title: Bronchoalveolar lavage cytokine profiles in acute asthma and acute bronchiolitis.
abstract: BACKGROUND
  The pathogenetic basis for the relationship between acute bronchiolitis and asthma has not yet been completely elucidated.
  
  
  OBJECTIVE
  The aim of this study was to compare these 2 diseases in terms of their patterns of airway cytokine response (T(H)1 or T(H)2).
  
  
  METHODS
  By using a bronchoalveolar lavage (BAL) technique, this study investigated the cytokine levels of BAL fluid in children with acute asthma who had no identifiable respiratory syncytial virus (RSV) infection (n = 18) and in infants with acute bronchiolitis caused by RSV (n = 22). Comparisons were made with normal control subjects (n = 14). IFN-gamma (T(H)1) and IL-4 and IL-5 (T(H)2) levels were measured in concentrated BAL fluids by means of ELISA.
  
  
  RESULTS
  The IL-5 level (P <.001) and IL-5/IFN-gamma ratio (P <.001) were significantly increased in the asthmatic group with no identifiable RSV infection and in the RSV-induced bronchiolitis group compared with values in the control group. When infants in the bronchiolitis group were divided into eosinophil-positive and eosinophil-negative subgroups, the eosinophil-positive subgroup had significantly increased IL-5 levels (P <.001) and IL-5/IFN-gamma ratios (P <.01) compared with those in the control group, but similar cytokine responses were not induced in the eosinophil-negative subgroup. The percentage of BAL eosinophils correlated significantly with levels of BAL IL-5 in both the asthma group (r = 0.80, P =.000) and the bronchiolitis group (r = 0.82, P =.000).
  
  
  CONCLUSIONS
  These findings suggest that a subgroup of the RSV-induced bronchiolitis group results in a T(H)2-type response, and this could provide a valuable framework to explain the link between RSV-induced bronchiolitis and asthma.
authors.affiliation: Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea.
authors.forename: Chang Keun
authors.initials: CK
authors.lastname: Kim
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Choon Sik
authors.initials: CS
authors.lastname: Park
authors.forename: Beyong Il
authors.initials: BI
authors.lastname: Kim
authors.forename: Hee
authors.initials: H
authors.lastname: Kang
authors.forename: Young Yull
authors.initials: YY
authors.lastname: Koh
mesh_terms: D000208:Acute Disease; D001249:Asthma / Q000276:immunology*; D001988:Bronchiolitis / Q000276:immunology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology*; D001999:Bronchoscopy / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000032:analysis* / Q000235:genetics; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis; D015848:Interleukin-5 / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D016207:Cytokines; D015848:Interleukin-5; D012333:RNA, Messenger; D015847:Interleukin-4; D007371:Interferon-gamma