Morphologic characterization of alveolar macrophages from subjects with occupational exposure to inorganic particles.

Publication Type	Academic Article
Authors	Takemura T, Rom W, Ferrans V, Crystal R
Journal	Am Rev Respir Dis
Volume	140
Issue	6
Pagination	1674-85
Date Published	12/01/1989
ISSN	0003-0805
Keywords	Air Pollutants, Occupational, Dust, Macrophages, Pulmonary Alveoli
Abstract	Alveolar macrophages recovered by bronchoalveolar lavage from 43 nonsmoking or greater than 5-yr ex-smoking subjects with occupational exposure to inorganic particles (asbestos, n 1/2 19; silica, n 1/2 10; coal, n 1/2 14) were evaluated by light microscopy and transmission and scanning electron microscopy to determine the morphologic changes resulting in these cells from chronic inorganic particulate inhalation. Alveolar macrophages from dust-exposed subjects, including those who had been free of exposure to particles for more than 1 yr, contained particles of higher proportion than did those of normal unexposed subjects. Most of these particles were located within phagolysosomes. The frequency of multinucleated alveolar macrophages was significantly higher in the dust-exposed groups. Ultrastructural studies showed alterations of the morphologic aspects of the surfaces of alveolar macrophages from the dust-exposed subjects, including increased numbers of rufflings, filopodia, pinocytotic vesicles, subplasmalemmal linear densities, and increased frequency of macrophage-macrophage and macrophage-lymphocyte interactions. Furthermore, the numbers of lysosomes were significantly increased in alveolar macrophages from the dust-exposed subjects. Together, these morphologic changes are consistent with the sequelae of phagocytosis, and they emphasize both the role of alveolar macrophages in eliminating inorganic particles from the alveolar spaces and the consequences this role has in alveolar macrophage activation.
DOI	10.1164/ajrccm/140.6.1674
PubMed ID	2557785