Bone marrow (stem cell) transplantation

Published by Bupa's Health Information Team, October 2011.

This factsheet is for people who are having a bone marrow or stem cell transplant, or who would like information about the procedure.

A bone marrow or stem cell transplant is where stem cells from a person's bone marrow are destroyed and replaced with new ones, either from themselves or from a donor.

You will meet the doctor or nurse carrying out your procedure to discuss your care. It may differ from what is described here as it will be designed to meet your individual needs.

About bone marrow transplants

Bone marrow is a spongy substance in the centre of your bones. Your bone marrow contains stem cells, which are a type of cell from which other cells in your body can develop. The stem cells in your bone marrow mature into three types of cells. These are:

• white blood cells – help fight infection
• red blood cells – carry oxygen around your body
• platelets – help blood to clot

The cells are then released into your bloodstream.

Although it's often called a bone marrow transplant, this procedure is really a transplant of your bone marrow stem cells.

If you have a bone marrow transplant, your unhealthy bone marrow will be replaced with healthy stem cells. The healthy stem cells are fed into your blood through a drip and find their way to your bone marrow to make new cells. The stem cells can come from another person (a donor) – this is called an allogeneic transplant. Alternatively the cells can come from your own bone marrow – this is called an autologous treatment. However, this can only happen if the stem cells were removed at a time when they were healthy.

If you have stem cells from another person, they can come from the bone marrow or the blood of the donor. When they come from the blood, this is called peripheral stem cell harvest. If they come from the bone marrow, your donor will usually be a close relative because they are likely to have the best match. After a blood test, your doctor will compare both of your blood cells to see how well they match. This is called tissue typing.

Sometimes, doctors can find a matching donor who isn't related to you through the National Blood Service or a charity, such as the Anthony Nolan Trust.

Stem cells can also come from babies' umbilical cords, although this treatment is only suitable for children and small adults, and is still being tested.

Bone marrow transplantation is used to treat conditions that stop your stem cells working. You may have a bone marrow transplant if:

• you have certain types of leukaemia, lymphoma or myeloma
• your cancer is in remission (the symptoms go away and the disease is under control but not necessarily cured)
• your cancer relapses (returns) after earlier treatment
• your cancer hasn't responded to other treatment
• you have other conditions affecting your blood, such as sickle cell anaemia
• you have a condition affecting your immune system

What are the alternatives to a bone marrow transplant?

Doctors usually consider a bone marrow transplant only if other treatments don’t work or aren’t suitable for you.

A bone marrow transplant is a very intensive treatment. Your doctor will take your age and general health into consideration when deciding whether it's right for you. If you’re having a stem cell transplant from a donor, you generally need to be under 55.

Doctors are researching new, alternative treatments to a bone marrow transplant. Mini transplants involve giving a standard dose of chemotherapy because the person isn't fit enough or young enough for a high dose. It's given over five days and then donor stem cells or bone marrow are transplanted. Tandem transplants are when high-dose chemotherapy is given followed by a stem cell transplant, which is then repeated after several weeks or months.

Preparing for a bone marrow transplant

Your doctor and nurse will discuss with you what will happen before, during and after your transplant. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to a bone marrow transplant. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

What happens during a bone marrow transplant?

Chemotherapy

You may need to have chemotherapy, and possibly radiotherapy, before a bone marrow transplant if your cancer or leukaemia isn't in remission. This is because the cancer needs to be at the lowest possible level for a bone marrow transplant to work.

Harvesting the stem cells

The first step is to collect, or 'harvest', the stem cells. The exact process depends on whether the stem cells are coming from a donor or from you.

Peripheral blood stem cell harvest

You or your donor will be given injections of growth factors for around four days. These help the bone marrow to make lots of stem cells for harvesting. Growth factors can also help your stem cells to make blood cells more quickly to help you recover from the transplant.

Harvesting the stem cells from blood takes three to four hours. You or your donor will lie down on a bed and have a drip connected to each arm, or sometimes an arm and a leg. Blood is taken from one arm and goes through a machine called a cell separator. This separates out the stem cells from the other blood cells. It will keep the stem cells and return any other blood cells to the bloodstream through the drip in the other arm or leg. Sometimes the stem cells are cleaned or 'purged' to kill off any last cancer cells, although this is a new treatment and is still being tested.

The stem cells are then frozen until you have had your high dose of chemotherapy.

Harvesting stem cells directly from the bone marrow

Stem cells can also be harvested by taking them out of the bone marrow through a needle inserted into your own or your donor's pelvic bones, or sometimes breast bone. You will have usually have a general anaesthetic or an epidural before this procedure, and will feel sore for a few days afterwards. If you have a general anaesthetic, it means you will be asleep during the procedure.

High dose of chemotherapy

You will then have a high dose of chemotherapy to completely destroy your own bone marrow and any remaining cancer cells in your body. This treatment may take several days and can make you feel sick or vomit, and generally unwell. Your doctor or nurse will give you medicines to help relieve this.

The transplant

A day or more after chemotherapy, your own or your donor's stem cells are fed through a drip into your bloodstream. It will take between two and four weeks before there are enough new stem cells in your bone marrow to start making new blood cells.

What to expect afterwards

While your levels of blood cells are low, you will need blood and platelet transfusions. You will also need to take antibiotics to protect you from infection because of a lack of white blood cells. You may need to stay in hospital until your blood cells have gone back up to a safe level.

Autologous treatment usually causes fewer side-effects than a donor (allogeneic) transplant, because your body is less likely to reject stem cells that have come from your own body.

Donor stem cell transplants are physically and emotionally demanding. You may need to stay in hospital for four to six weeks and you will probably feel very ill for some of the time. You will have your own room to help protect you from infections.

Recovering from a bone marrow transplant

Once the levels of your blood cells have returned to a safe level, you will be able to leave the hospital. You will have regular outpatient appointments afterwards. Your doctor will tell you symptoms to look out for, such as fever, which may be a sign of a complication.

What are the risks?

As with every procedure, there are some risks associated with bone marrow transplantation. We have not included the chance of these happening as they are specific to you and differ for every person. Ask your doctor or nurse to explain how these risks apply to you.

Side-effects

Side-effects are the unwanted, but mostly temporary, effects you might get after having the procedure. Straight after a bone marrow transplant, the levels of blood cells in your body will be very low. Side-effects of this include:

• infections as a result of a lack of white blood cells
• anaemia – a condition when you have too few red blood cells or not enough haemoglobin in your blood
• bleeding because of a lack of platelets
• eating problems as a result of feeling sick, not feeling hungry or having a sore mouth after treatment

Complications

Complications are when problems occur during or after the procedure.

One possible complication of receiving bone marrow cells from a donor is graft versus host disease. This happens when the white blood cells of the donor attack the tissues of your body. You will be given medicines to prevent this so usually the symptoms are mild, although in some people they may be more serious.

The new stem cells that have been fed into your blood may not produce enough blood cells. If this happens, you will need another stem cell transplant.

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.

The bone marrow is a spongy substance in the centre of your bones. Your bone marrow contains stem cells, which are the most basic kind of blood cell. These stem cells in your bone marrow mature into three types of cells. These are:

• white blood cells - help fight infection
• red blood cells - carry oxygen around your body
• platelets - help blood to clot

The cells are then released into your bloodstream.