Journal of Laboratory Medicine and Quality Assurance  2005;27(2):237-242

Immunodiagnosis of Latent Tuberculosis through Interferon-gamma Measurement Following Stimulation of Tuberculosis-Specific Antigens (ESAT-6 and CFP-10).

Kyoung Un PARK 1 ; Hyun Jung LEE ; Mi Jung KIM ; Kwang Woo LEE ; Ju Young KIM ; Hong Bin KIM ; Eun Hwa CHOI ; Jae Ho LEE ; Choon Taek LEE ; Junghan SONG

Affiliations

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Keywords

Latent tuberculosis; Interferon-gamma; ESAT-6; CFP-10

Country

Republic of Korea

Language

Korean

Abstract

BACKGROUND:The tuberculin skin test, which has been used for years for the diagnosis of latent tuberculosis, has many limitations, including false-positive results in individuals who were vaccinated with BCG. We evaluated the usefulness of a recently developed interferon-gamma assay (QuantiFERON-TB Gold) in the diagnosis of latent tuberculosis. METHODS:We performed the QuantiFERON-TB Gold assay in the following groups: 1) individuals with negative responses of tuberculin skin test in the regular health checkups for two consecutive years (n = 14), 2) individuals with no abnormal findings in low dose computed tomography in a health checkup (n = 22), 3) individuals with stable tuberculosis in low dose computed tomography in a health checkup (n = 10), 4) patients with M. tuberculosis in culture (n = 23), 5) patients with nontuberculous mycobacteria in culture (n = 6). RESULTS:In the QuantiFERON-TB Gold assay, all the group 1 showed negative results. 65.2% of the group 4 showed positive QuantiFERON-TB Gold results, while all the group 5 showed negative results. 22.7% of the group 2 and 60.0% of the group 3 showed positive QuantiFERON-TB Gold results. In addition, it was revealed that the stimulation with CFP-10 played a major role in the induction of interferon-gamma secretion. CONCLUSION:The QuantiFERON-TB Gold assay shows promise for the immunodiagnosis of latent tuberculosis using a whole-blood.