Comparison of the tuberculin skin test and interferon-γ release assay for the diagnosis of latent tuberculosis infection before kidney transplantation.

PURPOSE: The evaluation of latent tuberculosis infection (LTBI) is recommended before kidney transplantation. The interferon-γ release assay has been reported to be more specific than the tuberculin skin test (TST) for detecting LTBI. We compared the TST and QuantiFERON-TB Gold In-Tube test (QFT-GIT) for the screening for LTBI and determined the agreement between the two tests in renal transplant recipients before transplantation.

METHODS

Adult patients who were evaluated for renal transplantation between May 2010 and February 2012 at Severance Hospital in South Korea were prospectively enrolled. We performed TST and QFT-GIT.

RESULTS

Of the 126 patients, 23 (19.3 %) had positive TST results and 53 (42.1 %) had positive QFT-GIT results. Agreement between the TST and QFT-GIT was fair (κ = 0.26, P < 0.001). The induration size of TST was significantly correlated with a positive rate of QFT-GIT (P = 0.015). Age (odds ratio [OR] 1.08, 95 % confidence interval [CI] 1.03-1.13, P = 0.003), male sex (OR 2.73, 95 % CI 1.17-6.38, P = 0.021), and risk for LTBI (OR 4.62, 95 % CI 1.15-18.64, P = 0.031) were significantly associated with positive QFT-GIT results. For positive TST results, only male sex was associated (OR 4.29, 95 % CI 1.40-13.20, P = 0.011).

CONCLUSION

The positivity for QFT-GIT was higher than the positivity for TST, and QFT-GIT more accurately reflected the risk for LTBI. However, a further longitudinal study is needed in order to confirm that the QFT-GIT test can truly predict the development of TB after renal transplantation.