To investigate the potential value of interferon-gamma release assay (IGRA) and detection of anti-Mycobacterium tuberculosis (MTB) in the diagnosis of tuberculosis.

Data of 512 cases with suspected tuberculosis diagnosed from June 2013 to December 2014 in Department of Tuberculosis, the Fifth Affiliated Infectious Hosptital of Soochow University were analyzed, retrospectively. The concentration of interferon-gamma in blood plasma were detected by the IGRA kit. The concentration of anti-MTB-16 kD, anti-MTB-38 kD and anti-lipoarabinomannan (Lam) were detected by protein chip recognition instrument. The level of anti-tuberculosis (TBAb) was analyzed by ELISA method. The accuracy of diagnosis of tuberculosis based on single measurement or combination of them were evaluated through parallel comparison.

For the cases with smear negative pulmonary tuberculosis, AUC of IGRA was the largest, indicating the best diagnostic accuracy. When combined with these indicators, a duplex combination of 16 kD + IGRA and a triple combination of IGG + 16 kD + IGRA showed better accuracy, but with no significant difference between the two combinations (Z = 1.622, P = 1.107). The AUC, sensitivity and specificity values of combination of 16 kD + IGRA were 0.694, 82% and 57%, respectively. The AUC, sensitivity and specificity values of combination of IGG + 16 kD + IGRA were 0.667, 96% and 36%, respectively.

Comparing with the single parameter, the combined multiple parameters may improve the sensitivity of diagnosis in smear negative pulmonary tuberculosis. The significant combinations of parameters in diagnosing smear negative pulmonary tuberculosis are 16 kD + IGRA and IGG + 16 kD + IGRA.