P2.01-042 T Cells Subsets with INF-Gamma, TNF-Alpha and ADA in Distinguishing Tuberculous from Malignant Pleural Effusions

Abstract

The differential diagnosis of tuberculous and malignant pleural effusion (PE) is extremely difficult and continues to pose clinical challenges. We aimed to evaluate the utility of pleural fluid Interferon gamma (IFN- γ), Adenosine deaminase (ADA), Tumar necrosis factor-alpha (TNF-a) levels with T cells subsets in differential diagnosis of malignant (MPE) and tuberculous pleural effusions (TPE). Forty patients with pleural effusion (20 tuberculous and 20 malignant) were included in the study. The percentages of CD3 lymphocyte, CD4 lymphocyte and Treg (CD4 CD25) T cells in pleural effusion from patients with tuberculous and malignant pleurisy were determined by flow cytometry. The concentrations of TNF-a, IFN-γ and ADA were simultaneously determined in pleural fluids by enzyme linked immunosorbent assay and colorimetric method. The ADA activity, TNF-a and IFN-g concentration were significantly higher in tuberculous than MPE (84.22±41.47 vs. 23.19±17.93 U/l : P<0.0001, 122.45±47.69 vs. 35.03±31.88 pg/ml : P < 0.0001 and 2.26±1.62 vs. 0.3±0.20 IU/ml : P<0.0001 respectively ). T-cells subsets (CD3 T-cells, CD4 T-cells and T reg cells) were significantly higher in TPE than MPE (76.46% vs. 65.29%; P 0.004, 51.21% vs. 43.50%; P 0.044 and 14.60% vs. 12.43%; P 0.032 respectively). CD3 plus CD4 as well as CD3 plus CD4 plus T reg combinations were all 100% specific for discriminating TPE from MPE. TNF-α plus IFN-γ, TNF-α plus ADA, as well as TNF-α plus IFN-γ plus ADA, were 100% specific for discriminating TPE from MPE. Furthermore, the specificity of combined-diagnostic value of TNF-α, IFN-γ, ADA with T cells subsets was > 95 %. The combinations of pleural fluid IFN-γ, ADA, TNF-a levels and T cells subsets could effectively address the challenge of distinguishing tuberculous pleural effusion from malignant pleural effusion.