ABSTRACT:

Background: Tuberculosis (TB) remains a major health problem across the world and commonly involves the lungs. Analysis of adenosine deaminase activity is a very useful diagnostic approach to achieve a more rapid and precise diagnosis in serosal fluids and serum of pulmonary tuberculosis.

Objectives: To estimate the serum adenosine deaminase (ADA) levels in pulmonary tuberculosis and other common respiratory diseases & to evaluate the role of serum ADA estimation in differentiation of tubercular and common non tubercular respiratory diseases.

Methods: The study was a hospital based, non randomized comparative study conducted at Kempegowda Institute of Medical Sciences, Bangalore and DOT centres of RNTCP, BBMP, Bangalore. We measured serum adenosine deaminase levels in 3 groups, group Ι: 41 cases of pulmonary tuberculosis, group ΙΙ: 30 cases of tubercular pleural effusion, group ΙΙΙ: 49 cases of non tubercular respiratory diseases viz, bronchiectasis, chronic bronchitis in the age group of 20 – 64 years over a period of one year. Age and sex matched 30 healthy volunteers, were taken as controls. Estimation of serum ADA was done by sensitive colorimetric method described by Giusti and Galantim

Results: Mean serum ADA levels in cases of pulmonary tuberculosis (50.93 ± 9.22 U/L), tubercular pleural effusion (42.48 ± 8.2 U/L), non tubercular respiratory diseases (21.03±3.64 U/L) were significantly more than controls (17.07±2.71U/L). But the mean serum ADA value between pulmonary tuberculosis and non tubercular respiratory diseases shows higher significant mean difference and was statistically significant with a p value < 0.01. The mean difference of serum ADA levels between the tubercular pleural effusion and non tubercular respiratory diseases was also statistical significant with a p value < 0.01.

Conclusion: We conclude that elevated serum ADA level in pulmonary tuberculosis is statistically significant compared to non tubercular respiratory diseases and healthy controls.

Key words: Tuberculosis(TB), Adenosine deaminase(ADA)