Interferon-Gamma Release Assay is Not Appropriate for the Diagnosis of Active Tuberculosis in High-Burden Tuberculosis Settings: A Retrospective Multicenter Investigation.

Wan-li Kang; Gui-rong Wang; Mei-ying WU; Kun-yun Yang; A Er-tai; Shu-cai WU; Shu-jun Geng; Zhi-hui LI; Ming-wu LI; Liang LI; Shen-jie Tang

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Interferon-Gamma Release Assay is Not Appropriate for the Diagnosis of Active Tuberculosis in High-Burden Tuberculosis Settings: A Retrospective Multicenter Investigation.

Author: Wan-Li KANG ¹ ; Gui-Rong WANG ² ; Mei-Ying WU ³ ; Kun-Yun YANG ⁴ ; A ER-TAI ⁵ ; Shu-Cai WU ⁶ ; Shu-Jun GENG ⁶ ; Zhi-Hui LI ⁶ ; Ming-Wu LI ⁷ ; Liang LI ⁸ ; Shen-Jie TANG ⁸
Author Information

1. Epidemiology Research Department, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing 101149, China.
2. Tuberculosis Clinical Laboratory, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing 101149, China.
3. Department of Tuberculosis, Souzhou 5th-+- People's Hospital, Souzhou, Jiangsu 215007, China.
4. Department of Tuberculosis, Hunan Chest Hospital, Changsha, Hunan 410013, China.
5. Department of Tuberculosis, Chest Hospital of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang 830049, China.
6. Department of Tuberculosis, Hebei Chest Hospital, Shijiazhuang, Hebei 050041, China.
7. Department of Tuberculosis, Kunming 3rd People's Hospital, Kunming, Yunnan 650041, China.
8. Department of Tuberculosis, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing 101149, China.
Publication Type:Journal Article
From: Chinese Medical Journal 2018;131(3):268-275
CountryChina
Language:English
Abstract:
BACKGROUNDInterferon-gamma release assay (IGRA) has been used in latent tuberculosis (TB) infection and TB diagnosis, but the results from different high TB-endemic countries are different. The aim of this study was to investigate the value of IGRA in the diagnosis of active pulmonary TB (PTB) in China.
METHODSWe conducted a large-scale retrospective multicenter investigation to further evaluate the role of IGRA in the diagnosis of active PTB in high TB-epidemic populations and the factors affecting the performance of the assay. All patients who underwent valid T-SPOT.TB assays from December 2012 to November 2015 in six large-scale specialized TB hospitals in China and met the study criteria were retrospectively evaluated. Patients were divided into three groups: Group 1, sputum culture-positive PTB patients, confirmed by positive Mycobacterium tuberculosis sputum culture; Group 2, sputum culture-negative PTB patients; and Group 3, non-TB respiratory diseases. The medical records of all patients were collected. Chi-square tests and Fisher's exact test were used to compare categorical data. Multivariable logistic analyses were performed to evaluate the relationship between the results of T-SPOT in TB patients and other factors.
RESULTSA total of 3082 patients for whom complete information was available were included in the investigation, including 905 sputum culture-positive PTB cases, 914 sputum culture-negative PTB cases, and 1263 non-TB respiratory disease cases. The positive rate of T-SPOT.TB was 93.3% in the culture-positive PTB group and 86.1% in the culture-negative PTB group. In the non-PTB group, the positive rate of T-SPOT.TB was 43.6%. The positive rate of T-SPOT.TB in the culture-positive PTB group was significantly higher than that in the culture-negative PTB group (χ2 = 25.118, P < 0.01), which in turn was significantly higher than that in the non-TB group (χ2 = 566.116, P < 0.01). The overall results were as follows: sensitivity, 89.7%; specificity, 56.37%; positive predictive value, 74.75%; negative predictive value, 79.11%; and accuracy, 76.02%.
CONCLUSIONSHigh false-positive rates of T-SPOT.TB assays in the non-TB group limit the usefulness as a single test to diagnose active TB in China. We highly recommend that IGRAs not be used for the diagnosis of active TB in high-burden TB settings.