title: Positive predictive value of ELISpot in BAL and pleural fluid from patients with suspected pulmonary tuberculosis.
abstract: BACKGROUND
  The aim of this study was to evaluate the positive predictive value (PPV) of ELISpot in bronchoalveolar lavage (BAL) and pleural fluid for the diagnosis of active tuberculosis (TB) in real-life clinical practice, together with the added value of a cut-off >1.0 for the ratio between the extra-sanguineous and systemic interferon-gamma responses in positive samples.
  
  
  METHODS
  A retrospective, single-centre study was performed. Patients with positive ELISpot in BAL and pleural fluid were included.
  
  
  RESULTS
  The PPV for TB in patients with positive ELISpot in BAL (n = 40) was 64.9%, which increased to 82.6% for the ESAT-6 panel and 71.4% for the CFP-10 panel after the introduction of a cut-off >1.0 for the ratio between the BAL and blood interferon-gamma responses. In patients with positive ELISpot in pleural fluid (n = 16), the PPV for TB was 85.7%, which increased to 91.7% for the ESAT-6 panel and 92.3% for the CFP-10 panel after the introduction of a cut-off >1.0 for the ratio between the pleural fluid and blood interferon-gamma responses.
  
  
  CONCLUSIONS
  This report describes the PPV of ELISpot in BAL and pleural fluid for the diagnosis of active TB in real-life clinical practice. The results indicate the possibility of an increase of the PPV using a cut-off >1.0 for the ratio between the extra-sanguineous and systemic interferon-gamma responses. Further studies are needed to underline this ratio-approach and to evaluate the full diagnostic accuracy of ELISpot in extra-sanguineous fluids like BAL and pleural fluid.
authors.affiliation: a Department of Respiratory Medicine , Diakonessenhuis , Utrecht , The Netherlands.|b Department of Respiratory Medicine , University Medical Centre Utrecht , Utrecht , The Netherlands.
authors.forename: Regina W
authors.initials: RW
authors.lastname: Hofland
authors.affiliation: c Department of Medical Microbiology and Immunology , Diakonessenhuis , Utrecht , The Netherlands.
authors.forename: Steven F T
authors.initials: SF
authors.lastname: Thijsen
authors.affiliation: b Department of Respiratory Medicine , University Medical Centre Utrecht , Utrecht , The Netherlands.
authors.forename: Anne S R
authors.initials: AS
authors.lastname: van Lindert
authors.affiliation: d Department of Tuberculosis , Beatrixoord Haren, University Medical Centre Groningen , Groningen , The Netherlands.
authors.forename: Wiel C M
authors.initials: WC
authors.lastname: de Lange
authors.affiliation: c Department of Medical Microbiology and Immunology , Diakonessenhuis , Utrecht , The Netherlands.
authors.forename: Tamara
authors.initials: T
authors.lastname: van Gorkom
authors.affiliation: e Department of Biostatistics and Research Support , Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht , Utrecht , The Netherlands.
authors.forename: Ingeborg
authors.initials: I
authors.lastname: van der Tweel
authors.affiliation: b Department of Respiratory Medicine , University Medical Centre Utrecht , Utrecht , The Netherlands.
authors.forename: Jan-Willem J
authors.initials: JJ
authors.lastname: Lammers
authors.affiliation: a Department of Respiratory Medicine , Diakonessenhuis , Utrecht , The Netherlands.
authors.forename: Aik W J
authors.initials: AW
authors.lastname: Bossink
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D058501:Enzyme-Linked Immunospot Assay / Q000379:methods*; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D007371:Interferon-gamma
keywords: ELISpot; Tuberculosis; bronchoalveolar lavage; interferon-gamma release assays; pleural fluid