Assessment of the N-PCR assay in diagnosis of pleural tuberculosis: detection of M. tuberculosis in pleural fluid and sputum collected in tandem

• Published in: PloS one 2010-04, Vol.5 (4), p.e10220-e10220
• Main Authors: Kumar, Parameet, Sen, Manas K, Chauhan, Devendra S, Katoch, Vishwa M, Singh, Sarman, Prasad, Hanumanthappa K
• Format: Article
• Language: English
• Subjects: Humans; Mycobacterium tuberculosis - isolation & purification; Pleural Effusion - microbiology; Polymerase Chain Reaction - methods; Polymerase Chain Reaction - standards; Sensitivity and Specificity; Sputum - microbiology; Tuberculosis, Pleural - diagnosis
• ISSN: 1932-6203
• DOI: 10.1371/journal.pone.0010220

The nonspecific clinical presentation and paucibacillary nature of tuberculous pleuritis remains a challenge for diagnosis. Diagnosis of tuberculous pleural effusion depends on the demonstration of the presence of tubercle bacilli in the sputum, pleural fluid, or pleural biopsy specimen, or demonstration of granuloma in pleura by histological examination. We examined the clinical utility of the diagnosis of pleural tuberculosis using the in house N-PCR assay, AFB smear microscopy and culture. Besides pleural fluid the inclusion of sputum in the efficacy of diagnosis of pleural tuberculosis was scrutinized. Pleural fluid and sputum samples of 58 tuberculous and 42 non-tuberculous pleural effusion patients were processed for AFB smear microscopy, culture and the N-PCR assay. Mycobacteria were detected exclusively in tuberculous pleural effusion samples. None of the non-tuberculous pleural effusion samples were positive for mycobacteria. Comparative analysis showed that the N-PCR assay had the highest sensitivity. Inclusion of sputum along with pleural fluid increased N-PCR sensitivity from 51.7 to 70.6% (p