Diagnostic accuracy of interferon-gamma in differential diagnosis between tubercular pleural effusion and malignant pleural effusion

In India, most Common cause of pleural effusion is tuberculosis followed by malignancy. Aim of
present study was to evaluate IFN-gamma in tubercular and malignant pleural pleural effusion by
ELISA method to know its diagnostic accuracy in differentiating both conditions. This observational
and case‐control study was conducted between june2015 to august 2016. 31 patients of Tubercular
pleural effusion and 31 of Malignant pleural effusion were taken in the study. Concenteration of IFNgamma in pleural fluid was measured by ELISA-kit. Mean age of tubercular pleural effusion patients
was significantly lower [33.2±17.1 years, (p<.001)] as compared to malignancy [56.4± 13.3
years].Mean value of interferon-gamma (617.0pg/ml) was significantly high in tubercular effusion
(p<.001). Cut off level of interferon-gamma was decided to 15 pg/ml by ROC curve analysis. About
80.6% patients of tubercular effusion hadinterferon-gamma above 15 pg/ml. Sensitvity was (80.65%),
specificity was (96.77%), positive predictive value was (96.15%), negative predictive value was
(83.33%) and the diagnostic accuracy was 88.71%.Thus our study concludes that Interferon-gamma
concenteration in pleural fluid can be used as arapid precise diagnostic test in differentiating
tubercular from malignant pleural effusion.