What is a stem cell or bone marrow transplant for acute lymphoblastic leukaemia (ALL)?

You might have a stem cell or bone marrow transplant as part of your treatment for acute lymphoblastic leukaemia (ALL).

A transplant allows you to have high doses of chemotherapy and other treatments. The stem cells are collected from the bloodstream or the bone marrow.

What are stem cells?

Stem cells are very early cells made in the bone marrow. Bone marrow is a spongy material that fills the bones.

Diagram of bone marrow

These stem cells develop into red blood cells, white blood cells and platelets. 

Diagram of three different types of blood cell

Red blood cells contain haemoglobin which carries oxygen around the body. White blood cells are part of your immune system and help to fight infection. Platelets help to clot the blood to prevent bleeding. 

How transplants work

To prepare you for a stem cell transplant you usually have very high doses of chemotherapy first. You might have other treatment as well. This might be radiotherapy to the whole body (total body irradiation or TBI), or targeted cancer drugs, or both. This preparation is also known as conditioning treatment.  

The treatment kills the leukaemia cells as well as the healthy stem cells in your bone marrow. This makes space in your bone marrow for the donor stem cells. And dampens down your immune system so you don’t reject the donor cells. 

Before your high dose chemotherapy, your team either collects:

  • someone else's (donor) stem cells
  • your own stem cells (this is very rare in ALL)

After the conditioning treatment you have the stem cells into your bloodstream through a drip. The cells find their way back to your bone marrow. You start making blood cells again and your bone marrow slowly recovers.

Photograph showing a stem cell transplant

A stem cell or bone marrow transplant

The main difference between a stem cell and bone marrow transplant is whether stem cells are collected from the bloodstream or bone marrow.

A stem cell transplant uses stem cells from a donor’s bloodstream or your bloodstream. This is also called a peripheral blood stem cell transplant (PBSCT).

A bone marrow transplant uses stem cells from a donor’s bone marrow or your bone marrow.

Stem cell transplants are the most common type of transplant. Bone marrow transplants are not used as much. This is because:

  • it’s easier to collect stem cells from the bloodstream than bone marrow
  • blood cell levels tend to recover quicker after a stem cell transplant

Giving stem cells rather than bone marrow is better for the donor. They don't need an anaesthetic for the stem cell collection and tend to recover more quickly.

Your doctor will explain how they have decided what kind of transplant is best for you.

Why you might have a transplant

The aim of treatment is to put it into complete remission. Complete remission means there is no sign of leukaemia cells.

Your doctor might suggest a transplant if your ALL:

  • has features that show it is likely to come back (high risk)
  • has comes back (relapsed ALL)
Last reviewed: 
15 Jul 2021
Next review due: 
15 Jul 2024
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  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in if you need additional references for this information.

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