title: Value of adenosine deaminase (ADA) in ascitic fluid for the diagnosis of tuberculous peritonitis: a meta-analysis.
abstract: OBJECTIVE
  Adenosine deaminase (ADA) levels are used for diagnosing tuberculosis in several locations and although many studies have evaluated ADA levels in ascitic fluid. These studies have defined arbitrary cut-off points creating difficulties in the clinical application of the results. The goals of this study are: to determine the usefulness of ADA levels in ascitic fluid as a diagnostic test for peritoneal tuberculosis (PTB) and define the best cut-off point.
  
  
  METHODS
  A systematic review was done on the basis of 2 independent searches. We selected prospective studies that included consecutive patients. Diagnosis of PTB had to be confirmed by bacteriologic or histologic methods and ADA levels determined by the Giusti method. Inclusion/exclusion criteria were applied by 2 independent reviewers. A receiver operating characteristic curve was constructed to establish the optimal cut-off point and the likelihood ratios (LRs) estimated using fixed-effect pooled method.
  
  
  RESULTS
  Twelve prospective studies were found. Four of them met the inclusion criteria and were thus included in the meta-analysis. They included 264 patients, of which 50 (18.9%) had PTB. ADA levels showed high sensitivity (100%) and specificity (97%) using cut-off values from 36 to 40 IU/L. The included studies were homogeneous. Optimal cut-off point was determined at 39 IU/L, and LRs were 26.8 and 0.038 for values above and below this cut-off.
  
  
  CONCLUSIONS
  This study supports the proposition that ADA determination is a fast and discriminating test for diagnosing PTB with an optimal cut-off value of 39 IU/L.
authors.affiliation: Faculty of Medicine, Department of Gastroenterology, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Arnoldo
authors.initials: A
authors.lastname: Riquelme
authors.forename: Mario
authors.initials: M
authors.lastname: Calvo
authors.forename: Felipe
authors.initials: F
authors.lastname: Salech
authors.forename: Sebastián
authors.initials: S
authors.lastname: Valderrama
authors.forename: Alejandro
authors.initials: A
authors.lastname: Pattillo
authors.forename: Marco
authors.initials: M
authors.lastname: Arellano
authors.forename: Marco
authors.initials: M
authors.lastname: Arrese
authors.forename: Alejandro
authors.initials: A
authors.lastname: Soza
authors.forename: Paola
authors.initials: P
authors.lastname: Viviani
authors.forename: Luz María
authors.initials: LM
authors.lastname: Letelier
mesh_terms: D000243:Adenosine Deaminase / Q000378:metabolism*; D001202:Ascitic Fluid / Q000201:enzymology*; D004796:Clinical Enzyme Tests; D006801:Humans; D014395:Peritonitis, Tuberculous / Q000175:diagnosis*; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D000243:Adenosine Deaminase