Orthopedic Traumatology
Bone marrow is a sponge like substance inside bones. It is composed of semi-solid hematopoietic stem cells. Hematopoietic stem cells produce white blood cells (leukocytes- fight infections), red blood cells (erythrocytes- carry oxygen in the blood)thrombocytes (clot the blood). Hematopoietic stem cells are usually in the bone marrow, but occasionally they can be found in peripheral blood, too. Navel also has hematopoietic blood cellsstem cells can be collected from each source. The main purpose of the bone marrowperipheral blood stem cell transplant is to restore destroyeddamaged bone marrow cells after chemotherapyradiotherapy. Bone marrowhematopoietic stem cells transplant has 4 main types: Autologous transplant- putting back stem cells after chemotherapy which were removed beforehand; Allogeneic transplant- taking bone marrow cells from another person called “donor”. If the donor is sister, brothera parent it is called “related”, otherwise it is called “unrelated”.
Syngeneic- stem cells are taken from a twin sibling; Cord blood- transplant of stem cells from umbilical cord; Transplant from a completely genetically matching donor is called “full match”from a not completely matching one is called “miss match”. High dosage of chemotherapyradiotherapy don’t only kill tumor cells, but also healthy cells. When is bone marrowhematopoietic stem cells transplant needed? This treatment method is mainly used for hematological- oncological diseases such as lymphomas, leukemia, myeloma, myelofibrosis, myelodysplastic syndrome, thalassemia, sickle cell anemia, aplastic anemiaother diseases. Transplant is more effective during remission of the disease.
In recent years, it was used also for other tumors along with the hematological diseases: for example, testicularbreast tumors. How is a donor ed? Before answering that question, we’d like to speak about a special exam method called “HLA ion”. HLA (Human Leukocyte antigen) is a protein complexis different in every person. But probability of it being similar is high in relatives. That’s why first donor choices are siblings. Special HLA typing genetic examination reveals their compatibility as a donor. After this, donor’s health is checked. Hematopoietic stem cells are collected from 3 sources: Bone marrow – this is a surgical procedure. Bone marrow is taken after local anesthesia. This is an absolutely harmless procedure. There can be just a little pain in the place whe-re cells were taken from.
Collecting cells from peripheral blood is called apheresisleukapheresis. 4-5 days prior to the procedure, the donor is given a special medicine to move stem cells from bone marrow to the peripheral blood. Stem cells are usually taken from thick veins at the sidesvia a venous catheter. When donor’s blood passes through the apheresis machine, required stem cells are separatedcollected. After collection, donor’s blood is returned back. Collected stem cells are frozenstored. During this procedure, the patient might feel pain in bones, general fatigue,numbness in lowerupper limbsaround lips. Cord blood – is taken from navel blood. Transplant is possible from the cells of the umbilical cord of a newborn, too. Blood of the umbilical cord is collected, frozenstored for long period. Bone marrow transplant allows using high dosage of chemotherapy for some hematological diseases. Because of this treatment, bone marrow diesbecause it is unable to produce new cells, healthy cells that were taken beforehand from the patient are transplanted back which allows to restore the functions of bone marrowhematopoiesis. That’s why high dosage of chemotherapyautologous bone marrow transplant have a huge importance in case low dosage of chemotherapy isn’t effective.
