Stem Cell Transplant
A stem cell transplant is a procedure that is coupled with high doses of chemotherapy and may be used to treat certain types of blood cancer, such as some forms of leukemia, lymphoma, and multiple myeloma. Stem cell transplants restore the immature cells (stem cells) that are depleted from the high doses of chemotherapy. Stem cells develop into the different types of blood cells, including red blood cells, white blood cells, and platelets.1
In some types of blood cancer, a stem cell transplant may provide the best chance of a cure for the disease. However, stem cell transplants are not an option in all types of blood cancer or in all patients. Stem cell transplants can be very taxing on a person's body and may not be an option for people with other health conditions or older patients.
Two types of stem cell transplants
There are two types of stem cell transplants:
- Autologous, in which the stem cells are retrieved from the patient prior to receiving chemotherapy
- Allogeneic, in which the stem cells are donated by another person1
In allogeneic stem cell transplants, the donor's blood cells must match the recipient's blood cells as closely as possible to reduce the risk of possible side effects and to reduce the possibility of the transplant not being successful. Doctors test the proteins, called human leukocyte-associated (HLA) antigens, found on the surface of the blood cells through a blood test.2
How a stem cell transplant works
Chemotherapy attacks fast-growing cells, which includes cancer cells but also healthy cells that grow quickly like blood cells. The high doses of chemotherapy used with a stem cell transplant are effective on blood cancer cells but can also damage the healthy blood cells. By replacing the stem cells with a self (autologous) or donor (allogeneic) transplant, the body can rebound as the infused stem cells become new, healthy blood cells.
In addition to replacing the stem cells, stem cell transplants also help treat certain blood cancers (like certain forms of leukemia) in a different way. The donor's stem cells can also directly fight the blood cancer cells. This is called a "graft-versus-cancer" effect (graft refers to the donor's cells).3
What to expect
Before a stem cell transplant, patients are evaluated with a series of tests, which may include blood tests, a complete health history and physical exam, and heart function tests. In general, younger people tend to do better with stem cell transplants than older patients. However, each individual should discuss with their doctor about their potential treatment options and the possible risks and benefits of each.4
In cases where an autologous transplant is used, the stem cells will be gathered from the patient using a machine which filters the stem cells out from the rest of the blood. The other blood components are returned to the patient. In an allogeneic stem cell transplant, the stem cells are collected from a donor who has a similar HLA profile to the patient. The donor may be someone related to the patient or someone who is not related.4
After the stem cells are collected, the patient will receive conditioning treatment: high-dose chemotherapy and/or radiation therapy. This treatment will kill any remaining cancer cells and also suppresses the patient's immune system to lessen the risk of a rejection of the donor's cells. The high doses of chemotherapy and/or full-body radiation can cause significant and painful side effects, and it may take many months to fully recover. In addition, some long-term side effects may be permanent, such as infertility (the inability to conceive a child).4
The stem cells are given to the patient a few days after the conditioning treatment. The stem cells are delivered similar to a blood transfusion, and while the process is pretty simple, the receiving of the stem cells can have great significance for the patient.4
After the stem cell transplant, the patient will be in a recovery stage. In the recovery stage, patients are monitored regularly to see if the stem cells engraft, meaning they begin to multiply and create new blood cells. During this time, blood cell counts are still very low, and there is an increased risk of infection. Patients may receive antibiotics or other medications to treat or prevent infections, and some patients may need a blood transfusion to replace the depleted blood cells.4
Possible side effects of stem cell transplants
The high doses of chemotherapy during the conditioning treatment can cause side effects such as nausea, vomiting, hair loss, mouth sores, breathing problems, and increased risks of infection and bleeding. The infusion of stem cells may cause side effects such as fever, chills, shortness of breath or coughing, hives, low blood pressure, chest pain, and weakness.1,4
For people who have an allogeneic stem cell transplant, there is a possible side effect called graft-versus-host disease (GVHD), in which the donor's cells attack certain organs in the patient's body. GVHD can range from mild to life-threatening.5
Patients should talk to their doctor if they have any questions, or if they have questions regarding their stem cell transplant. Before receiving a stem cell transplant, patients should tell their doctor about all their health conditions, as well as any medications (prescription and over-the-counter), herbal supplements, and vitamins they are taking.
These are not all the possible side effects of a stem cell transplant. Patients should talk to their doctor about what to expect when receiving a stem cell transplant.