Interstitial lung disease. Assessment by bronchoalveolar lavage.

Bronchoalveolar lavage is a new bronchoscopic technique that permits assessment of changes in the cellular traffic in the alveolar spaces. During a 16-month period, 120 patients underwent bronchoalveolar lavage at our institution. Control subjects (N = 11) had a predominance of alveolar macrophages (94 +/- 1%) with a few lymphocytes (4 +/- 1%), whereas 35 patients with idiopathic pulmonary fibrosis had a substantial increase in the number of polymorphonuclear leukocytes (17 +/- 2%), and 32 patients with sarcoidosis had an appreciable increase in the number of lymphocytes (27 +/- 2%). Further subtyping of these lymphocytes in 13 patients with sarcoidosis revealed the cells to be predominantly from the T-helper subclass (helper/suppressor ratio of 5.3/1.0; normal 1.8/1.0). In contrast, three other patients with a lymphocytic alveolitis (51 +/- 8% lymphocytes) had a pronounced predominance of T-suppressor lymphocytes (helper/suppressor ratio of 0.1/1.0) in the lavage fluid. Two of the three patients were thought to represent an unusual subset of patients with idiopathic pulmonary fibrosis, and the third patient had pulmonary involvement secondary to angioimmunoblastic lymphadenopathy. Thus, bronchoalveolar lavage may be a useful means by which to assess the influx of inflammatory or immune effector cells into the alveolar structures in patients with interstitial lung disease, and this procedure offers promise as a quantitative means by which to assess the disease activity and the response to therapeutic intervention in these patients.