What is bone marrow – it is a soft gel like substance in the long bones of the body, which produce red blood cells, white blood cells and platelets, which are important components of blood. In simple terms – bone marrow is the site where blood is manufactured.
Bone marrow transplant – it’s a very important procedure, where it can help in curing the patient diseases like blood cancer.
How it is done – by giving high dose of chemotherapy drugs, cancer cells are killed, in the process, the normal healthy stem cells will get killed. Marrow from a healthy donor is transplanted into patient, which regenerates into healthy cells and helps patient to recover.
Type of transplant
There are two main types of hematopoietic cell transplantation: autologous and allogeneic.
Autologous transplant — patient own stem cells are removed before the high dose chemotherapy or radiation is given, and they are then stored at 4 degrees centigrade of frozen at – 70 degree centigrade for later use.
After chemotherapy, the stem cells are warmed to room temperature and transfused into patient’s body.
Allogeneic transplant — in this procedure the stem cells are taken from donor, either from family member or unrelated donors.
What MSD - matched sibling donor or related donor, means, genetically related donors, who can be a sibling or parents.
They can be 100% matched or 50% matched (these types of donors are called as haploidentical donors)
MUD – matched unrelated donor – genetically matched unrelated donor from outside the family.
Where can we get MUD donor –
There are registries, like blood banks, where HLA information is stored and matched with patients on request.
Steps in bone marrow transplant
1. Donor evaluation – checking for the suitability of stem cell donation.
2. Collecting and storing of stem cells from donor
3. Stem cell collection is done by two methods – 1. From bone marrow. 2. From peripheral blood
4. Giving high dose chemotherapy – called as conditioning.
5. On day zero – stem cells are transfused into patient body.
6. Post-transplant care – blood transfusion, treating infections and other complications.
What are the complications of transplant?
1. Infections –
a. Bacterial infections during and post-transplant
b. Fungal infections during and post-transplant and
c. Viral infection – later part of transplant, mostly in 2 or 3 months
2. Graft versus host disease
i. Acute – in 100 days
ii. Chronic – after 100 days
b. Organs affected.
iii. Gastrointestinal – liver, stomach, colon
iv. It can affect other part of body also.
3. Relapse – of leukemia
4. Late onset of caner – transplant related cancer can arise years after transplant.
Consultant Medical & Hemato Oncologist and BMT Physician
KIMS Hospitals, Secunderabad.