Angiotensin-converting enzyme and lysozyme in silicosis and asbestosis

Serum angiotensin-converting enzyme (ACE) activity and lysozyme (LZM) concentration in 22 silicosis and 18 asbestosis patients were studied. These patients were compared with 57 untreated and 36 treated sarcoidosis patients. In all groups significantly raised ACE and LZM mean values were noted. Untreated sarcoidosis patients had the highest values. Raised ACE activity in silicosis and asbestosis has not been reported before, and weakens the differential diagnostic value of this enzyme determination for sarcoidosis. The similar patterns of increased ACE and LZM mean values in all three diseases suggest that these enzymes have a common source.