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What is an Allogeneic Transplant?

An allogeneic stem cell transplant (or allogeneic bone marrow transplant) is a procedure in which a patient receives healthy stem cells from a donor. Either blood or bone marrow is collected from the donor and then passed through a machine that separates the stem cells. The patient then receives the stem cells through a central venous catheter (central line).

Why is allogeneic hematopoietic stem cell transplantation used?

An allogeneic bone marrow transplant may be used to treat types of lymphomaleukemiamultiple myeloma and myelodysplastic syndrome, as well as other disorders. Conditions such as these affect the blood and/or bone marrow, so they can’t be treated by surgically removing a tumor, as may be the case with other cancers. Instead, systemic treatments (treatments that affect the whole body) like chemotherapy are typically the primary treatment.

However, there are many cases in which chemotherapy cannot provide a permanent cure, but an allogeneic transplant can. In these cases, replacing the cancerous bone marrow with healthy bone marrow from another person can permanently eliminate the cancer. In addition to replacing the patient’s bone marrow, the bone marrow from the donor also has the capability of attacking cancer cells that are still present after the transplant, which is called “graft-versus-tumor" effect.


Steps in an allogeneic bone marrow transplant


Allogeneic cell transplantation vs. autologous cell transplantation

There are two main types of stem cell transplants—allogeneic transplants and autologous transplants—and the difference between the two lies in who is donating the stem cells. As was noted above, during an allogeneic stem cell transplant, the patient receives stem cells from a donor. During an autologous stem cell transplant, the patient receives their own stem cells (the patient’s stem cells are removed and frozen before he or she undergoes chemotherapy and/or radiation therapy, and then thawed and returned once those other treatments are complete).

Each type of stem cell transplant offers its own set of risks and benefits. With autologous stem cell transplant, the chemotherapy kills the cancer but also kills the patient’s bone marrow. Thus, bone marrow from the patient is stored before the chemotherapy starts and then is infused into the patient after the chemotherapy to restore the bone marrow. The transplant also can reduce the side effects from the chemotherapy destroying the bone marrow.  

With an allogeneic stem cell transplant, chemotherapy is used to weaken the patient’s bone marrow. Donor stem cells are then infused and take over the patient’s bone marrow. The patient’s bone marrow is then replaced by donor cells and these cells then attack the cancer. With this type of transplant, the transplant itself is able to eliminate the cancer.

Both types of transplant include potential side effects from chemotherapy such as low blood counts, organ injury, or infections. Allogeneic transplant, however, is characterized by unique side effects that are caused because the donor cells are not the same as the patient. Because of genetic differences between the donor and the patient, the donor cells can sometimes attack the patient’s body causing a transplant complication called graft-versus-host disease (GVHD). Not all patients will experience GVHD. When it does happen, there are treatments available.

What you can expect

Doctor discussing allogeneic treatment with patientAt Moffitt Cancer Center, the multispecialty team within our Blood and Marrow Transplant and Cellular Immunotherapy Program collaborate to ensure each patient receives an individualized treatment plan that’s tailored to his or her needs. If an allogeneic transplant is recommended as part of your treatment, the first step involves finding a donor. An allogeneic stem cell transplant requires that someone donate marrow or blood stem cells for you. The donor may be:

  • A relative, such as a sibling, parent, son, daughter, and sometimes extended relatives
  • An anonymous volunteer donor from the National Marrow Donor Program ("Be The Match")

Patients undergoing an allogeneic transplant will be admitted to our specialized blood and bone marrow transplant inpatient unit to receive their preparative chemotherapy and transplant. Patients may remain in the hospital for several days to weeks and will be closely monitored by our medical team until it is safe for the patient to be discharged to an outpatient setting. Upon discharge, patients who have received an allogeneic bone marrow transplant are required to remain close to Moffitt for follow-up care, which is provided in our outpatient clinic and treatment center. Moffitt’s transplant program has several options for local lodging; you can discuss this with your assigned social worker.

What bone marrow donors can expect

The donor must first undergo a medical evaluation to confirm they are healthy enough to donate. This includes a clinical appointment with a physician, blood tests, and usually a chest X-ray and EKG. Once these tests are completed, the physician will clear the donor to proceed with the donation.

Bone marrow donation can be done in one of two ways. The type of donation is decided by the physician of the patient depending on the patient’s disease and medical condition.

  • Peripheral blood stem cell transplant: In this type of donation, the donor receives a medication called granulocyte colony stimulating factor (GCSF) for a few days that causes the stem cells to leave the bones and move into the blood. This medication may cause some side effects such as headaches or bone pain. The donor then proceeds with an apheresis procedure where blood is drawn through an IV into a machine that collects the stem cells. This procedure typically takes one to two days. This is generally done outside of the hospital and does not usually cause significant side effects.
  • Bone marrow harvest: This type of donation is a surgical procedure done in the operating room. While bone marrow is being collected, the donor will be under general anesthesia. A provider will insert a hollow needle into the donation site (commonly the hip bone) to extract the marrow manually. This is repeated until enough bone marrow is collected. Once the procedure is complete, the donor will likely continue to experience pain and tenderness at the donation site for about a week.

While bone marrow is being collected, the donor will most likely be under general anesthesia. A provider will insert a hollow needle into the donation site (commonly the hip bone) to extract the marrow. Once the procedure is complete, the donor will likely continue to experience pain and tenderness at the donation site for about a week.

Allogeneic stem cell transplant precautions

Researcher in the lab studying stem cellsThe allogeneic stem cell transplant process begins by finding a matching donor. If you’ve been told that you need to undergo a transplant, you may have had friends and family members offer to donate their stem cells to you. While that is certainly a generous offer, it’s critical that a patient and their donor have closely matched human leukocyte antigens (HLA). In many cases, siblings who share both parents will be the best match. However, it’s also possible for another family member or even an unrelated volunteer to be a match.

If a patient and their donor are a compatible match, the patient will have less of a risk of developing graft-versus-host disease (GVHD). This condition occurs when the donor’s stem cells view the patient’s body as foreign, and as a result, begin attacking the patient’s organs and tissues as part of an immune response. There are two types of GVHD: acute and chronic. Some of the symptoms common to both types include:

  • A skin rash
  • Yellowing of the skin and/or eyes (jaundice)
  • Nausea
  • Vomiting
  • Diarrhea
  • Loss of appetite
  • Blood test results indicating abnormal liver function

GVHD is a serious condition that has the potential to become life-threatening. With that being said, this condition is generally treatable, often using immunosuppressive medication.

Medically reviewed by Hany Elmariah, MD, MS

Learn More

For more information on receiving an allogeneic stem cell transplant at Moffitt, call 1-888-663-3488 or complete a new patient registration form online. We stand apart from other cancer centers due to our remarkably fast response time—once you reach out, you can expect to be connected to a cancer expert within one day. This is faster than the turnaround times offered by every other cancer hospital in the country.