Collection of stem cells from your blood

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

• red blood cells, which carry oxygen to all cells in the body
• white blood cells, which help to fight infections caused by bacteria and viruses
• platelets, which help blood to clot and prevent bleeding

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.

We want to collect your stem cells to protect them before your treatment.

One of the treatment options available to you in the future is high- dose chemotherapy. This can be either alone or in combination with radiotherapy. This type of treatment aims to destroy cancer cells. But it also damages healthy stem cells, which are important for making blood cells.

When the stem cells are damaged, your blood cell levels drop. This can make you prone to infections, bleeding or anaemia. It can also take a long time for your bone marrow to recover and start making blood cells again.

By collecting some of your stem cells now, we can rescue them from being damaged. We can then return them to you through a drip a day or two after the high-dose treatment. The stem cells go to your bone marrow and start to develop into healthy blood cells. This process is called an autologous stem cell transplant, or autograft. For more information about the transplant, visit our webpage ‘A guide to autologous stem cell transplant’.

Once you and your consultant decide to go ahead with high-dose treatment, a stem cell transplant clinical nurse specialist (CNS) will organise your stem cell collection. This will include arranging any tests or treatment you may need beforehand.

The CNS will explain the process step by step and answer your questions. They will also give you a contact number in case you have any questions or problems later.

The CNS will talk to you about:

• tests needed before collection
• giving your consent for the treatment
• any treatment you may need before the collection, including a dental check-up
• preparing your stem cells for collection (mobilisation)
• blood tests during mobilization, if needed
• assessing your veins
• how your stem cells will be collected and stored
• fertility and contraception

After all tests are done or scheduled, you will get a timetable with all the steps you need to complete before and during mobilisation. This will also include provisional dates for collecting your stem cells.

Let your CNS know if:

• you are taking medicines that thin your blood
• you have had radiotherapy before

You will have various tests to make sure you are healthy enough for the stem cell mobilisation and collection.

Blood tests

• You will have several blood tests, including:
• full blood count to check your haemoglobin, white blood cells and platelets
• liver and kidney function tests
• blood type to confirm your blood group
• viral infection tests to check for Hepatitis B, Hepatitis C, HIV, syphilis and HTLV

In the UK, the law requires to check for certain viral infections before collecting and storing stem cells. This helps to prevent infections from spreading to healthy cells during storage. Having these tests does not mean that we think you have any of these infections.

Bone marrow biopsy (if needed)

You may also have a bone marrow biopsy. This test checks for any signs of disease in your bone marrow. It can be done at your local hospital or at the transplant centre.

Re-staging scans (if needed)

You may also have re-staging scans, such as:

• PET
• CT
• MRI

These scans check how well your recent treatment has worked. Depending on the results, you may need further tests or treatment before starting high-dose therapy.

Your hospital doctor and stem cell transplant CNS will ask you to sign a consent form for stem cell mobilisation and collection. This will confirm that you agree to have the procedure and understand what it involves. If you have any questions or are unsure about anything, please ask – they are there to help.

Mobilisation can be done in one of two ways:

• chemotherapy combined with daily injections of growth factor G-CSF
• G-CSF injections alone

G-CSF helps your bone marrow to make more stem cells. It also helps to release the mature blood cells into your bloodstream.

If you need both chemotherapy and G-CSF, you will have either:

• a course of treatment chemotherapy followed by daily G-CSF injections, or
• a single dose of cyclophosphamide chemotherapy followed by daily G-CSF injections

Treatment chemotherapy aims to reduce any remaining disease after your initial treatment. After this, you will have daily G-CSF injections for about 8 to 11 days, depending on the type of chemotherapy.

Cyclophosphamide chemotherapy is used if your disease is in remission or stable. It is given over a couple of hours in a daycare setting. After that, you will have 8 to 10 days of G-CSF injections.

As your white blood cells recover from the chemotherapy and G-CSF, your stem cells move from your bone marrow into your bloodstream. Once this happens, your stem cells can be collected or ‘harvested’.

Some people need plerixafor injections as well as G-CSF to help their stem cells move into the bloodstream.

Plerixafor helps to release more stem cells from the bone marrow into the blood. This increases the number of stem cells available for collection.

Your consultant and stem cell transplant CNS will advise you which mobilisation method is best for you. They will also tell you if you need plerixafor injections.

G-CSF is a natural substance your body makes. It helps to turn stem cells in your bone marrow into mature blood cells.

