SIGNIFICANCE OF SERUM ANGIOTENSIN CONVERTING ENZYME AND GALLIUM SCAN IN NON-INVASIVE DIAGNOSIS OF SARCOIDOSIS

Abstract

Serum angiotensin converting enzyme (SACE) assays, chest roentgenograms and Ga scans were obtained in 28 patients with active sarcoidosis, 2 patients with resolved sarcoidosis and 43 nonsarcoid patients. In patients with active sarcoidosis, 23 had elevated SACE activity and 26 had diffuse uptake of Ga in the lung parenchyma. Normal SACE and Ga 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 Ga, although some had elevated SACE activity and abnormal Ga scans. Combination of elevated SACE activity and diffuse accumulation of Ga in the lung parenchyma are suggestive of sarcoidosis. In view of the reports of abnormal Ga 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.