Abstract:Background: pleural TB is a diagnostic challenge because of its nonspecific clinical manifestation. The efficiency of conventional laboratory method and the reliance on pleural biopsy have motivated the evaluation of alternative diagnostic strategies. The objective of the current study is to evaluate the diagnostic efficiency of IFN-γ and sIL-2R levels in pleural effusion for differential diagnosis of tuberculous pleurisy. Methods: estimated levels of IFN-γ and sIL-2R were compared with the result of conventional PCR and Z-N staining used for detection of M. tuberculosis DNA and acid fast bacilli screening of pleural effusion, respectively. Involved study population included 60 patients with pleural effusion, divided into two groups: Tuberculous group (40 patients: 7 confirmed TB and 33 probable TB cases) and control group (20 patients: 10 cases due to malignancy and 10 cases due to heart failure). Results: our results showed that IFN-γ and sIL-2R levels are significantly higher in tuberculous group than in control group. Conclusion: current study suggested that measurement of IFN-γ and sIL-2R in pleural effusion could be less invasive and quicker diagnostic tools of TPE compared to conventional microbiological diagnostic methods.