R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, NAS of
Ukraine, Kyiv, Ukraine
Abstract. The immunophenotypic profile of hematopoietic stem cells (HSC) and hematopoietic
precursor cells as well as leukemic stem cells (LSC) has been extensively studied in
several laboratories worldwide. The results of our studies suggest that the standard panel
for classification of acute leukemias should be supplemented with several new markers
allowing us to identify more precisely the different forms of the leukemias being of the
closely related origin, for example AML M6b and AML M7. The common bipotent LSC in AML M7
of low grade and AML M6b may exist analogous to precursor cell common for
megakaryocytopoiesis and erythropoiesis. We have also found the similarity between blast
cells in pro-B-ALL [t (4;11), 11q23] and AML M5a [t (9;11), 11q23]. Such similarity of
immunophenotype and cytogenetic abnormalities in blast cells in pro-B-ALL and AML M5a may
be considered as hint explaining the cases of AML M5a as a recurrence of leukemia in
children with originally diagnosed pro-B-ALL.
