Stem cells are made by your bone marrow – a spongy substance in the centre of your bones (mainly in your pelvis, ribs, skull and spine). When they’re produced by your body, stem cells aren’t fully developed yet. They can either remain as a stem cell or become another type of cell such as a muscle cell or a brain cell. They act as your body’s internal repair system and replenish other cells.
Some of the stem cells in your bone marrow mature to make certain types of blood cells. These include:
- white blood cells, which help your body fight infections
- red blood cells, which carry oxygen around your body
- platelets, which help your blood to clot
Once these blood cells are fully developed, they’re released from your bone marrow into your bloodstream.
You may need a stem cell transplant if you have a condition that affects your bone marrow or your red blood cells.
These conditions include cancers that affect your bone marrow, for example leukaemia, lymphoma and myeloma. This is because the treatment used to destroy cancer cells found in your bone marrow also destroys your healthy stem cells. A stem cell transplant can replace these. You may be able to have higher doses of chemotherapy treatment if you have a stem cell transplant.
Stem cell transplants are also used to treat other conditions such as those that affect:
- your blood cells (for example, aplastic anaemia)
- your immune system (for example, multiple sclerosis)
Doctors are using stem cell transplants to treat a wide range of conditions now, but they aren’t suitable for everyone. Your doctor will take your age and general health into account when they decide whether the procedure is right for you. You can ask your doctor for more information.
Where healthy stem cells for transplanting come from can vary. There are three options, which are:
- the blood – known as a peripheral blood stem cell harvest (PBSCH)
- blood cells in a donated umbilical cord – this is being used much more now than in the past
- the bone marrow – called a bone marrow transplant
Stem cells are usually now collected from the blood rather than the bone marrow because it’s easier. More stem cells can usually be collected from the blood than from the bone marrow too. Your blood cell levels will also usually recover faster than your bone marrow (for more information on this, see our section: What to expect afterwards below).
There are different types of stem cell transplant depending on who the stem cells are taken from.
- Allogeneic transplant. In this case, the stem cells come from another person (a stem cell transplant donor). You may have a related donor such as a brother or sister, or a matched unrelated donor.
- Autologous transplant. This is when the stem cells come from your own bone marrow. This is only possible if your stem cells are removed when they’re still healthy.
- Syngeneic transplant. If you have an identical twin who donates stem cells to you, this is called a syngeneic transplant.
Your doctor or nurse will explain how to prepare for a stem cell transplant.
They’ll start looking for a suitable stem cell donor if your stem cells are to come from another person. Ideally, your donor will be a close relative – usually a brother or sister. This is because their blood cells are more likely to be similar to yours so your body is less likely to reject them. If your hospital team can’t find a relative who’s a close match, they’ll look for someone unrelated to you. Organisations like the British Bone Marrow Registry or the Anthony Nolan Trust can help with this.
You and any possible donors will need to have some tests, including blood tests. Your doctor will compare your blood cells with those of the donor to see whether they’re a good match for you.
Your nurse or doctor will discuss with you what will happen before, during and after your procedure, including any pain you might have. If you’re unsure about anything, ask. No question is too small. Being fully informed will help you feel more at ease and will allow you to give your consent for the procedure to go ahead. You’ll be asked to do this by signing a consent form.
After your procedure, you may need to stay in a hospital room on your own, possibly for about a month. This will reduce your chances of catching an infection while your immune system recovers. So, when you pack your hospital bag, it’s a good idea to take some things to keep you entertained during this time. For example, books and magazines, your mobile phone, tablet or laptop may all help you to pass the time. Electronic devices will also help you keep in touch with people.
When you have a stem cell transplant procedure, there are usually three steps involved. These are explained in more detail below.
- First, the stem cells will be collected either from you or from a donor.
- Next, you may have high-dose chemotherapy and/or radiotherapy.
- Finally, the collected stem cells will be transplanted into your body.
Collecting the stem cells
The first step is to collect (harvest) the stem cells from you, your donor or donated umbilical cord blood.Collecting stem cells from blood
If the stem cells are to be collected from your or your donor’s blood, it’s called a peripheral blood stem cell harvest (PBSCH). In this procedure, you or your donor will first be given daily injections of a growth factor for about five to 10 days. The growth factor triggers your body to make more stem cells and release them from your bone marrow and into your bloodstream. They can cause pain in your muscles and joints but over-the-counter painkillers should help.
