Understanding Bone Marrow Transplant (BMT)
Hematopoietic stem cell transplantation (HSCT), also known as bone marrow transplant, is a medical procedure where doctors give a patient healthy blood-forming stem cells through a vein. These new cells help the body make new blood cells when the patient’s bone marrow or immune system has been damaged or isn’t working properly. Over the past 50 years, this treatment has been used more and more to help people with different kinds of cancers and other serious diseases.
The stem cells used for the transplant can come from the patient’s own body (autologous transplant), another person, such as a brother, sister, or unrelated donor (allogeneic transplant), or an identical twin (syngeneic transplant). The stem cells themselves can be collected from bone marrow, blood, umbilical cord blood, or rarely, from fetal liver. Each source has its own pros and cons, and doctors choose the best one depending on the patient’s situation.
The list of diseases for which BMT is being used is rapidly increasing, with currently more than 70. More than half of autologous transplantations are performed for multiple myeloma and non-Hodgkin lymphoma, and the vast majority of allogeneic transplants are performed for hematologic and lymphoid cancers.
Worldwide, approximately 90,000 first BMTs are performed every year and the number continues to increase by 10-20% annually. Modern advances seem to be contributing to improved outcomes.
The Transplant Process
The stem cell transplant process usually happens in five main stages:
- Conditioning: This is the preparation stage before the transplant and takes about 1 – 2 weeks. Patients receive chemotherapy, immunotherapy, and/or radiation to destroy any remaining cancer cells, suppress the immune system so the body doesn’t reject the new stem cells, and make space in the bone marrow for the new cells to grow.
- Stem cell infusion: The patient receives the new stem cells through an IV, much like a blood transfusion. This step is usually simple and doesn’t cause major side effects for most patients
- Neutropenic phase: This stage lasts about 2 – 4 weeks. The patient has almost no working immune system. Because of this, the body can’t fight infection well, healing is slow, and patients often need antibiotics and careful medical support to stay safe.
- Engraftment phase: This stage lasts several weeks and is when the new stem cells start making healthy blood cells. During this time, mouth sores and other wounds begin to heal, fever usually goes down, and infections start to clear. Doctors focus on preventing and treating BMT-related infections and problems.
- Post-engraftment period: This long-term recovery period lasts months to years while the immune system continues to rebuild and get stronger and medications that suppress the immune system are slowly reduced. Some BMT-related problems may still need ongoing care.
Role of Immune Globulin Therapy
Immune globulins are found naturally in the body and help fight infection. When the marrow is “wiped out” from BMT, the patient’s immune globulins may decrease to a level where the patient develops frequent infections. Some patients may benefit from replacement immune globulins while the body recovers from BMT. Immune globulin is extracted from a large pool of human plasma and contains all the important antibodies present in the normal population. Immune globulin therapy can be administered into the blood stream intravenously (IVIG) or under the skin subcutaneously (SCIG).
Resources
References:
- National Marrow Donor Program
- Medscape | Hematopoietic Stem Cell Transplantation (Accessed on October 21, 2025)
Last reviewed 12/16/2025
