Serum angiotensin-converting enzyme activity in evaluating the clinical course of sarcoidosis.

Thirty-five patients with sarcoidosis were serially monitored for serum angiotensin-converting enzyme activity by a simple radiochemical assay, and we analyzed the relation of such activity to the clinical status as judged from changes in chest roentgenograms, pulmonary function, or symptoms. Converting enzyme levels closely paralleled and occasionally antedated changes in clinical status in patients either undergoing spontaneous remission or being treated with prednisone. Converting enzyme activity seems to be a sensitive index for evaluating the clinical course of sarcoidosis. Converting enzyme determinations may be helpful in corroborating the diagnosis, assessing the likelihood of spontaneous remission, confirming the clinical status of the patient, and determining the adequacy of glucocorticoid therapy.