Tumor necrosis factor alpha in bronchoalveolar lavage fluid and its production by alveolar macrophages with asbestos exposure

: It is generally accepted that asbestos exposure causes pulmonary fibrosis and carcinogenesis. Several studies have suggested that TNF alpha is produced principally by mononuclear phagocytes and that it may play a role in inflammation, fibrosis and anti-tumor activity. We studied TNF alpha production by alveolar macrophages and the TNF alpha concentration in bronchoalveolar lavage fluid harvested from asbestos-exposed subjects and healthy controls. TNF alpha production by alveolar macrophages was significantly higher in the asbestos-exposed subjects than in healthy controls (3696 +/- 1606, 1938 +/- 753 pg/ml; p < 0.01). The period from first exposure correlated inversely with TNF alpha production (r = -0.6; p < 0.05). The TNF alpha concentration in bronchoalveolar lavage fluid was also significantly higher in the asbestos-exposed subjects than in healthy controls. These results suggest that abnormal TNF alpha production by alveolar macrophages may be related to fibrosis and carcinogenesis due to asbestos.