Types of Transplants

The name for what is being transplanted has changed over the years. The cell that is being transplanted is the stem cell that is made in the bone marrow. Stem cells are immature cells that grow into mature red blood cells, white blood cells, platelets or plasma cells. Stem cells are an essential part of a person’s immune system.

Names you will hear include:

• Bone-Marrow Transplant
• Marrow Transplant
• Peripheral Blood Stem Cell Transplant
• Stem Cell Transplant
• Hemopoietic Stem Cell Transplant
• Hemopoietic Progenitor Cell Transplant
• Pluripotent Stem Cell Transplant

There are five types of transplants:

1. Autologous transplant -- Transplanted cells come from your own body
2. Syngeneic transplant -- Transplanted cells come from an identical twin sibling
3. Allogeneic transplant -- Transplanted cells come from a donor who may be related to you (a family member) or unrelated. The type of transplant you receive depends on your situation.
4. Cord blood -- Transplanted cells come from the umbilical cord and placenta after a baby is born. This blood is rich in blood-forming cells.
5. Mixed chimeric ("mini") transplant -- Transplanted cells come from a family donor or unrelated donor, after a moderate dose of chemotherapy and radiation to set up a mixed immune system.

The difference between the types of transplants has to do with the source of the transplanted cells. In each case, doctors are transplanting stem cells, immature blood cells that are made in the bone marrow. Stem cells grow into mature blood cells of various types.

Autologous Transplant Advantage
The advantage to using your own stem cells is that you will not face the complications of graft-vs.-host disease. However, with an autologous transplant you also do not have the same graft-vs.-tumor benefits. As a result there is a higher relapse rate with autologous transplants, and this type is not suitable for a number of diseases.

Whatever type of transplant you receive, our doctors will pick a donor whose tissue most closely matches yours. The closer the match, the greater your chances for a positive outcome. If you do not have a closely matched relative who can donate bone marrow or stem cells, we will work with the national registries to find an unrelated donor.

Stem Cell Sources

Bone marrow
If you have a bone-marrow transplant, you will receive bone marrow that has been collected from a donor. The donor may be a family member or an unrelated donor whose tissue type closely matches yours.

The doctors collect bone marrow from the hip using large needles. The procedure (harvest) takes about two hours and is performed on the day of transplant while the donor is sedated under anesthesia. Most donors do not need to stay at the hospital overnight. If your donor is a family member who comes with you to Seattle, this procedure will be done at Seattle Children’s or at University of Washington Medical Center, both SCCA partners.

If your donor is an unrelated adult who is not in Seattle, the bone-marrow harvest will be done at a hospital close to where the donor lives and then hand-carried to SCCA.

You will receive the bone-marrow cells by infusion in a procedure that is similar to receiving a blood transfusion. This takes several hours and is not painful.

Peripheral blood
Stem cells are produced in the bone marrow and circulate in the bloodstream. These cells are called peripheral blood stem cells, or PBSCs. If you have a stem cell transplant, you will receive stem cells that have been collected from the blood of the donor—who may be you (autologous transplant) or a sibling, other relative, or a closely matched, unrelated donor (allogeneic transplant).

The autologous stem cell transplant donor may be of any age, but the allogeneic stem cell transplant donor must be older than 12 years.

Before collection, the donor will need to receive several days of daily injections of special proteins called growth factors (G-CSF). These injections encourage stem cells to enter the blood from the bone marrow.

We do PBSC collection in the Apheresis Unit on the fifth floor of the SCCA clinic. The procedure takes several hours, usually over one or two days.

During PBSC collection, the donor’s blood is withdrawn and circulated through a machine that separates out the stem cells and returns the remaining blood cells to the patient. For an autologous transplant, the collection is painless for the donor, who has blood withdrawn through a central intravenous catheter. For an allogeneic transplant, there may be some pain when needles are inserted into the donor’s arms to collect the cells. The donor can watch TV or read during this time. If the donor is a child, parents are encouraged to bring along favorite videos, games, or other quiet activities.

If your donor is an unrelated adult who is not in Seattle, the PBSC collection will be done at a hospital close to where the donor lives and then hand-carried to SCCA.

Cord blood
Like bone marrow, umbilical cord blood contains stem cells. It comes from the umbilical cord of newborn infants and is removed from the placenta after birth and then stored. Once a cord blood match has been identified through the cord blood registry, the cord blood is shipped to SCCA before you start receiving the transplant conditioning regimen.