Hematogones in acute leukemia during and after therapy

After each leukemia therapy phase, characteristics of normal regenerating B-cells may be reminiscent of and mistaken for a relapse. We compared the incidence and phenotypic characteristics of hematogone stages in a total of 669 bone marrow aspirates from 107 patients with B-ALL, 97 patients of AML, and 27 patients with T-ALL at diagnosis, during, and after therapy. The three individual physiological maturation phases of B-lymphocytes (hematogone stages 1, 2, and 3) were studied by four-color flow cytometry in the course of bone marrow regeneration in leukemia patients. Multiple stages of hematogones were observed twice as frequently in B-ALL (73.8%) and T-ALL (69.2%) samples as in AML aspirates (34.1%). Stage 3 hematogones were found usually in children and were thus frequent in B-ALL. The hematogones had an extremely high phenotypic stability unaffected by disease or therapy or by their coincidence with leukemia cells.