PROGNOSTIC-SIGNIFICANCE OF THE ACTIVITY O F NUCLEOLAR ORGANIZER REGIONS IN MEGAKARYOCYTES FROM PATIENTS WITH ACUTE LYMPHOBLASTIC LUKEMIA

Bone marrow films from 20 patients with acute lymphoblastic leukemia ( ALL) and 40 patients with acute nonlymphoblastic leukemia (ANLL) were investigated using Ag-NOR staining. The control group comprised 12 don ors. The activity of-nucleolar organizer regions (NOR) in the whole po pulation of megakaryocytes (MK) and in groups of MK with 1-3, 4-6, 7 a nd more lobules per nucleus was assessed. The division into groups mad e it possible to judge about NOR activity in MK with different ploidy. The MK with both high ploidy and high NOR activity in residual megaka ryocytopoiesis In patients with ALL are associated with good response to chemotherapy and complete remission, whereas these with low ploidy and low NOR activity suggest poor prognosis. In patients with ANLL no stable correlation between NOR activity and prognosis was found.