Serum adenosine deaminase in pulmonary tuberculosis, malignancy and non-tubercular respiratory diseases.

Abstract The study has been conducted to find out the serum ADA levels in 120 patients with various pulmonary diseases which included patients with tubercular pleural effusion (n = 86), lung cancer (n = 10) and patients with non-tubercular pulmonary diseases like pneumonia, etc (n = 24). Twenty healthy individuals served as control subjects. The mean (+/- SD) of ADA activity was 23.38 (4.47), 7.29 (1.08), 12.71 (1.95) and 2.23 (1.00) units/litre in tuberculosis, malignancy, non-tubercular pulmonary diseases and healthy controls respectively with significant difference between each other (P less than 0.001). Patients with tuberculosis (100%) fall in 97% sensitivity range with a lower cut off limit at 17 units/litre ADA activity, while for malignancy and non-tubercular respiratory diseases, the sensitivity was 90% and 83% respectively. Within the sensitivity limits, the serum ADA activity can be used for the differential diagnosis of pulmonary diseases.