TITLE:
Diagnostic Value of TB-IGRA, PPD, TB-DNA-PCR and TB-Ab in Silicosis Complicated with Tuberculosis
AUTHORS:
Weijia Lin, Zhi Liu, Yaping Zhang, Feng Li, Xiulong Zhang, Zhihua Zhang
KEYWORDS:
TB-IGRA, PPD, TB-DNA-PCR, TB-Ab, Diagnosis
JOURNAL NAME:
Journal of Tuberculosis Research,
Vol.9 No.2,
June
28,
2021
ABSTRACT: Purpose: The purpose of this article is to investigate the clinical value of TB-IGRA (Tuberculosis-Interferon Gamma Release Assay),
PPD (Intradermal Terbuculin Test), TB-DNA-PCR
(Tuberculosis-Deoxyribonucleic-Polymerase Chain Reaction) and TB-Ab (Tuberculosis-Antibody)
in diagnosing silicosis complicated with pulmonary tuberculosis. Methods: 53 cases of suspected silicosis complicated with pulmonary tuberculosis were
selected in the time span ranging from February 2017 to May 2019. TB-IGRA test,
PPD test, TB-DNA-PCR and TB-Ab detection were performed. The sensitivity, specificity,
positive predictive value and negative predictive value were calculated. Results: Silicosis and pulmonary tuberculosis were diagnosed in
11 cases, with an incidence of 20.75%. The positive rates of TB-IGRA, PPD, TB-DNA-PCR
and TB-Ab were 66.04%, 30.19%, 5.67% and 26.42%, respectively. The sensitivity was
90.91%, 81.82%, 27.27% and 54.55% respectively. The specificity was 42.86%, 80.95%,
100% and 80.95% respectively. The positive predictive values were 28.57%, 50%, 100%
and 42.86% respectively. The negative predictive values were 94.44%, 91.89%, 84%
and 87.18%. The positive rate, sensitivity and negative predictive value of TB-IGRA
were the highest, while the specificity of TB-DNA-PCR was the highest yet with low
positive rate, sensitivity and positive predictive value. Conclusion: The positive rate and sensitivity of TB-IGRA were high, yet with poor specificity,
so it was impossible to judge whether the cases belonged to active pulmonary tuberculosis.
The combination of PPD and TB-DNA-PCR could improve the sensitivity, specificity
and positive predictive value, and the diagnostic accuracy of active pulmonary tuberculosis,
which showed satisfactory clinical value.