When given at higher doses, G-CSF also helps to move some of your stem cells from the bone marrow into your bloodstream.

After several days of G-CSF injections, your white blood cell count will rise and stem cells will move into your bloodstream. Your stem cell transplant CNS will mark on your timetable when this is likely to happen.

It’s very important that you do not miss any of your G-CSF injections. Missing a dose can lower the number of stem cells in your blood. This can make it harder to collect enough for your treatment.

Are there any side effects of G-CSF injections?

Yes, there are some side effects of G-CSF injections. The most common ones include:

• back pain
• flu-like symptoms
• headaches

These should get better once you finish your course of injections.

You can take paracetamol to help with these symptoms. The usual dose is two tablets (1g), and you can take this up to four times a day. This is a maximum of eight tablets, or 4g, in 24 hours).

If paracetamol is not helping, you can try co-codamol. This is a mix of paracetamol and codeine, and you can get it in any pharmacy. If co-codamol doesn’t relieve your pain or your symptoms get worse, contact the stem cell transplant CNS for advice.

Do not take aspirin, or medicines that contain or are similar to aspirin (such as ibuprofen), while you are having G-CSF injections. If you already take aspirin for medical reasons, please tell your CNS.

Allergic reactions (very rare)

Go to your local Emergency Department (A&E) without delay if you notice:

• itching
• rash
• fast heartbeat
• dizziness
• shortness of breath

Extremely rare but serious side effect

In extremely rare cases, G-CSF can cause the spleen to become swollen and even tear. If you feel pain or tenderness in the upper left side of your abdomen, just under your ribs, go to your local Emergency Department (A&E) immediately. You should also contact us on 07852 220900.

How is the G-CSF given?

G-CSF is given as an injection under the skin, usually in the abdomen, thigh or arm. You can do these injections yourself at home. They can also be given by:

• a family member
• a district nurse
• a nurse at your local hospital or UCLH

If you or a family member want to do the injections yourselves, a nurse will teach you how to do this safely.

You will need to keep the injections in the fridge. Try to use them at the same time each day. Taking the injection out of the fridge 20 minutes before using it can help reduce any stinging.

What do plerixafor injections do?

Plerixafor increases the number of stem cells in your bloodstream by helping to move them from your bone marrow.

How is plerixafor given?

Plerixafor is given as an injection under the skin, usually in the abdomen, thigh or arm.

A nurse at UCLH will give these injections – you will not be able to do them yourself.

Are there any side effects?

Yes, there are some side effects you can expect. The most common ones are:

• feeling sick (nausea)
• being sick (vomiting)
• diarrhoea
• tiredness
• headache
• dizziness
• joint pain

These usually go away within a few hours after the injection.

Very rare side effects

Go to your local Emergency Department (A&E) straight away if you notice:

• a rash, swelling around the eyes, shortness of breath and feeling faint

• pain in the upper left side of your abdomen or at the tip of your shoulder

• chest discomfort

You should also contact us on 07852 220900.

You may have some blood tests during the mobilisation process. These tests help us to check when your stem cells are moving to your bloodstream. This usually happens when your white blood cell count rises quickly. We can often estimate the day of this increase, and we will include this in your timetable.

If you need any extra blood tests before your stem cell collection, your stem cell transplant CNS will tell you when and where to go. The results are sent to the nurses at the transplant centre who will be doing the collection.

Your stem cell collection will take place in the Apheresis Unit on the 4th Floor University College Hospital Macmillan Cancer Centre. Please arrive at 8am.

What to expect on the day

• First, you will have a blood test to check your blood counts. If your levels are not high enough, we will ask you to go home for another G-CSF injection. You will need to return the next day for a blood test.
• We collect your stem cells using a procedure called apheresis. This involves taking blood from your body, passing it through a machine called a ‘cell separator’, and collecting the stem cells. The rest of your blood goes back into your body.
• An apheresis nurse (a nurse who will carry out the collection) will check the veins in your arms. This is to make sure they are suitable for the procedure.

If your veins are suitable

• You will have two needles, one in each arm:
  • a larger needle in your non-dominant arm (the arm you don’t write with), if possible
  • a smaller needle in your other arm
• Blood will flow from the larger needle into the cell separator, where your stem cells are collected into a bag. The rest of your blood will then return to you through the smaller needle.

