Background: Pleural tuberculosis (TB) is one of the most common forms of extra-pulmonary TB. Since diagnosis is challenging through microbiological tests, discovering new diagnostic techniques with higher accuracy could help us improve early detection and lead to better outcomes. This study aims to investigate the sensitivity and specificity of interleukin 27 (IL27) as a diagnostic test for pleural Tuberculosis.
Materials and Methods: The current study was conducted on 121 adult patients admitted to Masih Daneshvari Hospital due to pleural effusion with an unknown cause. 36 cases had transudative, and 85 cases had exudative pleural effusions. Among them, TB (33.1%) and malignant pleurisy (23.1%) were the most common causes. In addition to routine studies for pleural effusion workups, pleural interleukin-27 concentrations were measured by ELISA and compared between groups of TB-affected patients and those without TB.
Results: We found that the value 679 pg/ml was the most appropriate cut-off threshold for interleukin 27 in pleural fluid with 95% sensitivity, 69% specificity, 94% negative predictive value, and 73% positive predictive value (P value<0.001) for diagnosis of TB pleurisy. ADA levels were not significantly different between TB and non-TB cases.
Conclusion: Compared to other groups, interleukin 27 levels in patients with a final diagnosis of TB-pleurisy were significantly higher, indicating the significant value of this interleukin as a diagnostic biomarker.