title: Transforming growth factor-beta 1 in asthma. Measurement in bronchoalveolar lavage fluid.
abstract: Airway wall remodeling is an established pathological feature in asthma. Its causes are not well understood, but one mediator of potential relevance is transforming growth factor-beta 1 (TGF-beta 1). We have measured levels of immunoreactive TGF-beta 1 in bronchoalveolar lavage (BAL) fluid from clinically stable atopic asthmatics and healthy control subjects. We have also examined the influence of allergen exposure on TGF-beta 1 release in the airways using a segmental bronchoprovocation model, with BAL performed at two time points following endobronchial allergen and sham saline challenges. Basal concentrations of TGF-beta 1 were significantly higher in asthmatics than control subjects (median 8.0 versus 5.5 pg/ml, p = 0.027). Following segmental bronchoprovocation, concentrations of TGF-beta 1 at the allergen- and saline-challenged sites were not significantly different after 10 min, (31.3 versus 25.0 pg/ml, p = 0.78), but after 24 h there were significantly higher TGF-beta 1 concentrations at the allergen-challenged sites (46.0 versus 21.5 pg/ml, p = 0.017). We conclude that basal TGF-beta 1 levels in the airways are elevated in atopic asthma and that these levels increase further in response to allergen exposure. These findings are consistent with the hypothesis that TGF-beta 1 is implicated in airway wall remodeling in asthma.
authors.affiliation: University Medicine, Southampton General Hospital, United Kingdom.
authors.forename: A E
authors.initials: AE
authors.lastname: Redington
authors.forename: J
authors.initials: J
authors.lastname: Madden
authors.forename: A J
authors.initials: AJ
authors.lastname: Frew
authors.forename: R
authors.initials: R
authors.lastname: Djukanovic
authors.forename: W R
authors.initials: WR
authors.lastname: Roche
authors.forename: S T
authors.initials: ST
authors.lastname: Holgate
authors.forename: P H
authors.initials: PH
authors.lastname: Howarth
mesh_terms: D000328:Adult; D000485:Allergens; D001249:Asthma / Q000276:immunology* / Q000473:pathology; D001706:Biopsy; D001980:Bronchi / Q000473:pathology; D001985:Bronchial Provocation Tests / Q000379:methods / Q000706:statistics & numerical data; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000166:cytology; D001999:Bronchoscopy; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology / Q000473:pathology; D008297:Male; D018709:Statistics, Nonparametric; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000032:analysis*
chemical_list: D000485:Allergens; D016212:Transforming Growth Factor beta