Abstract: ObjectiveTo explore the diagnostic value of adenosine deaminase (ADA) activity, IFN-γ level and Tb-Ab-IgG expression in tuberculous pleurisy. MethodsFifty-six patients with tubercular pleural effusion, 20 patients with malignant pleural effusion and 12 patients with other pleural effusion were recruited. ADA activity, IFN-γ level and TB-Ab-IgG were detected from pleural effusion and peripheral blood among these patients.ResultsThe mean levels of ADA, IFN-γ in tubercular pleural effusion were (50.98±13.07)U/L and (139.46±70.43)pg/ml.They were significantly higher than those in malignant effusion which were (10.88±9.22)U/L and (12.15±9.31)pg/ml respectively (P<0.001),and significantly higher than those in the other pleural effusion too(P<0.001). The positive rate of TB-Ab-IgG in tubercular pleural effusion were 60.7%, it was significantly higher than that in other two groups(P<0.05). When 45U/L was regarded as cut off value for ADA,the sensitivity and specificity for ADA in the diagnosis of tuberculous pleurisy were 80.4% and 96.9% respectively. The coincidence rate of clinical diagnosis was 86.4%. If 100 pg/ml was regarded as cut off value for IFN-γ in tubercular pleural effusion, the sensitivity and specificity were 83.9% and 93.8% respectively. The coincidence rate of clinical diagnosis was 87.5%. The sensitivity and specificity for TB-Ab-IgG were 60.7% and 87.5%. The coincidence rate of clinical diagnosis was 70.5%. The combined detection of the three markers for diagnosis of tuberculous pleurisy had a sensitivity of 92.9% and a specificity of 100%. The coincidence rate of clinical diagnosis was 95.5%. ConclusionThe accuracy of diagnosis for tuberculous pleurisy was significantly improved with combined detection of ADA, IFN-γ and TB-Ab-IgG.

Key words: tuberculosis，pleural/diagnosis, adenosine deaminase, interferon type Ⅱ, Mycobacterium tuberculosis, immunoglobulin G