Bone marrow transplants are the need of the hour as whiter platelet formation depends on bone marrow. This is why bone marrow and how to take care of it is curcial.
Types of Bone Marrow Transplant
Bone marrow is a spongy, fatty tissue found in our bones. It is responsible for creating red blood cells which carry oxygen and nutrients throughout the body, white blood cells which are responsible for fighting against infection and finally, platelets which are responsible for the formation of clots.
A bone marrow transplant is carried out to cure many diseases and types of cancer. It is a medical procedure to replace bone marrow which has been destroyed or damaged by disease, infection or chemotherapy with healthy bone marrow. The process involves replacing the damaged bone marrow with a new one, promoting the growth of new bone marrow.
A transplant is performed with the help of patient’s own healthy stem cells, if available or with the help of a donor. A donor can be anyone from the family like parents or siblings where there is 50% chance to match to the patient’s stem cells. While sometimes where family samples don’t match, you can get a donor through a registry for transplantation. The healthy stem cells are harvested before the chemotherapy or radiation starts. According to the type of bone marrow severity, an oncologist decides which route to travel.
Before the transplant, chemotherapy, radiation or both may be performed.
Myeloablative (Ablative) treatment: High dose of chemotherapy, radiation or both are performed to kill cancerous cells. It allows growing new stem cells in the bone marrow. The downside of this treatment that it also kills healthy cells.
Reduced intensity treatment: Usually known as a mini-transplant, mostly preferred for older patients or patients with other health problems. The treatment includes a low dose of chemotherapy and radiation.
There are three types of bone marrow transplants :
1.Autologous transplant: To undergo this particular transplant ablative treatment is carried out. The patient own healthy cells are used in this transplant before the chemotherapy and radiation treatment. They are stored in the freezer and after the treatment, stem cells are put back into the patient’s body to reproduce normal blood cells. In this transplant, the patient act as their own donor as their own stem cells act as healthy bone marrow which is required. The only advantage of this transplant is the absence of graft-versus-host disease which usually can be the case in donor transplant.
2.Allogeneic bone marrow transplant: When patient own healthy stem cells cannot be used, so donor’s genes are used. A donor can be anyone from the family such as a parent or a sibling. Special tests are performed to get the closest match to the patient’s genes. The oncologist will pick the match assuring a positive outcome. If the patient has damaged bone marrow cells, the allogeneic transplant is preferred. Unlike autologous transplant, allogenic has a risk of developing graft-versus-host disease. The success of this transplant highly depends on how closely the donor cells match the patient’s cells.
3.Umbilical cord transplant: It is a type of allogeneic transplant. The stem cells are harvested from the newborn baby’s umbilical cord right after birth. They are then stored at a much lower temperature and preserved until put in to use for a transplant. The cells from umbilical cords are immature and are in the budding stage, so the threat is minimal of counter-attack. With many advantages, oncologists are opting for this method. Benefits such as-
- Availability- The umbilical cord cells are easily available. They are stored at the time of birth. The time required for the donor’s sample to reach the patient is nearly halved when this transplant is used.
- Easier match- As discussed, the umbilical cord cells are naïve and possess the least amount of threat for the bone marrow transplant. It is time-consuming to find the best match (Allogenic) for the cells, so umbilical cord remains the best option.
- Lower risk of rejection- Graft-versus-host disease (GVHD), a condition where the host cells don’t accept the cells from the donor. But umbilical cord transplant has fewer cases of GVHD, proving to be most accepted transplant among others.