Telomerase Activity as a Marker For Mobilization Quality

Autologous hematopoietic cell transplantation (HCT) is a treatment strategy used as advanced line therapy for different malignancies, mainly hematological. Its main advantage lies in the ability to provide hematologic and immune rescue after high dose chemotherapy therapy. The first requirement of a successful transplantation is recruitment of sufficient amount of cells. This is achieved by mobilizing CD34+ stem cells from the bone marrow to the peripheral blood, by G-CSF priming, and then harvesting the cells from the peripheral blood at the right timing by means of apheresis. Currently, the decision on the optimal collection timing is based on the pre-collection CD34 cells blood concentrations. The investigators goal is to investigate whether telomerase, the telomere elongation enzyme, which constitutionally and solely expressed in progenitor cells, is correlated with collection and post HCT engraftment characteristics. The investigators will collect blood from patients when starting GCSF and on the day of planned apheresis. Pearson correlation test will be used to correlate between telomerase activity in the samples and with collection and engraftment characteristics.