title: Cockade-like structures in alveolar macrophages in extrinsic allergic alveolitis.
abstract: OBJECTIVE
  In immunocytochemical preparations of bronchoalveolar lavage (BAL) cells from patients with extrinsic allergic alveolitis (EAA), we observed the presence of alveolar macrophages with cockade-like structures in their cytoplasm (cockade+ alveolar macrophages). These cockade+ alveolar macrophages may reflect a subpopulation of alveolar macrophages which may show a different predominance in various interstitial lung diseases. In this study we aimed to compare the frequency of cockade+ alveolar macrophages in patients with EAA (n = 14) with the results obtained in patients with sarcoidosis (n = 11), idiopathic interstitial pneumonia (IIP; n = 10) and control subjects (n = 8). We also investigated the expression of the transferrin receptor CD71 on cockade+ alveolar macrophages.
  
  
  METHODS
  In BAL fluid, the total number of cells and differential counts were determined, and immunocytologic examinations of macrophages and lymphocytes were done using monoclonal antibodies. The percentage of cockade+ alveolar macrophages was determined by counting 300 macrophages in the CD20 field of an immunocytochemical slide.
  
  
  RESULTS
  The percentage of cockade+ alveolar macrophages was significantly higher in the EAA group (36 +/- 9%) compared to patients with sarcoidosis (12 +/- 5%) or IIP (11 +/- 10%) and control subjects (3 +/- 1%; p < 0.001). The proportion of CD71+ alveolar macrophages was significantly lower in EAA than in the other groups (p < 0.01), and the CD71 antigen was expressed on a significantly lower proportion of cockade+ alveolar macrophages compared to cockade- alveolar macrophages in EAA (p < 0.001).
  
  
  CONCLUSIONS
  We conclude that cockade+ alveolar macrophages could play a role in the pathogenesis and differential diagnosis EAA.
authors.affiliation: Department of Pneumology and Allergy, Ruhrlandklinik, Essen, Germany.
authors.forename: Esra
authors.initials: E
authors.lastname: Uzaslan
authors.forename: Josune
authors.initials: J
authors.lastname: Guzman
authors.forename: Ulrich
authors.initials: U
authors.lastname: Costabel
mesh_terms: D000328:Adult; D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000276:immunology* / Q000473:pathology; D000911:Antibodies, Monoclonal; D015415:Biomarkers / Q000378:metabolism; D018893:Bronchoalveolar Lavage; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D015815:Cell Adhesion Molecules / Q000378:metabolism; D005260:Female; D006683:HLA-DQ Antigens / Q000378:metabolism; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D002479:Inclusion Bodies / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure*; D016676:Macrophages, Alveolar / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure*; D008297:Male; D008875:Middle Aged; D011971:Receptors, Immunologic / Q000378:metabolism; D011990:Receptors, Transferrin / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D015815:Cell Adhesion Molecules; D006683:HLA-DQ Antigens; D007136:Immunoglobulins; D011971:Receptors, Immunologic; D011990:Receptors, Transferrin; C048071:endotoxin receptor