Effect of prednisolone treatment in chronic silicosis. We evaluated the effects of daily oral prednisolone therapy on alveolitis parameters and pulmonary function tests over a 6-month period in patients with chronic silicosis. Pulmonary function tests were done in 34 patients, and bronchoalveolar lavage (BAL) was done in 21 of them. Pulmonary function tests showed a significant improvement in lung volumes, FEV1, PEFR, SGaw, DLCO, and PaO2. Analysis of BAL fluid revealed a significant decrease in total cell count. Mean fibronectin and immunoglobulin values in BAL fluid also were lower after treatment, but the change was not statistically significant. No serious side effects were encountered with prednisolone therapy. These results indicate that daily oral prednisolone therapy may suppress the alveolitis in certain patients with chronic silicosis and bring about a significant improvement in lung functions and gas exchange. 