Articles from prior issues of The Advocate

September/October, 1998

Revolutionizing Donation Options
Peripheral Blood Stem Cell Transplant Becomes New Treatment Option

ONE OF THE MOST EXCITING aspects of the marrow transplant field is the ongoing research to improve the outcomes for patients who need marrow transplants. One donation technique showing promise in sibling donor transplantation is now being considered for unrelated donors. This new procedure is called peripheral blood stem cell (PBSC) donation. Instead of undergoing a surgical procedure for donation, donating PBSC is similar to donating platelets at a blood bank. The donor’s blood is taken from a vein in one arm and passed through an apheresis machine that separates out the stem cells. The remaining blood, minus the stem cells is returned to the donor through a needle placed in a vein in the other arm. (See 8 steps of PBSC Donation on the following page) Stem cells, the cells that transplant patients need to make new healthy marrow, usually live in bone marrow, but are also released in small numbers into the circulating (peripheral) blood. Stem cells are the immature cells that can develop into any of the cells present in the blood stream: red blood cells, white blood cells, or platelets. The numbers of stem cells normally present in the blood are very low, but they can be increased dramatically by medications (growth factors such as Filgrastim) that stimulate the bone marrow. Peripheral blood stem cell transplantation is becoming the preferred treatment for many transplant patients. The reason is that stem cells transplanted from peripheral blood start to produce new white cells and platelets faster than stem cells transplanted from bone marrow. This is important because transplant patients are susceptible to life threatening infections and bleeding until their white blood cell and platelet counts return to normal levels. PBSC collection may have advantage for donors as well. Unlike a marrow donation, a PBSC donation doesn’t require anesthesia, which is a primary health consideration for some donors. (See comparison chart of donation procedures below.)

SOME BACKGROUND

In 1997, the NMDP, working with the Food and Drug Administration (FDA), developed a program that allowed PBSC to be donated to patients whose first transplant failed to grow (engraft), or whose disease returned. Because PBSC usually engraft faster than marrow, physicians believe that a second transplant using PBSC is potentially more beneficial for these patients. Already, more than 70 NMDP donors have donated PBSC to patients who needed a second transplant. Because of the promising results of PBSC for transplantation, the NMDP is asking permission from the FDA to collect PBSC instead of marrow when the transplant physician believes it to be the best choice for a patient’s first transplant. This means that if physicians believe PBSC to be the best choice for their patients, volunteer donors may be asked to consider PBSC donations instead of marrow for patients in the near future. When an NMDP volunteer donor is identified as a potential match for a patient, the donor is asked to undergo additional tests to determine whether he or she is a full match. At this point, potential donors will be told which type of stem cell donation (marrow or PBSC) the transplant physician is seeking. The donation type, therefore, will depend on the physician’s request. As always, volunteer donors are free to decline a stem cell request (either bone marrow or PBSC) without affecting their future relationship with the NMDP. However, with two donation procedures now available, the NMDP hopes to give donors more opportunities to assist patients needing a second chance at life through a stem cell transplant. Peripheral blood stem cell collections are now being used for some second donations for the same patients, and may be used for primary donations in the near future. The process will proceed as follows:

1You are identified as a match and contacted for donation. The trans- plant center will determine whether it prefers peripheral blood stem cells or marrow or either product for the patient who needs a transplant.

2 An information session is ar- ranged between you, the donor center coordinator and the medical director. At the information session, the blood stem cell donation process will be explained to you, including the side-effects of the growth factor along with the possible benefits of this procedure to the patient. Information about marrow donation may also be presented.

3You decide whether to participate After being fully informed about the blood stem cell donation process, you make the decision - with the support of your family and friends - to go through with the blood stem cell collection after receiving the growth factor. After you have made your decision and before the process begins, you will undergo a physical examination.

4You receive a growth factor by injection daily for five consecu- tive days. The injections are usually given by a medical professional and may be administered at the donor center of a designated clinic near you. In some cases, a home health nurse may administer the injections. Common side effects include bone or muscle aches, headaches and fatigue. Less often, nausea, vomiting, insomnia and irritability may occur. These risks will be explained to you, in detail, at your information session.

5Your stem cells multiply as you receive the injections. The growth factor causes the bone marrow to release the necessary cells (stem cells) into your blood stream.

6Your stem cells are collected through a blood cell separation procedure called apheresis. This is the same procedure used by blood centers to collect platelets. In that procedure, blood is removed with a needle inserted in one arm and is sent to a machine that separates out the stem cells. The remaining blood is returned through a tube and needle inserted in your other arm. The collection procedure will require approximately 4 1/2 hours to complete. If your stem cells cannot be collected using the veins in your forearm, a plastic tube, called a central line, is placed in a large vein. (According to recent studies, 1 in 6 PBSC donors required a central line.)

7The patient is transferred with your blood stem cells. Early re- sults indicate that patients receiving stimulated peripheral blood stem cells may experience more rapid blood count recovery than those receiving bone marrow.

8Your recovery should be rapid. A hospital stay is not a part of the peripheral blood stem cell collection since general anesthesia is not used. The side effects of the growth factor diminish over one to two days after the last dose of the drug is given.