title: Accuracy of polimerase chain reaction for the diagnosis of pleural tuberculosis.
abstract: BACKGROUND
  Polymerase chain reaction (PCR)-based techniques to detect Mycobacterium tuberculosis DNA in respiratory specimens have been increasingly used to diagnose pulmonary tuberculosis. Their use in non-respiratory specimens to diagnose extrapulmonary tuberculosis is, however, controversial. In this study, we estimated the accuracy of three in-country commercialized PCR-based diagnostic techniques in pleural fluid samples for the diagnosis of pleural tuberculosis.
  
  
  METHODS
  Patients underwent thoracenthesis for diagnosis purposes; pleural fluid aliquots were frozen and subsequently submitted to two real time PCR tests (COBAS(®)TAQMAN(®)MTB and Xpert(®)MTB/Rif) and one conventional PCR test (Detect-TB(®)). Two different reference standards were considered: probable tuberculosis (based on clinical grounds) and confirmed tuberculosis (bacteriologically or histologically).
  
  
  RESULTS
  Ninety-three patients were included, of whom 65 with pleural tuberculosis, 35 of them confirmed. Sensitivities were 29% for COBAS(®)TAQMAN(®)MTB, 3% for Xpert(®)MTB/Rif and 3% for Detect-TB(®); specificities were 86%, 100% and 97% respectively, considering confirmed tuberculosis. Considering all cases, sensitivities were 16%, 3% and 2%, and specificities, 86%, 100%, and 97%.
  
  
  CONCLUSIONS
  Compared to the 95% sensitivity of adenosine deaminase, the most sensitive test for pleural tuberculosis, the sensitivities of the three PCR-based tests were very low. We conclude that at present, there is no major place for such tests in routine clinical use.
authors.affiliation: Graduate Program in Health Education, Gama Filho University, Rio de Janeiro, Brazil; Graduate Program in Internal Medicine, Federal University of Rio de Janeiro, Brazil; McGill University, Montreal Chest Institute, Montreal, Canada. Electronic address: atrajman@gmail.com.
authors.forename: Anete
authors.initials: A
authors.lastname: Trajman
authors.affiliation: Graduate Program in Internal Medicine, Federal University of Rio de Janeiro, Brazil; Tuberculosis Academic Program - Medical School, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Elen Fabricia
authors.initials: EF
authors.lastname: da Silva Santos Kleiz de Oliveira
authors.affiliation: Graduate Program in Health Education, Gama Filho University, Rio de Janeiro, Brazil. Electronic address: mayara_bastos@yahoo.com.br.
authors.forename: Mayara Lisboa
authors.initials: ML
authors.lastname: Bastos
authors.affiliation: Medical School, Souza Marques Foundation, Rio de Janeiro, Brazil.
authors.forename: Epaminondas
authors.initials: E
authors.lastname: Belo Neto
authors.affiliation: Clemente Ferreira Institute, São Paulo, Brazil.
authors.forename: Edgar Manoel
authors.initials: EM
authors.lastname: Silva
authors.affiliation: Evandro Chagas Clinical Research Institute, Fiocruz, Rio de Janeiro, Brazil.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: da Silva Lourenço
authors.affiliation: Graduate Program in Internal Medicine, Federal University of Rio de Janeiro, Brazil; Tuberculosis Academic Program - Medical School, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Afrânio
authors.initials: A
authors.lastname: Kritski
authors.affiliation: Tuberculosis Academic Program - Medical School, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Martha Maria
authors.initials: MM
authors.lastname: Oliveira
mesh_terms: D000328:Adult; D004269:DNA, Bacterial / Q000302:isolation & purification; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D016133:Polymerase Chain Reaction / Q000592:standards*; D012680:Sensitivity and Specificity; D014396:Tuberculosis, Pleural / Q000175:diagnosis*
chemical_list: D004269:DNA, Bacterial
keywords: Diagnosis; Nucleic acid amplification techniques; Pleural; Polymerase chain reaction; Tuberculosis