Stem cell transplants

Stem cell transplants, sometimes called bone marrow transplants or high-dose treatment with stem cell support, are sometimes used to treat leukaemia, lymphoma and some solid tumours.

Stem cell transplant

To understand these treatments, you need to know what bone marrow and stem cells are:

  • Bone marrow is a spongy material in the middle of your bones where blood cells are made.
  • Stem cells are the cells in your bone marrow that develop into all the other types of blood cells.

Having a stem cell transplant means doctors can give you a higher dose of treatment (usually chemotherapy but sometimes radiotherapy). The aim of high-dose treatment is to give the best possible chance of killing off cancer cells in your body. Giving you stem cells or bone marrow via a transplant afterwards means your body can start creating healthy blood cells again after the treatment.

Autologous (self) transplants

In an autologous transplant, stem cells are the patient’s own. This type of transplant is more likely to be done for solid tumours according to the treatment plan for the particular tumour.

Allogeneic (donor) transplants

This is where stem cells are donated from a close relative or unrelated donor. This type of transplant is a complex procedure and can be subdivided into the following:

  • Sibling: The donor stem cells are from a brother or sister. Each of your siblings has a 1 in 4 chance of being a match with you.
  • Syngeneic: The donor stem cells are from an identical twin.
  • Umbilical cord: The donor stem cells are taken from a related or unrelated umbilical cord.
  • Haploididentical: The donor stem cells are from a parent or sibling that will only be a 50% match. This is not a common type of transplant.
  • Unrelated: Stem cells are taken from a matched or partially mismatched donor that has been found on a donor panel and closely matches your tissue type.

Conditioning treatment

The conditioning treatment (high-dose therapy to prepare you for a stem cell transplant) takes place approximately 7–10 days before receiving the stem cells, depending on whether you have a related or unrelated donor and require admission to the stem cell transplant unit.

Strong chemotherapy drugs are given through the central line in order to destroy the old bone marrow. Some young adults also have radiotherapy treatment to the whole of the body which also destroys the bone marrow – this is known as total body irradiation (TBI).

This may be done at a different hospital as not all hospitals have a radiotherapy unit. You will need to go to the radiotherapy department for your treatments which may be over one to four days. Each treatment will be for about twenty minutes.

Your SCT nurse will discuss your individual treatments with you. You will have to lie in the room alone and keep very still. You can usually take music which may help to pass the time. You will be able to communicate with staff and family and will be closely monitored via CCTV. The treatment does not hurt but may make you feel sick. Anti-sickness drugs are given to help prevent this. It may also give you a sore throat and diarrhoea.

Having your stem cell transplant

The stem cells are given as a transfusion (just like a blood transfusion) through the central line. This may take between fifteen minutes and two hours depending on the amount being given. The amount of bone marrow/stem cells needed is calculated from the weight of the person receiving the transplant.

You will have your blood pressure, pulse and temperature monitored during the transfusion to watch for an allergic reaction. This can be treated with drugs if it occurs.

The new cells enter the bloodstream and in the next few hours make their way to the empty bone marrow spaces in the bones produced by the conditioning treatment. Once they are in place they gradually begin to produce blood cells – this is known as engrafting.

The new cells will take two to four weeks before they make enough white cells to fight infection and there will not be enough to fight major infections, in particular viral infections, for at least six months.

You may still need transfusions of red blood cells and platelets even after discharge, but eventually the stem cells will produce enough blood cells of its own. The whole transplant process from the beginning of conditioning treatment to the time when there are enough white cells to fight infection can take six to eight weeks, with a further three to six months before the bone marrow is working fully. For an allogeneic transplant, recovery may take up to a year.

Side effects and complications during transplant

Stem cell transplant is an intensive form of treatment which can result in serious side effects and complications. These are outlined below and will be discussed with you fully when you speak to the transplant consultant and transplant coordinator/ clinical nurse specialist prior to admission.

Graft versus host disease (GvHD)
GvHD can only occur if you have received stem cells from a donor (allogeneic transplant). As the stem cells begin to engraft, sometimes they recognise they are in a different body and react to this. This may cause redness of the skin on the palms of the hands and on the feet, diarrhoea and liver problems. This is known as graft versus host disease (GvHD), i.e. new donor stem cells versus recipient receiving stem cells. This is usually mild as drugs are given to prevent this occurring, but in some cases it can become very severe and even life threatening. If this occurs it does not mean that the transplant has failed and drugs are given to treat GvHD.

For more information, download or order our free factsheet on graft versus host disease from

You will be at risk of infection following stem cell transplant. These include bacterial, fungal and viral infections. Infection is a very common problem in SCT and can usually be easily treated with antibiotic, antiviral or antifungal drugs. Infections can be more difficult to treat, and may in some instances be life threatening, but this is rare.

Irradiation and chemotherapy can affect long term growth. This will be carefully monitored post-transplant. If necessary, growth hormone treatment can be given.

Sinusoidal obstructive syndrome (SOS)/Venoocclusive disease (VOD)
This can be a serious complication, occurring usually within the first 30 days of the transplant, which affects the function of the liver. Drugs are given to prevent this if you are at risk. It only occurs with certain conditioning treatment and is rare. For more information, download or order our free factsheet on venoocclusive disease from

Haemorrhagic cystitis
This is where there is blood present in the urine and can cause pain. This occurs with certain conditioning treatments or can be a result of various viruses and can happen anytime up to three or four months post-transplant. It can be treated.

Some chemotherapy and radiotherapy treatments are highly likely to cause infertility, which means that you will be unable to have children. With males of pubertal age, sperm banking may be arranged. You will be referred to a specialist for help when you are ready to start a family. We have more information on fertility and cancer treatment for teenagers and young adults.

Radiotherapy can cause cataracts. This is blurring of the vision caused by clouding of the lens in your eye. This can be corrected by surgery and replacing the lens with an artificial one.

Further information

We have produced a booklet about stem cell transplants for teenagers and young adults.

Download or order a free copy