title: Sputum eosinophilia can predict responsiveness to inhaled corticosteroid treatment in patients with overlap syndrome of COPD and asthma.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) and asthma may overlap and converge in older people (overlap syndrome). It was hypothesized that patients with overlap syndrome may have different clinical characteristics such as sputum eosinophilia, and better responsiveness to treatment with inhaled corticosteroid (ICS).
  
  
  METHODS
  Sixty-three patients with stable COPD (forced expiratory volume in 1 second [FEV(1)] ≤80%) underwent pulmonary function tests, including reversibility of airflow limitation, arterial blood gas analysis, analysis of inflammatory cells in induced sputum, and chest high-resolution computed tomography. The inclusion criteria for COPD patients with asthmatic symptoms included having asthmatic symptoms such as episodic breathlessness, wheezing, cough, and chest tightness worsening at night or in the early morning (COPD with asthma group). The clinical features of COPD patients with asthmatic symptoms were compared with those of COPD patients without asthmatic symptoms (COPD without asthma group).
  
  
  RESULTS
  The increases in FEV(1) in response to treatment with ICS were significantly higher in the COPD with asthma group. The peripheral eosinophil counts and sputum eosinophil counts were significantly higher. The prevalence of patients with bronchial wall thickening on chest high-resolution computed tomography was significantly higher. A significant correlation was observed between the increases in FEV(1) in response to treatment with ICS and sputum eosinophil counts, and between the increases in FEV(1) in response to treatment with ICS and the grade of bronchial wall thickening. Receiver operating characteristic curve analysis revealed 82.4% sensitivity and 84.8% specificity of sputum eosinophil count for detecting COPD with asthma, using 2.5% as the cutoff value.
  
  
  CONCLUSIONS
  COPD patients with asthmatic symptoms had some clinical features. ICS should be considered earlier as a potential treatment in such patients. High sputum eosinophil counts and bronchial wall thickening on chest high-resolution computed tomography might therefore be a good predictor of response to ICS.
authors.affiliation: First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kitaguchi
authors.forename: Yoshimichi
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Keisaku
authors.initials: K
authors.lastname: Fujimoto
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hanaoka
authors.forename: Keishi
authors.initials: K
authors.lastname: Kubo
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000494:pharmacology*; D058666:Adrenergic beta-2 Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology; D000368:Aged; D001249:Asthma / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D004804:Eosinophils / Q000187:drug effects / Q000473:pathology; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D012129:Respiratory Function Tests; D013183:Sputum / Q000378:metabolism*; D013194:Staining and Labeling; D016896:Treatment Outcome
chemical_list: D000305:Adrenal Cortex Hormones; D058666:Adrenergic beta-2 Receptor Agonists