Stem cell collection and donation: Information for people donating their stem cells to a family member : University College London Hospitals NHS Foundation Trust

This page explains what stem cells are and how they are collected and donated to your family member who needs a transplant. Here, ‘family member’ means a sibling, parent or child. If you have any questions about the procedure, please talk to your doctor or nurse.

You may hear your healthcare team refer to stem cells as haematopoietic progenitor cells (HPCs).

Stem cells are blood cells at a very early stage of development. They can divide and develop into three main types of blood cells:

Red blood cells, which carry oxygen to all cells in the body
White blood cells, which help fight infections caused by bacteria and viruses
Platelets, which help blood to clot and prevent bleeding.

bone marrow and the blood cells it produces_Lymphoma Action copyright.png

Image produced by Lymphoma Action and reused with permission

Stem cells are formed and develop into blood cells in the bone marrow, which is spongy tissue inside the bones. Once the blood cells are fully mature, they are released into the bloodstream from the bone marrow. A very small number of stem cells are also released and can be found in the blood.

To collect your stem cells we need to move them from the bone marrow into your blood. This is called peripheral blood mobilisation and we will refer to it as mobilisation. Once the stem cells are in the blood, we will use a procedure called apheresis to collect (harvest) them. Apheresis means removal or extraction.

As a stem cell donor, you will have various tests and a detailed medical check before the donation. This is to make sure that you are healthy enough for the procedure.

We will examine you and review your health history. This may include any operations you have had, adverse reactions to medicines, and your travel and sexual health history.
We will ask if you smoke or drink.
You will have a chest X-ray to check your lungs.
We will check your blood pressure, your weight and your height.
We will take your urine sample to check for infections.
You will have an electrocardiogram (ECG) to check your heart’s rhythm.
You will have several blood tests. These include tests for:
- full blood count
- blood type
- liver and kidney function
- viruses, including HIV, Hepatitis B, Hepatitis C and syphilis.

These tests help us find any underlying conditions or infections that could affect you or your family member who will receive your stem cells. Please drink plenty of water before your blood tests. This helps to make your veins easier to find.

In the UK, the law requires us to check for viral infections before collecting and storing stem cells. The results of the viral blood test are valid for 30 days. If your stem cell donation is delayed, we may need to repeat this test.

We will review your family health history.
We will ask you some questions about your personal life. For example, what your marital status and occupation is.
We will review any medicines you may be taking and advise if any of them need to be stopped for the donation.
We will check the veins in your arms to make sure they are suitable for the collection of stem cells. If your veins aren’t suitable, you may need to have a catheter inserted into one of the larger veins at the top of your leg instead. This happens in five out of 100 people. There’s more information about this in the section On the day of the stem cell collection (harvest).
We will ask you to use contraception throughout the process and for one month after. Barrier contraception, such as condoms, is fine.
If you are a female of child-bearing age, you will need to take a pregnancy test before the collection. We will let you know when you need to take the test and we can also give you a pregnancy test kit.
We will ask you to avoid raw or undercooked meat (especially pork) and shellfish until after your donation. This will lower your risk of getting Hepatitis E. In recent years, more people in the UK have been getting Hepatitis E. Most people don’t have any symptoms, and the infection usually goes away on its own. But it can be harmful if passed to someone with a weak immune system.

It’s very important that you tell us if you feel unwell or develop flu-like symptoms between your assessment and donation. Having an infection can affect the quality of your stem cells. It can also contaminate the cells, passing the infection on to your family member.

If we have any concerns, even small ones, about your health and ability to donate, you will need extra tests to make sure you can be a donor. If these tests show that you cannot donate, this is to protect your health and safety.

If you need more tests to check your health, we will talk to you about it and make the arrangements. Some or all of these tests may be done through your own GP. We will send a letter to your GP with all the necessary details.

Travelling abroad

We will ask you not to travel abroad from the time of your medical check until two days after donating your cells. This is because you may need extra travel-related blood tests which can interfere with your donation schedule.

If you have already made plans, please talk to your clinical nurse specialist (CNS).

The doctor and clinical nurse specialist (CNS) will ask you to sign a consent form to undergo stem cell mobilisation and collection. This will confirm that you agree to have the procedure and understand what it involves.

They will review the donation process and go over the consent form with you before you sign. They will also answer any questions you may have so please ask if anything is unclear.

