Krzysztof Gawroński

Sources of Hematopoietic Stem Cells

Hematopoietic stem cell transplantation (HSCT) has the potential to cure a variety of malignant and nonmalignant diseases. Sources of hematopoietic stem cells for transplantation have expanded progressively since the beginning of the modern era of transplantation in the late 1960s. Although bone marrow was the main source of stem cells in the early years of transplantation, in the past 10 to 15 years peripheral blood has assumed increasing importance. The initial impetus for the use of PBSCs for transplantation was to be able to offer transplantation to patients who were not candidates for the use of bone marrow cells (tumor contamination of the marrow or those with hypocellular marrows). Subsequent studies demonstrated that PBSCs could be mobilized from the bone marrow with either hematopoietic growth factors (GM-CSF, G-CSF) or a combination of chemotherapy and growth factors, which increased the number of hematopoietic progenitors collected from the blood by 10to 1000fold compared with steady-state conditions. Umbilical cord blood represents the newest source of stem cells for transplantation. At now peripheral blood is the main source in the autologous setting. Within the allogeneic setting, multiple sources of stem cells are possible and include those derived from individuals related or unrelated to the patient. Hematopoietic progenitor cell (HPC) products contain hematopoietic stem and lineagecommitted progenitor cells capable of providing hematopoietic and immune reconstitution after myeloablative or reduced-intensity preparative regimens. HPCs administered intravenously migrate to the marrow, where they adhere, expand, selfrenew (stem cells only), and differentiate. The differentiated cells are released into the blood, restoring blood counts and immunity. The time from administration of HPCs to recovery of adequate or normal blood counts is variable. Recipients of peripheral blood stem cells recover counts faster than recipients of bone marrow. Cord blood tends to be the slowest to engraft. The minimum number of HPCs necessary for engraftment in a myeloablated recipient has not been established. Different products have widely different numbers of progenitors and stem cells. However, eligibility criteria for some protocols usually dictate a minimum number of cells to be collected and infused. Several methods are used to measure the number of cells in an HPC collection. Simple cell count may be adequate for many marrow collections. Most centers use flow cytometric enumeration of CD34+ cells for the majority of cellular products. The discovery of the CD34 antigen in the early 1980s revolutionized our understanding of hematopoiesis. Cells expressing CD34 are capable of reconstituting hematopoiesis in lethally irradiated animals and humans, indicating that the putative hematopoietic stem cell expresses CD34.

Mobilization of Hematopoietic Stem Cells for Hematopoietic Cells Autologous Transplantation with Use of Plerixafor

BACKGROUND To increase the number of circulating hematopoietic stem cells (HSC) in the blood, mobilization treatments are currently being used. G-CSF and G-CSF plus chemotherapy are the most common methods of hematopoietic stem cells separation used in Poland. MATERIAL AND METHODS We observed patients who failed an effective hematopoietic stem cell mobilization with G-CSF or with G-CSF plus chemotherapy. The separation was considered unsuccessful if within a period of 4 consecutive days of separation, the number of obtained CD 34+ cells was lower than 2.0×10^6/kg of bodyweight. The study involved 32 patients whose CD34+ cells were collected and the collection for autologous transplantation failed. The study included 20 men and 12 women. Among all 32 patients, 28 had multiple myeloma, 3 had DLBCL lymphoma, and 1 had Hodgkins disease. RESULTS Separation was unsuccessful in only 3 patients; the remaining 29 achieved an average of 4.83×10^6 CD34+ cells per kg of bodyweight. We conclude that plerixafor is an important tool in obtaining sufficient quantities of cells for hematopoietic stem cells separation. CONCLUSIONS The use of plerixafor is a sufficient and safe option for stem cells mobilization in autologous transplantations.

Acute Phase Proteins for Monitoring Hematopoietic Recovery After Early Engrafting of CD34+ Peripheral-Blood-Stem-Cells for Autografting or Allografting in Patients with Malignant Diseases

BACKGROUND Neutropenic fever (NF) is associated with delayed engraftment after peripheral blood stem cell transplantation (PBSCT). MATERIAL AND METHODS We followed the levels of acute-phase proteins (APPs) serially in 60 patients after peripheral blood stem-cell autograft (n=39) or peripheral blood stem-cell allograft (n=21) for hematologic malignancies and germinal tumors; we then examined the correlation of those levels with the presence of fever and with markers of engraftment. RESULTS Fever (present in 60% of patients) was associated with a highly statistically significant delay in reaching conventional engraftment targets (ANC >500/μL [0.5×10^9/L]; platelets >20,000/μL [20×10^9/L]; reticulocytes >20,000/μL [20×10^9/L]) (for all associations, p<0.001). Every 4th day for 24 days, we measured the APPs levels and the number of neutrophils (ANC), platelets (PL), and reticulocytes (RET) to reach the reference values of >0.5 G/L or >1.0 G/L for ANC, >20 G/L or >50 G/L for PL, and >20 G/L for RET, respectively. The presence of NF resulted in longer time to engraft hematopoietic stem cells with ANC, PL, and PET counts statistically significant (range 0.001-0.004). The median day range for NF patients was 21.22-26.89 versus 13.88-19.13 for no NF patients. CONCLUSIONS Our results provide additional information for monitoring hematopoietic engraftment in patients following PBSCT; the presence of NF can be tracked by serial measurements in serum of three investigated APPs throughout an early phase of hematopoietic recovery.

The evaluation of NT-proCNP, C-reactive protein and serum amyloid A protein concentration in patients with multiple myeloma undergoing stem cell transplantation

The importance of proinflamatory cytokines and acute phase proteins in pathogenesis and progression of MM is well known. However, there are any studies evaluating the role of NT-proCN in management and treatment of MM. The aim of our study was to evaluate the concentration of NT-proCNP and acute phase proteins in patients with MM before and after stem cell transplantation. We involved 40 newly diagnosed MM patients in stage III according to the Durie-Salmon classification and treated with high dose of melphalan (200mg/m2) prior to ASCT. Concentration of NT-proCNP, hs-CRP and SAA were measured before conditioning treatment and every 4days until the 24th day after stem cell infusion. We observed low NT-proCNP levels before conditioning treatment (0.121±0.04pmol/l), the higher in day on ASCT (0.28±0.14pmol/l). Further we showed significant gradual increase concentration of NT-proCNP up to 12days after stem cells infusion (1.07±0.72pmol/l). The kinetics of hs-CRP and SAA levels were similar to NT-proCNP. We showed positive correlation between NT-proCNP levels and absolute neutrophil and platelets count in patients after ASCT. NT-proCNP can be useful parameter to assess effectiveness of treatment and monitoring of hematopoetic recovery time in patients with MM after stem cell transplantations.