title: A role for IgE in extrinsic allergic alveolitis?
abstract: Receptors for the Fc portion of immunoglobulin E (IgE; CD23) can be detected on the surface of alveolar macrophages (AM) in extrinsic allergic alveolitis (EAA), using monoclonal antibodies in immunocytology. More than 50% of AM were positive in 16 of the 20 patients reported here, while the remaining 4 had 11-47% positive cells. Staining with anti-IgE antibody can, in addition, demonstrate endogenous IgE bound to the AM. This suggests that IgE might be involved in the process. Since IgE-mediated asthma is associated with bronchoconstriction, we asked whether EAA patients do in fact exhibit an obstructive component. In 3 out of 10 patients we did indeed find clearly increased airway resistance (greater than 30 kPa x s x l-1). These findings are consistent with the observation of immediate bronchoconstriction observed in some patients upon allergen challenge. Since only 1 of the 20 patients studied was a smoker, and since in the literature the majority of reported cases of EAA are in nonsmokers, we speculate that smoking may interfere with immunological processes leading to EAA.
authors.affiliation: Medizinische Klinik, Klinikum Innenstadt, Universität München.
authors.forename: A
authors.initials: A
authors.lastname: Pforte
authors.forename: U
authors.initials: U
authors.lastname: Schild
authors.forename: G
authors.initials: G
authors.lastname: Breyer
authors.forename: K
authors.initials: K
authors.lastname: Häussinger
authors.forename: H W
authors.initials: HW
authors.lastname: Ziegler-Heitbrock
mesh_terms: D000328:Adult; D000368:Aged; D000403:Airway Resistance; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis / Q000502:physiology*; D001716:Bird Fancier's Lung / Q000276:immunology* / Q000503:physiopathology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D016084:Bronchoconstriction; D001999:Bronchoscopy; D005203:Farmer's Lung / Q000276:immunology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000502:physiology*; D016676:Macrophages, Alveolar / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D011961:Receptors, Fc / Q000032:analysis / Q000502:physiology*; D017455:Receptors, IgE; D012907:Smoking / Q000276:immunology*; D015854:Up-Regulation
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D011947:Receptors, Antigen, B-Cell; D011961:Receptors, Fc; D017455:Receptors, IgE; D007073:Immunoglobulin E