Further information
1. Chance of a match for stem cell transplant patients
2. Why is my height and weight so important?
3. Donor information for consent to PBSC (Peripheral Blood Stem Cell) donation
4. Donor information for consent to bone marrow donation
5. How does the type of bone marrow/stem cell donation get decided?
6. Will you cover any expenses/loss of earnings?
7. What if something goes wrong?
About one third of patients have a suitably matched brother or sister. But the remainder rely upon the generosity of a complete stranger to donate bone marrow or blood stem cells for them and finding a suitable donor can be really difficult. This is because the patient and donor need to have the same tissue type (known as a HLA type).
There are many millions of potential tissue type combinations, which is why we always need more donors and why it’s so amazing if you are identified as a potential match for a patient in need.
To give the patient the best chance, we need to find an unrelated donor with the same HLA (Human Leukocyte Antigen) type. Your HLA type (also often referred to as your ‘tissue type’) defines a complex protein on the surface of many cells in your body: this acts in a sense like a barcode on your cells which your immune system constantly checks.
The closer a HLA match the donor and patient are, the less likely that the patient’s immune system will reject the new cells.
The challenge is to find an unrelated donor with the same antigens. Even with millions of donors around the world on globally on registries like the NHS Stem Cell Donor Registry, this is not always possible.
- Looking at the NHS Stem Cell Donor Registry as a whole, there is approximately a 1 in 240 chance that a donor will come up as a potential match in any given year.
- If a donor is found as a potential match for a patient, we will contact them and ask for more blood samples to conduct further suitability tests.
- Following these suitability tests, there is approximately a 1 in 5 chance that a potentially matched donor will ultimately be asked to donate stem cells from your blood stream or bone marrow for a patient.
If you are found to be a potential match, we will contact you to discuss the next steps. It is rare to be found as a match – the overwhelming majority of donors will never be contacted as a
potential match.
We would never ask you to donate if we believed that this might harm you.
There are established limits to the maximum Body Mass Index that are allowed for donor safety.
Your Body Mass Index is calculated by using your height and weight. If your Body Mass Index is more than 33, we would ask you to get it confirmed outside of your home – this is because home scales can easily be used incorrectly whereas scales in, for example, a pharmacy will be independently calibrated.
If you inadvertently understate your BMI, we would not know this is the case until you arrive at our facility for a medical assessment prior to donation – if we then found that you could not donate, this could cause significant problems for a patient as they would then need to continue or restart their search for a suitable donor.
There are two phases to this:
Medication to release stem cells into the bloodstream – G-CSF administration
For the four days preceding the donation a nurse will inject you with a medication which vastly increases the number of stem cells in your circulating blood: G-CSF (Granulocyte-Colony Stimulating Factor).
G-CSF is a protein which occurs naturally in the body and regulates the production of certain white blood cells called granulocytes.
G-CSF induces blood stem cells to leave the bone marrow cavity and enter the blood – a process known as “mobilization”. They can be collected in the second phase of the donation procedure.
G-CSF Administration
G-CSF is given by injections under the skin (a bit like insulin injections for diabetes) once a day for 4 days before your donation. They are usually given into the skin of the abdomen, thighs or upper arms by a homecare nurse who will visit you at home or at your workplace. The 4th set of injections may be administered at the designated collection centre.
Possible side-effects of G-CSF
The commonest side-effect is feeling like you have the flu with fatigue, a “muzzy” head and muscle or bone aches and pains. The latter are common in the back, pelvis and sternum (breastbone). Paracetamol usually relieves these symptoms. (You should avoid aspirin and aspirin-like medications during and for 2 weeks after G-CSF administration as such medicines can affect your blood cells (platelets)).
You may experience swelling, redness or a tingling sensation at the injection site.
Occasionally donors have nausea, vomiting, night sweats and difficulty in sleeping.
All of these side-effects wear off very quickly after the last injection, usually within 48 hours.
More serious side-effects are very rare.
Collecting stem cells from the bloodstream – apheresis
On the fifth day you will be seen at the designated collection centre. A sterile needle is inserted into one vein in each arm and blood is removed from one arm and passed through the cell separator (apheresis) machine. The blood is centrifuged such that it separates into “layers” of its different components.
