Leukocyte immunophenotypes in bronchoalveolar lavage fluid and peripheral blood of paracoccidioidomycosis, sarcoidosis and silicosis.

Leukocyte subsets in bronchoalveolar lavage (BAL) fluid and peripheral blood of patients with paraccoccidioidomycosis, sarcoidosis and silicosis were characterized using monoclonal antibodies and an immunoperoxidase technique. In paraccocidioidomycosis, the number of T-helper/inducer CD4-positive lymphocytes was lower in peripheral blood than in BAL fluid. Additional analysis showed that the expression of HLA-DR was very similar in alveolar macrophages, lung and blood T-cells. In sarcoidosis and silicosis there were higher proportions of T-helper/inducer cells in peripheral blood than in BAL fluid. The alterations in the T-helper/inducer/T-suppressor/cytoxic CD4/CD8 ratio in sarcoidosis and silicosis were more appreciable in peripheral blood than in BAL fluid, contrasting with the results in paracoccidioidomycosis. The expression of HLA-DR by alveolar macrophages in sarcoidosis was the highest of all the disease studied. No statistically significant differences were observed between chronic multifocal and chronic unifocal paracoccidioidomycosis disease, stage II and stage III sarcoidosis, and chronic and accelerated silicosis. The three granulomatous diseases analyzed had a few alveolar macrophages expressing the CD4 molecule on their surface. These findings and the technique of analyzing both peripheral blood and BAL leukocyte subsets may help to understand the pathogenesis of interstitial lung diseases.