Diagnostic performance of interferon-γ release assay for lymph node tuberculosis

Abstract The aim of the study was to evaluate the performance of interferon-γ (IFN-γ) release assay (IGRA) (T-SPOT. TB ) for patients with suspected lymph node tuberculosis (TB). Of the 405 patients with suspected lymph node TB, enrolled from Beijing Chest Hospital between July 2011 and April 2015, 83 (20.5%) were microbiologically/histopathologically confirmed lymph node TB, and 282 (69.6%) did not have active TB. The remaining 21 inconclusive TB and 19 clinical TB were excluded from the final analysis (9.9%). T-SPOT. TB using peripheral blood mononuclear cells was performed to examine the IFN-γ response to the Mycobacterium tuberculosis –specific antigens early secretory antigenic target 6 and culture filtrate protein 10. The overall sensitivity and specificity for T-SPOT. TB were 90.4% and 70.5%, respectively. Spot-forming cells in the lymph node TB group (184 [48–596/10 6 peripheral blood mononuclear cells {PBMCs}]) were significantly higher than that in the nonactive TB group (0 [0–41]/10 6 PBMCs) ( P