title: CD11b and L-selectin expression on eosinophils and neutrophils in blood and induced sputum of patients with asthma compared with normal subjects.
abstract: BACKGROUND
  Patients with asthma show altered surface expression of the adhesion molecules CD11b and L-selectin on airway granulocytes compared with blood granulocytes.
  
  
  OBJECTIVE
  To investigate whether this modulation is related to disease activity or due to transendothelial migration, we compared the CD11b and L-selectin expression on blood and induced sputum eosinophils and neutrophils between patients with asthma and normal subjects.
  
  
  METHODS
  Eleven normal subjects (21-43 years), nine patients (21-34 years) with mild atopic asthma and 10 patients (20-47 years) with moderate to severe atopic asthma on regular treatment with inhaled steroids underwent sputum induction by inhalation of nebulized hypertonic saline (4.5%). CD11b and L-selectin expression on granulocytes from blood and DTT-homogenized sputum were analysed by flow cytometry. Eosinophils could be discriminated from neutrophils by using depolarized light scatter. Disease activity was assessed by baseline FEV1 and airway responsiveness to histamine (PC20).
  
  
  RESULTS
  Sputum eosinophils showed higher expression of CD11b (P<0.001) and lower expression of L-selectin (P<0.001) compared with peripheral blood eosinophils. CD11b and L-selectin expression on eosinophils from blood or sputum did not differ between the three groups. Similar results were obtained for neutrophils. The PC20 in the patients with moderate-to-severe asthma was related to CD11b expression on blood (R=-0.92, P=0.001) and sputum eosinophils (R=0.75, P=0.02).
  
  
  CONCLUSIONS
  Flow cytometry of induced sputum granulocytes from asthmatic as well as normal subjects is feasible. We conclude that the modulated expression of CD11b and L-selectin on airway granulocytes is not specific for asthmatic airway inflammation, but is probably the result of tissue migration per sé. This implies that CD11b and L-selectin expression on granulocytes in induced sputum cannot be used as marker of disease activity.
authors.affiliation: Department of Pulmonology, Leiden University Medical Centre, The Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: in 't Veen
authors.forename: D C
authors.initials: DC
authors.lastname: Grootendorst
authors.forename: E H
authors.initials: EH
authors.lastname: Bel
authors.forename: H H
authors.initials: HH
authors.lastname: Smits
authors.forename: M
authors.initials: M
authors.lastname: Van Der Keur
authors.forename: P J
authors.initials: PJ
authors.lastname: Sterk
authors.forename: P S
authors.initials: PS
authors.lastname: Hiemstra
mesh_terms: D000328:Adult; D001249:Asthma / Q000097:blood / Q000276:immunology*; D004804:Eosinophils / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D005541:Forced Expiratory Volume; D006632:Histamine / Q000008:administration & dosage; D006801:Humans; D019041:L-Selectin / Q000032:analysis* / Q000097:blood; D016177:Macrophage-1 Antigen / Q000032:analysis* / Q000097:blood; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology*; D013183:Sputum / Q000166:cytology* / Q000276:immunology*
chemical_list: D016177:Macrophage-1 Antigen; D019041:L-Selectin; D006632:Histamine