[Evaluation of immunity based on bronchoalveolar lavage fluid in patients with pleural plaque in the chest X-ray].

Alveolar and lower respiratory tract immunity in addition to systemic immunity in 31 patients with pleural plaques found on chest X-rays were evaluated. All cases had occupational histories of asbestos exposure, but ferruginous bodies in BAL fluid were only detected in 21 of 31 cases. The percentage of cell components in BAL fluid was evaluated according to the number of ferruginous bodies found in the BAL fluid. As the number of ferruginous bodies increased, neutrophils and T lymphocytes decreased, but B lymphocytes increased. Furthermore, CD25-positive cells were remarkably increased in patients with high exposure to asbestos. In addition, CD25-positive cells in the peripheral blood and serum soluble IL-2 receptors were elevated in the patients with high exposure to asbestos.