Published: 2018-01-18

The advantage of PCR for MTB in comparison to ADA in diagnosing tubercular pleural effusion

Abhishek Agarwal, Ahbab Hussain, Rajendra Prasad, Anand Verma, Amitabh Banka, Tasleem Raza


Background: Tuberculosis continues to be an important health problem globally. The bacteriological confirmation of diagnosis in extrapulmonary tuberculosis patients is more difficult because most of the cases of extrapulmonary tuberculosis are paucibacillary in nature. In this study we have compared the pleural fluid ADA levels with PCR for MTB in pleural fluid to confirm the diagnosis of tuberculosis in the pleural fluid.

Methods: The study was done over two years and a total of 106 patients with a clinico-radiological diagnosis of pleural effusion were enrolled for the study. The pleural fluid was aspirated and examined for total cell count, differential cell count, protein, sugar, ADA and PCR for MTB.A CT Thorax was done in all the 106 patients of pleural effusion and underlying consolidation along with pleural effusion was found in 60 patients.

Results: The pleural fluid was exudative in nature in all the patients. 90 patients (84.9%) had lymphocyte predominant pleural effusion while 16 patients (15.1%) had neutrophil predominant pleural effusion. The overall sensitivity of ADA in all the cases of pleural effusion was 85.2% while the overall sensitivity of PCR for MTB in all the cases of pleural effusion was 51.1%. However, in the 60 patients of pleural effusion with underlying lung consolidation, the overall sensitivity of ADA was 69.1% while the overall sensitivity of PCR for MTB was 92.8% for diagnosing tubercular pleural effusion.

Conclusions: PCR for MTB is a useful test along with ADA for diagnosing tubercular pleural effusion. PCR for MTB is especially useful in the diagnosis of tubercular pleural effusion in patients with underlying lung consolidation.



ADA, PCR for MTB, Pleural effusion, Tuberculosis

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