What is a bone marrow transplant?
Unlike a regular organ transplant (heart, liver, kidney e.g.) where the diseased organ is removed and replaced by a healthy donor organ, the bone marrow is not one organ. It is the loose tissue in the center of every bone in our body. The outer hard part is the cortex; the marrow occupies the inner hollow. It consists of a loose mesh of blood vessels and a fibrin network, which support “stem” cells, which go on to differentiate into the different cell lines, which go on to be circulating blood cells, which we talked about earlier in “what is a CBC”.
When we give chemotherapy to eradicate cancer cells in most other organ systems, we are limited by the damage that is done to the stem cells in the bone marrow. We need enough surviving stem cells, to replace the ones that are destroyed by chemotherapy.
Sometimes it is necessary to give that amount of chemotherapy to eradicate the cancer cells. Then, the bone marrow needs to be repopulated by stem cells, or bone marrow cells. This is the essence of a bone marrow transplant.
What is an autologous transplant?
Stem cells can be harvested from the patient in a multistep process. First the cancer is eradicated by regular chemotherapy. Next, the bone marrow is stimulated by injections to make it go into overdrive, and an abundance of stem cells get into circulation. The stem cells are separated from regular cells by running the circulating blood through a cell separator machine, and giving the remaining blood back, somewhat like dialysis. Next, the patient gets immunosuppressive chemotherapy, and the stem cells are infused back to complete the recovery. Antibiotics and anti viral medications are required till the normal white cells are present in adequate numbers.
What is an allogeneic transplant?
If the disease is in the bone marrow itself, can you get rid of the disease and harvest enough stem cells to do the job? Some leukemias require donor marrow to repopulate. The donor marrow has to be properly matched to the host tissue. In addition to providing the stem cells, the donor cells also provoke a “graft vs. host” effect, which can actually be beneficial. However, this may also result in additional toxicity, as the immune battle is carried out in the liver, skin and gastrointestinal tract.
Should I store my baby’s umbilical cord cells, for future use, in case he or she needs it?
It’s good business for the companies providing the service. It’s unlikely you will need it. If you do, it will likely be decades hence. Will those cells be viable decades down the road? If doing so buys you peace of mind, sure.
I haven’t stored any umbilical cord cells. When my children grow up, the landscape of treating cancer will be vastly different from today. The transplant wards that I did my residency and fellowship rotations are dramatically different in the technology and medications. The odds are very low that they will need their cord cells, and I would rather save the money in a college fund.