[Two cases of budgerigar breeder's lung].

We report 2 patients with Bird breeder's lung associated with keeping budgerigars. Patient 1 kept a budgerigar indoors for 13 years. Histological examination revealed fibrosis and granulomatous changes in the alveolar septa. Among T lymphocyte subsets in BALF, helper T cell were increased. In the serum, precipitating antibodies to budgerigar dropping extract were observed. Patient 2 had kept Budgerigar for 7 months. Histologically, alveolitis was the primary finding, and suppressor T cell in the BALF were increased. Precipitating antibodies to budgerigar dropping extract was observed only in the BALF but not in serum. In patient 1 who showed a chronic course and granuloma formation, helper T cell in the BALF were increased while in patient 2 who showed an acute course and alveolitis, suppressor T cell in the BALF were increased, and precipitating antibody was observed only in the BALF. These findings suggest that T lymphocyte subsets in the BALF differ depending on the stage of hypersensitivity pneumonitis, and specific local antibody production precedes systemic antibody production.