title: Effects of allergen challenge on eosinophils, eosinophil cationic protein, and granulocyte-macrophage colony-stimulating factor in mild asthma.
abstract: Allergen inhalation challenge is associated with increases in eosinophil number and activation, and provides a useful model for investigating airway inflammation in asthma. Limited information, however, is available on the effect of allergen challenge on cytokines regulating eosinophil function. We investigated allergen-induced changes in eosinophil number and activation and in granulocyte-macrophage colony-stimulating factor (GM-CSF), a cytokine known to regulate eosinophil function in vitro. Seven subjects with mild atopic asthma and late asthmatic responses completed diluent- and allergen-inhalation challenges. Blood, bronchoalveolar lavage fluid (BALF), and biopsy samples were collected 24 h after challenge. Allergen inhalation caused a significant increase in eosinophils in BALF and biopsy samples. Eosinophil activation, as assessed by secretion of eosinophil cationic protein, and GM-CSF levels were significantly increased in BALF and bronchoalveolar lavage (BAL) cells. Allergen inhalation did not cause a significant change in eosinophil activation in biopsy tissue but did result in a significant decrease in GM-CSF in the tissue. Significant correlations were shown between the concentration of GM-CSF in BALF and the percentage of BAL eosinophils (Rs = 0.75, p = 0.05), severity of the late asthmatic response, and number of BAL eosinophils (Rs = 0.82, p = 0.02). A trend was seen between the late response and the concentration of GM-CSF in BALF. These results are consistent with the hypothesis that eosinophils, regulated by GM-CSF, contribute to allergen-induced decreases in airway function.
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: K L
authors.initials: KL
authors.lastname: Woolley
authors.forename: E
authors.initials: E
authors.lastname: Adelroth
authors.forename: M J
authors.initials: MJ
authors.lastname: Woolley
authors.forename: R
authors.initials: R
authors.lastname: Ellis
authors.forename: M
authors.initials: M
authors.lastname: Jordana
authors.forename: P M
authors.initials: PM
authors.lastname: O'Byrne
mesh_terms: D000328:Adult; D000485:Allergens; D001249:Asthma / Q000276:immunology / Q000473:pathology / Q000503:physiopathology*; D001706:Biopsy; D001798:Blood Proteins / Q000378:metabolism*; D016535:Bronchial Hyperreactivity / Q000503:physiopathology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D001999:Bronchoscopy; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000276:immunology* / Q000378:metabolism; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D018836:Inflammation Mediators / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D016210:Methacholine Chloride; D012260:Ribonucleases; D012882:Skin Tests
chemical_list: D000485:Allergens; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D018836:Inflammation Mediators; D016210:Methacholine Chloride; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D012260:Ribonucleases