Bone Marrow Transplant Glossary

A comprehensive glossary about bone marrow transplant / stem cell transplant / hematopoietic cell transplantation.


  • Acute Graft-Versus-Host Disease (aGVHD): A short-term complication of allogeneic transplants, typically occurring within the first few months.
  • Acute Lymphoblastic Leukemia (ALL): A type of cancer of the blood and bone marrow that affects white blood cells.
  • Acute Myeloid Leukemia (AML): A rapidly progressing cancer that starts in the bone marrow and results in the production of abnormal blood cells.
  • Allogeneic Transplant: A transplant using stem cells from a donor.
  • Alloimmunization: Development of antibodies in response to foreign cells, which can occur after transfusions.
  • Apheresis: A procedure to collect peripheral blood stem cells from the bloodstream.
  • Aplastic Anemia: A condition where the bone marrow fails to produce sufficient amounts of blood cells.
  • Autologous Recovery: The recovery of a patient’s own marrow function after a failed allogeneic transplant.
  • Autologous Transplant: A transplant using the patient’s own stem cells.


  • Biopsy: A diagnostic procedure that involves the removal of tissue or cells for examination.
  • Bone Marrow Aspiration: A procedure to collect a sample of bone marrow.
  • Bone Marrow Edema: Increased fluid in the marrow, often seen in imaging studies.
  • Bone Marrow Failure: A condition where the marrow does not produce enough blood cells.
  • Bone Marrow Microenvironment: The environment within the bone marrow that supports stem cell growth and differentiation.
  • Bone Marrow: The soft, fatty tissue inside bones where blood cells are produced.


  • Cellular Therapy: Treatments including the infusion of cellular material, such as in stem cell transplants.
  • Chimerism: The presence of two genetically distinct cell lines in the body, often seen after an allogeneic transplant.
  • Chronic Graft-Versus-Host Disease (cGVHD): A long-term complication of allogeneic transplants where donor cells attack the recipient’s body.
  • Chronic Lymphocytic Leukemia (CLL): A type of cancer that starts from white blood cells in the bone marrow and progresses slowly.
  • Chronic Myeloid Leukemia (CML): A type of cancer that begins in the blood-forming cells of the bone marrow and invades the blood.
  • Conditioning Regimen: Pre-transplant treatment to prepare the body for the transplant.
  • Cord Blood Transplant: A transplant using stem cells from umbilical cord blood.
  • Cord Blood Unit: A single collected and stored unit of umbilical cord blood, used for transplantation.
  • Cryopreservation: The process of freezing cells, tissue, or organs for preservation.
  • Cytokine Release Syndrome (CRS): A potential side effect of certain cancer therapies, including some forms of cellular therapy.
  • Cytomegalovirus (CMV): A common virus that can cause complications post-transplant.


  • Donor Lymphocyte Infusion (DLI): A treatment involving the infusion of donor lymphocytes to boost the immune system or combat cancer cells.
  • Donor Registry: A database of individuals willing to donate bone marrow or stem cells.


  • Engraftment Syndrome: A complication characterized by fever, rash, and pulmonary symptoms after engraftment.
  • Engraftment: The process where transplanted stem cells start to grow and produce healthy blood cells.
  • Erythrocytes: Red blood cells responsible for carrying oxygen throughout the body.
  • Erythropoiesis: The process of producing red blood cells in the bone marrow.
  • Ex Vivo Expansion: A process to grow more stem cells outside the body before transplantation.


  • Fanconi Anemia: A rare genetic disorder that leads to bone marrow failure.


  • Graft Failure: A condition where the transplanted cells do not engraft or the new marrow does not start producing cells.
  • Graft Rejection: When the recipient’s immune system attacks the transplanted stem cells or bone marrow.
  • Graft Versus Leukemia (GVL) Effect: The beneficial effect of donor immune cells attacking leukemia or other cancer cells in the recipient.
  • Graft Versus Tumor Effect: A beneficial effect of allogeneic bone marrow transplant where the donor’s immune cells attack any remaining cancer cells in the recipient.
  • Graft-Versus-Host Disease (GVHD): A complication where donor cells attack the recipient’s body.
  • Graft-Versus-Tumor Effect: The donor immune cells attacking any remaining cancer cells.
  • Granulocyte: A type of white blood cell important in fighting bacterial infections.


