A transplant allows you to have high doses of chemotherapy and other treatments.
When you have a stem cell transplant using another person’s stem cells, it is called an allogeneic transplant. It's more usual to have stem cells collected from the donor’s bloodstream. But some donors might have stem cells collected from their bone marrow.
Some people might have stem cells from umbilical cord blood. But this is not as commonly used.
Why you might have a donor transplant
Your medical team look at a number of factors to decide whether you have a donor transplant. These include:
- your type of cancer
- what other treatments you have had
- how fit and well you are
- whether your medical team is able to find a suitable donor or match
There are different steps or stages of an allogeneic transplant.
To prepare you for your transplant, you have:
- various tests
- a central line put in
Your treatment could mean that you are then unable to have children in the future. Talk to your medical team if this is a concern for you.
As part of your preparation, you might have chemotherapy to get rid of as many cancer cells as possible.
Finding a donor
Ideally, your donated stem cells need to match your own. A brother or sister is most likely to be a close match.
Sometimes, if you don't have a brother or sister who is a match, you can have stem cells from a donor. This could be a donor who is not related to you but whose stem cells are similar to yours. This is called a matched unrelated donor (MUD) transplant.
Or some people might have stem cells that are not a perfect match (but partly match). This is called a mismatched transplant.
To make sure that your donor's cells match, you and your donor have blood tests.
First, laboratory staff check the surface of your blood cells and the donor blood cells for certain proteins. The proteins are called HLA markers or histocompatibility antigens. So the test is called HLA typing or tissue typing.
Everyone has their own set of proteins. Staff compare the proteins on the cells in the blood samples to see if the HLA markers are the same or very similar. Usually 10 HLA markers are checked.
The results of your blood test and the donor's test tell your doctor how good the HLA match is between you. Members of your close family (such as your brother or sister) are most likely to have similar proteins to yours.
A mismatched transplant is when you have donor stem cells that partly match. For example, the donor might be at least an 80 to 90% match with you.
With a mismatched transplant, you are more likely to have a reaction afterwards. The reaction is called graft versus host disease (GvHD). This means the immune cells from the donated stem cells attack some of your body cells.
GvHD typically causes skin rashes, diarrhoea and liver damage. You have anti rejection drugs to help stop it developing. GvHD can be severe and even life threatening for some people.
But mild GvHD can also be helpful for some people. It is an immune system reaction and can help to kill off any cancer cells left after your treatment.
Your doctor may consider a half matched transplant (haplo identical transplant). This means the donor is at least a 50% match with you. This could be one of your parents, a sibling or your child.
In the past, these transplants have been difficult to do. This was because of the increased risk of severe GVHD and infection. But doctors are finding new ways of improving this type of transplant and reducing the risk of GVHD.
You might have a stem cell transplant using stem cells from umbilical cord blood.
In some hospitals, a woman can donate their cord and placenta. Soon after birth, a doctor takes blood from the cord and placenta, which is very rich in stem cells.
The stem cells in the cord blood are still tested to find a good match. But cord blood does not have to match closely to be successful.
Cord transplants are mostly used for children. This is because cord blood contains a smaller amount of cells. Adults could have a stem cell transplant from 2 different umbilical cords. This is called a double cord transplant. You might have cord blood stem cells as part of a clinical trial.
High dose treatment
Once a donor is found, you have high dose treatment. This is also called conditioning treatment.
You have chemotherapy and you might have targeted drugs, depending on your type of cancer. You may also have radiotherapy to your whole body. This is called total body irradiation or TBI.
You have chemotherapy and other drugs over about 5 or 6 days. If you are having whole body radiotherapy, you might have it at the beginning or at the end of the chemotherapy.
You have most of your drugs through a central line. This line runs up under your skin to a large vein close to your collarbone. You can also have anti sickness medicines and antibiotics through your central line. And your nurses can take blood samples from your line.
Some people might have a mini transplant. This is also called a reduced intensity conditioning (RIC) transplant. You have lower doses of chemotherapy than in a traditional stem cell transplant.
You might have this treatment if you are not fit or well enough for a traditional transplant.
Your medical team will explain which drugs you are going to have and the possible side effects.
Stem cell collection
Donors giving stem cells from their bloodstream have growth factor injections once a day for 4 days. The growth factor makes the stem cells spill out into the blood. When there are enough stem cells, they have these collected through a drip from their bloodstream.
Your donor has a general anaesthetic if they are having stem cells taken from their bone marrow. A doctor puts a needle into their hip bone to remove the bone marrow.
The Anthony Nolan charity has more information for donor’s and what is involved.
You have your donor’s stem cells
After you have your chemotherapy and other treatments you have your donor’s stem cells. You have these through your central line into your bloodstream.
Blood count recovery
These stem cells find their way back into your bone marrow where they make the blood cells you need. This recovery of blood cells is called engraftment.
You have regular blood tests to check when your bone marrow starts to make new blood cells.
During this time, you continue to have treatment for any side effects and symptoms. This might include:
- antibiotics and antiviral medicines to treat and prevent infection
- platelet transfusions if the number of platelets in your blood are low
- blood transfusions if your red blood cells are low
- medicines to relieve a sore mouth, diarrhoea and sickness
After high dose chemotherapy, you have low numbers of blood cells for some time. This means you are at risk of picking up infections. You usually stay in hospital until:
your blood cells have recovered enough to go home
you no longer have any severe side effects
This might take 4 or 5 weeks following a donor transplant, although this time can vary from one person to another.
You might have a single room in the hospital ward to help protect you from infection. Your medical team might call this being in isolation.
While you are in isolation you can have visitors, but your nurses may suggest that you only have one or two each day. Your friends and relatives should not come to see you if they are not well. Or if they have been in contact with anyone with an infectious disease.
You might need to follow a special diet including foods that are unlikely to give you an infection.
Coping with isolation
Staying in a single room in hospital can feel lonely. Some people find it frightening. It can help to talk to the nurses about your worries. They can reassure you.
Taking in some of your personal things can make the room feel more homely. Books and photos can brighten it up. You can also take in a laptop, tablet, mobile and music. This can help the time to pass and you can keep in touch with friends and family.
Side effects of transplants
The possible side effects of having a stem cell transplant are caused by high dose treatment and radiotherapy. These treatments lower the number of the different blood cells. Side effects include:
- increased risk of getting an infection
- tiredness and lacking energy
- increased risk of bleeding
- sickness and diarrhoea