The National Transplant Organization (ONT) is confident that by the end of 2016 there will be more than 250,000 bone marrow donors in Spain. There are currently 230,000 and 120 new ones are added every day, as reflected in the Spanish Bone Marrow Donor Registry (REDMO).
These figures are the result of the National Bone Marrow Plan, which began in 2013 sponsored by the ONT and REDMO, with the goal of reaching 200,000 donors in 2,016, a figure that was reached last year.
According to reports, today more than 80% of patients in need can find a donor in international registries in less than 2.5 months. This is encouraging, since only a minority of patients have a family donor.
The success of international bone marrow donation lies in the intercommunication of the various national registries. There are currently more than 23 million voluntary donors in the world. Another remarkable fact is that Spain is one of the European countries with the highest number of Hematopoietic Progenitor Transplants (a figure that has quintupled since 1994, going from 500 per year to more than 3,000, with some 1,000 being unrelated donors).
What is bone marrow?
Bone marrow is a tissue formed by a mixture of cells in suspension between a network of bone trabeculae and fat found inside the bones (marrow). These cells are what we know as hemopoietic progenitors, since they give rise to all the adult cells that circulate in the blood (red blood cells, white blood cells and platelets). All these cells come from the division and maturation of a common precursor cell that is called a pluripotent stem cell, because it has the capacity for self-renewal and differentiation.
As a cell suspension, bone marrow can be easily obtained by aspiration, using a needle connected to a syringe, and has the same appearance as blood.
Bone marrow transplantation – hematopoietic stem cell transplantation
Bone marrow transplantation, also called hematopoietic progenitor transplantation, is indicated for the treatment of neoplastic diseases of bone marrow origin for which conventional treatment is ineffective or has previously failed.
The main indications for bone marrow transplantation are: different types of blood cancer, especially acute leukemias, lymphomas or multiple myeloma. But it is also indicated when the bone marrow fails in non-neoplastic processes, such as bone marrow aplasia or various hereditary diseases.
The issue is that the chemo and/or radiotherapy administered pre-transplant destroy not only the disease but also the bone marrow, so, in order to prevent the patient from dying due to the lack of bone marrow production, after these treatments the patient is given a sufficient quantity of stem cells to repopulate the destroyed marrow.
Types of bone marrow transplants
The different types of transplants depend on:
On the source of progenitors. Depending on these, the following can be used:
- The marrow itself, which is obtained from the pelvic bones by aspiration.
- Stem cells from peripheral blood. They can be greatly increased by previously administering to the donor a hemopoiesis stimulator, which causes them to detach from their marrow niche and go out into the blood, from where they can be collected by means of an apheresis machine.
- The umbilical cord blood of a newborn, which contains a high amount of stem cells, also capable of being transplanted and repopulating the marrow.
The type of donor. They can be:
- Allogeneic, when it is from a sibling donor ( related) or volunteer (unrelated).
- Haploidentical, from a partially compatible relative who shares a haplotype. This modality is increasing due to the easy availability of the donor.
- Singenic, when it is from a univetiline twin.
- Autologous, when it is from the patient’s own marrow that has been previously cleansed of the disease that afflicts it as much as possible.
Bone marrow donation
Nowadays, in most cases, bone marrow progenitors are extracted from the peripheral blood after administering a subcutaneous drug for 4 days that causes the progenitors to be released into circulation. There are few cases in which it is necessary to extract the marrow with bone punctures in the hips under general anesthesia. The procedure is harmless and has little effect on the donor, who does not require hospitalization or anesthesia.
To become a donor, it is sufficient to extract peripheral blood in an analysis tube. This is analyzed to be included in international registries.
Being a voluntary bone marrow donor entails firmly accepting the moral commitment to donate bone marrow to a patient anywhere in the world who does not have compatible relatives and requires a transplant. The only initial requirement is to fill out a form and undergo a blood collection.
Who can be a bone marrow donor?
“You can be a Bone Marrow Donor, if you are between 18 and 55 years old, by registering at the Blood Bank of the many Hospitals that are part of the program or at the Transfusion Centers or through the REDMO (Spanish Registry of Bone Marrow Donors).
To do so, you must not suffer from any cardiovascular, renal, pulmonary, liver or other chronic disease that requires continuous treatment. Nor must you have a history of positive tests for hepatitis B, C and AIDS virus infections.
More information is available at www.ont.es, www.fcarreras.org or [email protected].