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Glossary of Terms



Allogeneic Transplant: A transplant using a tissue matched or partially matched to a related or unrelated donor
Anemia: A decreased number or insufficient function of red blood cells which causes fatigue and paleness
Antibodies: Proteins produced by the body’s immune system which identify and help remove harmful substances or antigens such as viruses and bacteria
Antithymocyte Globulin (ATG): A protein-containing drug used to treat and prevent graft-versus-host disease
Apheresis: The process of removing only a selected type of blood cells from a blood donor and simultaneously returning all the others
Autologous Transplant: A transplant using the patient’s own stem cells, which are collected, treated in the laboratory (sometimes) and stored to be given to the patient later after treatment
Blasts: Young, ineffective white blood cells in leukemia. There are a few normal blasts found in all marrow. Tumor blasts, though, are found in leukemia
Bone Marrow: The spongy center of bones that is the “factory” for all blood cells in circulation
Bone Marrow Aspirate: A procedure by which a sample of bone marrow is taken from the hip bone
Cardiomyopathy: Heart damage that can occur after high doses of chemotherapy, causing a weakening of the heart muscle and decrease in its pumping function
Cataracts: Changes in the lens of the eye which cause cloudy vision, a condition that can occur months to years after total body irradiation and steroid therapy
Chemotherapy: Treatment for cancer using chemical substances designed to kill cancer cells. It is used in large doses to help destroy a patient’s diseased marrow in preparation for a marrow transplant
Conditioning: The process of preparing the patient to receive donated stem cells. Often done through the use of chemotherapy and radiation therapy
Cord Blood: The blood of newborns found in the umbilical cord and placenta. It contains large numbers of blood stem cells important for transplantation. For this reason, stem cells from the placenta and umbilical cord are collected after birth, then frozen and stored
Cystitis: An inflammatory condition of the urinary bladder. Hemorrhagic cystitis is a rare side effect of certain chemotherapy drugs (e.g. cyclophosphamide) that results in bleeding from the bladder and bloody urine
Cytogenetics: Testing of the chromosomes (DNA) in the bone marrow or blood cells
Donor: A volunteer (related or unrelated) who has donated stem cells for a patient
Engraftment: Successful transplantation of donor bone marrow cells into the patient. This is shown by the growth and differentiation of donor cells to achieve normal blood counts in the recipient
Fungus: A type of germ – different from bacteria – which can cause life-threatening infection (examples: candida, aspergillus and other molds)
Graft-Versus-Host Disease: A condition in which the donor’s transplanted marrow or stem cells react against the patient’s tissues. It is referred to as GVHD and most often affects the skin, gastrointestinal tract and/or liver
Harvesting: The procedure performed under anesthesia to remove bone marrow from the patient or a donor (bone marrow harvest); or the procedure to remove peripheral blood stem cells (PBSC harvest or pheresis)
Hematopoiesis: The formation and maturation of blood cells (red blood cells, platelets and white blood cells) from progenitor stem cells
Hematopoietic Stem Cells: Cells with the ability to make other stem cells (self-renew) and divide and differentiate into mature white blood cells, red blood cells and platelets
Hemoglobin: The protein within the red blood cell which carries oxygen. Reduced levels of this protein result in anemia
HLA (Human Leukocyte Antigen): Proteins on cells that are determined by genes (DNA) and are used to match a recipient and donor for a bone marrow transplant
IgG: Antibodies which fight germs; they are produced by “B” lymphocytes (a type of white cell)
Immunoglobulin: General term for antibodies, which are proteins made by normal lymphocytes to fight infections. Transplant patients often become deficient in immunoglobulins and require intravenous replacement. This infusion may also be referred to as IVIG
Immunosuppression: A condition in which the body’s ability to fight infection (immune system) is decreased
Interstitial Pneumonia: Inflammation of the lung tissue, usually caused by a virus, or – rarely – after radiation or chemotherapy
Irradiated Blood Products: Blood products are treated with radiation in the blood bank to inactivate or prevent T-cells from causing graft-versus-host disease in the recipient. Radiation of blood products does not make the blood radioactive and does not endanger your child in any way
Jaundice: A yellowish color in the skin or the whites of the eyes associated with liver inflammation
Leukemia: Any of a group of potentially fatal diseases involving uncontrolled growth of white blood cells. Leukemias are classified based upon rapidity of the course of the disease and the cell type affected
Lumbar Puncture: “LP” or spinal tap is a test or procedure to remove a small amount of spinal fluid that surrounds the spinal cord in order to check for infection or leukemia. A small needle is briefly inserted into the lower back to obtain fluid
Lymphocyte: A category of white blood cells including T cells and B cells
Lymphoma: A cancer of lymph tissue or lymph nodes
Monoclonal Antibodies: Specially-prepared antibodies made specifically to attack certain kind of cells such as T cells or leukemia. Many of the newer immune-suppressive medications are monoclonal antibodies
Mucositis: Inflammation of the mucous membranes inside the mouth, tongue, gums, throat, stomach or intestines; commonly called mouth sores
Neuroblastoma: A solid tumor occurring in children which, in an advanced widespread stage, may be treated by autologous stem cell transplant
Neutrophil: One type of white blood cell important in fighting bacterial germs and fungi
Peripheral Blood Stem Cells: Cells with the potential to produce all the components of blood. Peripheral blood stem cells (PBSC) are obtained from “circulating” blood rather than from bone marrow
Platelet: A component of the blood important in clotting. Inadequate amounts of platelets will lead to bleeding and bruising easily
Protocol: A specific plan for treatment of a disease or disorder
Red Blood Cell: A type of blood cell made in the bone marrow that carries oxygen to all parts of the body
Rejection: The body’s refusal to accept the transplanted marrow
Relapse: The recurrence of leukemia or other underlying disease after treatment
Remission: The disappearance of cancer cells following treatment. Also, the period during which the reduction or disappearance of symptoms occurs
Steroids: A type of drug used to treat certain types of leukemias, to reduce inflammation or to prevent and treat graft-versus-host disease
T Cell: A category of white blood cell (lymphocyte) responsible for regulating the immune system and protecting us from viral and fungal infections. T cells are also the cells responsible for graft rejection and graft-versus-host disease
Total Body Irradiation: Radiation – or x-ray – therapy given to the whole body in multiple fractions over several days to treat cancer. It also helps clear out the existing bone marrow to allow space for the transplanted marrow. “Fractionated” TBI means that the total dose is split into smaller, more frequent doses in order to reduce side effects
Total Lymphoid Irradiation: Irradiation directed only at lymph node sites such as the neck, upper midline chest and underarms
Transplant: A medical treatment to replace a recipient’s diseased organ or tissues with a healthy organ or tissue from a donor
Veno-Occlusive Disease: A rare condition which may occur in the first few weeks after a hematopoietic stem cell transplant (HSCT); caused by obstruction in the liver veins due to damage from chemotherapy and radiation
Virus: A type of germ that causes infections, most of which are not effectively treated with antibiotics. Examples: cytomegalovirus (CMV), herpes, varicella (chickenpox), adenovirus, hepatitis
White Blood Cell: Also called a “leukocyte;” a type of blood cell produced by the bone marrow to help fight infection