Diagnostic performance of the QuantiFERON-TB Gold In-Tube assay and factors associated with nonpositive results in patients with miliary tuberculosis.

The QuantiFERON-TB Gold In-Tube (QFT-GIT) assay provides suboptimal diagnostic performance in patients with miliary tuberculosis. QFT-GIT results should be carefully interpreted, particularly in patients suspected of having miliary tuberculosis with severe lymphocytopenia or an extent of ground glass opacity (GGO) >50% on chest computed tomography (CT). Diagnostic performance of the QFT-GIT assay was evaluated in 44 patients with miliary tuberculosis. Among these individuals, 30 (68%) had true-positive QFT-GIT results. Severe lymphocytopenia and an extent of GGO >50% on chest CT were independent risk factors for nonpositive QFT-GIT results.