Efficacy of cartridge based nucleic acid amplification test to diagnose tubercular pleural effusion

• Published in: International journal of research in medical sciences Vol. 5; no. 8; p. 3637
• Main Authors: Gupta, Prem P., Mynalli, Adarsh B., Yadav, Aparna
• Format: Journal Article
• Language: English
• Published: 26.07.2017
• ISSN: 2320-6071; 2320-6012
• DOI: 10.18203/2320-6012.ijrms20173577

Background: Tuberculosis (TB) remains a major health concern worldwide. Extra pulmonary tuberculosis (EPTB) in India accounts up to 20% of all tuberculosis cases. EPTB often remains undetected and untreated due to variable clinical presentation and lack of diagnostic means. Early detection of TB and drug resistance is important in the management of TB. The aim of present study was to assess the role of cartridge based nucleic acid amplification test in rapid diagnosis of tubercular pleural effusion.Methods: The study screened 211 symptomatic patients. The patients with clinical and radiological presentations suggestive of pleural effusion were analyzed using light’s criteria to make a diagnosis of tubercular pleural effusion; these patients submitted pleural fluid sample for smear microscopy after concentration for presence of acid fast bacilli under light emitting diode based fluorescent microscopy (LED-FM), and for cartridge based nucleic acid amplification test (CBNAAT) using GX4 GeneXpert MTB/Rif test system. The results were statistically analyzed.Results: Out of patients who had pleural effusion without any pulmonary tuberculosis, pleural fluid biochemistry analyses using light’s criteria detected 20 tubercular pleural effusions (11 male and 9 female). Seven patients had history of extrapulmonary tuberculosis in past, all of them received treatment with effective treatment compliance in past. Pleural fluid microscopic examination for detection of acid-fast bacilli was not able to detect acid-fast bacilli in any of these 20 patients diagnosed with tubercular pleural effusion. CBNAAT could authentically detect M. tuberculosis in 5/20 patients diagnosed with tubercular pleural effusion. There was no impact of gender, previous history of tuberculosis, history of anti-tuberculosis treatment (ATT) intake, or compliance to ATT on CBNAAT status in this study.Conclusions: CBNAAT has the potential to significantly authenticate tubercular etiology in some of smear-negative pleural fluid specimens with rapid test results. It has an added advantage to assess the rifampicin drug sensitivity. All this contribute hugely in diagnosis and management of tubercular pleural effusion.