It is very important that you are sure about donating before your family member starts their pre-transplant conditioning treatment. Depending on their chemotherapy regime, they will start this treatment 10 to 14 days before your stem cell collection. After this treatment, they will need your stem cells to survive. So, it is critical that you are fully committed to donating before they start their pre-transplant treatment.

If you are fit to proceed with the donation, you will receive a four or five-day course of G-CSF injections. G-CSF is a substance produced naturally by the body. Its major function is to turn stem cells in the bone marrow into mature blood cells. When G-CSF is given at higher doses than the body would normally produce, it also helps to move some of the stem cells in your bone marrow into your bloodstream.

The G-CSF injections are given under the skin (subcutaneously), usually in the abdomen, thighs or upper arms. You can do the injections yourself at home or a family/friend can give them to you. You can also have the injections administered at your GP surgery on weekdays.

Cancer Research UK has developed a video explaining how to give an injection just under your skin. You can watch it on YouTube. 

Are there any side effects of G-CSF injections?

Yes, there are some side effects of G-CSF injections. The most common ones affecting 10 out of 100 people include:

Headaches
Feeling tired or unwell
Back pain
Flu-like symptoms

You can take paracetamol tablets (two tablets = 1g) to help with these symptoms. You can take a maximum of eight tablets (4g) in 24 hours. This is two tablets every six hours.

Note: Do not take aspirin, or medicines that contain or are similar to aspirin, such as ibuprofen while you are having G-CSF injections and for two weeks after. This is because your platelet levels may be lower than normal and you may be at a higher risk of bleeding. If you take aspirin for medical reasons, please tell us. You should also avoid intense exercise during this period for the same reason..

Rare side effects (affecting between one and 10 out of 100 people):

You may experience swelling, redness or tingling at the injection site.
Very rarely an allergic reaction can occur. If you experience rapid heart rate, dizziness, shortness of breath, itching or rash, go to your local Emergency Department (A&E).

Extremely rare side effects (affecting one in 10,000 people):

Your spleen could become enlarged and potentially rupture, which would result in internal bleeding. If you experience any unusual tenderness in the upper left side of your abdomen, just underneath your rib cage, contact us straight away on 07852 220900 or go to your local Emergency Department (A&E).

It is important that you don’t take any new medication during the course of G-CSF injections unless your haematology team advises you otherwise. All syptoms generally disappear within two to three days of stopping G-CSF. If you have any queries or concerns while you are having G-CSF injections, contact the bone marrow transplant team on 020 3447 9712 or 020 3447 7375 (Monday to Friday, 9am to 5pm). Out of hours, call the urgent advice line on 07852 220900.

Are there any long-term side effects of G-CSF injections?

The course of G-CSF injections you will need to have is classed as a short course and will not extend beyond five days. To date, no long-term adverse effects have been reported following a short course of G-CSF.

We have monitored several thousand donors for more than five years, and long-term follow-up continues. We are also examining whether G-CSF could potentially increase the risk of a blood cancer in some people with known abnormal blood cells. But based on available data from healthy people who have received G-CSF, no long-term risks have been found so far.

Your stem cell collection will take place in the Apheresis Unit, 4th Floor University College Hospital Macmillan Cancer Centre. You will need to arrive to the Apheresis Unit at 8.30am.
First, you will have a blood test to check your blood counts.
We will collect your stem cells using a procedure called apheresis. During apheresis, a constant flow of blood is taken from the bloodstream, passed through a machine called a ‘cell separator’, and then put back into your bloodstream.
An apheresis nurse (a nurse who will carry out the collection) will assess the veins in your arms. This is to make sure that they are suitable for the stem cell collection.
If your veins are suitable, you will have two needles. We will insert a larger needle in your non-dominant arm (the arm that you don’t write with), if possible, and a smaller needle in the other arm. During the collection, blood will be taken from the larger needle into the cell separator. The cell separator will separate the blood into the different types of blood cells and collect the stem cells into a collection bag. Some of your plasma will also be collected. Plasma is the fluid in the blood in which all the blood cells are suspended. The rest of your blood, together with the remaining plasma, will then be returned to you via the smaller needle in the other arm.
If your veins are not suitable, we will insert a special catheter (thin, semi-rigid tube called a vascath) into the large vein at the top of your leg. This will allow a constant flow of blood to be taken from and returned to your bloodstream. We will apply local anaesthetic (pain relief) on to your skin before inserting the vascath. The vascath will remain in place as long as the stem cells are being collected and will be removed once the collection is finished. If you have a vascath and we need to collect more cells the next day, you will need to stay in hospital overnight. We will advise you if you need a vascath and should pack an overnight bag during your assessment.

