Methylthioadenosine phosphorylase and purine nucleoside phosphorylase in B-chronic lymphocytic leukemia.

Enzymes of purine metabolism have potential utility as biological markers of normal lymphocytes and their neoplastic counterparts. The activity of two of them, methylthioadenosine phosphorylase (MTA phosphorylase) and purine nucleoside phosphorylase (PNP) were measured in peripheral mononuclear cells from 11 patients with B-chronic lymphocytic leukemia (B-CLL) and compared with those obtained in cells from 10 normal volunteers. An inverse relationship between the two phosphorylases was demonstrated in patients, with higher MTA-phosphorylase and lower PNP activities than in control subjects.