Bone Marrow Transplantation - Stem cell transplantation in India

Having a bone marrow transplant is a complicated five stage process.

The five stages are:

• a physical examination of your body to assess your general level of health
• obtaining the stem cells that will be used in the transplant (known as harvesting)
• preparing your body for the transplant (known as conditioning)
• transplanting the stem cells
• the recovery period, during which you will be monitored for any complications or side effects

The five stages are described in more detail below.

Physical examination

You will have a thorough physical examination before having a stem cell transplant. Your overall level of health before the transplant will play a big part in how well you recover after the procedure. As part of the examination, you may have some scans to check the condition of internal organs, such as your liver, heart and lungs.

Some medicines used in the conditioning and recovery process can occasionally cause problems with your organs, so it is important to know how well they are functioning beforehand. After the transplant, your risk of developing an infection will be increased, so it is vital to ensure you do not have any current underlying infections. If you have a cancer-related condition, you may need to have a biopsy. This involves removing a small sample of cancerous cells so they can be checked in a laboratory. The results of a biopsy can show whether your cancer is in remission (under control) and whether there is a high risk of it returning after your transplant.

Obtaining stem cells

When you've had a physical examination, the stem cells will need to be harvested. The usual method involves removing blood from the body, separating the stem cells from the other cells in the blood and then returning the blood to the body. Alternatively, the bone marrow itself can be collected by removing stem cells from the hip bone using a special needle and syringe. This may be recommended for certain conditions that require a transplant, or if the donor is a child.

Autologous transplantation

If they are suitable, it may be possible to use your own stem cells. This is known as an autologous transplantation. They can be harvested using either method described above. Your stem cells may need to be treated with radiation or chemotherapy to ensure that there are no cancerous cells left. If your bone marrow is being extracted, a needle will be used to remove about a litre of bone marrow. It will usually be removed from your hip bone while you are under general anaesthetic. The procedure is low risk but the area where the needle is inserted may be painful afterwards. The procedure may need to be carried out several times before enough bone marrow is harvested.

Allogeneic transplantation

If your own stem cells are not suitable, stem cells will be harvested from a healthy donor. This is known as allogeneic transplantation. There is a particular shortage of donors from African, African-Caribbean, Asian, Jewish, eastern European and Mediterranean communities.

The process of harvesting cells from a healthy donor is similar to the one used for an autologous transplant. For four days before the transplant, the donor will be given medication to stimulate the production of stem cells in their blood. On the fifth day, they will have a blood test to check they have enough circulating stem cells. They will then be connected to a cell-separator machine. A general anaesthetic is not needed, which means the harvesting can be done as an outpatient procedure. Blood is removed through a vein in one arm and passed through a filtering machine to separate the stem cells from other blood cells. It is then returned to the body through a vein in the other arm.

Preparing your body

As part of your conditioning, you will need to be given a range of medicines, so a tube will be inserted into a large vein near your heart. This is known as a central line and will avoid the need for you to have many painful injections.
The conditioning process involves using high doses of chemotherapy and possibly radiation. It is done for three reasons:

• to destroy the existing bone marrow and make room for the transplanted tissue
• to destroy any existing cancer cells
• to stop your immune system working in order to reduce the chance of the transplant being rejected 

The conditioning process usually takes four to seven days. You will probably need to stay in hospital throughout the procedure. Side effects from chemotherapy are common and include:

• nausea (feeling sick)
• vomiting
• loss of appetite
• mouth ulcers 
• tiredness

The transplant

It is usually possible to carry out the transplant one to two days after conditioning has finished. The donated stem cells will be passed into your body through the central line. The process can take from half an hour to several hours to complete, depending on the type of blood cells being used. The transplant is not painful and you will be awake throughout the procedure.

Recovery

You may feel weak after the transplant, and you may experience vomiting, diarrhoea and have a loss of appetite. To prevent malnutrition (a lack of essential nutrients), you will need to have nutritional support, with high-protein fluids taken by mouth or through a tube running through your nose to your stomach. The first stage of the recovery process involves waiting for the stem cells to reach your bone marrow and start producing new blood cells. This is known as engraftment and it usually occurs 15-30 days after the transplant takes place.
During this period, you will need to have regular blood transfusions because you will have a low number of red blood cells.You will also be at increased risk of developing an infection because you will have a low number of white blood cells. This means that you will need to stay in hospital in a germ-free environment.