Cockade-like structures in alveolar macrophages in extrinsic allergic alveolitis.
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.
Uzaslan
Esra
E
Department of Pneumology and Allergy, Ruhrlandklinik, Essen, Germany.
Guzman
Josune
J
Costabel
Ulrich
U
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
D000911:Antibodies, Monoclonal; D015415:Biomarkers; D015815:Cell Adhesion Molecules; D006683:HLA-DQ Antigens; D007136:Immunoglobulins; D011971:Receptors, Immunologic; D011990:Receptors, Transferrin; C048071:endotoxin receptor