  • Haploidentical Transplant: A transplant from a half-matched donor, usually a family member.
  • Hematologic Remission: The absence of disease symptoms in blood disorders, often a goal post-transplant.
  • Hematology: The branch of medicine concerned with the study of blood, blood-forming organs, and blood diseases.
  • Hematopoietic Cell Transplantation (HCT): Another term for bone marrow or stem cell transplant, involving the infusion of hematopoietic cells.
  • Hematopoietic Growth Factors: Substances that stimulate the production of blood cells and are often used in conjunction with bone marrow transplants.
  • Hematopoietic Progenitor Cells: Early-stage cells in the bone marrow that can develop into different types of blood cells.
  • Hematopoietic Stem Cells: Cells in the bone marrow that give rise to all blood cells.
  • Hemoglobinopathy: A group of disorders characterized by abnormal hemoglobin in the blood.
  • HLA Matching (Human Leukocyte Antigen): Testing to determine compatibility between donor and recipient.
  • Hodgkin’s Lymphoma: A type of lymphoma, which is a cancer of the lymphatic system.


  • Immune Reconstitution: The process of rebuilding the immune system after a bone marrow transplant.
  • Immune Thrombocytopenic Purpura (ITP): A disorder that can lead to easy or excessive bruising and bleeding, resulting from unusually low levels of platelets.
  • Immunocompromised: A state in which the immune system’s ability to fight infections is weakened or absent.
  • Immunophenotyping: A laboratory process used to identify and classify cells, especially in leukemia and lymphoma.
  • Immunosuppression: Medication or therapy used to suppress the immune system.
  • Intravenous Immunoglobulin (IVIG): Blood product used to treat various immune deficiencies, often used in transplant patients.
  • Isoimmunization: The development of antibodies against antigens from the same species, relevant in transfusions and transplants.
  • Isolation and Protective Environments: Specialized care environments to protect immunocompromised transplant patients from infections.


  • Karnofsky/Lansky Performance Status: A scale to assess a patient’s level of functioning and ability to perform daily activities.


  • Leukapheresis: A procedure to reduce a very high white blood cell count, often used in leukemia treatment.
  • Leukemia: A type of cancer that affects blood and bone marrow.
  • Leukocytes: White blood cells involved in protecting the body against infections and foreign invaders.
  • Lymphocyte Infusion: The infusion of lymphocytes to help fight infection or disease after a transplant.
  • Lymphocyte Recovery: The rebuilding of lymphocyte (a type of white blood cell) counts after a transplant.
  • Lymphoma: A type of cancer that affects the lymphatic system.


  • Marrow Extraction: The surgical procedure to remove bone marrow from a donor.
  • Matched Sibling Donor (MSD): A bone marrow or stem cell donor who is a full genetic match, typically a brother or sister.
  • Matched Unrelated Donor (MUD): A stem cell or bone marrow donor who is not related to the patient but is a close HLA match.
  • Mixed Chimerism: A condition post-transplant where both donor and recipient cells coexist in the body.
  • Mobilization: The process of stimulating the bone marrow to produce more stem cells.
  • Multiple Myeloma: A cancer that forms in a type of white blood cell called a plasma cell.
  • Myeloablative Therapy: High-dose chemotherapy or radiation therapy to destroy diseased bone marrow.
  • Myelodysplastic Syndromes (MDS): A group of disorders caused by poorly formed or dysfunctional blood cells.
  • Myeloproliferative Disorders: A group of diseases where the bone marrow makes too many red blood cells, white blood cells, or platelets.


