Adenosine deaminase activity in bronchoalveolar lavage of pulmonary tuberculosis

ABSTRACT

Adenosine deaminase [ADA] activity, lymphocytes and T-cell subsets% [CD3%, CD4% and CD8%] were measured in BAL from 15 patients with active pulmonary TB, 15 persons with inactive pulmonary TB and 15 normal nonsmoker volunteers. ADA activity in BAL and serum, lymphocytes%, CD3%, CD4% and CD4 CD8 ratio in BAL were statistically highly significantly [p <0.001] increased among patients with active pulmonary TB compared with inactive cases and normal controls, whereas no statistical difference [p >0.05] was found as regard CD8%. ADA activity showed positive correlation more with CD4% in BAL [r = +0.93] and both showed positive correlation with tuberculin test. So, ADA may constitute a new marker of cell-mediated immune response and tuberculous lung infection is characterized by T- cell [CD4] alveolitis. It is suggested that, ADA activity in BAL over 3 U/L and/or serum BAL ADA ratio below 7, BAL lymphocytes >10%, CD3 >50% or CD4 CD8 ratio >2.5 denoted active pulmonary TB, whereas lower values serve to diagnose inactive disease. So, measurement of ADA activity and T-cell subsets% in BAL may be valuable parameters for diagnosis and follow up of pulmonary TB