Bone Marrow Transplant - BMT
There are some cells in our body that can give rise to all types of blood cells and also the immune system (defense). They are known as hematopoietic progenitor cells, or stem cells.
In BMT, diseased bone marrow cells are replaced by healthy ones. The indication for this procedure will depend on some factors, such as the need to perform the procedure, the patient's clinical condition, age, previous illnesses, and whether there is a compatible donor (in the case of an allogeneic transplant).
BMT is a complex procedure that provides a cure for some malignant and benign hematological diseases, non-hematological neoplasms and autoimmune diseases.
There are two types of BMT: autologous (where the patient himself is the donor) and allogeneic (where another donor is used: family, unrelated donor or umbilical cord).
During BMT, progenitor cells will be infused into the patient through a procedure similar to a blood transfusion; these will lodge in the bone marrow and begin to be produced. Around 2 to 4 weeks after the infusion, the marrow will “take”. This procedure is the only curative alternative in many cases.
About bone marrow donation
There are three sources of cells that can be used for BMT: peripheral blood, the bone marrow itself and the umbilical cord. The donor will have confirmation of compatibility carried out by an HLA (human leukocyte antigen) test, and will undergo some blood tests and a pre-procedure consultation to clarify doubts and details about the process, in addition to confirming their good health. and suitability for donation. There are two types of procedures to perform the collection: non-surgical and surgical.
Non-surgical procedure: Five days before the donation, the donor receives subcutaneous injections of a medicine called filgrastim. This medication stimulates the release of stem cells into the bloodstream. On the day of donation, the blood is removed through a procedure called apheresis, in which a venipuncture is performed, normally peripheral, and the donor is connected to a machine where the stem cells are separated from the rest of the blood. resembles a blood donation. The remaining blood returns to the donor and the procedure lasts around 3 to 4 hours.
Surgical procedure: Stem cells are removed using punctures in the region of the posterior pelvic bones (pelvis). The donor undergoes anesthesia and does not feel anything during the procedure, which lasts between 90 and 120 minutes. He may be discharged on the same day or the next day after surgery, depending on the assessment of the doctor who will collect the cells.
Risks related to donation: when donating peripheral blood, bone pain may occur due to the stimulation of the bone marrow by filgrastim. During apheresis, tingling in the hands and lips may occur. Donors can return to their activities the next day. When donating through a surgical procedure, pain may occur at the puncture site, which tends to disappear within a few days, and anemia, which will improve quickly – iron supplementation may be instituted if the doctor deems it necessary. In rare cases, a blood transfusion will be necessary. Most donors are able to return to their usual activities within 3 to 7 days. Hematopoietic progenitor cells proliferate naturally and, for this reason, approximately two weeks after donation, the donor's body will be completely recovered.