title: Evaluation of real-time PCR of patient pleural effusion for diagnosis of tuberculosis.
abstract: BACKGROUND
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  The real-time PCR test of pleural fluid specimens is a useful and non-invasive additional assay for fast diagnosis of pleural TB.
authors.affiliation: Centro de Desenvolvimento Científico e Tecnológico, Fundação Estadual de Produção e Pesquisa em Saúde - Av, Ipiranga, 5400, ZIP code: 90610-000, Porto Alegre, Brazil. mrossett@terra.com.br.
authors.forename: Franciele
authors.initials: F
authors.lastname: Rosso
authors.forename: Candice T
authors.initials: CT
authors.lastname: Michelon
authors.forename: Rosa D
authors.initials: RD
authors.lastname: Sperhacke
authors.forename: Mirela
authors.initials: M
authors.lastname: Verza
authors.forename: Liliane
authors.initials: L
authors.lastname: Olival
authors.forename: Marcus B
authors.initials: MB
authors.lastname: Conde
authors.forename: Renata L
authors.initials: RL
authors.lastname: Guerra
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Zaha
authors.forename: Maria Lr
authors.initials: ML
authors.lastname: Rossetti