Department of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, No. 507, Zhengmin Road, Shanghai, 200433, China.
Shanghai Clinical Research Center for Infectious Disease (Tuberculosis), Shanghai, 200433, China.
Respir Res. 2021 Jun 1;22(1):165. doi: 10.1186/s12931-021-01753-5.
The positive rate of pathogenic examination about tuberculosis is low. It is still difficult to achieve early diagnosis for some TB patients. The value of Interferon-gamma release assays (IGRA) in the diagnosis of active tuberculosis remains controversial. The purpose of this multicenter prospective study was to verify and validate the role of TBAg/PHA ratio (TB-specific antigen to phytohaemagglutinin) of T-SPOT.TB assay in diagnosing ATB.
We prospectively enrolled 2390 suspected pulmonary tuberculosis patients with positive T-SPOT assay results from three tertiary hospitals.
A total of 1549 ATB (active tuberculosis) patients (including 1091 confirmed and 458 probable ATB) and 724 non-tuberculosis (non-TB) patients with positive T-SPOT results were included. The results of this study showed that ESAT-6 and CFP-10 in the T-SPOT.TB assay were significantly higher in the ATB group compared with the non-TB group, while PHA was lower in the ATB group. Results of ESAT-6, CFP-10 and PHA show a certain diagnostic performance, but moderate sensitivity and specificity. The TBAg/PHA ratio, a further calculation of ESAT-6, CFP-10 and PHA in T-SPOT.TB assay showed improved performance in the diagnosis of active Tuberculosis. If using the threshold value of 0.2004, the specificity and sensitivity of TBAg/PHA ratio in distinguishing ATB from non-TB were 92.3% and 74.4%, PPV was 95.4, PLR was 9.6.
By recalculating the results of T-SPOT.TB Assay, the TBAg/PHA ratio shows high prospect value in the diagnosis of active tuberculosis in high prediction areas.
结核病病原学检查阳性率低，部分结核病患者仍难以早期诊断。干扰素 -γ 释放试验（IGRA）在结核病中的诊断价值仍存在争议。本多中心前瞻性研究旨在验证 T-SPOT.TB 试验中 TBAg/PHA 比值（结核特异抗原/植物血凝素）在诊断活动性结核病（ATB）中的作用。
我们前瞻性纳入了三家三级医院中 T-SPOT 检测阳性的 2390 例疑似肺结核患者。
共纳入 1549 例 ATB（活动性结核病）患者（包括 1091 例确诊和 458 例可能 ATB）和 724 例 T-SPOT 阳性的非结核患者。结果显示，ATB 组的 T-SPOT.TB 试验中 ESAT-6 和 CFP-10 明显高于非 TB 组，而 PHA 则较低。ESAT-6、CFP-10 和 PHA 的结果显示出一定的诊断性能，但敏感性和特异性中等。T-SPOT.TB 试验中 ESAT-6、CFP-10 和 PHA 的 TBAg/PHA 比值进一步计算显示，在诊断活动性肺结核方面表现出较好的性能。如果采用阈值 0.2004，TBAg/PHA 比值在区分 ATB 和非 TB 方面的特异性和敏感性分别为 92.3%和 74.4%，PPV 为 95.4，PLR 为 9.6。
通过重新计算 T-SPOT.TB 检测结果，TBAg/PHA 比值在高预测地区诊断活动性结核病方面具有较高的应用价值。