You’ll have blood tests every day to monitor the number of stem cells in your blood. Once there are enough, they’ll be harvested. Your nurse will put a drip into both of your (or your donor’s) arms and use a machine to collect these cells from the blood. The stem cells will be separated from other cells in your blood.Collecting stem cells from bone marrow
If the stem cells are to be collected from your or your donor’s bone marrow, you’ll first be given a general anaesthetic or epidural. Your doctor will then insert a needle into the pelvic bone to take stem cells out of the bone marrow.
Once the stem cells have been collected, you’ll be treated with high-dose chemotherapy, and possibly high-dose radiotherapy (called total body irradiation). This prepares your bone marrow and immune system to receive the new stem cells. It will supress your immune system enough to prevent it rejecting the new cells, and aims to destroy the disease that you’re having a stem cell transplant for.
This treatment usually takes around three to four days but this may vary, so speak to your doctor for advice that’s specific to you. This treatment can make you feel sick or vomit and feel generally unwell. Your doctor or nurse will give you medicines to help relieve this.
After you’ve finished chemotherapy, the new stem cells will be fed through a drip into your bloodstream. This usually takes several hours. The stem cells will find their way to your bone marrow where they’ll begin to make new cells. It will take at least a few weeks before there are enough new stem cells in your bone marrow to start making new blood cells.
After a stem cell transplant, you’re likely to have low levels of blood cells in your body. You might need to have a blood and platelet transfusion to correct this. You’ll also need to take antibiotics to protect you from infections. Your immune system won’t be working properly because your body will contain only low levels of white blood cells. You may need to stay in a room on your own in hospital until your blood cell numbers have gone back up to a safe level. This can take a few weeks, but can vary depending on your individual circumstances – check with your doctor how long it will be for you.
Immediately after a bone marrow transplant, your mouth may feel sore and you might find it difficult to swallow. Your nurse will give you advice on how to deal with this. It’s possible that you might need to be fed through a tube placed in a vein, or directly into your stomach while your mouth recovers.
The overall success of a bone marrow transplant depends on many things. These include what health condition you have, how far it’s progressed, your age, and how good a match your donor is. Ask your doctor what you can expect from your stem cell transplant.
How long it takes to recover from a stem cell transplant will depend on whether your stem cells came from a donor or from you. Recovery time can vary from person to person, so it’s important to follow your doctor’s advice. It can take months or sometimes even years to recover properly as your body gets used to the newly transplanted cells.
Once the number of blood cells in your body has returned to a safe level, you’ll be able to leave the hospital. For a while, you might need to avoid eating certain foods which could be contaminated with bacteria or fungi. This includes foods like raw or lightly cooked fish, blue cheese and raw or undercooked eggs. You’ll also need to be very careful with food hygiene when you prepare, cook, eat out or store food. Continue to follow this food safety advice for at least six months after you’re discharged from hospital.
After a stem cell transplant, you lose your immunity to common childhood infections. You’ll need to be vaccinated again to protect you against conditions like tetanus and diphtheria. This usually happens about six months to a year after your transplant. Your doctor will suggest that you have a flu vaccine as well.
Side-effects are the unwanted but mostly temporary effects you may get after having a procedure. Straight after a stem cell transplant, the levels of blood cells in your body will be very low. This may cause:
- a low immunity to infections – due to a lack of white blood cells
- anaemia – where you have too few red blood cells or not enough haemoglobin in your blood
- bleeding because of a lack of platelets in your blood – these normally help your blood to clot
- problems eating as a result of feeling sick, not feeling hungry or having a sore mouth after treatment
You may need to have a blood transfusion to increase your levels of platelets and red blood cells.
If you have a transplant using your own stem cells, this usually causes fewer side-effects than a transplant using stem cells from a donor. This is because your body is less likely to reject stem cells that have come from its own bone marrow or blood.
Complications are when problems occur during or after a procedure.
Infections are a common complication of a stem cell transplant while your levels of white blood cells are low. You’ll be given medicines that stop your body rejecting the new stem cells and these may increase your risk of infections even more. You’ll need to stay in your own room in hospital after your transplant to limit your exposure to bacteria, fungi and viruses. You’ll also need to be careful about what you eat and drink. For more information, see our section: Recovering from a stem cell transplant above.
Graft-versus-host disease (GVHD) is a possible complication of receiving stem cells from a donor. This happens when the white blood cells of the donor recognise your cells as being different and attack them. For more information on this, see our FAQ: Stem cells and graft-versus-host disease below.
If the transplant isn’t working, your new stem cells may not produce enough, or any, new blood cells. This will show up in blood tests. If this happens, your doctor may give you growth factors to help your body make more blood cells. If the growth factors don’t work, you may need to have another stem cell transplant.
