Kyung-Wook Jo and Kyeongman Jeon contributed equally to this work.
Poor correlation between tuberculin skin tests and interferon-γ assays in close contacts of patients with multidrug-resistant tuberculosis
Article first published online: 21 SEP 2012
© 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology
Volume 17, Issue 7, pages 1125–1130, October 2012
How to Cite
JO, K.-W., JEON, K., KANG, Y. A., KOH, W.-J., KIM, K. C., KIM, Y. H., YOO, K. H., LEE, S. H., YIM, J.-J., CHOI, S. B., CHOI, W.-I., CHOI, J. C., HWANG, Y. I. and SHIM, T. S. (2012), Poor correlation between tuberculin skin tests and interferon-γ assays in close contacts of patients with multidrug-resistant tuberculosis. Respirology, 17: 1125–1130. doi: 10.1111/j.1440-1843.2012.02218.x
- Issue published online: 21 SEP 2012
- Article first published online: 21 SEP 2012
- Accepted manuscript online: 4 JUL 2012 02:35AM EST
- Received 6 December 2011; Invited to revise 23 January 2012; revised 8 March 2012; accepted 21 April 2012 (Associate Editor: Chi Chiu Leung).
- close contact;
- interferon-γ assay;
- multi-drug-resistant tuberculosis;
- tuberculin skin test
Background and Objective: The results of tuberculin skin tests (TST) and QuantiFERON TB-Gold In-Tube (QFT-GIT) assays were compared in close contacts of patients with multidrug-resistant tuberculosis (MDR-TB).
Methods: Close contacts of patients with bacteriologically confirmed MDR-TB (n = 101) were assessed. Most contacts were members of the households of patients, and 79 (78.2%) had received Bacille Calmette-Guerin (BCG) vaccination. Samples from each contact were tested using the TST and the QFT-GIT assay on the same day, and the concordance between these results was assessed using kappa (κ) coefficients.
Results: Forty-eight subjects (47.5%) showed positive responses on TST, using a 10-mm induration cut-off, and 54 (53.5%) were positive for the QFT-GIT assay. Of the 48 individuals who were TST positive, 34 (70.8%) were positive for the QFT-GIT assay. Of the 53 subjects who were TST negative, 33 (62.5%) were negative for the QFT-GIT assay. The overall agreement between the two tests (κ coefficient) was 0.33. The κ coefficient was higher in the 22 subjects who had not received BCG vaccination (κ = 0.48) than in the 79 subjects who had received BCG vaccination (κ = 0.29).
Conclusion: The TST and QFT-GIT assays showed poor correlation in close contacts of patients with MDR-TB, especially those contacts who had received BCG vaccination.