If your veins are not suitable

• We will insert a special tube called a vascath into a large vein at the top of your leg (groin area).
• You will have local anaesthetic to numb the area before the vascath is inserted.
• The vascath allows blood to flow in and out continuously during the collection.
• We usually collect enough stem cells in one day. If we need more time, you will stay in hospital overnight with the vascath in place. We will continue the collection the next day.
• Please note that we cannot use a PICC that you may already have in place for the collection.

Preparing the cell separator

An apheresis nurse will set up the cell separator and stay with you throughout your stem cell collection. The procedure usually takes about four to five hours. You will need to stay fairly still on a reclining bed during this time.

The nurse will place a sterile kit into the cell separator to protect your blood from infection. Once the two lines from the kit are connected to you, the nurse will enter your height, weight and morning blood test results into the machine. Then the collection can begin.

How much blood goes into the cell separator?

At any time, the cell separator holds less than 250ml of your blood (less than a small glass of water). The amount of blood cells taken from you by the end of the procedure is no more than 200ml.

Beginning the stem cell collection

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

Possible side effects during the collection

The most common side effects are caused by ACD-A.

You may experience:

• feeling sick (nauseous)
• tingling around your lips, nose or fingertips

These side effects are short-lasting and should stop once you have some calcium supplements. These could be chewable tablets or a calcium infusion.

Tell your nurse straight away if you have any of these symptoms. They will help to relieve them quickly. It may also be a good idea to have a milky breakfast before the collection.

Why does ACD-A cause side effects?

Calcium helps your blood to clot. ACD-A works by absorbing calcium to prevent the blood from clotting inside the cell separator. This lowers the calcium levels in your blood and may cause temporary side effects.

Other problems that can occur

• Your blood pressure may drop at the start of the collection, which may make you feel light-headed. Please tell your nurse if this happens.
• Sometimes blood flow through the needle can slow down. Your apheresis nurse may need to adjust the needle to improve the flow. This should not hurt but please tell the nurse if you feel any discomfort.

What can I do during the collection?

• You will need to stay in the bed or chair for the full 4 to 5 hours.
• Wear loose-fitting clothes so you are comfortable during that time.
• Bring something to 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 need the toilet, a nurse can help you use a commode or urine bottle by your 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 some blood tests before you can get up and move around.

What happens to your stem cells?

• The laboratory will count your stem cells to check if we have collected enough. This takes about one hour. You will need to wait in the Apheresis Unit until the results are ready.
• Your stem cells are then frozen (cryopreserved) until you need them for treatment, or until they can be disposed of (more information below).

If we collected enough stem cells

You can go home.

If you had a vascath in place, the nurse will remove it before you leave.

If we did not collect enough stem cells

You will have another dose of G-CSF, and possibly plerixafor. We will repeat the collection the next day.

If we don’t collect enough cells after two or three days, we will arrange an appointment with your consultant. They will talk to you about your options and advise if you can still go ahead with the transplant.

Photo courtesy of Canva.com

There are a few possible reasons why your stem cells may not be used for a transplant:

• There may not be enough cells for a transplant.
• The cells may not be suitable (for example, if they have an infection).
• There may be a medical reason why your transplant no longer goes ahead as planned.

If your stem cells are safe to us and infection-free, we will freeze and store them at UCLH, usually for up to five years. They may be stored for a shorter time if they are no longer needed or are unsuitable.

After five years, your consultant will review your records. If the cells are no longer needed or suitable, we will dispose of them following strict national and EU regulations.

If your cells are still safe to use after this time, you can choose to transfer them to another storage facility outside of UCLH. We will ask you during the consent process if you would like us to contact you about this in the future. Please keep us updated with your current address and contact number.

If the collected cells have a potentially contagious infection, we will store them separately for at least 12 weeks. After this time, if they are no longer needed or suitable for use, we may dispose of them. This will follow the same process described above.

Macmillan Cancer Support
Offers information, support and advice for anyone affected by cancer.
Tel: 0808 808 00 00

Blood Cancer UK
Supports anyone worried about blood cancer with expert information and advice.
Tel: 0808 2080 888

Anthony Nolan
Offers support for people with blood cancer who need a stem cell or bone marrow transplant.
Tel: 0303 303 0303

Cancer Research UK 
Provides information about cancer and clinical trials.
Tel: 0808 800 4040

University College London Hospitals NHS Foundation Trust cannot accept responsibility for information provided by external organisations.

Stem cell transplant CNSs
Tel: 020 3447 7359 (Monday to Friday, 9am to 5pm)

Out of hours for urgent medical advice
Tel: 07852 220900