[Value of angiotensin I-converting enzyme in the diagnosis of sarcoidosis (author's transl)].

Serum ACE activity measured fluorimetrically was found to be 2.95 +/- (SD) 1.76 mu mol/ml x h in 31 untreated patients with sarcoidosis. It was significantly elevated (p less than 0.001) in comparison to 38 healthy controls 0.97 +/- (SD) 0.30 mu mol/ml x h), 81 subjects with miscellaneous lung diseases, 20 corticosteroid treated patients with sarcoidosis and 15 subjects with resolved sarcoidosis. Resolution of sarcoidosis spontaneously or induced by corticosteroids was accompanied in all 17 cases by a decrease of serum ACE activity, in most cases, to normal values. On the other hand 7 out of 9 untreated patients with a chronic course of sarcoidosis did not show a comparable change of ACE. Our results reveal a close relationship between the activity of the disease and the level of ACE in the serum. The determination of the serum activity of ACE and its variations with time is quite useful in the diagnosis and follow-up of sarcoidosis and contributes to a further restriction of necessary operative procedures in the diagnosis of sarcoidosis.