Adenosine deaminase in plasma of patients with adult T-cell leukemia (ATL): correlation between enzyme activity and the ATL subtypes.

Adenosine deaminase (ADA) was assayed in plasma from 14 patients with adult T-cell leukemia (ATL) (eight with acute ATL and six with smoldering or chronic ATL), 20 male family members (ten were anti-ATLA antibody positive and the other ten negative), and 25 normal individuals. ADA activity was uniformly higher in plasma from patients with ATL than normal controls. This enzyme activity significantly increased in acute ATL in comparison to smoldering or chronic ATL. In families of ATL patients, no statistical difference in ADA activity between the anti-ATLA antibody-positive group and -negative group could be discerned. The enzyme activity in a patient with acute ATL, after a bone-marrow transplant, rapidly increased as leukemic cells increased in peripheral blood. These findings indicate that the levels of ADA activities in plasma from ATL patients reflect the condition of this disease. Thus, measurement of this enzyme activity offers a further parameter to distinguish subtypes of ATL, and is of prognostic and therapeutic value.