Bronchoalveolar lavage in chronic eosinophilic pneumonia. Analysis of six cases in comparison with other interstitial lung diseases.

We describe 6 patients with chronic eosinophilic pneumonia (CEP) investigated clinically and by bronchoalveolar lavage (BAL). The BAL findings of these 6 patients were compared with those of 293 patients with other interstitial lung diseases (ILD): 184 with sarcoidosis, 63 with hypersensitivity pneumonitis, 46 with idiopathic pulmonary fibrosis (IPF). In patients with CEP, BAL analysis was characterized by a markedly increased number of eosinophils (mean +/- 1 SD: 54.2 +/- 26.4 of effector cells; in control subjects, eosinophils were less than 1% of effector cells). In patients with other ILD, BAL fluid analysis showed a significant increase in the percentage of eosinophils only in the group of IPF, but in IPF the increased number of eosinophils is linked with a significant increase in the percentage of neutrophils. These findings indicate that besides the classic patterns of lymphocytosis or polymorphonuclear leukocytosis, a predominantly eosinophilic pattern may also be present in the BAL fluid. Moreover, BAL may contribute to understanding the pathogenesis of lung tissue damage in CEP.