Peripheral blood stem cell harvests

Prior to peripheral blood stem cell harvesting, however, the stem cells must be mobilized or stimulated to enter the peripheral blood. The mobilization process is set into motion by stressing neutrophils and osteoclasts into activity by the use of cytokines with, or without chemotherapy. This results in the shedding and release of membrane-bound stem cell factor (SCF), proliferation of progenitor cells and activation or degradation of various adhesion molecules. Stem cells can be mobilized to enter the peripheral... 

PROBLEMS ASSOCIATED WITH BONE MARROW AND PERIPHERAL BLOOD STEM CELL HARVESTING... 

With peripheral blood stem cell harvesting, the most frequent problems relate to central venous catheter occlusion and bone pain in association with the G-CSF priming. Infectious complications during harvesting were experienced in 16% of patients during the PBSC harvesting. 

The G-CSF commonly used to prime patients and donors before peripheral blood stem cell harvesting can be given to normal, nonpatient donors and has not been shown to have... 

Goldberg SL, Mangan KF, Klumpp TR et al. (1995). Complications of peripheral blood stem cell harvesting review of 554 PBSC.JHematother, 4, 85-90. 

The bone marrow is not the only source of hematopoietic stem cells. Such cells are present in low numbers in peripheral blood, and these can be expanded in number with specific factors. Peripheral blood stem cells have the major therapeutic advantage that their harvest is relatively painless and less invasive. Likewise, umbilical cord stem cells can also be obtained in a non-invasive manner from... 

Stem cell therapy involves infusion of specialized cells utilized to perform specific functions. The traditional use of cell therapy includes harvest and cryopreservation of autologous hematopoietic cells either from the bone marrow (old approach) or mobilization and pheresis of hematopoietic stem cells from peripheral blood using stem cell-mobilizing cytokines such as hematopoietic colony-stimulating factors (G-CSF, GM-CSF) or chemokine inhibitors (AMD-3100). A more recent stem cell source is umbilical cord blood that has rich pleuripotent potential and can engraft at lower doses than bone marrow or mobilized peripheral blood stem cells. 

Weaver CH, Schulman KA, Wilson-Relyea B, Birch R, et al. 2000. Randomized trial of Filgrastim, Sargramostim, or sequential sargramostim and filgrastim after myelosuppressive chemotherapy for the harvesting of peripheral blood stem cells. J Clin Oncol. 18 43-53. 

Prior interferon alfa treatment lasting for more than 6 months and withdrawn for 2-3 months was also one of the most significant factors to explain a reduced yield of peripheral blood stem cells in 88 previously autografted patients with myeloma undergoing G-CSF stimulation for future autotransplantation (211). As suggested by this study, the myelosuppressive effects of interferon alfa may be prolonged to such an extent that a minimum delay of more than 2-3 months after interferon alfa withdrawal should be considered before harvesting bone marrow cells. 

The success of transplantation with peripheral blood stem cells depends upon infusion of adequate numbers of hematopoietic stem cells. Administration of G-CSF to the donor (in the case of autologous transplantation, the patient who also will be the recipient of the transplantation) greatly increases the number of hematopoietic stem cells harvested from the donor s blood and available for the transplantation procedure. The answer is (B). 

Figure 1 Forward scatter (FSC) and right-hand scatter (RHS) from (a) peripheral blood stem cell, and (b) bone marrow harvests.

Assessment of the progenitor cell content in bone marrow (BM) and peripheral blood stem cell (PBSC) harvests... 

Various designs of cell separators have been used since the technique of stem cell harvesting from peripheral blood first became an option. In the main, these have relied upon the principle of... 

Autologous hematopoietic stem cells are obtained (or harvested ) from bone marrow or peripheral blood. The technique for harvesting autologous hematopoietic cells depends on the anatomic source (i.e., bone marrow or peripheral blood). A surgical procedure is necessary for obtaining bone marrow. Multiple aspirations of marrow are obtained from the anterior and posterior iliac crests until a volume with a sufficient number of hematopoietic cells is collected (i.e., 600-1200 mL of bone marrow). The bone marrow then is processed to remove fat or marrow emboli and usually is infused intravenously into the patient like a blood transfusion. 

In addition to bone marrow and peripheral blood, hematopoietic stem cells are also found in umbihcal cord blood (UCB). UCB is an attractive source for several reasons. Because the stem cells are collected from placental blood, there is no risk to the mother or the baby. There is also very low risk of hansmissible infectious diseases such as cytomegalovhus and Epstein-Barr virus. In addition, the cells are available immediately because the donor does not have to be located and harvested. Initially, UCB was obtained from sibhngs but now recipients of transplants from unrelated donors accountfor almost all patients who receive UCB transplants. It is estimated that more than 2,000 unrelated UCB transplants have been performed worldwide. ... 

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