There are many terms that describe the transplant process: bone marrow transplant, stem cell transplant, peripheral blood transplant and umbilical cord blood transplant. These terms generally refer to the same type of transplant, using different sources of stem cells.
Patients requiring transplant have stem cells taken from one of these sources: bone marrow, peripheral blood or umbilical cord blood. The stem cells are primitive cells in the marrow that are important in making red blood cells, white blood cells and platelets. The stem cells are largely found in the marrow, but some leave the marrow and circulate in the peripheral blood.
The stem cells can be harvested or collected from the bone marrow, the peripheral blood or the cord blood of a newborn child. Regardless of the source from where the stem cells are collected, we refer to this process as a Blood and Marrow Transplant.
There are two basic types of transplants – Autologous and Allogeneic.
Autologous Stem Cell Transplant
In an autologous stem cell transplant, the stem cells are collected from the patient and stored. An important component of transplant is that enough stem cells are collected to ensure engraftment. Peripheral blood stem cell collection and/or bone marrow harvest are necessary to obtain a satisfactory number of stem cells. This type of transplant can be used to treat many diseases such as multiple myeloma, non-Hodgkin’s lymphoma, Hodgkin’s disease, testicular cancer and occasionally leukemia.
After the stem cells are collected from the patient and stored, he/she is admitted to the hospital. High doses of chemotherapy are given through a central line directly into the venous (vein) system. The chemotherapy regimen will last over a period of days, depending on the specific treatment protocol.
This high-dose therapy reduces the disease by attacking any remaining cancer cells. As with all chemotherapy, healthy cells are also affected. It is common to have side effects such as nausea, vomiting, diarrhea, hair loss and mouth sores. Medications will be given to help control these symptoms. Prior to transplant, patients will also meet with one of our experienced transplant coordinators and inpatient clinicians to discuss what to expect with their treatment regimen and symptom management.
Following the preparative regimen (high-dose chemotherapy), the stem cells are then re-infused through the central catheter. Growth factors begin five days following the stem cell infusion, continuing daily until the white blood cell (WBC) count recovers.
The immune system will be affected by the chemotherapy, and there is a risk for developing serious infections. There is the need for antibiotics, blood and platelet transfusions and frequent blood tests to monitor blood counts. Special precautions are followed in order to prevent infection and bleeding. Hospitalization is usually required for two to four weeks. However, we do offer a limited-stay transplant option for some of our autologous transplant patients who meet certain criteria. Ask your transplant coordinator or physician if you’re interested in this option.
Following discharge from the hospital, there are frequent doctor visits, blood tests, blood and platelet transfusions and growth factor injections. Full recovery can take up to three to six months and in some cases longer.
Allogeneic Stem Cell Transplant
An allogeneic stem cell transplant uses the stem cells collected from a donor rather than using the patient’s own stem cells. Allogeneic stem cell transplants are most frequently used to treat patients with leukemia, lymphomas, including Hodgkin’s disease and non-Hodgkin’s lymphoma, and types of bone marrow failure disorders. However, the types of diseases that are treated with allogeneic transplant are constantly expanding.
An allogeneic stem cell transplant differs from autologous transplant because the patient requires a donation of stem cells from a closely matched family member (usually a brother or sister) or a person unrelated to the patient.
Identifying a donor can take weeks to months. A well-matched donor is important to the success of the transplant, and the time it takes to locate a match varies from patient to patient.
Once a donor is identified and screened for eligibility, the patient’s treatment is scheduled. The patient receives a central venous catheter upon admission, or shortly before admission. Before transplant, the patient will receive a high-dose chemotherapy regimen and in some cases total body irradiation. This can take up to a week depending on the treatment protocol.
The donor’s stem cells may be harvested before the patient starts high-dose chemotherapy, but frequently the donor’s stem cells are collected the day of infusion (transplant day 0).
Following completion of chemotherapy and/or radiation, there may or may not be a period of rest for one to two days. Then the donor stem cells or bone marrow is infused into the patient via the central venous catheter.
Over the next two to four weeks, the patient is at severe risk for developing infection and side effects related to chemotherapy. Antibiotics are given to try to prevent and treat infection. Blood and platelet transfusions are administered and frequent tests and monitoring will be done to try to prevent serious chemotherapy side effects. Medications can be given to help control any symptoms that may be experienced including nausea, diarrhea and pain. Our transplant nurses and staff are all specially trained to care for our patients during this highly critical time and monitor patients very closely for side effects.
When the WBC count starts to recover, patients are at risk for developing graft-versus-host disease. Graft-versus-host disease is a side effect caused when the donated stem cells (the graft) recognize specific cells and tissue in the patient’s body (the host) as being foreign and launch an attack. Patients are monitored very closely for this side effect by our staff, as it can become very serious if not treated quickly. Medications are given to prevent and treat graft-versus-host disease.
Patients receiving allogeneic stem cell transplants are usually admitted to the hospital for three to four weeks. Following discharge from the hospital, daily outpatient visits are required for an extended period of time. Patients will be evaluated for graft-versus-host disease, infection, and any other adverse effects. Depending on the severity of symptoms, some patients may require readmission to the hospital for treatment of complications. Recovery is complex and varies from patient to patient.
Types of Allogeneic Stem Cell Transplant
Listed below are the different types of allogeneic stem cell transplant options available for patients. Be sure to discuss all of your options with your physician to find out which transplant type is right for you.
Matched Related Transplant
This transplant option is the classic option for patients and involves a fully matched sibling donor. Typically physicians will start a search for a donor by typing any full-blooded siblings who are willing to donate. Each brother and sister with the same parents as you has a 25% (1 in 4) chance of matching you. Fully matched sibling transplants are preferred due to the decreased risk for graft-versus-host disease.
Syngeneic Stem Cell Transplant
This transplant option is available to patients who have an identical twin sibling to donate stem cells. Although a syngeneic transplant consists of cells collected from a donor (making it an allogeneic transplant), this type of transplant is very similar to an autologous transplant. This is because the twin’s genetic makeup is exactly the same as the patient’s genetic makeup, thereby eliminating the risk of graft-versus-host disease.
Matched Unrelated Donor Transplant
Although physicians typically try to find a matched sibling donor transplant, this option isn’t always available for all of our patients. In fact, 70% of patients (7 of 10) do not have a match in their family. For these patients, doctors and transplant coordinators work together with the National Marrow Donor Program (NMDP) and other registries around the world to find a matching unrelated donor. Patients receiving stem cells from an unrelated donor may have more complications associated with graft-versus-host disease.
A haploidentical transplant option is an alternative donor option for patients who do not have a fully matched sibling or unrelated donor. When no matched donor is available, half-matched (haploidentical) donors are now safely used in stem cell transplantation. These donors may be related or unrelated. There are some increased risks associated with this type of transplant, including engraftment failure and increased risk of graft-versus-host disease; however, the Blood Cancer Center has found great success using this alternative donor source. As with every transplant we do, patients receiving this type of transplant are closely monitored for side effects.
Umbilical Cord Blood Transplant
An umbilical cord blood transplant is another type of alternative donor option for patients who do not have a fully matched sibling or unrelated donor. It is a stem cell transplant that uses cord blood from a newborn baby instead of bone marrow or peripheral blood as the source of stem cells. This process does not harm the mother or baby. Umbilical cord transplants are a great option; however, due to the small volume, they may not work for every patient and are typically more successful in children. Risks include delayed engraftment and risk for graft rejection.