title: Ascitic fluid adenosine deaminase insensitivity in detecting tuberculous peritonitis in the United States.
abstract: Tuberculous peritonitis, although common in Third World countries, remains an uncommon cause of ascites in the United States. Ascitic fluid adenosine deaminase (ADA) activity has been proposed as a useful diagnostic test. The aim of this retrospective study was to determine the clinical utility of ascitic fluid ADA activity in diagnosing tuberculous peritonitis in a U.S. patient population. A total of 368 ascitic fluid specimens from a well-characterized ascitic fluid bank, including tuberculous peritonitis (n = 7), tuberculous peritonitis in the setting of cirrhosis (n = 10), and consecutive specimens of widely varied etiologies (n = 351) were analyzed for ADA activity by ultraviolet spectrophotometry at 265 nm. The overall sensitivity of the ADA determination in diagnosing tuberculous peritonitis was only 58.8%, and the specificity was 95.4%. The accuracy of ADA determination (93.8%) compared favorably with that of the common ascitic fluid tests of white blood cell (WBC) count (>500/mm3), total protein (>2.5 g/dL), and combined WBC count and total protein (45.8%, 74.4%, and 81.3%, respectively). However, ADA was only 30% sensitive in detecting tuberculous peritonitis in the setting of cirrhosis, and cirrhosis was present in 59% of the tuberculous peritonitis patients in our population. In addition, malignancy-related ascites (13%) and bacterial peritonitis specimens (5.8%) occasionally yielded false-positive results. In conclusion, our results indicate that the ascitic fluid ADA activity has good accuracy but poor sensitivity and imperfect specificity in a U.S. patient population in which the prevalence of tuberculosis is low and underlying cirrhosis is common.
authors.affiliation: University of Iowa College of Medicine, Iowa City, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Hillebrand
authors.forename: B A
authors.initials: BA
authors.lastname: Runyon
authors.forename: W G
authors.initials: WG
authors.lastname: Yasmineh
authors.forename: G P
authors.initials: GP
authors.lastname: Rynders
mesh_terms: D000243:Adenosine Deaminase / Q000032:analysis*; D001201:Ascites / Q000201:enzymology* / Q000209:etiology; D001798:Blood Proteins / Q000032:analysis; D004796:Clinical Enzyme Tests; D003906:Developing Countries; D005189:False Positive Reactions; D006801:Humans; D007958:Leukocyte Count; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000503:physiopathology; D014395:Peritonitis, Tuberculous / Q000175:diagnosis* / Q000503:physiopathology; D011446:Prospective Studies; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014481:United States
chemical_list: D001798:Blood Proteins; D000243:Adenosine Deaminase