title: Airway wall thickening in patients with cough variant asthma and nonasthmatic chronic cough.
abstract: BACKGROUND
  Chronic cough, which may be of asthmatic or nonasthmatic origin, is an important clinical issue. Airway inflammation, and remodeling demonstrated by subbasement membrane thickening has been associated with cough variant asthma (CVA) as well as with nonasthmatic chronic cough (NAC). CT studies have shown airway wall thickening in patients with asthma who wheeze. We examined airway wall thickness by CT in adult patients with chronic cough and examined its pathophysiologic implication.
  
  
  METHODS
  Nonsmoking, steroid-naïve patients with CVA (n = 27), NAC (n = 26), and healthy control subjects (n = 15) were studied. Airway dimensions were assessed by a validated CT technique, in which we measured airway wall area (WA) corrected by body surface area (BSA), the ratio of WA to outer wall area (percentage of wall area [WA%]), absolute wall thickness (T)/ square root BSA, and airway luminal area/BSA of a segmental bronchus. Correlations between CT parameters and clinical indexes such as disease duration and cough sensitivity were examined.
  
  
  RESULTS
  In patients with CVA, WA/BSA, WA%, and T/ square root BSA were all significantly greater than those in control subjects. In patients with NAC, WA/BSA and T/ square root BSA were significantly greater than in control subjects. The increase of WA/BSA and T/ square root BSA of NAC patients was less than that of CVA patients. In a subset of patients with NAC, WA% correlated with capsaicin cough sensitivity (n = 9, r = 0.75, p = 0.034).
  
  
  CONCLUSIONS
  Walls of central airways are thickened in patients with CVA, and also to a lesser degree in patients with NAC. Airway wall thickening in NAC may be associated with cough hypersensitivity.
authors.affiliation: Department of Respiratory Medicine, Kyoto University, Sakyo-ku, Kyoto, 606-8507, Japan. hmatsumo@kuhp.kyoto-u.ac.jp
authors.forename: Hisako
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Akio
authors.initials: A
authors.lastname: Niimi
authors.forename: Rollin P
authors.initials: RP
authors.lastname: Tabuena
authors.forename: Masaya
authors.initials: M
authors.lastname: Takemura
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ueda
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Matsuoka
authors.forename: Makiko
authors.initials: M
authors.lastname: Jinnai
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chin
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
mesh_terms: D001249:Asthma / Q000150:complications / Q000000981:diagnostic imaging*; D001980:Bronchi; D002908:Chronic Disease; D003371:Cough / Q000000981:diagnostic imaging* / Q000209:etiology; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D005764:Gastroesophageal Reflux / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed