Abstract: Objective To analyze the clinical value of Mycobacterium tuberculosis IFN-γ release assay (TB-IGRA) in diagnosis of tuberculosis. Methods The serum specimens of 249 patients with tuberculosis and 140 healthy people  were detected by Mycobacterium tuberculosis-IFN-γ release assay with Wantai quantitative diagnostic kit (WT-IGRA, Beijing Wantai Biological Pharmacy Corporation Ltd.) and QuantiFERON^®-TB GOLD in tube (QFT^®-GIT, Cellestis Limited, Australia), respectively. The results of TB-IGRA with WT-IGRA and QFT-GIT were compared with BCG-PPD skin test, Sputum smear and mycobacterial culture. Results Among 249 patients with tuberculosis, the positive rate of TB-IGRA with WT-IGRA and QFT-GIT were 76.3%（190/249）and 67.1%（167/249),respectively,and the specificity with two methods were all  83.3%（100/120). There were no statistical significant differences on positive rates of TB-IGRA and QFT-GIT between smear-positive patients and smear-negative patients which were 74.1%（43/58）,76.1%（83/109）with WT-IGRA（χ²=0.082，P＞0.05） and  67.2%（39/58），65.1%（71/109）with QFT-GIT(χ²=0.075，P＞0.05). The coincidence rate of the two kits is 84.3%. Conclusion TB-IGRA has certain diagnostic value in tuberculosis.

Key words: Tuberculosis/diagnosis, Interferon type Ⅱ, Enzyme-linked immunosorbent assay