Serum
angiotensin converting enzyme (SACE) assays, chest roentgenograms and
gallium scans were obtained in 28 patients with active
sarcoidosis, two patients with resolved
sarcoidosis and 43 nonsarcoid patients. In patients with active
sarcoidosis, 23 had elevated SACE activity and 26 had diffuse uptake of
gallium in the lung parenchyma. Normal SACE and
gallium scans were found in patients with resolved
sarcoidosis. None of the nonsarcoid patients had a combination of elevated SACE activity and diffuse pulmonary parenchymal uptake of
gallium, although some had elevated SACE activity and abnormal
gallium scans. These results suggest that combination of elevated SACE activity and diffuse accumulation of
gallium in the lung parenchyma are suggestive of
sarcoidosis. However, in view of the reports of abnormal
gallium accumulation, and occasional elevation of SACE activity in
silicosis,
asbestosis and
miliary tuberculosis, it is still necessary to require histological evidence of noncaseating
granuloma to confirm the diagnosis of
sarcoidosis.