Skip to Main Content

Welcome to

Together is a new resource for anyone affected by pediatric cancer - patients and their parents, family members, and friends.

Learn More

Allogeneic Stem Cell (Bone Marrow) Transplant

bone marrow medical illustration showing bone marrow, blood stem cells, platelets, red blood cells, and white blood cells

An allogeneic stem cell transplant uses a donor's healthy blood-forming cells. These cells are also known as hematopoietic stem cells. Stem cells are made in the spongy part of bones, called bone marrow. They make all types of blood cells in the body.

What is an allogeneic transplant?

An allogeneic transplant replaces damaged or destroyed blood-forming cells (stem cells) with healthy ones from another person. This person is called a donor.

The donor stem cells travel to your child's bone marrow. They grow and make healthy blood cells, including red blood cells, platelets, and white blood cells.

Learn about transplants using the patient’s own cells: autologous stem cell transplant.

Diseases allogeneic transplants treat

Allogeneic transplants are used for certain cancers and blood disorders such as: 

  • High-risk leukemia or lymphoma
  • Immune system diseases 
  • Sickle cell disease 
  • Thalassemia 
  • Bone marrow failure syndromes 
  • Metabolic storage disorders 
  • Some high-risk solid tumors 

 Steps of an allogeneic transplant 

The allogeneic transplant process involves:

  • Finding a donor
  • Pre-transplant testing and evaluation
  • Conditioning or preparative regimen using chemotherapy, antibodies, or radiation
  • Infusion of the donor's stem cells
  • Engraftment
  • Supportive care to manage side effects

Risks of an allogeneic transplant 

Some patients have few side effects. Others have serious complications that require long hospital stays. Some problems can be life-threatening.

Possible side effects that may occur soon after allogeneic transplant include:  

  • Side effects from chemotherapy or radiation therapy used during conditioning or as part of treatment  
  • Infection because of a low white blood cell count (neutropenia)  
  • Weakness or fatigue caused by fewer red blood cells (anemia)
  • Increased risk of bleeding or bruising caused by low platelets (thrombocytopenia) 
  • Graft failure or rejection if the cells do not grow well or are destroyed
  • Problems with the heart, lung, kidneys, liver, or other organs

After the new donor cells have grown, other risks include:

  • Graft-versus-host disease (GVHD) may occur if the donor cells see the patient's normal cells as different and attack them. Other immune system problems can also occur.
  • Infections are an ongoing risk for several months as the new donor cells grow and mature.
  • Disease relapse or progression may occur if treatments are not successful.
  • Long-term or late effects may develop due to the transplant or any treatments a patient received before transplant.

Taking care of your child after allogeneic transplant

Important points to keep in mind:

  • Your child will stay in the hospital for at least a month after admission for treatment.
  • Watch for signs of infection or illness. Call your doctor if your child develops a fever or symptoms such as rash, nausea, vomiting, diarrhea, abdominal pain, mouth sores, bruising or bleeding, trouble breathing, headache, or other change in condition.
  • Your child will have a very weak immune system for weeks after the transplant. Take steps to prevent infection. Avoid public areas, wash hands often, stay away from people who are sick, and wear a mask as instructed. Limit visitors and screen for signs of illness.
  • Give medicines as instructed. Let your care team know if your child has any problems taking medicines or keeping them down.
  • Follow your child's mouth care plan.
  • Make sure your child has a daily bath.
  • Encourage your child to be active throughout the day as tolerated.
  • Let your care team know if you have questions or concerns.
  • Avoid sun exposure when possible. Protect the skin from the sun and use sunscreen with a SPF of 30 or higher.

Key Points

  • Allogeneic transplant steps include pre-transplant testing and evaluation, conditioning, infusion, engraftment, and monitoring for side effects of the transplant process.
  • An allogeneic transplant uses blood-forming stem cells (hematopoietic stem cells) from another person, called a donor.
  • After the conditioning treatment, the stem cells are given to the patient through an infusion.
  • The donor's infused stem cells travel to the patient's bone marrow and begin to divide to make new stem cells.
  • The blood-forming stem cells become white blood cells, platelets, and red blood cells.

Reviewed: August 2022