Bone marrow is a liquid-gelatinous tissue that fills every bone cavity in the human body. It plays a key role in the production of blood cells: leukocytes (white blood cells), red blood cells (RBCs), and platelets. Each of these cells has an essential role in the correct functioning of the body.
Spinal cord is a tissue that occupies the spinal column and transmits nerve impulses. Bone marrow, on the other hand, is a liquid-gelatinous tissue that fills the cavity of bones and produces blood cells.
Stem cells are those that are capable of transforming into any other cell in the body. They have the power to generate copies identical to themselves, through continuous cell division. They play an important role in the body’s regeneration.
The treatment of leukemias often involves bone marrow transplantation. Understanding this recommendation, again, goes through the basics of the origin of the disease. The malignant clones arise in the bone marrow and, from there, are distributed throughout the body. No matter how heavy chemotherapy regimens of induction, consolidation, and maintenance are used, there is still the possibility of cancer cells remaining. These treatment-resistant clones, in a considerable proportion of patients, can lead to a recurrence of the disease.
The solution found to increase the cure rates and control of the neoplasm is bone marrow transplantation (BMT). Simply put, this procedure involves three phases. The first is the recruitment of healthy marrow for donation. This can come from a selection of the patient’s own healthy cells in what is called an autologous transplant, or from a foreign donor who meets the compatibility requirements for the recipient in what is called an allogeneic transplant. In the second stage, the patient receives doses of chemotherapy and sometimes radiation, capable of destroying all of his or her bone marrow. Thus, in theory, even the most resistant malignant representatives are eliminated, which strongly minimises the chances of an eventual future recurrence. Finally, in the last phase, the healthy marrow that was reserved in a blood bank is reinfused into the patient. The stem cells gain circulation, and as they pass through the empty bone marrow, they find a favourable environment in which to settle. They then begin a new cycle of hematopoiesis, which, it is hoped, will again provide the patient with a normal functioning marrow, consisting only of healthy cell lines.
Bone marrow transplantation is indicated as a treatment for some diseases that affect blood cells, such as lymphoma and leukaemia. In the transplant, the diseased marrow is replaced by normal stem cells, which have the role of recomposing a new healthy marrow.
Bone marrow transplantation is like an ordinary blood transfusion. At first, the patient undergoes a chemotherapy treatment, associated or not with radiotherapy, that destroys the marrow itself. Then the patient is ready to receive marrow from a donor, rich in “progenitor” cells – cells that circulate in the bloodstream and become lodged in the bone marrow; they develop and reconstitute new marrow.
When there is no compatible donor in the family, it is necessary to look for a donor in the general population. In Brazil, there is a National Registry of Voluntary Bone Marrow Donors – Redome. This registry gathers data and information from people willing to become donors. It is a digital registry, capable of cross-referencing data between patients and volunteers, who are called upon when necessary to save lives.
