Clinical utility of bronchoalveolar lavage in the assessment of interstitial lung disease.

Bronchoalveolar lavage is a new bronchoscopic technique which permits assessment of changes in the cellular traffic in the alveolar spaces. One hundred and fourteen patients underwent bronchoalveolar lavage at the Mayo Clinic during a 16-month period. Whereas control subjects had a predominance of alveolar macrophages (93 +/- 1%) with few lymphocytes (5 +/- 1%), 35 subjects with idiopathic pulmonary fibrosis had a marked increase in the number of polymorphonuclear leukocytes (17 +/- 2%), and 32 subjects with sarcoidosis had a marked increase in the number of lymphocytes (26 +/- 2%). Further identification of these lymphocytes by the immunofluorescent detection of cell-surface antigens revealed the lymphocytes, in all 13 cases of sarcoidosis examined, to be from the T-helper subclass. Bronchoalveolar lavage represents an easy method to monitor the "alveolitis" in these disorders, and offers promise as a quantitative means by which to assess disease "activity" as well as the response to therapy.