Prognostic implication of ecto-5'-nucleotidase activity in acute lymphoblastic leukemia.
 Ecto-5'-nucleotidase (5'-N) activity was determined in 191 patients (71 children and 120 adults) with acute leukemia.
 Elevated values for 5'-N were registered in common acute lymphoblastic leukemia (ALL), but blast cells of T-cell ALL (T-ALL) and common ALL antigen-negative non-T-ALL had low enzyme activity comparable with the values of acute non-lymphocytic leukemia.
 Dependence of remission duration on 5'-N activity was analyzed in 74 adults with ALL, treated similarly in a prospective multicenter trial.
 The remission curves for ALL patients with 5'-N activity lower than 10 nmol/h x 10(6) cells were substantially and significantly better than those of patients with high activity (greater than 10 nmol/h x 10(6) cells).
 This difference was also evident in the immunologic subclass common ALL.
 Statistical evaluation showed that an interaction between immunologic subtype of the blast cells and their 5'-N activity had prognostic significance for remission duration.
 In addition to the independent factor, initial age, this interaction was also prognostic for survival.
