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Allogeneic Stem Cell Transplant

An allogeneic transplant uses stem cells from a healthy donor. The donor must closely match the patient's human leukocyte antigen (HLA) tissue type.

There are different types of donor transplants:

  • A matched related donor (MRD) transplant. Typically, a donor search begins with identifying siblings who may be the closest HLA match. There is a 25% chance that any one sibling with be a full HLA match.
  • A matched unrelated donor (MUD) transplant. A worldwide registry called the National Marrow Donor Program (NMDP) coordinates and oversees donations from unrelated donors.
  • Haploidentical transplant: First-degree family members (siblings, parents, children) who are HLA half-matched are potential donors.
  • Cord blood transplant. Stem cells are collected and stored from a newborn infant's placenta or umbilical cord after birth. These cells are kept frozen (cryopreserved) in an umbilical cord blood bank and are readily available.

Finding the Best Donor

It is very important to find the best donor for the recipient. Finding the best donor will lower the recipient's chances of developing graft-versus-host disease (GVHD). GVHD occurs when the immune cells given from the donor recognize the patient as foreign and attack the patient's tissues.

The best donors are identified using a test called human leukocyte antigen (HLA) testing. HLAs are proteins on the surface of most cells in the body. The proteins help the body tell the difference between normal cells and foreign cells.

Once the donor is identified, the patient's doctors will determine the best source of stem cells from the donor—either the donor's bone marrow or peripheral blood. After collection of stem cells, the donor’s blood counts are back to normal within 4-6 weeks.

Learn more about HLA Typing.

Learn more about the Transplant Process.

Types of Stem Cell Donation

There are two sources of stem cells: peripheral blood stem cell (PBSC) and bone marrow (BM). The patient's doctor chooses the donation method that is best for the patient.

PBSC donation: This procedure is non-surgical. It takes place at an outpatient hospital unit or at a blood center.

  • Before the stem cell collection, the donor receives injections that increase the number of stem cells in the peripheral bloodstream.
  • The donor's blood is then removed through a needle in the arm. This procedure is called leukopheresis or apheresis. During this process the donor's cells are passed through a machine that separates out and collects the stem cells, or blood-forming cells.
  • The rest of the cells are returned to the donor.

Bone marrow donation: This is a surgical procedure and must take place at a hospital.

  • The donor receives anesthesia so no pain is experienced during the procedure.
  • The procedure is similar to having a bone marrow biopsy where liquid bone marrow is removed, however multiple passes are made during this harvest.
  • The donor typically goes home the same day. He/she can expect to fully recover from the procedure in one week

Pre-Transplant Workup Testing

Preparative Transplant Regimen

All transplant patients are placed on drugs that suppress their immune system to avoid rejection of the donor graft. Depending on your transplant regimen, you will receive high doses of chemotherapy and/or Total Body Irradiation (TBI). These therapies will destroy your disease and prepare your marrow for new stem cells. These therapies are effective in eradicating cancerous cells, however they can also harm other healthy cells in your bone marrow.

Immunosuppressive drugs also work to prevent and control graft versus host disease (GVHD). GVHD is caused when the donor’s immune system (graft) attacks your body’s own tissues (host) because the new cells from the donor do not recognize the tissues and organs of your body.


After completion of your chemotherapy and/or TBI treatment, the bone marrow or stem cells will be infused.

The day of infusion of stem cells is referred to as Day 0. You will hear all days prior to your transplant referred to as a negative days. For example, you may receive chemotherapy/TBI on Day -6 through -1. All days post-transplant are considered positive. This time can vary from day +12 to day +21.

The infusion of stem cells will be much like a blood transfusion. The stem cell technician will thaw the frozen stem cells, and your nurse will infuse them through your IV line.

The new stem cells will migrate from the bloodstream to the bone marrow spaces. From here, the transplanted stem cells will begin to create new cells. This process is called engraftment. We will do lab tests on your blood often to see if you have engrafted.

Your immune system will be very weak at this point. Expect to be placed on several preventive medications during this period, such as antibiotics, antivirals, and antifungals. Your nurse will check your temperature often for fever, as fever is a sign of infection.

In the days after transplant, patients usually experience side effects from chemotherapy:

  • Nausea
  • Vomiting
  • Fatigue
  • Fevers
  • Rashes
  • Mouth sores
  • Diarrhea or constipation

You will receive instruction and education on ways to prevent some of these side effects, as well as ways to help minimize them.


Engraftment means that the stem cells have started producing their own white blood cells, red blood cells, and platelets. After your transplant, we continually do tests to see how many neutrophils, a type of white blood cell, are in your blood. This test is called an absolute neutrophil count (ANC). When your ANC is more than 500 for three consecutive days, engraftment has occurred.

Engraftment date varies from person to person and depends on the kind of transplant that you had. Once you have engrafted, your health care team will start taking away some of your preventive medications.

Discharge and Recovery

Once you have achieved engraftment and your health care team determines you are well enough, you will be discharged from the hospital. Your will still be recovering after discharge and may continue experiencing some fatigue, nausea, low appetite, and other side effects from your transplant. As well, you are still at risk for infection while you are on immunosuppressive medications. You will need to live within a specified distance from the cancer center, and you will need a caregiver to help you at home 24 hours every day for at least 100 days after your transplant. Our patient coordinators and social workers will work with you to meet these requirements.

In the period leading up to day 100, you will be followed very closely by a BMT provider in our Ambulatory Treatment Center (ATC). Visits may occur 1-3 times per week. At these visits, you will receive an examination, have routine blood tests drawn, receive IV fluids and possibly blood transfusions, and have medications adjusted. Any active post-transplant problems such as infections or graft versus host disease will be addressed at these visits. We also work with a home health care agency that can provide additional IV medications and fluids as indicated. Depending on your active issues, you may need more frequent visits to the BMT ATC or may need re-admission to the hospital.

Read more about graft-vs-host disease and home care after allogeneic transplant.

Homeward-Bound: 100 Days after Transplant

Around 100 days after your transplant, we will perform a bone marrow biopsy and other blood tests that indicate the status of your disease for which you were transplanted and the status of your donor cell engraftment (chimerism analysis). This is called your day +100 workup. Typically, you may return to your home after this workup, and the results of your tests will be reviewed and discussed with your BMT doctor on a subsequent visit to the BMT clinic. Your BMT physician will then determine your need and frequency for follow-up visits. You may also re-establish care with your referring oncologist or local PCP at this time.

You will no longer be required to have a 24-hour caregiver, but you are still at risk of infection. Good hand washing and avoiding large crowds are recommended.

Transitioning back to home can be a stressful time. We are here to make the process less overwhelming for you and your family. Prior to discharge from the ambulatory treatment center, you will attend our “Homeward Bound” class that is given by one of our BMT advanced practice clinicians. This class covers infection prevention strategies, nutrition/diet, medication management, and essentially, how to take care of you at home. Be sure to ask any questions you may have regarding care at home.



 For more information, or to schedule an appointment, call 801-587-4652