The Bone marrow transplants Bone are the last hope for many people suffering from serious diseases such as lymphomas or leukemia. About 20,000 people around the world need a bone marrow transplant each year (Health Resources and Services Administration, s.f.).
It is estimated that approximately 1000 people die each year without finding a bone marrow donor. If you have decided to be a donor, you are thinking about it or you need a bone marrow donation, I will explain the whole procedure step by step, as well as the previous considerations and the risks that it has.
What is a bone marrow transplant?
A bone marrow transplant is a procedure in which some mother cells Of the bone marrow that are damaged or destroyed by Cells Healthy
The cells transplanted in this procedure are multipotent hematopoietic stem cells which, in addition to the bone marrow, can come from the umbilical cord or from the blood.
Multipotent hematopoietic stem cells are a type of cells that can mature into any of the blood cells through a procedure called Hematopoiesis .
When these stem cells are transplanted, they are expected to mature and create healthy blood cells to heal or ameliorate the patient's symptoms.
There are three types of blood cells that fulfill the following vital functions:
- Red blood cells , Which carry oxygen and nutrients to all tissues of the body.
- Platelets , Which form a barrier (blood clots) to stop bleeding.
- White blood cells , Which are part of the immune system and fight infection and disease.
Types of Bone Marrow Transplants
There are three types of bone marrow transplantation:
Bone marrow transplant
In this type of transplantation the stem cells are the patient's own. This procedure is usually done when the person is going to receive a chemotherapy or radiation treatment to practice what is called a rescue transplant.
Stem cells are extracted from the marrow before the patient receives therapy and are stored frozen until the time of transplantation. Chemotherapy and radiation therapy damage cells , So when the patient finishes the therapy they are reintroduced their stem cells in the bone marrow so that they create new healthy cells.
Bone marrow transplant
In this type of bone marrow transplant, the stem cells come from another person, a donor. The donor stem cells must be compatible with those of the patient, so it is usually sought before a donor within the family, usually siblings or parents.
But, on many occasions, no compatible family member is found, so it is necessary to look for an unknown donor through the national register of bone marrow donors.
Umbilical cord blood transplantation
As I mentioned before, hematopoietic stem cells can also be obtained from the umbilical cord. In this procedure the stem cells are extracted from the umbilical cord of a baby just after it is born.
These cells are frozen and stored until transplantation is necessary. This type of transplant has advantages and disadvantages.
The main advantage is that cord stem cells are more immature than can be obtained from the cord, making them simpler (more generic) and easier to be compatible with the patient. But being immature is not always an advantage, as they also take longer to mature and become adult blood cells.
Why is this procedure performed?
Marrow transplants are performed to replace bone marrow cells that have been damaged or destroyed, either by disease or by treatment.
The main causes for needing a bone marrow transplant are:
- Having cancer of the blood or bone marrow, such as leukemia , Lymphoma , Myelodysplasia or multiple myeloma .
- Having a disease that affects the production of cells in the bone marrow, such as Aplastic anemia , Congenital neutropenia , Severe immunodeficiency syndromes , Sickle cell disease and Thalassemia .
- Have received chemotherapy or radiation therapy.
Who can be a donor?
Stem cell donors, whether from bone marrow, blood or umbilical cord, should have the following characteristics:
- Usually be between 18 and 60 years, although there are some countries in which the age varies a bit.
- Do not have health problems.
- Be prepared to donate to any person at any time, although the donor has the right to refuse to donate if called.
- If you want to donate the umbilical cord of your future baby you must register yourself in the national marrow donation system in your country well in advance of delivery.
There are currently 27,810,532 bone marrow donors registered worldwide, if you want to take the step and register you can find out how to do it on the website of the World Association of Donors (WMDA, World Marrow Donor Association ).
Risks
Like any medical procedure, bone marrow transplants have risks, both for the patient and the donor, that must be taken into account before performing the operation.
For the donor
Although there is some risk to the donor, in 99% of cases they recover completely after the procedure. The risks of the procedure depend on the type of transplant:
- Extraction of the bone marrow from the pelvis
The possible complications of this procedure are the same as those of any procedure requiring a general anesthesia .
When waking up from anesthesia the donor may feel nausea and / or pain or discomfort in the area where the extraction is being performed. You may have some bruises after the procedure.
However, the likelihood of further complications is quite low.
- Extraction of peripheral blood stem cells
To perform this procedure it is necessary that days before the donor receives injections of a substance called Granulocyte colony stimulating factor (GCSF) so that the stem cells leave the marrow and can be obtained from the blood.
Some donors experience some symptoms after receiving flu-like injections and bone pain. Most of these symptoms pass quickly after receiving the appropriate medication, only 1% of the donors experience more serious symptoms.
- Extraction of blood from the umbilical cord
This type of procedure has no risk since it is done once the cord has already been cut.
For the patient
The symptoms and complications that can arise to the patient after a bone marrow transplant depends on multiple factors, among which are:
- The specific illness of the patient.
- If you have received chemotherapy or radiation therapy before transplantation and what characteristics you have (duration, frequency and intensity).
- The patient's age and health status.
- Donor compatibility.
- The type of transplant.
During the procedure, the patient may experience symptoms such as chest pain, lowering of blood pressure, Headaches , Nausea, localized pain, and shortness of breath. Although the procedure has been markedly improved, there is still a high probability of complications, the most important being:
- Increased infections
The risk of infection increases markedly after transplantation as the patient's immune system is weakened. Some infections can have a drastic effect on the patient's health. The immune system is recovering as time passes, so the risk of getting infections is slowing.
