Abstract
In this study, we investigated the activity of alveolar macrophages (AM) obtained from bronchoalveolar lavage (BAL) fluid in terms of their immunological (IgG-Fc receptor activity) aspects in various diffuse pulmonary diseases (i. e., hypersensitivity pneumonitis, sarcoidosis, chronic beryllium disease, pulmonary fibrosis, including collagen vascular disease, and normal control subjects). Results are as follows 1) Rosette forming activity of AM with oxEAEA-IgG were significantly increased in epithelioid cell granulomatous pulmonary disease (i. e., hypersensitivity pneumonitis, sarcoidosis and chronic beryllium disease), while, in contrast, no difference was observed between pulmonary fibrosis and normal control subjects. 2) IgG-Fc receptor-mediated phagocytic activity of AM also showed an increase in epithelioid cell granulomatous pulmonary diseases as compared to pulmonary fibrosis and normal control subjects. 3) The percentages of rosette-forming AM using low sensitized erythrocytes (oxEAEA-IgG × 10-1) were very low in all pulmonary diseases tested, but the percentage in hypersensitivity pneumonitis showed a relative increase. 4) Almost all alveolar macrophages seem to have a IgG-Fc receptor, as seen from the fact that the percentages of rosette-forming alveolar macrophages using high sensitized erythrocytes (oxEA-IgG × 10) were nearly 100%.
We can thus conclude from BAL cell findings that alveolar macrophages are activated in epithelioid cell granulomatous pulmonary diseases. Therefore, activated alveolar macrophages play some role in epithelioid cell granulomatous pulmonary diseases.
On the other hand, the activity of alveolar macrophages in pulmonary fibrosis shows no difference with that of normal control subjects.
