LYMPHOCYTE POPULATIONS WITH 5'-NUCLEOTIDASE IN CHRONIC LYMPHOCYTIC-LEUKEMIA

5′-Nucleotidase (5′N) was studied histochemically in the isolated peripheral blood lymphocytes of 56 patients with chronic lymphocytic leukemia (Rai Stages 0-IV). Four patterns of enzyme distribution were observed. No enzyme was demonstrable in the lymphocytes of 18% of the patients and 45% had very low numbers of positive cells. Values within the normal range were present in 14% while 23% of the patients had supranormal numbers of 5′N-positive cells. The presence or absence of 5′N did not correlate with the B- and T-lymphocyte populations or with the serum immunoglobulin levels. The phytohemagglutinin stimulation ratio was greater than 20 in 5 of 8 patients in the normal pattern group but in only 2 of 24 in the low 5′N group. In the remaining patients this ratio was always less than 20. It was observed that although all four patterns of enzyme distribution were represented in patients classified clinical Stages 0, I, and II, none of the patients in Stages III and IV had a normal" 5′N pattern. © 1979."