Two exists ways to donate bone marrow, by aphaeresis or by puncture, although the method most used (in more than 70% of cases) is apheresis or peripheral blood donation. After contacting the donor who has greater compatibility with the cancer patient, and before initiating any of these procedures, make a series of tests to the donor.
As explained by Dr. José Luis Vicario, responsible for Histocompatibility of the Transfusion Center of the Community of Madrid, are the same as for any surgical intervention, to demonstrate that there is no risk to the donor in an effective donation of hematopoietic progenitors (PH) . Additional tests are also performed on the donor, basically framed in "determining the status of infections that may interfere with the recipient (patient)." And he adds that "other tests are not usually done, unless there is a direct or indirect cause of hidden pathologies."
Donation by apheresis or by puncture, in what they consist
We explain what apheresis or peripheral blood donation and puncture are, and what are the criteria to opt for one method or another.
- Apheresis or peripheral blood donation. It allows to selectively extract the stem cells present in the blood, and return the rest of the blood to the donor. Four or five days before the donation, the donor is given a drug called hematopoietic growth factor - by subcutaneous injections - that causes the stem cells of the bone marrow to enter the bloodstream.
On the fifth day the donation is carried out in a medical center, where a professional places a needle in each arm of the donor. With one of them blood is drawn, which is circulated through devices known as cell separators that are responsible for collecting the stem cells, while the rest of the blood is returned to the donor by the needle inserted into the vein of the another arm.
- Puncture or extraction of medullary blood from the iliac crests (upper back of the pelvis). In this case, the donor is given general or epidural anesthesia, and it is necessary that he remain hospitalized for 24 hours.
The product obtained after the donation is administered to the recipient as if it were a normal blood transfusion, and the stem cells stay in the bone marrow of the patient's bones, producing healthy blood cells that replace those that They are sick.
With respect to why one or the other procedure is used, Dr. Vicario affirms that the decision is based on "medical criteria based on the pathology of the patient. In general, bone marrow transplants performed on patients with tumor diseases are usually performed through the peripheral blood procedure. " In the clinical result of the transplant, stem cells are involved in a fundamental way, but also the donor's immune system, which is able to eradicate hematopoietic cells (malignant, or not) from the recipient. The use of bone marrow by puncture in the iliac crests is used for cases in which no substantial antireceptor response is sought ".