Bone marrow in our bones is responsible for formation of blood cells. In fact, all the blood cells are formed by a subset of bone marrow cells known as “hematopoietic stem cells” or simple “stem cells”. These stem cells have special characteristics, i.e. they can renew themselves, and have the capability to develop into any type of blood cells.
Nowadays, hematopoietic stem cells can also be obtained from peripheral blood after treatment with certain growth factors or from umbilical cord. Thus, “Hematopoietic stem cell transplantation” is now also referred to as “Bone Marrow Transplantation”, wherein the stem cells from bone marrow that produce red blood cells, white blood cells, and platelets are injected into a recipient after a short course of chemotherapy called conditioning. Today, this is a viable option for several disorders and with continued research, success has improved markedly.
A bone marrow transplant is a medical procedure performed to replace unhealthy bone marrow stem cells with the healthy ones. This transplant is carried out to treat people with conditions like leukaemia - Blood Cancer, multiple myeloma, severe blood diseases such as aplastic anaemia, thalassemia, sickle cell anaemia and certain immune deficiency diseases. Typically, the stem cells are collected via a peripheral vein. The whole bone marrow transplant procedure is like donating blood or platelets. The stem cells from the bone marrow are in charge for producing blood cells like platelets (thrombocytes), white blood cells (leukocytes) and red blood cells (erythrocytes), which later are injected in a recipient after a short course of chemotherapy.
There are two basic types of transplants, allogeneic and autologous, depending on who donates the bone marrow or stem cells.
Allogeneic Bone Marrow Transplant: Donor and Recipient are two separate individuals and transplant is done using the stem cells of donor. It may be-
Matched Related, where donor is HLA matched relative usually a sibling.
Matched Unrelated, where donor is not a relative of patient and usually found from one of the various national or international registries.
Partially Matched Related, where donor is from a patient’s family but partially matched (haploidentocal)
Cord blood from a cord blood registry
Autologous Bone Marrow Transplant: Donor and Recipient are same individuals, where transplant is done using patient’s own stem cells. The procedure involves giving high dose chemotherapy to patient in order to remove primary disease. Thereafter, an autologous transplant is conducted to rescue damaged bone marrow. This type of transplant has minimal complication and is preferred for diseases like multiple myeloma/lymphoma.
There are certain conditions for which Bone Marrow Transplant is recommended.
Fanconi anemia and other bone marrow failure syndromes
Inborn errors of metabolism
Congenital Immunodeficiency syndromes
Yes, Bone Marrow Transplant is a complex procedure that carries significant risks and serious complications. Generally, the risks are reduced if:
If patient is young – Studies have shown the younger you are, the more likely the treatment is to succeed
Patient receive stem cell donation from a sibling (brother or sister)
Patient have no serious health conditions (apart from the condition you're being treated for)
Bone marrow fluid (aspirate) and tissue samples (biopsies) are often obtained from the upper ridge of the back of a hipbone (posterior iliac crest). The front of the hip is sometimes utilised.
No, Bone Marrow Transplant is a medical procedure. Mostly, stem cells are collected via peripheral vein and the whole procedure is like donating blood or platelet. In some patients Bone marrow harvest is done which involves general anaesthesia to the donor.
No, there is no risk to the donor. Donors are usually able to resume their duties the next day after collection of the stem cells.
Reviewed by Dr. Amit Verma, Cancer Care/Oncology, Bone Marrow Transplant on 03-Sep-2022