title: Diagnostic accuracy of Xpert® MTB/RIF on bronchoscopy specimens in patients with suspected pulmonary tuberculosis.
abstract: OBJECTIVE
  To determine the diagnostic accuracy of the Xpert® MTB/RIF assay using samples obtained through bronchoscopy in patients with suspected pulmonary tuberculosis (PTB).
  
  
  METHODS
  We retrospectively reviewed the records of patients with suspected PTB for whom the Xpert MTB/RIF assay was performed on bronchoscopy specimens. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the diagnosis of active PTB were calculated for acid-fast bacilli (AFB) smear microscopy and the Xpert assay using culture of Mycobacterium tuberculosis from sputum or bronchoscopy specimens as a reference standard.
  
  
  RESULTS
  A total of 132 patients were included in the final analysis. Of these, 38 had culture-confirmed PTB. The sensitivity of the Xpert assay using bronchial washing or bronchoalveolar lavage (BAL) fluid for the diagnosis of PTB was 81.6%, and specificity was 100%. The PPV and NPV were 100% and 92.1%, respectively. The sensitivity and specificity of AFB smear microscopy were respectively 13.2% and 98.8%.
  
  
  CONCLUSIONS
  The Xpert assay on bronchoscopy specimens provided an accurate diagnosis of PTB in patients who had a negative AFB smear or who could not produce sputum.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: H Y
authors.initials: HY
authors.lastname: Lee
authors.forename: M W
authors.initials: MW
authors.lastname: Seong
authors.forename: S S
authors.initials: SS
authors.lastname: Park
authors.forename: S-S
authors.initials: SS
authors.lastname: Hwang
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.forename: Y S
authors.initials: YS
authors.lastname: Park
authors.forename: C H
authors.initials: CH
authors.lastname: Lee
authors.forename: S-M
authors.initials: SM
authors.lastname: Lee
authors.forename: C-G
authors.initials: CG
authors.lastname: Yoo
authors.forename: Y W
authors.initials: YW
authors.lastname: Kim
authors.forename: S K
authors.initials: SK
authors.lastname: Han
authors.forename: J-J
authors.initials: JJ
authors.lastname: Yim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001431:Bacteriological Techniques / Q000379:methods*; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D001999:Bronchoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology; D055815:Young Adult