Diagnostic value of pleural fluid adenosine deaminase among the patients with pleural tuberculosis

Abstract

Purpose Extra-pulmonary tuberculosis occurs in about 10-20% of patients most commonly 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 cross-sectional study, 113 patients with exudative pleural effusion with unknown underlying diagnosis, were enrolled. Physical examination, chest CT, measurement of ADA level of pleural fluid, direct thoracoscopic examination, and biopsy of pleura were performed for all individuals. Results The diagnosis of tuberculous pleurisy was established in 40 individuals regarding the pathology report of biopsy samples. 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, which was not statistically significant (P-value=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 on low sensitivity and specificity of ADA test, in patients with unexplained exudative pleural effusion especially in those who were suspicious for tuberculous pleurisy, despite the low level of ADA, direct thoracoscopic pleural observation and multiple biopsies of pleura is highly recommended.

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

“…Chest Radiography of these patients shows a small to moderate unilateral pleural effusion which is lymphocyte dominant in serologic evaluations. The condition also could be bilateral within the minority of cases [1,3]. The prevalence of tuberculosis among all patients with pleural effusion is between 4-22%, and pleura is involved in 3-23% of patients with tuberculosis [4,5].…”

“…Different diagnostic methods have been used to diagnose pleural tuberculosis, including thoracentesis, measurement of serum and pleural fluid adenosine deaminase (ADA) level, pleural biopsy, and thoracoscopy assisted pleural examination and biopsy [3].…”