Bone marrow transplant. Definition

Medical Definition: bone marrow transplant

Hematopoietic stem cell infusion to restore bone marrow function in a patient with defective bone marrow or destroyed by cancer treatment. According to the donor-recipient identity we talk about: 1) allogeneic transplantation: marrow from a healthy donor. Potential donors include a brother with identical HLA (the most common type), identical twin brother, with immunologic and genetic identity (in this case speak syngeneic transplant) altruistic donor unfamiliar (included in registrations), and 2) similar transplants, hematopoietic progenitors derived from the patient. Hematopoietic stem cell sources may be the bone marrow or peripheral blood, although in recent years are also being tested to obtain from the umbilical cord. However, the small volume of blood that can be obtained from each strand makes the total number of parents are not very high. Therefore, most of these transplants have been performed in children and adults under 50 kg in weight. The bone marrow extraction is performed under general anesthesia by multiple punctures aspirations in the iliac crests. In the case of peripheral blood transplants, requires a prior mobilization of marrow stem cells into the peripheral blood. The most used method is the administration of substances called growth factors. Sometimes, it combines the use of chemotherapy and growth factors. The collection of stem cells from peripheral blood cell separators is by. The most commonly used devices are streaming. The machine includes linfomonocitaria layer, returning the remaining blood components to the patient. The process takes about four hours. Cryopreservation involves cells obtained either from bone marrow or peripheral blood, frozen with cryoprotectants, dimethyl sulfoxide, and stored in liquid nitrogen until the completion of the transplant. Defrosting is performed in a bath at 37 ° C, and the infusion is performed through a catheter within 15 minutes. On the other hand it should be noted that at present working on ex vivo expansion of hematopoietic progenitors. This may allow in a few years, only needs a small amount of bone marrow or peripheral blood to perform the transplant.

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