Abstract

Alveolar angiotensin converting enzyme (ACE) and serum ACE were measured simultaneously in 16 patients with histologically confirmed sarcoidosis and in 16 control subjects. Although alveolar ACE was abnormally elevated in all 15 cases of active sarcoidosis, serum ACE was not. No correlations were found between radiographic staging of pulmonary sarcoidosis and the levels of these enzymes. There was a clear correlation, however, between the levels of alveolar ACE and counts made on bronchoalveolar lavage fluid. This correlation was closer than that existing between serum ACE and bronchoalveolar lavaged lymphocytes. It is suggested that alveolar ACE is an additional biological marker of pulmonary sarcoidosis which is possibly more sensitive than serum ACE.