title: The performance of an in-house nested-PCR technique for pleural tuberculosis diagnoses.
abstract: BACKGROUND
  This study evaluated the performance of an in-house nested-PCR system for the detection of the Mycobacterium tuberculosis complex in pleural fluid, blood and urine samples from pleural effusion tuberculosis patients by health services physicians in Pernambuco, Brazil.
  
  
  METHODS
  A prospective double-blind study with 37 hospitalized patients of both sexes, aged over 15, was used to investigate the diagnosis of pleural effusion. The criteria used to define the cases included the demonstration of bacillus in biological samples by smear or culture or by a granulomatous finding in the histopathological examination, associated with an evident response to specific treatments to each clinical situation. Pleural fluid, blood and urine samples were collected and subjected to routine tests and the nested PCR technique to assess for M. tuberculosis amplification.
  
  
  RESULTS
  In total, 37 pleural effusion patients took part in the study, of whom 19 (51.3%) had tubercular etiologies and 18 (48.7%) had etiologies from other causes. When the pleural fluid, blood and/or urine sample in-house nested-PCR sensitivities were evaluated simultaneously, the results were positive regardless of the biological specimen (the sensitivity was 84.2%); however, when the blood and/or urine samples were analyzed together, the sensitivity was 72.2%. When the pleural fluid samples were evaluated alone, the sensitivity was only 33.3%.
  
  
  CONCLUSIONS
  The performance of the diagnostic pleural tuberculosis nested-PCR was directly related to the diversity of the samples collected from the same patient. Additionally, this study may identify a need to prioritize non-invasive blood and urine collection for this diagnosis.
authors.affiliation: Centro de Pesquisas Aggeu Magalhães, Departamento de Imunologia, RecifePE.
authors.forename: Lílian Maria Lapa
authors.initials: LM
authors.lastname: Montenegro
authors.forename: Bruno César da
authors.initials: BC
authors.lastname: Silva
authors.forename: Juliana Figueirêdo da Costa
authors.initials: JF
authors.lastname: Lima
authors.forename: Heidi Lacerda Alves da
authors.initials: HL
authors.lastname: Cruz
authors.forename: Rosana de Albuquerque
authors.initials: Rde A
authors.lastname: Montenegro
authors.forename: Fernando Luiz Cavalcanti
authors.initials: FL
authors.lastname: Lundgren
authors.forename: Alfredo Pereira Leite de
authors.initials: AP
authors.lastname: Albuquerque Filho
authors.forename: Haiana Charifker
authors.initials: HC
authors.lastname: Schindler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004269:DNA, Bacterial / Q000032:analysis; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D010996:Pleural Effusion / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014396:Tuberculosis, Pleural / Q000097:blood / Q000175:diagnosis* / Q000652:urine; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial