title: Use of pleural fluid levels of adenosine deaminase and interferon gamma in the diagnosis of tuberculous pleuritis.
abstract: OBJECTIVE
  This review aims to define the role of adenosine deaminase (ADA) and interferon gamma (IFN-gamma) in the differential diagnosis of pleural effusion with special attention to their source, mechanism of release and methods of measurement in pleural fluid. The diagnostic performance of ADA and IFN-gamma is analyzed, and the advantages and limitations of their use in differentiating between tuberculous and nontuberculous pleural effusion are discussed.
  
  
  RESULTS
  Several potential biomarkers of tuberculous pleurisy have been evaluated, but none have been found to be clearly superior to pleural fluid level of ADA or IFN-gamma. The majority of recent studies confirm the high diagnostic utility of pleural fluid ADA and IFN-gamma measurement; hence, these markers are included in different diagnostic algorithms for patients suspected of tuberculous pleurisy. Other relatively new tests show a high variability [nucleic acid amplification tests (NAATs)] or are technically demanding, costly and give equivocal results in patients with active tuberculosis [IFN-gamma releasing assays (IGRAs)].
  
  
  CONCLUSIONS
  Pleural fluid ADA and IFN-gamma are both sensitive and specific biomarkers of tuberculous pleurisy. Their diagnostic accuracy across the different studies shows a smaller variability than that of other tests, for example NAATs. There is also no convincing evidence that IGRAs are superior to pleural fluid ADA or IFN-gamma measurement. Hence, the role of ADA and IFN-gamma in the differential diagnosis of tuberculous pleurisy is pivotal.
authors.affiliation: Department of Internal Medicine, Pneumonology and Allergology, Medical University of Warsaw, Warsaw, Poland. rkrenke@wum.edu.pl
authors.forename: Rafał
authors.initials: R
authors.lastname: Krenke
authors.forename: Piotr
authors.initials: P
authors.lastname: Korczyński
mesh_terms: D000243:Adenosine Deaminase; D015415:Biomarkers; D003937:Diagnosis, Differential; D005122:Exudates and Transudates; D006801:Humans; D007371:Interferon-gamma; D021141:Nucleic Acid Amplification Techniques; D010996:Pleural Effusion / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D014396:Tuberculosis, Pleural / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D007371:Interferon-gamma; D000243:Adenosine Deaminase