Adenosine deaminase (ADA) activity in lymphocytes of normal individuals and patients with chronic lymphatic leukaemia.

Adenosine deaminase (adenosine aminophydrolase, ADA) activity was found to be low in lymphocytes of chronic lymphatic leukaemia (CLL) patients compared to normal lymphocytes. This was determined on 42 controls and 49 CLL patients. The mean activity in normal lymphocytes was found to be 4.35 +/- 3.34 mumol/h/10(8) cells while in CLL cells it was 2.45 +/- 2.54 mumol/h/10(8) cells.