussel, Brussels, Belgium. Electronic address: shane.hanon@uzbrussel.be.
authors.forename: Shane
authors.initials: S
authors.lastname: Hanon
authors.affiliation: Respiratory Division, Universitair Ziekenhuis Brussel, Brussels, Belgium.
authors.forename: Daniel
authors.initials: D
authors.lastname: Schuermans
authors.affiliation: Respiratory Division, Universitair Ziekenhuis Brussel, Brussels, Belgium.
authors.forename: Walter
authors.initials: W
authors.lastname: Vincken
authors.affiliation: Respiratory Division, Universitair Ziekenhuis Brussel, Brussels, Belgium.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Verbanck
mesh_terms: D061354:Acinar Cells / Q000502:physiology; D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D001507:Beclomethasone / Q000008:administration & dosage*; D001993:Bronchodilator Agents / Q000008:administration & dosage; D019819:Budesonide / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D011446:Prospective Studies; D014797:Vital Capacity / Q000187:drug effects
chemical_list: D001993:Bronchodilator Agents; D005938:Glucocorticoids; D019819:Budesonide; D001507:Beclomethasone
keywords: Asthma; Fine particle inhaled steroids; Small airway function