Bone Marrow Transplants – Pushing the Frontiers of Modern Medicine
MAY 13, 2013
What is Bone Marrow Transplant?
Bone marrow is the tissue found in the centre of certain bones. When some of the stem cells turn abnormal or go missing, the whole system starts malfunctioning – the blood cells are no longer made in the way that your body needs. The only permanent solution is a Bone Marrow Transplant, which is a procedure where we destroy the ‘unhealthy’ stem cells, replacing them with ‘healthy’ stem cells called ‘donor’ cells.
Where do the donor cells come from?
Donor cells are collected from matching donors. Transplants are classified based on who these donors are.
How is a bone marrow match determined?
We look for a donor who matches the patient’s tissue type, specifically their human leukocyte antigen (HLA) type. HLAs are proteins (or markers) that are found on most cells in your body. The closer the match between the donor’s HLA markers and yours, the better. Even a ‘perfect’ match will vary slightly from your own cells, so the risk of rejection does exist.
When do you opt for a bone marrow transplant?
They are done for malignant conditions like acute & chronic leukemias, lymphomas, myelomas and certain solid tumours, and nonmalignant conditions like a plastic anemia, thalassemia, sickle cell disorders, auto-immune disorders and some immunodeficiency.
Is Bone Marrow Transplant a last stand treatment as is commonly believed?
Definitely not. In fact, in some cases, it is the only permanent solution. Once Bone Marrow Transplant has been identified as a treatment option, the sooner you start, the better your chances are. Excessive chemotherapy and radiotherapy prior to a transplant can actually kill the good cells to the extent that the transplant is futile or is not possible. To avoid this, patients should seek out centre’s that specialize in Haemato-oncology and have treatments planned with the concerned specialist’s right from the beginning.
What happens during the transplant?
This is not an easy procedure to undergo. We ensure that we explain the process to the patient and caregiver completely, so that they are prepared. First, we prepare you for the transplant – chemotherapy or radiation is given to destroy all the bone marrow in your body to make way for the new cells. We then harvest or collect donor stem cells from the donor’s bone marrow, condition or strengthen these cells if required, and cryopreserve them before radiation or chemotherapy. During the actual transplant, we put these millions of cells, which have now been treated, back into your body through a central line or vein. This takes about 30 minitues.
What happens after the procedure?
You will remain in the hospital for a few weeks while we monitor you closely. Until the donated cells engraft and start making blood cells and platelets, you will be completely dependent on transfusions of donor platelets and blood. Your immunity will be low and you will be susceptible to infections. To prevent this, we keep you quarantined in a HEPA ward that is 100% sterile. You will be given intravenous fluids, anti-viral, antibacterial and anti-fungal medications. We will also work to prevent a ‘graft versus host’ reaction – i.e. a rejection of the transplant. Finally, frequent blood checks are done to check that the grafted cells are taking hold.
What facilities are crucial for a successful transplant?
The essential facilities are: a fully functional Hematology lab with experienced hematologists, the 100% sterile HEPA filtered ward and the Cryopreservation unit where cells are stored at -170oC. At MIOT, we also use two highly efficient and state-of-the-art aphaeresis machines, Spectra Optia and Cobe Spectra, to collect, process and store the peripheral stem cells. Most importantly, you need experienced specialists to plan and monitor every step of the process.
What are the different methods of transplants?
We have Autologous transplants where you can donate your own cells, provided you have enough good cells. The match is naturally 100%. Then we have Allogeneic transplants, where relatives (siblings, parents or new born babies) or people who are not related to you, but whose blood almost matches yours (90%-100%), can donate their cells. When patients do not find a donor among relatives, they are forced to search international registries because we do not have an organized registry in India. In fact, we are heavily dependent on stem cell donations from Europe, which are prohibitively expensive. Precious lives are lost in this endless wait for a match. Today, we are also able to perform Haplo-identical transplants, where the donor cells are not a perfect match. This makes them very exciting!
What is a Haploidentical transplant?
Haplo-identical transplant is a relatively new procedure. The donor is usually your parent or child. The match is not 100%, but it is not less than 50%. The focus is on modulating the patient’s immune system to avoid rejection of the donor cells. This transplant requires more expertise and care and so there are very few centre’s in the world which can do it. But the good news is that the results of a successful haplo-identical transplant are as good as a completely matched transplant.
What does this mean for patients and especially for us in India?
It can be a game changer! It opens up a whole new option for patients who desperately need a transplant but can’t find a complete match. Doctors estimate that nearly all patients with blood cancers or auto-immune disorders and over 50% of sickle cell patients will find potential matches in their immediate family. It is also less expensive. Of course, the type of transplant recommended will finally depend on the patient’s disease, age, health condition and possible donors.
Can one store stem cells and umbilical cord blood for future use?
Yes you can. However, in India, very few institutions have the cryopreservation facilities necessary to store stem cells. Also, unless the donated cells match the intended recipient’s, there’s no guarantee that these cells can be used by the intended recipient in the future.
What should donors know about bone marrow donation?
It is not the painful surgical procedure that most people think it is. In 3 out of 4 donations, we extract stem cells from the donor’s blood via a needle in the arm. If it is a marrow donation, the liquid marrow is harvested from the donor’s pelvic bone. Also donating stem cells does not harm the donor’s health. Not more than 5% of the marrow is harvested and the cells replace themselves in 4 – 6 weeks.
Why are so few bone marrow transplants performed in India?
Firstly, few healthcare providers have made the investments necessary to offer this specialty, in both infrastructure and expertise. Secondly, poor public awareness means that by the time patients come to us, it is already too late. And as discussed earlier, we don’t have an organized Registry, which makes it very difficult to find matches within India.