Diagnostic evaluation of ascitic adenosine deaminase activity in tubercular peritonitis

Activity of adenosine deaminase (ADA) in serum and peritoneal fluid was studied prospectively in 24 aetiologically proved cases of ascites and 10 age-matched controls. Patients were divided into 3 groups according to causes of ascites, viz. malignant ascites (11), tubercular peritonitis (7) and cirrhosis of liver (6). Serum ADA values and peritoneal: serum ADA ratio did not show any consistent pattern in any group. But in patients with tubercular peritonitis ADA activity in ascitic fluid was significantly higher (P < .001) than in the other groups. An ascitic ADA level of 30 units/L had a sensitivity of 100% and specificity of 94.1% for tubercular peritonitis. These findings suggest that the ascitic fluid ADA activity is useful for the diagnosis of tubercular peritonitis; this method is simple and least invasive.