title: Expression of eotaxin in induced sputum of atopic and nonatopic asthmatics.
abstract: BACKGROUND
  The chemokine eotaxin has been implicated in airway eosinophilia in atopic asthma. We have compared airway eosinophils and eotaxin expression in induced sputum from well-matched atopic and nonatopic asthmatics.
  
  
  METHODS
  Eosinophil numbers, eosinophil cationic protein (ECP), and the expression of eotaxin were examined in induced sputum from atopic asthmatics (AA = 11), nonatopic asthmatics (NAA = 11), and atopic (AC = 12) and normal (NC = 10) controls. Slides were prepared for differential cell counts by Romanowsky stain, and ECP levels were measured by RIA. Eotaxin expression was detected by in situ hybridization, with 35S-labelled riboprobes and immunocytochemistry.
  
  
  RESULTS
  The numbers of eosinophils and ECP concentration were increased in the sputum of AA and NAA compared with AC and NC (P < 0.05). The numbers of eotaxin mRNA+ and immunoreactive cells were increased in NAA, but not AA, when compared with controls (P < 0.05). Eotaxin immunoreactive cells in NAA were significantly higher than in AA (P < 0.05). Eotaxin was expressed predominantly by macrophages, eosinophils, and epithelial cells. In NAA, but not AA, the numbers of eotaxin mRNA+ cells were correlated with histamine PC20 (r = -0.81, P < 0.01) and eosinophil numbers in sputum (r = 0.7, P < 0.05).
  
  
  CONCLUSIONS
  Eotaxin production by macrophages, eosinophils, and epithelial cells may play a more pronounced role in airway eosinophilia in nonatopic than in atopic asthma.
authors.affiliation: Allergy and Clinical Immunology, Imperial College School of Medicine, National Heart and Lung Institute, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Zeibecoglou
authors.forename: S
authors.initials: S
authors.lastname: Ying
authors.forename: Q
authors.initials: Q
authors.lastname: Meng
authors.forename: A B
authors.initials: AB
authors.lastname: Kay
authors.forename: D S
authors.initials: DS
authors.lastname: Robinson
authors.forename: N
authors.initials: N
authors.lastname: Papageorgiou
mesh_terms: D000328:Adult; D001249:Asthma / Q000378:metabolism*; D001798:Blood Proteins / Q000032:analysis; D054413:Chemokine CCL11; D019742:Chemokines, CC; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000502:physiology; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D006967:Hypersensitivity / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D012260:Ribonucleases; D013183:Sputum / Q000166:cytology / Q000378:metabolism*
chemical_list: D001798:Blood Proteins; C515456:CCL11 protein, human; D054413:Chemokine CCL11; D019742:Chemokines, CC; D016207:Cytokines; D047091:Eosinophil Granule Proteins; D012333:RNA, Messenger; D012260:Ribonucleases