Serum adenosine deaminase estimation in relation to BCG vaccination.

Serum adenosine deaminase (ADA) levels reflect activity of stimulated T lymphocytes and its levels are raised whenever cell mediated immunity is stimulated. One hundred term normal newborns were studied to evaluate effect of BCG vaccination on serum ADA levels. Serum ADA was measured at birth and 6 weeks after BCG vaccination. Only 67 subjects came for follow up after 6 weeks. The levels were 6.69 U/litre at birth and 13.83 U/litre after 6 weeks of vaccination showing a significant rise. It is concluded that serum ADA levels can be used as a measure of cell mediated immunity after BCG vaccination.