A comparative study of immunological and cytochemical profiles between adult and childhood acute lymphoblastic leukemias (ALLs): heterogeneity in adult common ALL.

To investigate the biological differences between adult and childhood acute lymphoblastic leukemia (ALL), leukemic blasts from 33 patients with ALL (22 adults and 11 children) and from 11 patients in the lymphoid crisis of chronic myeloid leukemia (CML) were studied using cytochemical and immunological markers and also by the outcome of their treatment. The cytochemical studies showed that blasts from seven of the adult ALL patients were dense-granular-positive (DG-positive) for beta-glucuronidase, whereas the blasts from the children were negative except for one (with T-ALL). In the adults with common ALL (cALL), survival of patients DG-positive for this enzyme were significantly shorter than that of eight patients with a scattered granular pattern (p less than 0.05). The mean ratio between the percentage of blasts positive for cALL antigen (cALLA) to that of blasts positive for terminal deoxynucleotidyl transferase (TdT) in the adult group with cALL (0.6 +/- 0.3) was significantly lower (p less than 0.01) than in the group of children with cALL (1.1 +/- 0.2) or in the lymphoid-crisis group (1.5 +/- 1.0). These findings indicate that adult cALL consists of two distinct subpopulations, one with less differentiated phenotype (cALL-/TdT+) and the other with more (cALL+/TdT+). In contrast, the blast cells in childhood cALL and some patients in lymphoid crisis had a relatively homogeneous population with the latter phenotypes. The results suggest that the clonotypic cells in adult ALL, particularly in cALL, appear to be more immature than those in childhood ALL. The beta-glucuronidase patterns indicate a further heterogeneity in adult ALL.