  • Neutropenia: A low level of neutrophils, increasing infection risk.
  • Neutropenic Fever: A common and potentially serious complication where the patient develops a fever while having a significantly low neutrophil count, indicating an infection risk.
  • Neutrophil Engraftment: The point post-transplant when neutrophils, a type of white blood cell, are sufficiently recovered.
  • Neutrophil Recovery: The period post-transplant when neutrophil counts return to safe levels, reducing the risk of infection.
  • Neutrophilic Granulocytes: A type of granulocyte, primarily involved in fighting bacterial and fungal infections.
  • Neutrophils: A type of white blood cell important in fighting bacterial infections.
  • Non-Hodgkin’s Lymphoma: A diverse group of blood cancers that include any type of lymphoma except Hodgkin’s lymphomas.
  • Nonmyeloablative Transplant: A type of transplant that uses lower doses of chemotherapy or radiation before the transplant.


  • Oncology: The branch of medicine that deals with the prevention, diagnosis, and treatment of cancer.
  • Osteonecrosis: A condition caused by reduced blood flow to bones, sometimes a side effect of steroid use post-transplant.


  • Peripheral Blood Stem Cell Transplant (PBSCT): A transplant using stem cells collected from the bloodstream.
  • Peripheral Blood: Blood that circulates through the body, as opposed to being located in the bone marrow.
  • Plasma Cell: A type of white blood cell that produces antibodies; important in the context of multiple myeloma.
  • Platelet Engraftment: The recovery of platelet counts to safe levels following a transplant.
  • Plateletpheresis: A procedure to collect platelets from a donor for transfusion.
  • Platelets: Small blood cells that help with blood clotting and wound healing.
  • Post-Transplant Lymphoproliferative Disorder (PTLD): A potential complication involving the uncontrolled growth of lymphocytes after transplant.


  • Red Blood Cell (RBC): A type of blood cell primarily responsible for carrying oxygen from the lungs to the rest of the body and returning carbon dioxide from the body to the lungs for exhalation. Red blood cells are a key focus in conditions like anemia and are often monitored closely before and after bone marrow transplants.
  • Red Blood Cell Transfusion: The process of transfusing red blood cells to treat or prevent anemia.
  • Red Cell Aplasia: A condition where the bone marrow fails to produce red blood cells.
  • Relapse: The return of disease after a period of improvement.


  • Secondary Graft Failure: A rare condition where initial engraftment is successful but then fails.
  • Severe Combined Immunodeficiency (SCID): A group of rare, life-threatening genetic disorders that result in combined abnormalities of the T- and B-lymphocyte systems.
  • Sickle Cell Disease: An inherited blood disorder that causes red blood cells to have an abnormal shape.
  • Stem Cell Boost: An additional infusion of stem cells, sometimes required if engraftment is slow or incomplete.
  • Stem Cell Harvesting: The process of collecting stem cells for transplant.
  • Stem Cell Mobilization: The process of stimulating the movement of stem cells from the bone marrow into the peripheral blood for collection.
  • Stem Cell Niche: The microenvironment within the bone marrow where stem cells reside.
  • Stem Cell: Cells that have the potential to develop into many different cell types in the body.


  • T-Cell Depletion: A process to remove T-cells from donor marrow or stem cells to reduce the risk of GVHD.
  • Thalassemia: A group of inherited blood disorders characterized by abnormal hemoglobin production.
  • Thrombocytopenia: A condition characterized by a low platelet count, leading to increased bleeding and bruising.
  • Total Body Irradiation (TBI): Radiation therapy used as part of the conditioning regimen.
  • Transfusion Reaction: An adverse reaction that may occur during or after a blood transfusion.
  • Transplant Coordinator: A healthcare professional who manages the transplant process.
  • Transplant Immunology: The study of the immune response related to transplantation.
  • Transplant Outpatient Clinic: A specialized clinic for managing patients’ care before and after transplantation.


  • Umbilical Cord Blood Banking: The collection and storage of umbilical cord blood for potential future use in stem cell transplants.


  • Veno-occlusive Disease (VOD): A complication involving blockage of liver blood vessels, potentially occurring after transplant.
  • Venous Access Device (VAD): A device used to administer treatments and collect blood samples.


  • White Blood Cell Transfusion: A rare procedure to increase the number of white blood cells, typically for patients with severe infections and low white cell counts.


  • Xenograft: A transplant of cells, tissues, or organs from one species to another.


  • Zygosity Testing: Genetic testing used to determine the degree of HLA match between donor and recipient.