Previously, blood stem cells were derived predominantly from the bone marrow, the site of their formation. Meanwhile, it is also possible to filter them directly from the blood. We refer the first procedure to as bone marrow removal, it refers the second to as peripheral stem cell sampling.
The body of the donor or the donor replaces the bone marrow or the blood stem cells within a few days on their own. During this time, some people feel cut off. Serious complications after a donation of blood stem cells are very rare. There may be temporary side effects.
Removal from the bone marrow
To get stem cells from the bone marrow, it would remove half a liter to one and a half liters of bone marrow using a special needle from the iliac crest. The amount depends on the stem cell content in the extracted bone marrow. For this purpose, we usually require several punctures at different points of the iliac crest. In the laboratory, the stem cells from the bone marrow are filtered out and processed for transplantation.
The removal of bone marrow is expensive. The donor will receive general anesthesia before surgery and usually stays in the hospital for one to two days. In the first few weeks after the donation, bruising and pain may occur at the injection sites of the needle. Some people are primarily dealing with temporary back pain. In addition, we associate any anesthesia with a risk of complications, and surgical intervention presents a risk of infection. Stem cells are usually removed from the blood nowadays.
Removal from the blood
Peripheral stem cell sampling has the advantage that we need no anesthesia and no hospitalization. Normally, the blood contains few stem cells. Therefore, four to five days before the planned withdrawal, one to two injections of an active ingredient under the skin (subcutaneously) resembles a body’s own hormone. The preparation is a so-called growth factor, the so-called G-CSF (granulocyte colony-stimulating factor). He stimulates the blood stem cells to migrate from the bone marrow into the blood.
After a few days there are enough stem cells in the blood. Then the blood from an arm vein is led via a tube into a special centrifuge, the so-called blood cell separator. There, it separates the stem cells from the blood (apheresis). It then returns the blood via a second tube in a vein on the other arm in the body. The apheresis takes about two to three hours. They usually perform the stem cell survey on an outpatient basis. However, to get enough stem cells, this process often has to be repeated once or twice on the following days.
The advantage of stem cell harvesting from the blood compared to harvesting from bone marrow is that it can be done without anesthesia.
But it can also cause side effects. The growth factor can temporarily cause discomfort such as limb, head or bone pain.
Stem cell production from umbilical cord blood
Another possibility is to extract stem cells from the umbilical cord blood and the infantile portion of the mother’s cake (placenta). With the consent of the parents, the blood can be donated anonymously to a public umbilical cord blood bank. There are also private umbilical cord blood banks where the umbilical cord blood can be kept at a charge for the child itself. However, according to the current state of knowledge, it is very unlikely that the newborn will benefit later in life. In the most common childhood and adolescent cancers, such as leukemia n, transplantation with its own stem cells is out of the question. The cancer cells may already be present in the graft and could then be retransmitted. Stem cells from umbilical cord blood are transplanted only to foreign recipients.