Comparison of cell profiles of bronchial and bronchoalveolar lavage fluids between normal subjects and patients with idiopathic pulmonary fibrosis.

The cell profiles of bronchial and bronchoalveolar lavage fluids (BLF and BALF) of patients with idiopathic pulmonary fibrosis (IPF) were compared with those of normal volunteers (NV) and age-matched control patients (CP), to characterize the cell profiles of the bronchoalveolar region in normals and patients with IPF. In BALF of nonsmokers from both control groups (NV and CP), alveolar macrophages (AM) were predominant and the percentage of neutrophil leukocytes and that of eosinophil leukocytes below 1% of the total cells. The percentage of neutrophils and that of bronchial epithelial cells were higher in BLF than in BALF of both control groups. Of the immune and inflammatory cells in BLF, the mean percentage of neutrophils was 12% in NV group and 42% in CP group. The percentage of neutrophils and that of eosinophils in BALF were higher in IPF group than in CP group, but the percentage of neutrophils in BLF of IPF group was comparable to that of CP group. In the IPF group, the percentage of neutrophils in BALF was lower than that in BLF. These results indicated that even in healthy subjects, a considerable number of neutrophils are present in the bronchial region and that the cell profile of the lavage fluid of the bronchoalveolar tree changes depending on the method of lavage. Presumably the higher percentage of neutrophils in BALF of patients with IPF is partly due to derangements of the alveolar structure, because the amount of saline infused into this region is limited.