title: Endobronchial secretion of interleukin-13 following local allergen challenge in atopic asthma: relationship to interleukin-4 and eosinophil counts.
abstract: We investigated the secretion of interleukin (IL)-13 into the airways in 10 mild allergic asthmatics by employing local allergen challenge, and compared the data both to IL-4 levels and eosinophil numbers obtained by bronchoalveolar lavage (BAL). Appropriate allergen or saline were endoscopically instilled into different airway segments, which were lavaged 10 min and 18 h after allergen or sham challenge. IL-4 and IL-13 were measured in unconcentrated BAL fluid using a double sandwich enzymes-linked immunosorbent assay (ELISA). Endobronchial allergen challenge induced a highly significant increase in the numbers of eosinophils after 18 h in the allergen exposed segment. Ten minutes following allergen exposure, low levels of IL-4 and IL-13 could be detected, whilst concentrations of both cytokines were significantly raised 18 h following local allergen exposure. In contrast to IL-4, the concentration of IL-13 strongly correlated with the eosinophil numbers found 18 h post-allergen challenge. The results suggest that interleukin-13 is actively secreted during the late asthmatic response in mild asthmatic subjects. In view of its action on eosinophils and other cell types, we conclude that interleukin-13, in addition to interleukin-4, may play an important role in the pathogenesis of eosinophil-related inflammation, such as bronchial asthma.
authors.affiliation: Dept. IV, Pneumology, Medical University Clinics, Friedrich-Schiller University, Jena, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Kroegel
authors.forename: P
authors.initials: P
authors.lastname: Julius
authors.forename: H
authors.initials: H
authors.lastname: Matthys
authors.forename: J C
authors.initials: JC
authors.lastname: Virchow
authors.forename: W
authors.initials: W
authors.lastname: Luttmann
mesh_terms: D000328:Adult; D000485:Allergens / Q000009:adverse effects; D000704:Analysis of Variance; D001249:Asthma / Q000209:etiology / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay; D004804:Eosinophils / Q000378:metabolism; D005260:Female; D006801:Humans; D018793:Interleukin-13 / Q000032:analysis / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000032:analysis / Q000096:biosynthesis*; D008297:Male
chemical_list: D000485:Allergens; D018793:Interleukin-13; D015847:Interleukin-4