Adenosine deaminase activity in various pathological effusions.

: Adenosine Deaminase (ADA) Activity in pathologic effusions was measured. The effusions were pleural (49 cases) peritoneal (38 cases) and pericardial (3 cases). The patients were divided into 6 groups: Group I included 10 cases with tuberculosis, group II included 6 cases with pleural effusions, group III included 46 cases of malignancy, group IV included 15 cases of transudates, group V included 4 miscellaneous cases and group VI included 8 cases of unknown diagnosis. Mean (ADA) activity was 102 +/- 37 U/L in Group I, 45 +/- 46 U/L in Group II, 27 +/- 30 U/L in Group III, 12 +/- 11 in Group IV, 36 +/- 32 in Group V and 38 +/- 42 in Group VI. Specificity and sensitivity for tuberculosis where a value > 41 U/L is taken is 85% and 100% respectively. Assessment of ADA in pathologic effusions is helpful in the diagnosis of tuberculosis but it does not replace the pleural or peritoneal biopsy.