What are stem cells?
Stem cells are the mother cells from which all the different blood cells arise: red blood cells, white blood cells, and platelets. Under normal conditions, stem cells are found almost exclusively in the bone marrow. The bone marrow is thus responsible for producing countless blood cells every day.
What is a stem cell collection?
A stem cell collection involves taking stem cells that circulate in the blood.
The first step is to ensure that a large number of stem cells, which are mainly found in the bone marrow, can move into the bloodstream. This process is called stem cell mobilisation. To achieve this, stem cells are released from the bone marrow using growth factors or chemotherapy. Growth factors are substances that stimulate the growth and development of blood cells, and thus also help to release stem cells from the bone marrow.
Following the administration of chemotherapy or growth factors, large quantities of stem cells are released into the bloodstream. This makes it possible to collect them using a cell separator. Growth factors are given once a day for four days, followed by a check-up on day five at Dagziekenhuis 6. If at that time there are still not enough stem cells in the blood, an additional dose of growth factor may be administered. Outpatients who are not hospitalised are admitted the day before the procedure and remain in hospital for one night.
In some patients or donors, the increased production of stem cells in the bone marrow due to growth factors may cause muscle or bone pain. This usually occurs in the pelvis, lower back, breastbone, or skull. The pain can be managed with a painkiller such as paracetamol (e.g. Dafalgan®).
How does a stem cell collection work?
The procedure is carried out using a cell separator, in which a centrifuge separates the different components of the blood.
- A vein is punctured in the crease of one arm. An infusion needle is inserted at this site for the blood collection. During the procedure, you may not bend this arm.
- An infusion needle is also inserted into your other arm for the return of the blood. You can usually move this arm. The blood return may also take place via a Hickman catheter, but not via a port-a-cath or PICC line.
- During the blood collection, an anticoagulant is used to prevent the blood from clotting in the tubes. The blood and anticoagulant flow into the centrifuge.
- In the centrifuge, the white blood cells (including the stem cells) are separated from the other blood components and directed into a collection bag. The remaining components are returned to you via the return infusion.
The collection bag containing stem cells is taken to the “transplantation laboratory”, where the stem cells are counted and frozen in liquid nitrogen. Depending on the result, you may need to return the following day for another stem cell collection.
If your veins are too narrow and blood cannot flow sufficiently through the infusion needle, the anaesthetist will insert a deep catheter (usually in the groin). This is done under local anaesthetic in the operating theatre. In this case, you will be admitted to hospital for the duration of the collection period.
Tip
Preferably wear comfortable and practical clothing with short sleeves.
How many days are needed to collect enough stem cells?
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It is not possible to predict in advance how many days will be needed to collect enough stem cells. This number varies from 1 to 3 days (with one collection per day), and depends on the success of the mobilisation and the quantity of stem cells required. It is very important that you only stop taking the growth factors once enough stem cells have been collected. The healthcare providers will inform you when this is the case.
Children weighing less than 25 kg
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In children who weigh less than 25 kilograms, it is usually possible to use a well-functioning Hickman catheter for both the collection and return of the blood. To maintain fluid balance, the cell separator is prefilled with red blood cells (a transfusion bag). If needed, the anaesthetist will place a deep catheter, usually in the groin. This is done under general anaesthesia in the operating theatre.
What might you experience during a stem cell collection?
- During the procedure, a small amount of blood is in the tubing of the cell separator. This may cause some people to feel slightly dizzy or light-headed. Always inform a nurse immediately if you start to feel unwell.
- A portion of the anticoagulant enters your bloodstream, which may cause tingling around the mouth or pins-and-needles sensations in the hands or feet. Please tell a nurse immediately if you notice any of these symptoms.
- You might feel cold, as the blood cools slightly while circulating through the machine. Don’t hesitate to ask the nurse for a blanket.
Frequently asked questions
No, you don’t need to be fasting. On the contrary, it’s better to eat something before the stem cell collection. We also recommend drinking plenty of fluids in the days leading up to the procedure.
You may also eat and drink during the stem cell collection. Use the arm that you’re still allowed to bend for this.
It’s a good idea to go to the toilet just before the procedure starts.
Discuss with the treating physician beforehand which medications can or should be postponed. Some medications may interfere with the smooth progress of the stem cell collection (e.g. blood thinners, blood pressure medication, etc.).
The procedure lasts up to 6 hours. This depends on your blood values and the amount of blood that needs to be processed.
You should arrive between 08:00 and 08:30 Make sure to allow enough time to get to the hospital and complete your registration.
A blood test will be done first. Once the results are available, the collection can begin.
Apart from inserting the infusion needles, the procedure is painless. The arm used for the blood collection will remain stretched and may not be bent during the procedure. This can be uncomfortable.
Most people experience no side effects during or after the procedure. However, you may feel slightly more tired afterwards. For this reason, we recommend not driving yourself home and arranging for someone to accompany you.
You’ll have a personal television screen available in the day hospital. You’re also welcome to use your own laptop, smartphone, or tablet (the hospital offers free Wi-Fi), read a book or magazine, or listen to music.
If you want to watch or listen to something, please bring your own headphones or earphones. Note: Bluetooth is not supported – you’ll need a wired set with a jack plug.
Yes, you may bring someone to keep you company during the stem cell collection. A nurse is always present in the apheresis room as well.
The number of collections required depends on your condition and, above all, on how many stem cells can be collected. The result of the first collection will determine whether another one is needed the following day.