title: Functional activity of CD34-positive cells in chronic myeloid leukemia patients with different response to imatinib therapy.
abstract: BACKGROUND
  It is believed that the reason of the leukemic clone cell resistance to treatment with tyrosine kinase inhibitors during chronic myeloid leukemia (CML) is mutations in the genome of an early bone marrow progenitor cells that are CD34-positive. Such cells, regardless of treatment, acquire ability to proliferation and differentiation. This leads to the re-expansion of the CD34(+) cells.
  
  
  OBJECTIVE
  to determine the CD34 antigen expression in bone marrow and peripheral blood cells in CML patients with different response to imatinib therapy using the results of hematopoietic cells culturing and the data of flow cytometry.
  
  
  METHODS
  Bone marrow aspirate from 39 patients who were treated with imatinib was studied with cytogenetic, flow cytometry and culture methods in vitro.
  
  
  RESULTS
  In patients with an optimal response to imatinib therapy the number of colonies was 1.8 times lower than the number of those in the group of patients with a suboptimal response to therapy. In turn, in patients with failure of imatinib therapy the number of colonies was the highest and was 2.1 times higher than the patients with optimal response. The results of cytometric studies have shown that the number of CD34(+) cells in bone marrow was significantly higher compared to the number of CD34(+) cells in peripheral blood cells and increased with the acquisition of leukemic cells the resistance to imatinib. There was a direct correlation between the number of colonies and clusters in semisolid agar in vitro and the number of CD34(+) cells in the bone marrow of patients.
  
  
  CONCLUSIONS
  The correlation between the number of CD34(+) cells and the number of cell aggregates in semisolid agar in vitro indicates the prognostic value of the method for determining CD34(+) cells in the patient bone marrow. The parallel increase of their number in the peripheral blood will allow developing express methods for the detection of individual patient response to imatinib therapy.
authors: Centre for Molecular and Cell Research of National University of "Kyiv-Mohyla Academy", Kyiv 04655, Ukraine.
authors: I O
authors: IO
authors: Sviezhentseva
authors: SI "Institute of Hematology and Transfusiology of the NAMS of Ukraine", Kyiv 04060, Ukraine.
authors: T P
authors: TP
authors: Perekhrestenko
authors: Centre for Molecular and Cell Research of National University of "Kyiv-Mohyla Academy", Kyiv 04655, Ukraine.
authors: D I
authors: DI
authors: Bilko
authors: SI "Institute of Hematology and Transfusiology of the NAMS of Ukraine", Kyiv 04060, Ukraine.
authors: A I
authors: AI
authors: Gordienko
authors: Centre for Molecular and Cell Research of National University of "Kyiv-Mohyla Academy", Kyiv 04655, Ukraine.
authors: M V
authors: MV
authors: Diachenko
authors: SI "The National Research Center for Radiation Medicine of the NAMS of Ukraine", Kyiv 04050, Ukraine.
authors: I S
authors: IS
authors: Dyagil
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis*; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001549:Benzamides / Q000494:pharmacology / Q000627:therapeutic use*; D001773:Blood Cells / Q000187:drug effects / Q000473:pathology; D001853:Bone Marrow / Q000187:drug effects* / Q000473:pathology*; D019008:Drug Resistance, Neoplasm; D005260:Female; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000473:pathology; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000494:pharmacology / Q000627:therapeutic use*; D011743:Pyrimidines / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D018952:Antigens, CD34; D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate