ABSTRACT
Objective To evaluate the diagnostic value of interferon-γ release assay of blood and pleural effusion for tuberculous pleurisy.Methods Fifty-six adult patients with suspected tuberculous pleurisy were enrolled in our study.The blood and pleural effusion interferon-γ release assay were measured by T-SPOT.TB test in 38 pleural tuberculosis patients and 18 nontuberculous pleurisy controls.The diagnostic sensitivity,specificity,predictive value of T-SPOT.TB in pleural effusion mononuclear cells (PE-MC) and peripheral mononuclear cells (PBMC) were analyzed.Results The sensitivities and specificities,positive predictive values and negative predictive values,respectively,of the PE-MC and PBMC for diagnosing were as follows:86.5％(95％ confidence interval[CI] 71.2％-95.5％) and 100％(95％CI 90.5％-100％);52.9％(95％CI 27.8％-77.0％) and 35.3％(95％CI 14.2％-61.7％);80.0％(95％CI 64.4％-90.9％) and 77.1％(95％CI 62.7％-88.0％);64.3％(95％CI 35.1％-87.2％) and 100％(95％CI 54.1％-100％).By ROC curve analysis,a cut-off value of 47SFC/2.5 × 105 cells in PE-MC showed a sensitivity of 89.2％ and a specificity of 88.2％.Conclusion T-SPOT.TB in PE-MC could be an accurate diagnostic method for tuberculous pleurisy in TB endemic settings.Moreover,47SFC/2.5 × 105 cells might be the optimal cut-off value for diagnosing tuberculous pleurisy.