Ivanivska T. Malignanty transformed hematopoietic progenitor cells in different forms of hematological malignancies

The thesis is a comprehensive study aimed to determining the degree of differentiation and lineage origin of leukemia cells in various forms of acute myeloid (AML) and lymphoid leukemias(ALL), MDS (refractory anemia with excess of blasts) and blast crisis of chronic myeloid leukemia (BC CML). Our study delineated three levels of blast differentiation in patients with acute monoblastic leukemia and two levels of blast differentiation in patients with acute megakaryoblastic leukemia. It was demonstrated that BC CML in 81% of the patients corresponds to the myeloid type. In monocytic variant of BC CML blasts of two levels of differentiation were characterized. The blasts observed in megakaryoblastic variant were similar to the blasts of low degree of differentiation in the patients with AML M7 occurring de novo. No differences between blasts in BC CML with minimal signs of myeloid differentiation and AML M0 occurring de novohave been observed. The cells in lymphoid type of blast crisis of CML were similar to the B-cell blasts in ALL of common type occurring de novo. In MDS (RAEB-1 and RAEB-2 type) the blasts had similar cytomorphological and cytochemical signs with a phenotype of the committed myeloid progenitor cells. It was established that the secondary leukemic transformation of BC CML takes place at the level of multipotent progenitor cell whereas the development of acute