title: Utility of T-cell interferon-γ release assays for diagnosing tuberculous serositis: a prospective study in Beijing, China.
abstract: BACKGROUND
  Diagnosis of tuberculous serositis remains a challenge. The aim of this study was to evaluate the diagnostic efficiency of T-SPOT.TB on serous effusion mononuclear cells (SEMC) for diagnosing tuberculous serositis in a high TB burden area.
  
  
  METHODS
  The present prospective study enrolled patients with suspected tuberculous serositis in a tertiary referral hospital in Beijing, China, to investigate the diagnostic sensitivity, specificity, predictive value (PV), and likelihood ratio(LR) of these tests. Clinical assessment, T-SPOT.TB on SEMC, and T-SPOT.TB on PBMC were performed. Test results were compared with the final confirmed diagnosis.
  
  
  RESULTS
  Of the 187 participants, 74 (39.6%) were microbiologically or clinically diagnosed as tuberculous serositis and 93(49.7%) were ruled out. The remaining 20 (10.7%) patients were clinically indeterminate and excluded from the final analysis. Compared to that on PBMC, T-SPOT.TB on SEMC showed higher sensitivity (91.9%vs73.0%, P = 0.002), specificity (87.1%vs.73.1%, P = 0.017), PPV (85.0%vs.68.4%, P = 0.013), NPV (93.1%vs.77.3%, P = 0.003), LR+ (7.12vs.2.72) and LR- (0.09vs.0.37), respectively. The frequencies of spot forming cells (SFCs) for T-SPOT.TB on SEMC were 636 per million SEMC (IQR, 143-3443) in patients with tuberculous serositis, which were 4.6-fold (IQR, 1.3-14.3) higher than those of PBMC. By ROC curve analysis, a cut-off value of 56 SFCs per million SEMC for T-SPOT.TB on SEMC showed a sensitivity of 90.5% and specificity of 89.2% for the diagnosis of tuberculous serositis.
  
  
  CONCLUSIONS
  T-SPOT.TB on SEMC could be an accurate diagnostic method for tuberculous serositis in TB endemic settings. And 56 SFCs per million SEMC might be the optimal cut-off value to diagnose tuberculous serositis.
authors.affiliation: Department of Infectious Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China ; Clinical Epidemiology Unit, Peking Union Medical College, International Clinical Epidemiology Network, Beijing, China.
authors.forename: Lifan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Infectious Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Yueqiu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Infectious Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Shi
authors.affiliation: Clinical Epidemiology Unit, Peking Union Medical College, International Clinical Epidemiology Network, Beijing, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Infectious Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Deng
authors.affiliation: Department of Respiratory Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom.
authors.forename: Ajit
authors.initials: A
authors.lastname: Lalvani
authors.affiliation: Department of Infectious Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China ; Clinical Epidemiology Unit, Peking Union Medical College, International Clinical Epidemiology Network, Beijing, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D001201:Ascites / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D002452:Cell Count; D002681:China; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010490:Pericardial Effusion / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D010996:Pleural Effusion / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D011933:Reagent Kits, Diagnostic; D012700:Serositis / Q000150:complications / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology; D062606:Tertiary Care Centers; D014376:Tuberculosis / Q000150:complications / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology
chemical_list: D011933:Reagent Kits, Diagnostic; D007371:Interferon-gamma