FAQ: Stem cells and graft-versus-host disease (GVHD) What if I get graft-versus-host disease (GVHD)?
If you have graft-versus-host disease (GVHD), it means the new donor stem cells are attacking your body. This is because they see your body as ‘foreign’. In some people, GVHD causes minor symptoms, but it can cause a lot of damage to your body’s organs and be potentially life-threatening.
GVHD can happen immediately after your bone marrow transplant or several months later. If it’s immediately – or within 100 days of your transplant – it’s called acute GVHD. If it happens more than 100 days after your transplant, it’s considered chronic GVHD.
Symptoms of acute GVHD include:
- a severe itchy or painful skin rash
- feeling sick and vomiting
- yellowing of your skin (jaundice)
Chronic GVHD can cause the symptoms of acute GVHD, as well as other symptoms that include:
- a bumpy rash on your skin
- sore muscles and stiff painful joints
- difficulty breathing
- a swollen mouth, which might also have sores
- dry, burning and/or irritated eyes
Your doctor will monitor you carefully in the days and weeks after you have a stem cell transplant. If necessary, they’ll prescribe medicines to weaken or switch off (suppress) your new immune system. This will make you less likely to develop GVHD.
FAQ: Stem cells and a failed immune system Why do I need a stem cell transplant if my immune system has failed?
In a stem cell transplant, your unhealthy stem cells will be replaced with healthy stem cells. This will help your immune system to recover.
Bone marrow is a spongy substance in the centre of your bones that makes stem cells. Stem cells develop and mature into the other cells in your body, including white blood cells. These are an essential part of your immune system. They spot bacteria or viruses and co-ordinate an attack against them, which helps to protect your body from infections.
Some illnesses can affect your bone marrow and destroy the stem cells. This means that you can’t make enough white blood cells, so you’re more likely to catch infections. A stem cell transplant can help your body to produce normal white blood cells again.
Not all conditions or diseases that damage your immune system can be treated with a stem cell transplant. If you’re unsure if a stem cell transplant can help you, ask your doctor for advice.
- Hematopoietic stem cell transplantation. Medscape. emedicine.medscape.com, updated 13 November 2017
- Bone marrow and bone marrow failure. PatientPlus. patient.info/patientplus, last checked 3 February 2014
- Stem cell basics. National Institutes of Health. stemcells.nih.gov, published 2016
- Bone marrow anatomy. Medscape. emedicine.medscape.com, updated 29 November 2017
- Nursing patients with haematology problems. Oxford handbook of adult nursing. Oxford Medicine Online. oxfordmedicine.com, published August 2010
- Myeloma: diagnosis and management. National Institute for Health and Care Excellence (NICE), 10 February 2016. www.nice.org.uk
- Sureda A, Bader P, Cesaro S, et al. Indications for allo- and auto-SCT for haematological diseases, solid tumours and immune disorders: current practice in Europe, 2015. Bone Marrow Transpl 2015; 50(8):10.37–56. doi:10.1038/bmt.2015.6
- Bone marrow transplantation. Medscape. emedicine.medscape.com, updated 20 January 2017
- Bone marrow transplants. Cancer Research UK. www.cancerresearchuk.org, last reviewed 16 March 2015
- Home. British Bone Marrow Registry. www.nhsbt.nhs.uk, accessed 7 February 2018
- Finding a donor for your stem cell or bone marrow transplant. Anthony Nolan. www.anthonynolan.org, published 7 October 2016
- Having a transplant. Cancer Research UK. www.cancerresearchuk.org, last reviewed 17 March 2015
- Infections after bone marrow transplantation. Medscape. emedicine.medscape.com, updated 7 April 2015
- Stem cell transplants. Cancer Research UK. www.cancerresearchuk.org, last reviewed 16 March 2015
- Bone marrow donor procedure. Medscape. emedicine.medscape.com, updated 15 September 2017
- Finding a donor and collecting stem cells. Macmillan. www.macmillan.org.uk, reviewed 31 July 2014
- Total body irradiation (TBI). Cancer Research UK. www.cancerresearchuk.org, last reviewed 16 March 2015
- Cancer and leukaemia. Oxford handbook of nutrition and dietetics. Oxford Medicine Online. oxfordmedicine.com, published January 2012
- The seven steps. The next steps. Anthony Nolan. www.anthonynolan.org, published September 2014
- Graft-versus-host disease. BMJ Best Practice. bestpractice.bmj.com, last updated 26 September 2016
- Immune system anatomy. Medscape. emedicine.medscape.com, updated 22 November 2013
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