Research Paper Volume 13, Issue 7 pp 9693—9703

Diagnostic values of peripheral blood T-cell spot of tuberculosis assay (T-SPOT.TB) and magnetic resonance imaging for osteoarticular tuberculosis: a case-control study

Xiaoliang Li1, , Junli Wang2, , Zhigang Yang1, , Qiongzhu Song1, ,

  • 1 Department of Respiratory and Critical Care Medicine, Henan Provincial People’s Hospital, Zhengzhou University People’s Hospital, Zhengzhou, Henan, China
  • 2 Department of Cardiopulmonary Function, Fuwai Central China Cardiovascular Hospital, Zhengzhou, Henan, China

Received: September 21, 2020       Accepted: February 8, 2021       Published: March 19, 2021
How to Cite

Copyright: © 2021 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Objective: Early diagnosis of osteoarticular tuberculosis helps improve patients’ outcomes, but little is known about the accuracy of noninvasive diagnostic methods. This case-control study aimed to assess the diagnostic value of peripheral blood T-cell spot of tuberculosis assay (T-SPOT.TB) and magnetic resonance imaging (MRI).

Methods: Patients suspected with osteoarticular tuberculosis were retrospectively included and diagnosed according to the composite reference standard. T-SPOT.TB was used to detect the number of cells secreting Interferon gamma. Diagnostic performance of T-SPOT.TB and MRI alone and combined were evaluated.

Results: Among the suspected patients, 92 had osteoarticular tuberculosis and 137 non- osteoarticular tuberculosis. T-SPOT.TB assay alone had a higher sensitivity (0.73 vs. 0.60) but a lower specificity (0.69 vs. 0.91 P>0.05) in diagnosing osteoarticular tuberculosis. Combined serial test showed a sensitivity and specificity 0.47, 0.97, respectively, whereas combined parallel test showed a sensitivity and specificity of 0.86, 0.65, respectively. Specificity was higher in the combined serial test than in the T-SPOT.TB assay (P=0.007) or MRI alone (P < 0.001). Furthermore, sensitivity was higher in the combined parallel test than in the T-SPOT.TB assay (P < 0.001) or MRI alone (P < 0.001).

Conclusions: Combined blood T-cell spot of tuberculosis assay and osteoarticular MRI have higher sensitivity and specificity for noninvasive osteoarticular tuberculosis diagnosis, compared with either method alone.


T-SPOT.TB: T-cell spot of tuberculosis; MRI: magnetic resonance imaging; OTB: osteoarticular tuberculosis; CRS: composite reference standards; IGRAs: interferon-γrelease assays; Mtb: Mycobacterium tuberculosis; PBMCs: peripheral blood mononuclear cells; ESAT-6: early secretory antigentic target 6; CFP-10: culture filtrate protein 10; SFCs: spot-forming cells; AFB: acid fast bacilli; LR+: positive likelihood ratio; LR-: negative likelihood ratio; PPV: positive predictive value; NPV: negative predictive value; ROC: receiver operating characteristic curve.