Frequently asked questions

This page provides answers to frequently asked questions and explains how you can register with DKMS and potentially become a lifesaver. Our frequently asked questions cover areas such as how suitable donors are found, the blood stem cell collection process and other elements of our work.
General Questions

What is blood cancer/leukaemia?

'Blood cancer' is the umbrella term used for a variety of malignant diseases of the blood-forming (haematopoietic) system. A distinction is made between two kinds, depending on how they originated: leukaemias and lymphomas. Leukaemias begin in the bone marrow, whereas lymphomas start in the lymphatic system. All blood cancers involve the degeneration of certain blood cells, which multiply uncontrollably and suppress the healthy blood-forming system. This prevents the blood from performing vital functions, such as fighting infections, transporting oxygen or stopping bleeding.

The three most common forms of blood cancer are:

Why did I receive an email about special tissue characteristics?

Whether or not a stem cell donor matches a patient depends on their HLA characteristics. HLA characteristics occur in a wide range of variations, which in turn occur at various frequencies across the population. Many patients can already find a matching stem cell donor, but for those with less common characteristics it is much more difficult.

DKMS is trying to improve the situation for patients with rarer HLA characteristics by running a targeted initiative. Tissue characteristics are hereditary, so the chances of finding rare combinations are highest within the patient’s family, especially among immediate relatives but also among second-degree relatives.

You received our email about special tissue characteristics because your HLA characteristics are rare, so donors like you and your family members are exactly what we need. We would greatly appreciate it, if you could encourage your eligible family members to also sign up as a donor.

It is important to remember that rare combinations of tissue characteristics do not affect your health in any way.

What quality projects is DKMS currently running?

DKMS regularly launches new projects to enhance the quality of donor typing and to expand typing profiles. This allows us to improve the quality of the data we have, even for donors who have been registered with us for a long time, because you never know when a donor will match with a patient. If we find we need more information, we contact the donors concerned and ask them to provide a new sample, usually by a regular cheek swab, like when someone registers as a new donor. DKMS contacts selected donors by post and email as part of the following quality projects:

  • CMV antibody detection: All new donors are now typed including their cytomegalovirus (CMV) status, however, this was not possible in the past. We are now contacting specific donors to ask them for another sample so that we can include this status as part of their profile. CMV antibody detection allows us to analyse whether donors have already been subject to a CMV infection or had no previous contact at all with the virus. The status is also relevant when matching donors with patients.
  • Further typing of transplant-relevant tissue characteristics (e.g. identification of further HLA tissue characteristics, blood group AB0 and Rh., CCR5-receptors and KIR).
  • Health questionnaire: A survey of the medical data of donors who have combinations of tissue characteristics that are common in Europe.

When DKMS contacts you as part of any of these projects, there is no specific patient involved. We are merely proactively assessing further parameters, to improve the quality of our data, which means that we can improve the speed of donor searches, because for a patient looking for a match, sometimes every day counts!

What is the quality of the DKMS typing?

HLA characteristics are the most important factor in identifying a matching donor. In order for a stem cell transplant to have the highest chance of success, ideally 10 out of 10 relevant HLA characteristics should match between the patient and the donor. If a patient is fortunate enough to have several matches, other factors will be analysed to find the optimal match. This is why we test more than 10 HLA characteristics. As part of the initial typing, we also tissue type for further parameters that could prove advantageous, either now or in the future, such as the entire KIR receptor family, MICA/B, CCR5, HLA-DPB1, HLA-E, HLA-DQA1, HLA-DPA1, HLA-DRB3/4/5 and the ABO and Rh blood groups. In addition, our donors are also tested for cytomegalovirus (CMV), a common herpes virus. All of these markers are currently typed at high-resolution when someone registers as a donor.

At DKMS, we use cutting-edge science to continuously expand the typing profiles of donors and to meet or define state-of-the-art standards in technology and medicine. That way, we ensure constant enhancements and even more precision in donor selection. All of these quality improvements are crucial for the benefit of patients.

All the samples we receive are typed at the DKMS Life Science Lab located in Dresden, Germany. The lab is a world leader in HLA diagnostics and accredited to international standards. In 2013, the DKMS Life Science Lab became the first HLA-typing lab in the world to introduce the new sequencing technology NGS (Next Generation Sequencing), for high-parallel, high-throughput typing.

Why is DKMS keen for people from different parts of the world to sign up?

Tissue characteristics vary from person to person – but they are also different between ethnicities. So when it comes to finding a matching donor, a person’s ethnic background is important. Blood cancer, on the other hand, can happen to anyone. So we need as many people as possible with the widest possible variety of genetic characteristics to register in our database. A donor with the same ethnic background as a patient may be a better match than one who comes from an entirely different background.

