title: Rapid diagnosis of pleural tuberculosis by Xpert MTB/RIF assay using pleural biopsy and pleural fluid specimens.
abstract: BACKGROUND
  Early pleural tuberculosis (TB) diagnosis is particularly difficult. The aim of this study was to investigate the diagnostic accuracy of the Xpert MTB/RIF (Xpert) (Cepheid, Sunnyvale, CA) assay using pleural biopsy and pleural fluid specimens in patients with suspected pleural TB but who had a negative sputum acid-fast bacilli (AFB) smear.
  
  
  METHODS
  In this study, 134 sputum smear-negative suspected pleural TB patients were selected. Paired pleural fluid and pleural biopsy specimens were tested for Mycobacterium tuberculosis by standard smear-microscopy, Lowenstein-Jensen and mycobacterial growth indicator tube (MGIT) culture, and the Xpert assay. Mycobacterial culture from pleural biopsy specimens was used as a reference standard for sensitivity and specificity calculations. Detection of rifampicin resistance was compared with the MGIT method.
  
  
  RESULTS
  Of 126 evaluable patients, 55 received a diagnosis of pleural TB. The sensitivity of the Xpert assay using pleural biopsy specimens for the diagnosis of pleural TB was 85.5%, and specificity was 97.2%. The sensitivity and specificity of the Xpert assay in pleural fluid were 43.6% and 98.6%, respectively. The Xpert assay correctly identified 90.0% of phenotypic rifampicin-resistant cases and 93.9% of phenotypic rifampicin-susceptible cases.
  
  
  CONCLUSIONS
  The Xpert assay on pleural biopsy specimens may provide an accurate diagnosis of pleural TB in patients who had a negative AFB smear.
authors.affiliation: Department of Clinical Laboratory, First Teaching Hospital of Tianjin University of TCM, Tianjin, 300193, China.
authors.forename: Jinghui
authors.initials: J
authors.lastname: Du
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China.
authors.forename: Zikun
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Luo
authors.affiliation: Department of Clinical Laboratory, The Chest Hospital of Jiangxi Province, Nanchang, Jiangxi 330006, China.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Xiong
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China.
authors.forename: Weiting
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Clinical Laboratory, First Teaching Hospital of Tianjin University of TCM, Tianjin, 300193, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China.
authors.forename: Junming
authors.initials: J
authors.lastname: Li
keywords: Diagnosis; Xpert MTB/RIF assay; pleural tuberculosis