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.