Abstract
BACKGROUND: No head-to-head studies have simultaneously compared the performances of QuantiFERON-TB Gold In-Tube (QFT-GIT), QuantiFERON-TB Gold Plus (QFT-Plus), ESAT6-CFP10 (EC) skin test, and Tuberculin skin test (TST) in adolescents. This study aimed to conduct a comparative assessment of QFT-GIT and QFT-Plus for detecting Mycobacterium tuberculosis(Mtb) infection in high school freshmen. METHODS: We concurrently administered QFT-GIT, QFT-Plus, EC skin test, and TST to first-year high school students. Blood samples were obtained for the QFT-GIT and QFT-Plus assays before the administration of the EC skin test and TST. The diagnostic values were compared. Discrepancies between the tests were quantified using Cohen's kappa coefficient. RESULTS: A total of 787 freshmen were recruited in this study. Among 787 subjects, EC was positive in 0.8%, TST in 5.3%, QFT-GIT in 1.1%, and QFT-Plus in 3.2%. Overall agreements for QFT-GIT vs. QFT-Plus, QFT-Plus TB1, and QFT-Plus TB2 were 95.7% (95% CI, 94.0-97.0), 97.3% (95% CI, 95.9-98.3), and 95.9% (95% CI, 94.3-97.2), respectively. Cohen's kappa values were 0.485 (95% CI, 0.319-0.621), 0.593 (95% CI, 0.413-0.744), and 0.451 (95% CI, 0.274-0.600). Consistency rates for QFT-GIT, QFT-Plus, EC skin test, and TST were 96.6% (95% CI, 95.0, 97.0), 92.1% (95% CI, 89.0, 94.0), 94.5% (95% CI, 92.6, 96.1), and 91.2% (95% CI, 88.8, 93.1) with Cohen's kappa values of 0.19 (95% CI, -0.01, 0.38), 0.07 (95% CI, -0.02, 0.19), 0.08 (95% CI, -0.01, 0.23), and 0.12 (95% CI, 0.01, 0.21). CONCLUSION: The QFT-GIT and QFT-Plus assays exhibited a high level of agreement but demonstrated a moderate correlation. IFN-γ levels measured by both QFT-GIT and QFT-Plus were comparable. Notably, Our study suggests QFT-Plus may detect a higher rate of Mtb infection among high school freshmen compared to QFT-GIT, EC skin test, and TST, though this requires cautious interpretation due to the absence of a gold standard for Mtb infection diagnosis.