The stem cells are separated and collected into a special bag and the remaining white blood cells, red blood cells, platelets and plasma (the liquid component of blood) are returned to you via the needle in your other arm. If you are already a platelet donor you will be familiar with this type of machine. The procedure lasts about 4-5 hours with an additional hour for the stem cells to be processed in a laboratory.
You will lie on a special reclining bed or couch in a day care ward with a nurse in attendance throughout.
You may be asked back on the sixth day for a further donation, if the dose of cells obtained is not sufficient. This would necessitate a 5th injection of G-CSF and you would be asked to stay in a local hotel overnight.
At the pre-donation medical assessment donors are occasionally found to have veins that are not suitable for donation (e.g. they are too small) or, rarely, veins fail to work on the day of collection.
If you fall into this category you will be asked to consider having a temporary catheter, known as a central line (or CVC), inserted into one of your larger veins (in the neck or groin) to make the procedure easier and more comfortable for you. Alternatively, if the assessment is at your pre-donation medical you may prefer to consider a bone marrow harvest. Fewer than 5% of our donors require a central line.
After care
If you experience any of the side-effects of apheresis, they will wear off very quickly after the procedure ends. The nursing and medical team will check that you have recovered sufficiently to travel back to your hotel or, if it is the last day of donation, back home.
Any aches and pains caused by G-CSF usually subside within 24-48 hours of the last dose and your arms may be a bit bruised or sore where the needles were inserted for a couple of days. We do not recommend a particular time away from work to convalesce, but you may experience some initial fatigue which may be helped by taking a further 24-48 hours away from work or your normal duties.
Your recovery will be monitored by a member of our team who works in conjunction with the our medical team and your general practitioner.
For further information, please read our donor information booklet (PDF 1.63MB).
While you are under anaesthetic you will be laid on your stomach and the marrow cells will be collected using hollow needles and syringes placed in your pelvic bones on both sides (right and left iliac crests).
No surgical incision or stitches are needed but several puncture holes will be made in the skin and then through the outer layer of the bone to the marrow cavities inside.
A maximum of 1.5 litres of marrow and blood will be extracted (or less if you weigh less than 75 kg) and the procedure typically takes 30-60 minutes.
Possible side-effects of the harvest
You are likely to be sore and have bruising around the sites of the needle insertions and may have a dull ache and stiffness over your lower back.
The hospital team are able to provide you with medication to ease this with a supply to take home if needed. It is normal to feel tired after the procedure and some of your red blood cell will have been removed at the harvest so you may be a bit anaemic. Sometimes donors are given iron supplements to help speed the return to normal of their blood counts and all will have a check blood test done, usually at their GP’s, a few weeks after donation.
Most donors achieve a reasonable recovery within 7-10 days. If you have a physical job or very active lifestyle, it may take a couple of weeks to return to your activity levels pre-donation.
More serious side-effects are very rare.
After care
Your recovery will be monitored by a member of our team who works in conjunction with our medical team and your general practitioner. They will help arrange and check blood tests with your GP and make routine follow-up phone calls to you at set intervals following your donation.
For further information, please read our donor information booklet (PDF 1.63MB).
For most patients, the best method of donation is for these blood stem cells to be collected from the donor’s peripheral blood stream.
For some patients and disease types, the patient’s doctor will prefer the donor to donate by bone marrow retrieval, as this method of donation will contain both the blood stem cells needed to produce new cells as well as mature cells to help fight infections in particular.
We will discuss with you any preference from the patient’s doctor but of course, as donation is voluntary, the final decision will rest with you.
Yes. The NHS Stem Cell Donor Registry will arrange for travel and accommodation travelling to and from our facility for medical assessment and the actual donation. Please keep any receipts for expenses such as food and refreshments to claim this back from us.
We will also cover any loss of earnings – we will discuss the process with you should you be selected to donate.
For further information, please read our donor information booklet (PDF 1.63MB).
Should something out of the ordinary happen with your donation process and you are adversely affected; our collection centres all have local arrangements to offer the best possible healthcare should something go wrong.
The NHS Stem Cell Donor Registry also operates a donor compensation policy with insurers.
For further information, please read our Donor Information Booklet (link to INF1326)