Serum angiotensin-converting enzyme estimation and the Kveim-Siltzbach test in sarcoidosis.

Serum angiotensin-converting enzyme (SACE) and Kveim-Siltzbach test results were obtained in 25 patients with clinically active sarcoidosis. Twenty of these patients had elevated SACE levels and 17 had positive Kveim-Siltzbach tests. One patient had normal SACE activity and a negative Kveim-Siltzbach test. Four of the 6 patients with a normal SACE level had a positive Kveim-Siltzbach test and 7 of the 8 patients with a negative Kveim-Siltzbach test had elevated SACE levels. These results indicate that the two tests are complementary and increase the diagnostic specificity in sarcoidosis. We conclude that the concurrent use of SACE measurement and Kveim-Siltzbach tests is of value in the diagnosis of sarcoidosis.