If you register with DKMS as a potential blood stem cell donor, one of the questions we ask you will be about your etnic background. This information allows us to better organize our database. This could make it easier and faster for doctors to search for a matching donor for their patient.

Does a donor have to have the same blood group as the patient?

For blood stem cell transplants, what matters is not so much the same blood group but the best possible match between the tissue characteristics from the donor and patient. A perfect match is very complicated to find and much like looking for a needle in a haystack. When blood stem cells are transplanted, the recipient acquires the same blood group as the donor.

At most, your blood group would be an additional factor in your selection.

What is the DKMS Life Science Lab?

Based in Dresden, Germany the DKMS Life Science Lab GmbH (LSL) is one of the world’s largest and most advanced genotyping laboratories focusing on high-resolution HLA typing for stem cell donor registers. Over 100,000 donor samples a month can be analysed there.

From the outset, LSL has aimed to incorporate the latest scientific findings and developments into the standard typing process. This has led to the typing profile being extended beyond the standard HLA characteristics to include numerous additional parameters (e.g. ABO, RhD, CCR5, KIR, HLA-E, MICA/B, and CMV IgG).

When fast action is needed, this is the best and quickest way to check whether – and how well – a potential blood stem cell donor matches a blood cancer patient. Thanks to our high-quality typing, search times have decreased, while the chances of a successful transplant have increased.

The DKMS Life Science Lab employs cutting-edge biotechnology procedures. In 2013, for instance, it was the first HLA-typing laboratory in the world to introduce the new NGS technology (Next Generation Sequencing), for high-throughput typing. Today, well over a million potential blood stem cell donors a year are typed using this procedure.

Attached to the DKMS Life Science Lab are a clinical laboratory for patient-based typing or confirmatory typing (CT), and a clinical search unit accredited by the ZKRD (German National Bone Marrow Donor Registry). For more information please visit

Who do we need as donors?

Every healthy person between 17 and 55 can be a donor. “Tissue-types” are inherited characteristics, and this is what is used to match donors and patients. As ethnic origin plays a significant role in the search for a donor, South Africa’s rainbow nation requires a large pool of prospective stem cell donors.

About DKMS

What does the abbreviation DKMS stand for?

DKMS stands for ‘Deutsche Knochenmarkspenderdatei’, or German Bone Marrow Donor Centre. But as we became more international, we extended our mission to include Poland, the US, the UK, Chile, India and South Africa. To give ourselves a standard identity worldwide, we decided in 2016 to use the same name everywhere – DKMS – to make us identifiable worldwide as a single organisation that operates under a single name.

DKMS careers

DKMS is an international non-profit organisation committed to the fight against blood cancer. Our mission is to give as many patients as possible a second chance at life.

DKMS is active not only in South Africa but also in the US, Chile, Poland, Germany, India and the UK. It also carries out scientific research, and the DKMS Life Science Lab sets new standards in stem cell donor typing.

In the fight against blood cancer, we are always looking for the best possible people to join our team!

What qualifications do I need to work for DKMS? What kind of professionals are they looking for?

DKMS offers a wide range of job opportunities at its various sites across the UK, Germany, USA, India, Poland, Chile and South Africa. We need employees for various medical positions, such as medical laboratory assistants, biologists, and doctors, but also for a host of other positions that require only basic medical knowledge. In addition, we need qualified staff for our IT, accounting, administration, marketing, fundraising & events, and press departments.

Since 2011, DKMS has been offering traineeships for various professions as well.

Patients’ questions

When are blood stem cell transplants carried out?

In most cases, blood stem cell transplants are used for patients who have a disorder of the blood-forming system, such as any form of leukaemia and lymph node cancer in children and adults, severe aplastic anaemia, severe congenital immune defects (in children only), and various disorders of the red blood cells. But the most common reason for a blood stem cell transplant is to treat one of several types of blood cancer.

What are the first signs that a blood stem cell transplant has been a success?

After two to four weeks, an increase in the patient’s white corpuscle count offers an initial indication that the new blood stem cells are doing their job and creating healthy blood cells. If the corpuscles continue steadily increasing, the outlook for the patient improves. The success of the therapy is affected by a range of factors, such as the type of basic illness, the stage at which it was diagnosed and treated with a transplant, the age and general fitness of the patient, possible accompanying illnesses, type of conditioning, and the closeness of the match between patient and donor tissue characteristics.

What happens if no matching donor can be found?

The doctors will try to treat the patient by alternative means, possibly with radio- or chemotherapy, depending on the illness. For many patients, however, a blood stem cell transplant from a matching donor is the only treatment offering any hope of a cure.

Eligibility & Registration

Who can register as a potential blood stem cell donor?

If you are aged between 17 and 55 years and in general good health, then you may be able to register as a blood stem cell donor.

