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Bone marrow versus stem cell transplant – what’s the difference?

May 09, 2019 by Gift of Life News

Nicole donating stem cells through apheresis. A small bag of hematopoietic stem cells has the power to save a life!


Leukemia. Lymphoma. Sickle cell disease. Hyper IGM.

These are just four of nearly 100 frightening and life-threatening diseases that modern medicine can now often cure through a bone marrow or stem cell transplant. But why are there two kinds of transplants? The short answer is that there aren’t, it’s just two ways of collecting the stem cells needed for transplant.

Both methods collect hematopoietic stem cells (HSC) from the volunteer donor. The red bone marrow produces HSC, which give rise to all blood cells in the amounts needed for us (and all other vertebrates) to thrive. The average person makes more than 500 billion blood cells each day. Hematopoietic stem cells renew themselves, so collecting them does no harm to the donor.

The goal of transplantation is to completely replace a patient’s bone marrow and immune system with a new system that works as it should, and is free of cancer or the other dysfunctions that are threatening the patient’s life.


Stem cell collection

Peripheral blood stem cell collection is through a process called apheresis. The circulating blood (the blood in our veins) contains smaller amounts of HSC, but we can increase this amount by administering a bone marrow stimulant called filgrastim. The extra stem cells produced flow into the bloodstream where they are easy to collect.

While the donor sits up in a hospital bed or chair, a needle in one arm sends blood to the apheresis machine, where a centrifuge and filters sort the stem cells from the rest of the blood. The stem cells are sent to a small collection bag, and the remaining blood is returned through the donor’s other arm. The process takes four to six hours, depending on the amount of cells requested by the transplant center.

Most stem cell donors feel a bit tired afterward, but fully recover within 24 to 48 hours. Eighty percent of collections use this method.Stem cells collected from bone marrow have the power to cure blood cancer, sickle cell disease, and inherited immune disorders.


Bone marrow collection

Bone marrow collection requires the donor to be under general anesthesia. A doctor uses a syringe to draw bone marrow from within the iliac crest of the hip bone. The process takes one-two hours, and once donors recover from the anesthesia, they go home. Most donors feel some form of back ache for one to three days afterwards, easily treated with Tylenol and similar products. Most donors feel fully recovered in two to five days. Twenty percent of collections are for bone marrow, most often requested for children.

For either method of collection, the transplanted stem cells are given to the recipient through an infusion into the bloodstream. The cells naturally find their way into the patient’s largest bones and begin creating new, healthy bone marrow, blood cells and immune system that all function as they should.


Julio Rivera was saved by a marrow transplant from his donor Ryan Corning.


The chance to become a hero

Stem cell and marrow transplants are the treatment of last resort, used to cure about 100 life threatening conditions. That number grows every year as researchers discover new medical advancements.

For the transplant to work, the recipient’s own bone marrow is destroyed through a combination of chemo- and radiation therapies. Once this process begins, the patient will not survive if the collection and transplant do not happen on time, so it’s incredibly important that every donor called for transplant be committed to completing the process.

Nearly every donor tells us that they knew they’d be changing someone else’s life, but did not expect that saving a life would lead to a big personal change in them. The chance to give life to another person is an incredible opportunity, and many donors and recipients go on to become friends for life.

To learn more about how we find matches between donors and patients, click here to read our article on Tissue Typing. 


To order your swab kit and join the registry for your chance to save a life, click here

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