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Evaluation of real-time PCR of patient pleural effusion for diagnosis of tuberculosis

Franciele Rosso1, Candice T Michelon2, Rosa D Sperhacke3, Mirela Verza2, Liliane Olival4, Marcus B Conde4, Renata L Guerra4, Arnaldo Zaha1 and Maria LR Rossetti25*

Author Affiliations

1 Programa de Pós Graduação em Biologia Celular e Molecular - Universidade Federal do Rio Grande do Sul - Av. Bento Gonçalves, 9500, Cx. Postal 15005, ZIP code: 91501-970 - Porto Alegre, Brazil

2 Centro de Desenvolvimento Científico e Tecnológico, Fundação Estadual de Produção e Pesquisa em Saúde - Av. Ipiranga, 5400, ZIP code: 90610-000, Porto Alegre, Brazil

3 Laboratório de Pesquisa em HIV1AIDS, Centro de Ciências da Saúde, Universidade de Caxias do Sul - Rua Francisco Getúlio Vargas, 1130, Bloco S, Sala 315, ZIP code: 95070-560, Caxias do Sul, Brazil

4 Instituto de Doenças do Tórax, Universidade Federal do Rio de Janeiro - Rua Professor Rodolpho Paulo Rocco, 255, 6° andar, ZIP code: 21941-913, Rio de Janeiro, Brazil

5 Universidade Luterana do Brasil - Av. Farroupilha, 8001, ZIP code: 92425-900, Canoas, Brazil

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BMC Research Notes 2011, 4:279  doi:10.1186/1756-0500-4-279

Published: 5 August 2011



Pleural tuberculosis (TB) diagnosis often requires invasive procedures such as pleural biopsy. The aim of this study was to evaluate the role of real-time polymerase chain reaction (PCR) for the IS6110 sequence of M. tuberculosis in pleural fluid specimens as a rapid and non-invasive test for pleural TB diagnosis.


For this cross-sectional study, 150 consecutive patients with pleural effusion diagnosed by chest radiography, who were referred for diagnostic thoracocentesis and pleural biopsy and met eligibility criteria, had a pleural fluid specimen submitted for real-time PCR testing. Overall, 98 patients had pleural TB and 52 had pleural effusion secondary to other disease. TB diagnosis was obtained using acid-fast bacilli (AFB) smear or culture for mycobacteria and/or histopathologic examination in 94 cases and by clinical findings in 4 cases. Sensitivity, specificity, positive and negative predictive values of PCR testing for pleural TB diagnosis were 42.8% (95% CI 38.4 - 44.8), 94.2% (95% CI 85.8 - 98.0), 93.3% (95% CI 83.6 - 97.7), and 48.5% (95% CI 44.2 - 50.4), respectively. The real-time PCR test improved TB detection from 30.6% to 42.9% when compared to AFB smear and culture methods performed on pleural fluid specimens, although the best sensitivity was achieved by combining the results of culture and histopathology of pleural tissue specimens.


The real-time PCR test of pleural fluid specimens is a useful and non-invasive additional assay for fast diagnosis of pleural TB.