title: Interstitial changes in asthma-COPD overlap syndrome.
abstract: BACKGROUND
  Asthma-COPD overlap syndrome (ACOS) is the widely recognized syndrome of asthma and COPD coexisting together. Cigarette smoking is a known risk factor for ACOS and is reported to be associated with interstitial lung diseases (ILDs). Subclinical ILDs have been frequently detected in smokers' lungs by radiological and pathological examinations. This finding raises the possibility that unrecognized mild interstitial changes take place in lungs with ACOS.
  
  
  OBJECTIVE
  We sought to determine whether interstitial changes were present in the lungs of patients with ACOS and to characterize the clinical features of ACOS with interstitial changes.
  
  
  METHODS
  Thirty patients with ACOS were enrolled in the study (26 men and 4 women, mean age 70.1 years). Interstitial changes in the lungs were estimated by high-resolution computed tomography (HRCT). Clinical findings and airway wall thickness on HRCT were assessed retrospectively and compared between ACOS patients with and without interstitial changes.
  
  
  RESULTS
  Interstitial changes were found in seven patients (23.3%) with ACOS who had HRCT. The age and smoking amount were significantly higher in ACOS with interstitial changes than in ACOS without interstitial changes. ACOS with interstitial changes tended to have a higher rate of fungal sensitisation. Multivariate analysis showed pack-years were significantly related to the presence of interstitial changes. Airway walls assessed by HRCT were significantly thicker in ACOS with interstitial changes than in ACOS without interstitial changes.
  
  
  CONCLUSIONS
  The ACOS patients with interstitial changes were heavier smokers and had thicker airway walls on HRCT compared to the ACOS patients without interstitial changes.
authors.affiliation: Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Sahoko
authors.initials: S
authors.lastname: Chiba
authors.affiliation: Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Kimitake
authors.initials: K
authors.lastname: Tsuchiya
authors.affiliation: Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Nukui
authors.affiliation: Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Sema
authors.affiliation: Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Meiyo
authors.initials: M
authors.lastname: Tamaoka
authors.affiliation: Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sumi
authors.affiliation: Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Miyazaki
authors.affiliation: Department of Respiratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Naohiko
authors.initials: N
authors.lastname: Inase
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D017563:Lung Diseases, Interstitial / Q000097:blood / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D012129:Respiratory Function Tests / Q000379:methods; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: asthma-COPD overlap syndrome - asthma - chronic obstructive pulmonary disease - interstitial lung diseases