Use of the QuantiFERON-TB Gold test in Japanese patients with sarcoidosis.

BACKGROUND AND OBJECTIVE Mycobacterium tuberculosis has been proposed as a candidate agent for the cause of sarcoidosis. The QuantiFERON-TB Gold test has a higher specificity for detecting M. tuberculosis infection than the conventional tuberculin skin test. This study aimed to investigate the rate of positive QuantiFERON-TB Gold results in Japanese sarcoidosis patients. PATIENTS AND METHODS The QuantiFERON-TB Gold test, an enzyme-linked immunosorbent assay, was used to assess the levels of interferon-gamma resulting from immune responses to M. tuberculosis-specific antigens, namely early secretory antigen target 6 and culture filtrate protein 10, in 90 Japanese sarcoidosis patients. RESULTS The QuantiFERON-TB Gold result was positive in 3 of the 90 patients tested. CONCLUSION The positivity rate of QuantiFERON-TB Gold was 3.3% in Japanese sarcoidosis patients.