Diagnostic Value of Pleural Fluid Adenosine Deaminase In Patients With Pleural Tuberculosis

Abstract

Fariborz Rousta, Mohsen Sokouti, Samad Beheshty Rouy, Sina Parsay

Background and Objectives: Extra-pulmonary tuberculosis occurs in about 10-20% of patients with tuberculosis. It most commonly manifests as tuberculous lymphadenitis or pleural effusion. Pleural fluid Adenosine deaminase (ADA) activity considered as a useful biomarker for detecting pleural tuberculosis. The purpose of this study was to evaluate the diagnostic accuracy of pleural fluid adenosine deaminase level in patients with pleural tuberculosis.

Methods: In this study, 113 patients with exudative pleural effusion with unknown underlying diagnosis, were enrolled. Phys- ical examination, chest CT, ADA level of pleural fluid, direct thoracoscopic examination, and biopsy of pleura were obtained for all individuals. ADA level and thoracoscipoc appearance of the lesions was then compaierd among the patients with regard to the pleural biopsy report as the diagnostic goldstandard.

Results: The diagnosis of tuberculous pleurisy was established in 40 individuals based on the pathology reports. The mean ADA level of the TB and the non-TB group was 39.90±22.93 IU/L and 30.74±38.27 IU/L, respectively (P-val- ue=0.167). Sensitivity, specificity, positive predictive value, and negative predictive value of ADA test were 35%, 86.30%, 58.33%, and 70.79%, respectively.

Conclusion: Based insuffiecient sensitivity and specificity of ADA, in patients with unexplained exudative pleural effusion espe- cially in those with a high suspicion of tuberculous pleurisy, despite the low level of ADA, direct thoracoscopic pleu- ral evaluation with obtaining multiple biopsies of pleura is highly recommended.

PDF