Lung and blood lymphocyte subsets in asbestosis and in mixed dust pneumoconiosis

To study the local distribution of lymphocyte subsets in inorganic dust diseases, bronchoalveolar lavage (BAL) was performed in seven patients with asbestosis, and in 13 patients with mixed dust pneumoconiosis (anthracosidero-silicosis). Lymphocyte subsets in BAL and blood were determined by the monoclonal antibodies OKT3 (pan T), OKT4 (helper/inducer), OKT8 (suppressor/cytotoxic), B1 (B-cells), OKIa (HLA-DR antigens), and Leu-7 (natural killer). The BAL lymphocytes were moderately elevated to 15 +/- 8 percent (mean +/- SD) in mixed dust pneumoconiosis, and even more markedly increased to 28 +/- 21 percent in asbestosis. The OKT4/OKT8 ratio in BAL was significantly increased to 4.5 +/- 2.1 in asbestosis, and significantly reduced to 0.9 +/- 0.8 in mixed dust pneumoconiosis. In blood, the ratio of T-cell subsets remained unchanged, though total lymphocytes were decreased in asbestosis. These results suggest altered cellular immune processes in the lungs of patients with pneumoconiosis and may indicate different immunoregulatory changes depending on the nature of the inhaled dust.