Amplified mycobacterium tuberculosis direct test for diagnosing tuberculous pleurisy-a diagnostic accuracy study

Abstract

Background: The study was designed to investigate the clinical usefulness of Amplified Mycobacterium Tuberculosis Direct (AMTD) tests for diagnosing TB pleurisy. Methods: One hundred and fifty-two patients for whom the exclusion of tuberculous pleural effusion was necessary were retrospectively analyzed. Results: The sensitivity of AMTD in diagnosing pleural TB was 36.4% (20 of 55). Combining sputum and pleural effusion AFB smear, pleural biopsy, and AMTD test of pleural effusion increased sensitivity to 82.5% (33/40). There were significantly higher percentages of neutrophils in the pleural effusion in the positive than in the negative AMTD group (38.0 ± 6.7% vs. 11.1 ± 3.7%, p<0.001). Patients with symptom duration <18 days prior to pleural effusion studies had more positive AMTD tests than those with symptom >18 days (70% vs. 31.4%; OR 5.09; 95% CI 1.54-16.79; p = 0.011). Conclusions: Combining AMTD tests with conventional diagnostic methods offer good sensitivity for pleural TB diagnosis. Patients in the early course of the disease are better candidates for AMTD tests.