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ORIGINAL RESEARCH article

Front. Immunol.
Sec. Microbial Immunology
Volume 15 - 2024 | doi: 10.3389/fimmu.2024.1462222
This article is part of the Research Topic Discerning active TB from latent infection View all 4 articles

Diagnostic Accuracy of Mycobacterium Tuberculosis Specific Triple-color FluoroSpot Assay in Differentiating Tuberculosis Infection Status in febrile patients with suspected tuberculosis

Provisionally accepted
Lifan Zhang Lifan Zhang 1Yuanchun Li Yuanchun Li 1Xiaoqing Zou Xiaoqing Zou 1Huimin Ma Huimin Ma 1Mengqiu Gao Mengqiu Gao 2Qiping Ge Qiping Ge 2Yueqiu Zhang Yueqiu Zhang 1Zhengrong Yang Zhengrong Yang 1Xinuo Song Xinuo Song 1Qiwen Yang Qiwen Yang 1Xiaoqing Liu Xiaoqing Liu 1*
  • 1 Peking Union Medical College Hospital (CAMS), Beijing, China
  • 2 Beijing Chest Hospital, Capital Medical University, Beijing, Beijing Municipality, China

The final, formatted version of the article will be published soon.

    Abstract： Objective: To evaluate the diagnostic accuracy of a Mycobacterium tuberculosis (MTB) specific triple-color FluoroSpot assay (IFN-γ/IL-2/TNF-α) in the differentiation of tuberculosis (TB) infection status in febrile patients. Method: Febrile patients with suspected active TB (ATB) were consecutively enrolled. The frequencies and proportions of MTB-specific T cells secreting IFN-γ, IL-2, and TNF-α were detected at the single-cell level by triple-color FluoroSpot assay. The diagnostic index was fitted with a binary logistic regression model, and the diagnostic accuracy was evaluated according to the receiver operating characteristic (ROC) curve. The sensitivity, specificity, predictive values (PV) and likelihood ratios (LR) were calculated. Result: A total of 210 febrile patients were enrolled, 53 patients were diagnosed with ATB (28 pathogen-confirmed vs. 25 clinically diagnosed) and 157 patients were non-ATB (84 with latent tuberculosis infection (LTBI) vs. 73 uninfected with MTB). Additionally, 30 pathogen-confirmed ATB patients were assembled. When diagnosing ATB, the area under the ROC curve (AUROC) of the MTB-specific triple-color FluoroSpot assay was significantly better than that of T-SPOT.TB (0.882 vs. 0.811, p=0.017). With the fitted diagnostic index at a cut-off value of 0.378, the sensitivity, specificity, LR+ and LR- were 74.7%, 93.0%, 10.66, and 0.27, respectively. When differentiating ATB from LTBI, the AUROC of the FluoroSpot assay and T-SPOT.TB was 0.878 and 0.692, respectively (p<0.001). With a diagnostic index of 0.413, the sensitivity, specificity, LR+, and LR were 77.1%, 85.7%, 5.40, and 0.27, respectively. Conclusion: The MTB-specific triple-color FluoroSpot (IFN-γ/IL-2/TNF-α) might be helpful for the differentiation of TB infection status in febrile patients.

    Keywords: FluoroSpot, Triple-color, T-SPOT.TB, Active tuberculosis, latent tuberculosis infection

    Received: 09 Jul 2024; Accepted: 16 Dec 2024.

    Copyright: © 2024 Zhang, Li, Zou, Ma, Gao, Ge, Zhang, Yang, Song, Yang and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Xiaoqing Liu, Peking Union Medical College Hospital (CAMS), Beijing, China

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