The diagnostic value of adenosine deaminase activity in pulmonary tuberculosis: Comparison between sputum and serum

Abstract

BackgroundTuberculosis is a chronic specific bacterial infection caused by bacteria of the Mycobacterium tuberculosis. It remains one of the deadliest diseases in the world. It is the second leading infectious cause of death after HIV infection. Adenosine deaminase (ADA) activity is increased in various conditions such as liver disease, tuberculosis, typhoid, infective mononucleosis and certain malignancies, especially those of haematopoietic origin. ObjectiveThe aim of the work was to assess the diagnostic value of ADA in pulmonary tuberculosis by comparing levels in sputum and serum. Subjects and methodsThe present study included 15 patients with active pulmonary tuberculosis, 15 patients with pneumonia and 15 patients diagnosed as lung cancer. All patients were subjected to: Full history taking, complete clinical examination, laboratory investigations, and plain X-ray chest. Measurement of sputum and serum level of ADA of all patients using specific immunoassay method. ResultsThere was a significant increase in sputum ADA in tuberculous group in relation to the other groups (mean sputum ADA was 159.76±16.95, 84.34±6.87 and 67.30±7.47U/L, respectively). The mean serum ADA was 31.99±8.85, 24.15±4.22and 14.84±2.43U/L in tuberculous group, pneumonia group and bronchogenic carcinoma group, respectively. There was a statistically significant increase in serum ADA in the tuberculous group in relation to the other groups (F 10.65, P 0.001∗). There was a statistically significant positive correlation between sputum and serum ADA (r=0.75, P=0.0001). ConclusionThe results support the feasibility of using sputum ADA for diagnosis of pulmonary tuberculosis.