DOI: 10.36347/sjams.2017.v05i11.032

Pages: 4467-4471

The diagnosis of tuberculous pleural effusion (TPE) depends on the demonstration of tubercle bacilli in pleural fluid, a pleural biopsy specimen, or the demonstration of granulomas in the pleura. Since pleural tissue sampling is more difficult than simple thoracocentesis, pleural fluid markers of TPE like Adenosine deaminase (ADA) have been extensively evaluated as an attractive alternative to pleural biopsy. Gene Xpert Mycobacterium tuberculosis (MTB) assay is an automated system which employs real-time PCR and molecular probes to determine the presence of M. tuberculosis complex DNA rapidly and with high accuracy. The aim of this study was to investigate the utility of the Xpert MTB assay for diagnosing pleural TB from pleural fluid. The study population consisted of 146 probable patients of tuberculous pleural effusion admitted in Chest & TB ward of SHKM GMC, Nalhar. Pleural fluid was obtained during thoracocentesis. The sample was divided equally into three parts and sent for Gene Xpert analysis, AFB microscopy and for Bactec Mycobacteria growth indicator tube (MGIT-960) culture. Analysis was carried out by comparing the tuberculous pleural effusion positive by Bactec MGIT-960 culture with that of gene Xpert result. 146 pleural fluid samples from patients with probable tuberculous pleural effusion were tested by the Xpert MTB assay and the Bactec MGIT-960 culture system. Of these, 40 were positive in the MGIT-960 culture, and 21, in the Xpert MTB assay. The sensitivity and specificity of the Xpert MTB compared with the MGIT culture were 52.5% and 100%, respectively, Positive Predicted Value (PPV) of 100%, Negative Predicted Value (NPV) 84.8% and negative Likelihood Ratio (LR) of .47. The results of present study show that Gene Xpert MTB assay could come to play a significant role in routine tubercular pleural effusion diagnosis, where resources of pleural fluid culture are limited and time consuming and case burden is high. Results of Gene Xpert MTB are availabl