AbstractBackground and objective:
Early diagnosis of tuberculous pleural effusion (TPE) remains difficult. While some inflammatory markers in pleural effusion (PE) are helpful in diagnosis, the roles of anti-inflammatory cytokines and effector molecules of cytotoxic T lymphocytes have not been investigated.Methods:
Lymphocyte-predominant exudative PE samples were assayed for inflammatory and anti-inflammatory cytokines and effector molecules of cytotoxic T lymphocytes. Logistic regression analysis was used to predict the probability of TPE and identify independently associated factors. Receiver operating characteristic (ROC) curve analysis was applied to determine the optimal cut-off value for the predicted probability.Results:
Of 95 patients enrolled, 35 had TPE, 46 had malignant PE and 14 had PE due to other aetiologies. Interferon-γ (IFN-γ), adenosine deaminase (ADA), decoy receptor (DcR) 3, monocyte chemo-attractant protein (MCP)-1, IFN-induced protein (IP)-10, granzyme A and perforin were higher in TPE than in PE of other aetiologies. By logistic regression analysis, IFN-γ ≥ 75 pg/mL, ADA ≥ 40 IU/mL, DcR3 ≥ 9.3 ng/mL and soluble tumour necrosis factor receptor 1 (TNF-sR1) ≥ 3.2 ng/mL were independent factors associated with TPE. The predicted probability based on the four predictors had an area under the ROC curve of 0.920, with 82.9% sensitivity and 86.7% specificity under the cut-off value of 0.303. In the TPE group, patients with positive PE/pleural culture forMycobacterium tuberculosishad higher pleural IFN-γ, MCP-1, IP-10 and perforin than those with positive sputum but negative PE culture.Conclusions:
While pleural interferon-γ and ADA are conventional markers for diagnosing TPE, simultaneous measurements of DcR3 and TNF-sR1 can improve the diagnostic efficacy.SUMMARY AT A GLANCE
Early diagnosis of tuberculous pleural effusion remains difficult. Measuring pleural interferon-γ, adenosine deaminase, decoy receptor 3 and soluble tumour necrosis factor receptor-1 together can improve the low sensitivity of assaying either interferon-γ or adenosine deaminase alone, and may avoid pleural biopsy which is in some patients a high-risk procedure.