title: Decreased serum levels of P-selectin and eosinophil cationic protein in patients with mild asthma after inhaled salbutamol.
abstract: BACKGROUND
  Asthma is a chronic inflammatory disease of the airways associated with selective recruitment of activated eosinophils. P-selectin, a cell adhesion molecule, may be an important controller of the inflammation by mediating selective eosinophil cell influx to the lung. Serum levels of eosinophil cationic protein (ECP) have been used as a marker of eosinophil inflammation, and indirectly as a marker of disease activity of asthma. ECP levels may not be elevated in some patients with asthma, and this fact prompted us to search for additional surrogate markers for monitoring disease activity in asthma.
  
  
  OBJECTIVE
  To evaluate whether repeated inhalations of salbutamol, a beta-2-receptor agonist used for bronchodilation, would lead to reduced serum levels of P-selectin and/or ECP.
  
  
  METHODS
  Fourteen patients with asymptomatic mild stable asthma were enrolled into a randomised crossover study. Salbutamol was inhaled three times every 3 h. Blood was sampled 4 h after the last inhalation. Nine non-treated healthy volunteers served as control subjects. Serum ECP and P-selectin levels were measured using radioimmunoassay and ELISA, respectively.
  
  
  RESULTS
  P-selectin and ECP levels in serum obtained from asymptomatic asthmatics were close to those of the volunteers, and inter-day variability tended to be lower for levels of P-selectin than for ECP. Significant decreases of P-selectin (p = 0.01) and ECP (p = 0.03) were recorded after salbutamol inhalation. There was no association between the changes in ECP and P-selectin levels in serum.
  
  
  CONCLUSIONS
  We conclude that decreases in P-selectin and ECP may have different kinetics, suggesting different pathways of action of salbutamol. We judge that P-selectin may be used as a sensitive marker in mild asthma.
authors.affiliation: Institute of Medicine and Care, Faculty of Health, University of Linköping, Sweden.
authors.forename: Kerstin Naidu
authors.initials: KN
authors.lastname: Sjöswärd
authors.forename: Srinivas
authors.initials: S
authors.lastname: Uppugunduri
authors.forename: Birgitta
authors.initials: B
authors.lastname: Schmekel
mesh_terms: D000280:Administration, Inhalation; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage*; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage*; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology; D001798:Blood Proteins / Q000276:immunology; D018592:Cross-Over Studies; D047091:Eosinophil Granule Proteins; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000097:blood* / Q000276:immunology; D012129:Respiratory Function Tests; D012260:Ribonucleases / Q000097:blood* / Q000276:immunology; D012720:Severity of Illness Index
chemical_list: D000318:Adrenergic beta-Agonists; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D019007:P-Selectin; D012260:Ribonucleases; D000420:Albuterol