Adenosine deaminase in childhood pulmonary tuberculosis: diagnostic value in serum.

The diagnostic value of serum adenosine deaminase (ADA) activity was evaluated in childhood pulmonary tuberculosis. Serum ADA levels were measured in 20 children diagnosed with pulmonary tuberculosis (group 1) and 150 children (group 2) including 128 with tuberculosis infection (Mantoux test positive) and 22 healthy children. In group 1, the mean serum ADA activity was 74.06 +/- 18.5 U/l, which was significantly (p < 0.001) higher than that of group 2 (40.36 +/- 12.0 U/l). A serum ADA level of > or = 53.76 U/l had a sensitivity of 100 per cent, specificity of 90.7 per cent, positive predictive value of 58.8 per cent, and a negative predictive value of 100 per cent in children with tuberculosis disease. To conclude, measurement of serum ADA activity was a useful diagnostic tool in childhood pulmonary tuberculosis.