Comparison with Solid Organ Transplantation

If you are a payor familiar with solid organ transplantation, it is important to know that an unrelated hematopoietic cell transplant differs significantly from a solid organ transplant in several ways.

Availability of the organ or cells

Unrelated hematopoietic cells are only available after an unrelated donor or cord blood unit has been identified as a close match to the patient's human leukocyte antigen (HLA) tissue type. The search for closely matched cells can take weeks or months.

• Improves overall transplant survival
• Reduces post-transplant side-effects (such as graft-versus-host disease or GVHD)
• Improves the rate of engraftment (when the donated hematopoietic cells grow and re-generate new blood-forming cells)

Patients with a common HLA type may require HLA testing of only a few unrelated potential donors and cord blood units. Patients with a more challenging HLA type may require extensive HLA testing to identify the best match for the patient—in time for the transplant.

Timing of the transplant

Collecting the organ or hematopoietic cells

• Bone marrow is collected in a hospital operating room. The donor receives an anesthetic and marrow is aspirated from the iliac crest (back of pelvis bone). The donor may need to stay overnight in the hospital. Bone marrow is delivered to the patient’s hospital as soon as possible after it is collected, usually within 12 hours. The transplant is performed shortly after the donated marrow arrives, usually within 12 hours after the cells are received. 
• Cord blood is collected in a hospital. The blood is collected from the umbilical cord and placenta after a baby is born. These cells are tested and stored frozen until needed. A cord blood unit is delivered to the hospital several days before transplant so it can be thawed and prepared for transplant.
• PBSC is collected at an apheresis center (hospital lab or blood center) after the donor has received injections of filgrastim (G-CSF) for 5 days. (Filgrastim increases the number of hematopoietic (blood-forming) cells and moves these cells out of the marrow and into the bloodstream.) The hematopoietic cells are collected through a process similar to plasma or platelet donation. PBSC is delivered to the patient’s hospital as soon as possible after it is collected, usually within 12 hours. The transplant is performed shortly after the PBSC arrives, usually within 12 hours.