Serum angiotensin-converting enzyme levels in sarcoid arthritis.

The serum angiotensin-converting enzyme (SACE) level is elevated in 75% of patients with sarcoidosis and often is associated with disease activity. In an attempt to correlate the SACE level with sarcoid arthritis, we did a retrospective chart review of 116 patients with sarcoidosis. Of the 24 patients who complained of arthritis, five were excluded from the study because they were receiving corticosteroids, SACE levels were not determined, or another cause for their arthritis was found. The mean SACE levels were 65 units/mL for the patients with acute arthritis and 51 units/mL for the patients with chronic arthritis. Levels of SACE may be helpful in the differential diagnosis of patients with "seronegative polyarthritis."