[Serum angiotensin convertase activity and clinical course in sarcoidosis. Course studies in primary chronic...

The relationship between the clinical course and SACE activity was analyzed by observing 133 patients with histologically confirmed sarcoidosis (74 stage I, 59 stage II) at intervals of 6.2 +/- 2.6 months during a period of 32.9 +/- 11.9 months. At the end of the follow-up period the patients were grouped into 4 categories concerning their chest x-ray changes: (a) improved (53); (b) unchanged (38); (c) progressive (9); (d) relapses (33). In group (a) initially elevated SACE always decreased, in (b) it often remained above the normal range; (c) and (d) always coincided with rising SACE. Out of 56 relapses observed 53 (95%) were associated with pathologically elevated SACE. There were significantly more relapses (35) in stage II compared to 21 in stage I sarcoidosis. SACE activities were measured in 109 patients placed on steroids. As a rule initially elevated SACE concentrations fell rapidly after initiation of steroid therapy. However SACE was found to be above the normal range after four weeks of therapy in 21 patients (19,3%), 5 in stage I and 16 in stage II, indicating an unfavourable course of the disease. Serial measurements of SACE are a very useful indicator of the activity of sarcoidosis and are helpful for monitoring the effects of corticosteroid therapy, having also some prognostic significance.