title: Analysis of sputum cell counts during spontaneous moderate exacerbations of asthma in comparison to the stable phase.
abstract: BACKGROUND
  Acute airway inflammation is considered to characterize asthma exacerbations, but its specific cellular pattern has not yet been completely evaluated.
  
  
  OBJECTIVE
  To evaluate the prevalence of sputum eosinophilia during acute asthma exacerbations of moderate severity, compared with a stable phase of the disease, and to assess the concordance between changes in pulmonary function and sputum eosinophilia in the period between exacerbation and post exacerbation.
  
  
  METHODS
  We compared sputum and blood inflammatory cell counts in 29 asthmatic subjects during a spontaneous moderate exacerbation of asthma (visit 1) with sputum and blood cell counts measured 4 weeks after the resolution of asthma exacerbation (visit 2). At visit 1, all subjects required an appropriate 1 week treatment with oral corticosteroids.
  
  
  RESULTS
  At visit 1, all subjects were able to collect spontaneous sputum, whereas at visit 2 sputum was induced by inhalation of hypertonic saline (NaCl 3, 4, and 5%, 10 minutes each) with beta2-agonist pretreatment. Asthma exacerbation was accompanied by a significant increase in sputum eosinophil percentages compared with levels after exacerbation [25% (1-78) versus 4% (0-23), p<0.05). Only four subjects showed low sputum eosinophil percentages during exacerbation, and these showed no differences in main clinical findings with respect to subjects with sputum eosinophilia. At visit 2, the stability of asthma was assessed on the basis of PEF, FEV1, symptoms, and use of rescue beta2-agonist. Asthma was defined as stable in 21 out of 29 subjects. Sputum eosinophil percentages fell significantly between visit 1 and visit 2 in both stable and unstable patients, but at visit 2 sputum eosinophil percentages were still high in subjects with unstable asthma. In patients who proved to be stable at visit 2, there was a significant correlation between the changes recorded in sputum eosinophil percentages and in FEV1 between the two visits (rho: 0.723, p<0.001).
  
  
  CONCLUSIONS
  Sputum cosinophil but not neutrophil percentages increase in most asthmatic subjects during moderate exacerbation of asthma. Changes in the degree of airway eosinophilic inflammation are related to changes in the severity of airway obstruction during asthma exacerbation.
authors.affiliation: Cardiothoracic Department, University of Pisa, Pisa, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Di Franco
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Bartoli
authors.forename: Stefano
authors.initials: S
authors.lastname: Carnevali
authors.forename: Silvana
authors.initials: S
authors.lastname: Cianchetti
authors.forename: Elena
authors.initials: E
authors.lastname: Bacci
authors.forename: Federico L
authors.initials: FL
authors.lastname: Dente
authors.forename: Daniele
authors.initials: D
authors.lastname: Giannini
authors.forename: Mauro
authors.initials: M
authors.lastname: Taccola
authors.forename: Barbara
authors.initials: B
authors.lastname: Vagaggini
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Paggiaro
mesh_terms: D001249:Asthma / Q000473:pathology*; D016022:Case-Control Studies; D002452:Cell Count; D004802:Eosinophilia / Q000473:pathology*; D004804:Eosinophils / Q000473:pathology; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000473:pathology; D012462:Saline Solution, Hypertonic; D013183:Sputum / Q000166:cytology*
chemical_list: D012462:Saline Solution, Hypertonic