Preparing the cell separator

An apheresis nurse will prepare the cell separator for the collection and stay with you throughout the procedure. The collection will last about four to five hours. You will need to stay fairly still on a reclining bed during this time.

The nurse will fit a sterile kit into the cell separator so that your blood is not exposed to outside infections during the harvest.

Once the two lines from the kit are attached to you, the nurse will enter your height, weight and your morning blood test results into the cell separator control panel. Then the stem cell collection can begin.

How much blood will there be in the cell separator?

The amount of blood in the cell separator at any time is less than 160ml (about half a glass of water). The amount of blood cells taken from you by the end of the procedure will be about 500ml (just over a pint).

Beginning the stem cell collection

As the blood enters the cell separator, a drug called ACD-A is added to it. ACD-A stops the blood from clotting while it is going through the cell separator.

Are there any side effects that can occur during the collection?

Yes, the most common side effects are caused by ACD-A.

What side effects does ACD-A cause?

You may feel sick or you may have some tingling in your lips and nose or fingertips. These side effects are short-lasting and should stop once you have received calcium supplements. These will be chewable calcium tablets or a calcium infusion.

If you experience any of these side effects, tell your nurse straight away. They will help to relieve these symptoms very quickly. It may also be a good idea to have a milky breakfast before the stem cell collection.

Why does ACD-A cause side effects?

The blood would naturally clot within the cell separator. As calcium helps the blood to form clots, ACD-A is used to absorb the calcium from the bloodstream and prevent the blood from clotting. This lowers the calcium levels in the blood and may cause side effects.

What other side effects or problems can occur?

As your blood pressure drops during the collection, you may feel light-headed, especially at the beginning. Please tell your nurse if you experience this.

It is also sometimes difficult to get enough blood to flow from the veins in your arm. Your apheresis nurse may need to adjust the position of the needle to allow a better flow. This should not be painful but please tell the nurse if you feel any discomfort.

A small number of platelets may remain in the cell separator during the collection. This may cause your platelet levels to drop a little and lead to an increased chance of bruising or bleeding. For this reason, you should avoid taking aspirin during this process and for two weeks after. This also includes medicines that contain or are similar to aspirin. We will take a small blood sample at the beginning and end of the collection to monitor your blood cell counts, including platelets. Your blood counts will go back to normal within a few days of the collection.

What can I do during the collection?

You will need to remain in bed or seated for the entire time the collection takes (four to five hours).
Wear loose-fitting clothes so you are comfortable during that time.
Bring something that can help you pass the time, for example a book or a tablet.
You will be able to eat and drink so feel free to bring some snacks.
One visitor will be able to stay with you during the collection.
If you wish to use the toilet, a nurse can help you to use a commode or urine bottle by the bedside.

What happens when the collection has finished?

Your apheresis nurse will disconnect you from the cell separator and take the stem cells to the laboratory. You will have a blood test to check your full blood count. After that you will be free to get up and move around.

Your stem cells will be counted in the laboratory to check if enough have been collected. The results will be available about an hour after the collection has been completed. We will ask you to wait in the Apheresis Unit until the results are back.

If we have collected enough stem cells, you will be able to go home. If you have had a vascath inserted for the collection, this will be removed in daycare before you go home.

If we haven’t collected enough stem cells, you will have another injection of G-CSF (a 5th dose). If we have used the veins in your arms for the collection, you will be able to go home. If you had a vascath, you will need to stay in hospital overnight. A further stem cell collection will take place the next day.

You will be well enough to travel home by yourself after the collection.

Very rarely, mobilisation of stem cells into the bloodstream fails which means we are not able to collect enough cells. If this happens, a doctor will talk to you about undergoing a bone marrow harvest. They will give you more information and make sure you remain medically fit to have the procedure.

Please contact us if you notice any of the following:

signs of infection, such as raised temperature, body aches and feeling shivery or generally unwell
signs of anaemia, such as shortness of breath, palpitations, fatigue (extreme tiredness).