Figure 1

CD39 activity as measured in normal and malignant lymphocytes. The enzyme was measured by radio-TLC as described in methods. ADPase and ATPase activity was elevated in cells of all CLL patients, early (stage 0–2) CLL, and late (stage 3–4) CLL as compared to normal lymphocytes (p < 0.00001 for all and early CLL versus normal lymphocytes; p < 0.05 for late CLL). ADPase activity was elevated in early CLL versus normal B-lymphocytes (p = 0.05) but decreased in late CLL (p < 0.01).