Myelosuppression and Hematopoietic Growth Factor Use Hematopoietic growth

factors (HGFs) may be administered in order to mobilize PBPCs prior to an HSCT, to hasten hematopoietic recovery during the period of aplasia after an autologous HSCT,

and to stimulate hematopoietic recovery in cases where the patient fails to engraft.

Autologous HSCT is associated with profound aplasia owing to the myeloablative preparative regimen. Aplasia typically lasts 7 to 14 days after an autologous PBPC

transplant. During this period of aplasia, patients are at high risk for complications such as bleeding and infection. Filgrastim and sargramostim exert their effects by stimulating the proliferation of committed progenitor cells and accelerating recovery on hematopoiesis. Once engraftment occurs HGFs may be discontinued. The anatomic source of hematopoietic cells predicts the degree of benefit, with the greatest benefit reached when bone marrow is the graft source. With autologous PBPC transplant, the effect of HGF on neutrophil recovery is variable.

The use of HGF after allogeneic HSCT—whether from bone marrow or PBPC grafts—is controversial. The amount of data with sargramostim is limited in this setting; data with filgrastim have shown more rapid neutrophil but slower platelet en-graftment in those receiving grafts from bone marrow or PBPCs.28 The effects of post-HSCT filgrastim use on acute and chronic GVHD have been conflicting, with either no effect or increases in both the incidence of acute and chronic GVHD and

treatment-related mortality. Thus, there is little reason to treat allogeneic BMT with filgrastim as prophylaxis after HSCT.

Graft Failure A delicate balance between host and donor effector cells in the bone marrow is necessary to ensure adequate engraftment because residual host-versus-graft effects may lead to graft rejection. The incidence of graft rejection is higher in patients with aplastic anemia and those undergoing HSCT with histoincompatible marrow or T-cell-depleted marrow.1 Graft rejection is uncommon in leukemia patients receiving myeloablative preparative regimens with a histocompatible allogeneic donor.

Therapeutic options for the treatment of graft rejection or graft failure are limited. A second HSCT is the most definitive therapy, although the associated complications and toxicities may preclude its use. Graft rejection is best managed with immunosup-pressants such as ATG. Primary graft failure occasionally can be treated successfully using HGFs, although patients who received purged autografts are less likely to respond.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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