In the United States today, doctors diagnose a new case of blood cancer approximately every three minutes. For many, their only hope is a bone marrow transplant.
We take a look at 10 key facts about bone marrow transplants, from their development to their potential in curing a range of debilitating and life-threatening diseases.
The first successful bone marrow transplant took place in 1956.
Doctors first tried to treat patients by a bone marrow transplants in the early 1900s. Clinicians administered bone marrow by mouth. This method proved ineffective.
New York physician Dr. E. Donnall Thomas carried out the first successful bone marrow transplant in 1956. Sourcing healthy bone marrow from the patient’s identical twin, Dr. Thomas used it to treat the patient’s leukemia.
The donor and recipient need not be related for successful engraftment.
The first step in finding a match is usually to test family members. A patient’s sibling is far more likely to be a match than his or her parents, but a match can come from outside the family.
The key to deciding compatibility lies in human leukocyte antigens (HLA). These are proteins located on the surface of tissue and blood cells. Doctors must ensure donor and recipient HLA are a close match. If they do not, the recipient’s body will reject the donor’s bone marrow.
Additionally, if they are not a close enough match, a reaction known as “graft versus host disease” could arise in the patient. With this condition, the bone marrow begins reacting against the recipient’s body.
Bone marrow cells are a type of stem cell.
This soft, sponge-like material contains hematopoietic stem cells. These cells are responsible for producing blood cells through the cell division process. They generate red blood cells to deliver oxygen, white blood cells to fight infection, and platelets to make the blood clot.
Bone marrow transplant recipients undergo high doses of chemotherapy.
Sometimes specialists employ whole body radiotherapy, with the aim of killing off the recipient’s bone marrow stores completely. In blood cancer patients, this has the beneficial effect of killing cancer cells. In all recipients it is necessary to kill off existing bone marrow stem cells, effectively resetting the body to zero.
Clinicians harvest stem cells from the donor’s blood or bone marrow.
Doctors extract peripheral blood cells via a needle inserted in the donor’s arm. The donor’s blood then passes through a special machine. This machine removes stem cells from the donor’s blood before returning blood to the donor’s body via a second needle inserted in the other arm. Doctors may need to repeat the procedure several times in order to collect an adequate amount of stem cells for the transplant.
Alternatively, clinicians can harvest stem cells directly from bone marrow. Bone marrow is usually collected from the hip bone, or sometimes the sternum. Specialists anesthetize the donor, who should feel no pain during the process, though he or she may feel discomfort at the procedure site afterwards.
Doctors introduce bone marrow to the recipient through an IV drip.
Clinicians insert a catheter to introduce the donor stem cells to the recipient’s blood stream. The procedure, similar to a blood transfusion, effectively “seeds” the recipient’s body with healthy stem cells. They then migrate to bone marrow and begin producing normal red blood cells.
Engraftment occurs when the recipient begins producing red blood cells.
Engraftment usually begins 15-30 days after the transplant. However, delays can occur because of low stem cell count, infection, medicines, or graft failure. It may take months or even years for the recipient’s immune system to recover following a bone marrow transplant.
There are over 25 million people registered as bone marrow donors worldwide.
The first successful non-relative bone marrow transplant took place in 1973. Since then, international registries have played a pivotal role in matching donors and patients.
Internationally, doctors have carried out over 1 million stem cell transplants.
The majority of transplants were in the form of peripheral blood and bone marrow transplants. The procedure has improved a great deal since the dawn of the 21st century due to increased scientific awareness in stem cell research.
Bone marrow transplants have been used to cure a number of diseases.
Bone marrow transplants have been instrumental in the treatment of a range of cancers such as leukemia, germ cell ovarian cancer, testicular cancer, and medulloblastoma. The procedure has also proved very effective in the treatment of a range of rare genetic diseases, tackling the illness on a cellular level, in many cases curing the patient completely.
Bone marrow transplants have proven effective in the treatment of: Diamond Blackfan syndrome, thalassemia, Fanconi anemia, polycythemia vera, Hurler syndrome, Krabbe disease, sickle cell disease, and Hodgkin lymphoma.