- Graft-versus-host disease (GvHD)
This disease is very common in patients who have received a donation of blood stem cells and its effects can be from mild to fatal. He GvHD Occurs because the donor cells attack the patient's.
GvHD occurs between 90-100 days after receiving the transplant, although it can be chronified and remain throughout life.
- Graft failure
The graft is said to have failed when the transplanted cells fail to function properly, causing the patient's immune system, which is rejecting the cells received. This can occur if the number or quality of the transplanted cells is insufficient or if they were damaged or intoxicated before the transplant.
Other complications that can have this procedure are the anemia, the appearance of hemorrhages in internal organs (including intestines, brain And lungs), cataracts, clotting of veins in the liver, damage to some organs (such as kidneys, lungs, livers and heart), mucositis (inflammation and pain in the mouth, throat, esophagus and stomach) and problems Of stomach (eg, diarrhea, nausea and vomiting).
In addition, if the transplant is performed on children or women, it may have additional complications, such as growth retardation in the case of children and advancement of menopause in the case of women.
Procedure description
For donors
- Before the procedure
The first step, obviously, is to be informed and registered in your country's bone marrow donation system. Once done, you are likely to be called to perform a transplant.
Before proceeding, the doctor should inform you and explain both the procedure and the risks you have.
For the transplant, the doctors will check that it fulfills the requirements, for it will examine its state of health and will analyze its cells to see if it is compatible with the patient.
- The donation
There are three types of procedures through which stem cells can be donated:
- Extraction of the bone marrow from the pelvis . This procedure usually does not last more than two hours and consists of the extraction of stem cells from the part of the marrow that is inside the bone of the pelvis with a small surgery. Throughout the procedure the donor is under the effects of general anesthesia, so he will be asleep and will not feel pain.
- Extraction of peripheral blood stem cells . A few days before performing this procedure, the donor must have received injections of GCSF so that there is more amount of stem cells in his blood. The donation usually takes place in a hospital or a donation center with the necessary machinery.
The procedure consists of the insertion of a pathway in the vein of the arm so that the blood leaves and passes through a machine that separates the stem cells. The rest of the blood returns to the donor immediately. The whole procedure can last between 3 and 4 hours.
- Extraction of cord blood. This type of donation is very simple. Once he drinks he has been born and it has been proven that he and his mother are well cut off the umbilical cord and collect blood from him with a syringe to later freeze and store it.
- After the procedure
After donating bone marrow cells it is usually necessary to stay under observation one day to check that all is well.
If the donation has been of peripheral blood it is not necessary to stay entered but it is normal that they contact the donor by telephone to verify how it is.
For patients
- Before the procedure
Normally, prior to transplantation, the patient is treated with chemotherapy or radiotherapy . This is done, first, to destroy bone marrow blood cells that are not working well, and thus make room for the stem cells that will arrive with the transplant. And secondly to lower the patient's defenses so that his immune system does not attack the new cells.
The treatment of chemotherapy and / or radiotherapy can be done in two ways:
- Ablative treatment (myeloablative). The patient receives high doses of chemotherapy, radiation therapy or both to kill cancer cells (if cancer) and bone marrow cells that do not work well.
- Reduced intensity treatment (mini-transplant) . This therapy is used with children, the elderly and patients with other health problems (in addition to those who have taken the transplant). In this treatment the dose of chemotherapy or radiotherapy is much lower than in the previous treatment.
In addition to these treatments, before the transplant, the patient's health status will be evaluated, the procedure will be explained and he will be advised to leave some things closed before the transplant, as well as to consult a specialist to prepare him psychologically for the test if required.
Among the things that are advised to do before the transplant are:
- Fill in an advance directive for health care. These are the instructions doctors should follow if there is any medical complication.
- Warn on the job and unsubscribe if you had not already done so.
- Find someone who can take care of you and help you at home when you are discharged.
- Pay the bills.
- Agree who will take care of your children or pets.
The transplant
Stem cell transplantation is very simple, it is similar to a blood transfusion. The procedure is performed by inserting a catheter In the arm or neck of the patient where they will receive blood with healthy stem cells that travel through the bloodstream to the bone marrow and, if all goes well, will begin to create healthy blood cells.
Another catheter is usually inserted so that the patient can receive medication or nutrients if any complications arise.
After the Procedure
The patient should be admitted to the hospital under observation until their immune system has been recovered and the transplant has gone well.
During the hospital stay you will need to take medicines to prevent infections and GvHD disease, in addition you will receive blood transfusions and, if you suffer Mucositis , You will be given the nutrients intravenously.
The length of time you will stay in the hospital depends on what type of chemotherapy or radiation therapy you have received, the type of transplant, and any complications that may have arisen.
If you need a transplant of marrow, peripheral blood or umbilical cord blood, I recommend you read the following guide of the Josep Carreras Foundation against leukemia:
References
- Cancer.Net. (January 2016). Bone Marrow / Stem Cell Transplantation . Obtained from Cancer.Net.
- Chen, Y.-B. (January 27, 2015). Bone marrow transplant . Obtained from MedlinePlus.
- Josep Carreras Foundation. (S.f.). A total of 1 million stem cell transplants have been performed worldwide . Retrieved on June 16, 2016, from Josep Carreras Foundation.
- Health Resources and Services Administration (HRSA). (S.f.). Blood cell transplant: General Frequently Asked Questions . Retrieved on June 16, 2016, from HRSA.
- World Marrow Donor Association, WMDA. (S.f.). Retrieved on June 16, 2016, from WMDA.