title: Eotaxin level in induced sputum is increased in patients with bronchial asthma and in smokers.
abstract: BACKGROUND
  Airway eosinophilia is one of the hallmarks of asthma. Eotaxin may play an important role in eosinophil recruitment.
  
  
  OBJECTIVE
  To examine the relationship between eotaxin levels in the sputum and eosinophilic inflammation.
  
  
  METHODS
  The sputum was obtained from 11 non-smokers, 14 smokers and 13 asthmatic patients using a sputum induction method. Eotaxin and interleukin (IL)-5 levels in the sputum were determined by ELISA and immunocytochemical analysis.
  
  
  RESULTS
  Asthmatic patients had eosinophilia and smokers showed neutrophilia in their sputum. The eotaxin level in the sputum was significantly higher in smokers (median 412.5, range 91.1-872.2 pg/ml) and asthmatic patients (351.0, 185.0-928.0 pg/ml) compared with non-smokers (123.2, 0-369.0 pg/ml; both p < 0.05). IL-5 was detected in the sputum of 1 non-smoker, none of the smokers and 4 asthmatic patients. The percentage of eotaxin-positive cells was higher in smokers and asthmatic patients than in non-smokers, but the percentage of IL-5-positive cells was significantly higher only in asthmatic patients (p < 0.05).
  
  
  CONCLUSIONS
  These findings suggest that the elevated eotaxin level in the sputum does not always accompany the increase in eosinophils, and cooperation with another cytokine such as IL-5 may be required for the recruitment of eosinophils.
authors.affiliation: Second Department of Internal Medicine, Hirosaki University School of Medicine, 5 Zaifu-cho, 036-8562, Japan.
authors.forename: Katsumaru
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Shingo
authors.initials: S
authors.lastname: Takanashi
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Hasegawa
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kanehira
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Kaizuka
authors.forename: Ken
authors.initials: K
authors.lastname: Okumura
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000276:immunology* / Q000378:metabolism; D054413:Chemokine CCL11; D019742:Chemokines, CC / Q000032:analysis*; D002631:Chemotactic Factors, Eosinophil / Q000032:analysis*; D004802:Eosinophilia / Q000378:metabolism; D005260:Female; D006801:Humans; D015848:Interleukin-5 / Q000032:analysis; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism; D012907:Smoking / Q000276:immunology* / Q000378:metabolism; D013183:Sputum / Q000737:chemistry* / Q000166:cytology / Q000276:immunology
chemical_list: C515456:CCL11 protein, human; D054413:Chemokine CCL11; D019742:Chemokines, CC; D002631:Chemotactic Factors, Eosinophil; D015848:Interleukin-5