Alterations in airway inflammation and lung function during corticosteroid therapy for atopic asthma.
BACKGROUND
Although corticosteroid therapy for asthma improves lung function and reduces airway inflammation, the relation between these two events is unclear. This article investigates associations between changes in bronchial inflammation and lung function during high-dose inhaled corticosteroid therapy for asthma.


METHODS
Nine subjects with atopic asthma received high-dose inhaled fluticasone propionate (FP), 2,000 microg/d for 8 weeks. Fiberoptic bronchoscopy with endobronchial biopsies, spirometry, and histamine provocation challenge were performed on each subject at baseline, after 2 weeks, and again after 8 weeks of therapy. Spearman rank correlation coefficients between changes in parameters of bronchial inflammation and lung function were computed.


RESULTS
As expected, significant down-regulation of airway inflammation and improvements in lung function were observed after both short-term and long-term therapy with high-dose inhaled FP. During corticosteroid therapy, changes in lymphocyte and macrophage numbers in bronchial biopsy specimens were closely correlated. Changes in EG1+ eosinophils were associated with changes in EG2+ eosinophils after 8 weeks of therapy. Although changes in airway inflammation and changes in lung function were not closely associated after 2 weeks of therapy, changes in eosinophils (EG1) in bronchial biopsy specimens correlated with changes in bronchodilator response (r = 0.77, p = 0.016) after 8 weeks of therapy.


CONCLUSIONS
In patients with atopic asthma, changes in bronchial eosinophils and lung function during steroid therapy are closely related but do not occur simultaneously.
Faul
John L
JL
Division of Pulmonary Medicine, Stanford University, Stanford CA 94305-5236, USA. jfaul@stanford.edu
Demers
Elizabeth A
EA
Burke
Conor M
CM
Poulter
Leonard W
LW
D000280:Administration, Inhalation; D000287:Administration, Topical; D000328:Adult; D000730:Androstadienes / Q000008:administration & dosage*; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology / Q000503:physiopathology; D001706:Biopsy; D001980:Bronchi / Q000473:pathology*; D001985:Bronchial Provocation Tests; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D001999:Bronchoscopy; D002452:Cell Count; D004311:Double-Blind Method; D004804:Eosinophils / Q000473:pathology; D005260:Female; D000068298:Fluticasone; D005541:Forced Expiratory Volume; D005938:Glucocorticoids; D006632:Histamine; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis; D007249:Inflammation; D008214:Lymphocytes / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012882:Skin Tests; D013147:Spirometry
D000730:Androstadienes; D000893:Anti-Inflammatory Agents; D001993:Bronchodilator Agents; D005938:Glucocorticoids; D006632:Histamine; D000068298:Fluticasone