Not everyone is lucky to have a twin from whom bone marrow can be transplanted iwthout the worry of damaged stem cells. For the majority of cancer patients, a bone marrow transplant could be a never-ending ordeal without the right donor in sight.
Bone marrow as the term somewhat explains is the spongy tissue inside few bones, such as the hip and thigh. It contains immature cells, called stem cells. The stem cells can develop into red blood cells, which carry oxygen throughout the body, white blood cells, which fight infections, and platelets, which help the blood to clot. A bone marrow transplant is a procedure that replaces a person's diseased bone marrow cells. Bone marrow transplantation is performed for patients with certain cancers of the blood or bone marrow, such as multiple myeloma or leukaemia. In such cases, the patient’s immune system is usually destroyed by chemotherapy before the transplantation. This procedure is complex and is performed by specialised oncologist or a surgeon. These transplants are mainly used in cases of :
- Severe blood diseases such as thalassemia, aplastic anaemia, and sickle cell anaemia
- Multiple myeloma
- Certain immune deficiency diseases
There are 3 types of bone marrow transplantation:
1.Autologous (patient’s own stem cells are used
2.Allogeneic (stem cells come from a donor)
3.Syngeneic (from an identical twin)
Autologous bone marrow transplantation
The term auto means self. Stem cells are removed from patient before giving high-dose chemotherapy or radiation treatment. The stem cells are stored and after high-dose chemotherapy or radiation treatments, stems cells are put back in patient’s body to make normal blood cells; which probably explains why this type of transplantation is called a rescue transplant.
Allogeneic bone marrow transplantation
At times, stem cells need to be obtained from an external source, known as the donor. However, another person’s genes may not match the patient’s genes, completely but only partially and hence certain tests need to be carried out, to ascertain the suitability criteria. A brother or sister is most likely to be a good match. Sometimes parents, children, and other relatives are good matches.
Syngeneic bone marrow transplantation
An identical twin is an ideal donor because of the genetic identity between the donor and recipient. It is like using one's own cells, except that the cells are not damaged from prior exposure to chemotherapy, and the risk to tumour cell contamination is eliminated.
It is usually questioned that who can be a donor? Can any of the family member donate bone marrow?
To be a donor it is important that donor’s genes should match with that of the recipient’s.
If you are the brother or sister of someone needing bone marrow or stem cells, you might be a match. There is a 1 in 4 chance of your cells matching. Anyone else in the family is unlikely to match. It is sometimes possible to get a match from a matched unrelated donor.
For knowing whether the genes of donor matches with that of recipient or not specific test is performed – HLA typing or tissue typing.
Paediatric bone marrow transplantation
Paediatric bone marrow transplant is a treatment for children with certain types of cancer or other diseases. The goal of BMT is to replace a child’s diseased bone marrow with healthy bone marrow. The success rate of paediatric bone marrow transplantation is around 80-90%.
Bone marrow transplantation is a life saviour for the people suffering from different types of blood cancers.
Along with its benefits there are some risks too. The risks of bone marrow transplantation are:
- Venous occlusion disease
- Infections such as sepsis
- Graft-versus-host disease
- Development of new malignancies
All the benefits and complications are told to the patient by their respective oncologist before the bone marrow transplant.
Bone marrow transplantation is the best hope for a cure or a longer life for patients suffering from blood cancer.