EVALUATION OF THE SUBPOPULATION COMPOSITION OF CD34+ PLURIPOTENT HEMATOPOIETIC STEM CELLS IN BLOOD CANCERS

Abstract Introduction. Over the past decades, the incidence of malignant blood diseases has been steadily increasing. Unlike many other types of malignant neoplasms, blood cancers often occur at a young age, and are also the main cause of death among all pathologies of the hematopoietic tissue in pediatric patients. The cause of blood cancers is a mutation process in hematopoietic stem cells, which subsequently leads to an increase in the number of tumor clones and the displacement of healthy cells in the niches they occupy, which leads to a number of changes in the blood and bone marrow, including irreversible ones. The aim of this study was to assess the subpopulation composition of pluripotent hematopoietic stem cells in patients with blood cancers and healthy donors. Materials and methods. The study included patients blood cancers (n = 13), including patients with acute lymphoblastic leukemia (ALL) n=3, acute myeloid leukemia (AML) n=3 and patients with multiple myeloma (MM) n=7, and healthy donors (n = 4). The phenotypic composition of hematopoietic CD34+CD38- pluripotent cells was assessed by flow cytometry using the following monoclonal antibodies: CD34 APC (BioLegend, USA), CD38 PE-Cy7 (ElabScience, China), CD45RA PerCP (ElabScience, China), CD90 APC-Cy7 (Cloud-Clone Corp., USA), Lin- (cocktail CD3/14/16/19/20/56) FITC (BioLegend, USA). The following populations were assessed: hematopoietic stem cells (Lin-CD34+CD38-CD45RA-CD90+) and pluripotent progenitors (Lin-CD34+CD38-CD45RA-CD90-). Results. It was shown that in patients with hemoblastoses, the relative number of cells with the Lin-CD34+CD38-CD45RA-CD90+ phenotype increases, which corresponds to hematopoietic stem cells, but not pluripotent progenitor cells. At the same time, the number of pluripotent progenitor cells tends to decrease in acute myeloid leukemia. Conclusions. It was found that in patients with blood cancers, when compared with healthy donors, changes in the subpopulation composition of pluripotent hematopoietic stem cells are observed.