Angiotensin-converting enzyme activity in sarcoidosis and other disorders.

A review is given on S-angiotensin-converting enzyme (SACE) and its clinical value, based upon 327 sarcoidosis patients and 1,274 patients with various disorders. SACE was elevated in 55% of the sarcoidosis patients, although with a higher frequency in those with active disease. Erythema nodosum was associated with normal initial SACE, subsequently rising, and sarcoid hypercalcaemia was consistently followed by elevated SACE. In non-sarcoid patients, elevated SACE was observed in only 10 cases. The sensitivity and specificity were 0.55 and 0.99, respectively, and the positive and negative predictive values were 0.95 and 0.90, respectively. Elevated SACE pointed strongly towards the presence of sarcoidosis, although reservations must be made in patients with liver disorders, diabetes mellitus, hyperthyroidism, asbestosis or silicosis which are rather common disorders also associated with elevated SACE. Normal SACE does not exclude sarcoidosis.