If you have previously registered with DKMS or another donor centre, there is no need to do so again, as you will already be available for searches worldwide. If you have been diagnosed with any chronic or serious illnesses (whether current or in the past), please check with us before signing up.

Key conditions that do not prevent you from becoming a blood stem cell donor:

Enlarged or underactive thyroid, Hashimoto’s thyroiditis (You must be stable and symptom-free, even if you are taking thyroid hormones or iodine. However, you cannot donate if you have Graves’ disease)

An enlarged thyroid gland is often caused by a lack of iodine (iodine deficiency goitre), but it can also be attributed to a lack of thyroid hormones – because a thyroid gland forms increasing amounts of tissue as it attempts to compensate for insufficient hormone production. If you do not have any symptoms and your thyroid medication is properly balanced, there is no reason you cannot become a blood stem cell donor.

If the hypothyroidism is caused by thyroid surgery, there is also nothing to prevent you from joining our register — unless the intervention was for Graves’ disease or a thyroid carcinoma.

If the hypothyroidism is caused by an autoimmune disorder of the thyroid gland (Hashimoto’s thyroiditis), you may only be able to donate blood stem cells via a bone marrow collection from the pelvic bone. This point will be clarified if you are identified as a possible match for a patient.

If the hypothyroidism is caused by something other than a pre-existing thyroid condition, you can still sign up as a donor.

Morbus Hashimoto is one of the few autoimmune diseases that are not a major problem in blood stem cell donors. However, the thyroid gland must be properly regulated with medication. In addition, some people with the disorder may at times only be able to donate through a bone marrow collection from the pelvic bone. This point will be clarified as soon as you are identified as a possible match for a patient.

Graves’ disease is an autoimmune disorder of the thyroid gland that causes excessive thyroid production (hyperthyroidism). This can be problematic for both donor and recipient.

High blood pressure (stable and well-regulated)

As a rule, high blood pressure is not an issue when it comes to donating stem cells — but it must be well regulated by diet or medication, and not have damaged the eyes, heart, or blood vessels. If your blood pressure is well-regulated, you can register as a blood stem cell donor.

Hay fever, slight asthma (without attacks), food allergies

Allergies (including food and medication allergies, and hay fever) are not a problem for potential donors — unless they have previously experienced severe allergic reactions (e.g. allergic shock, Quincke’s edema). Please advise us if you have had severe reactions, as it could affect your suitability as a donor.

Unipolar depression (no impact on managing day-to-day life)
As with many other conditions, what matters is the severity of the depression or anxiety. The first thing to do is to find out whether the condition restricts you in any way, and check your general resilience — because donating blood stem cells is an additional mental strain for donors.

The question here is not so much whether a donor will reliably show up at the stem cell donation centre but whether they can handle the situation afterwards. After all, donating stem cells effectively means you gain a severely ill ‘blood relative’, and many of our donors are very concerned about the wellbeing of their recipient.

The use of psychotropic drugs also poses a particular problem, as they affect the blood count. Neuroleptics especially will prevent you from becoming a potential blood stem cell donor. Other conditions precluding registration as a stem cell donor include mental illnesses requiring treatment, such as severe depression, borderline syndrome, and any form of psychosis, schizoaffective disorder or bipolar/manic affective disorder.

Slight depression that requires only limited treatment is not an issue, as long as the donor feels fit enough to cope with everyday life. Anyone medicating with less problematic ingredients, such as Citalopram or Fluoxetine, can also still sign up as a blood stem cell donor.

Iron-deficiency anaemia (treatable with iron supplement)

For iron-deficiency anaemia, the determining factor is the haemoglobin level. If the level is frequently below 11.5 mg/dl for women and 13.5 mg/dl for men, this does cause problems for donors and registration is not permitted. However, if the iron supplement is well-tolerated and the iron level, as well as the haemoglobin level, are in a normal range , you would still be eligible to register as a potential blood stem cell donor.

Basal cell carcinoma and cervical carcinoma in situ

Basal cell carcinoma and cervical carcinoma in situ do not affect your eligibility as a blood stem cell donor, if they have been removed completely and the control check-ups since have been without pathological findings.

The reason for this is that in the cases of basal cell carcinoma and cervical carcinoma, it is not expected that the cancerous cells will spread (metastasizing).

Who is NOT ABLE TO register as a blood stem cell donor?

Obesity, body mass index (BMI) > 50 (BMI=weight/height²)

To register with us or to donate blood stem cells, your body mass index (BMI) must not be over 50 – for various reasons.

For people in general good health, donating blood stem cells does not have any significant risks. However, for people with additional risk factors, there may be some health concerns. Unfortunately, obesity is one such risk factor.

Severe obesity poses a problem because it leads to a degree of risk for the donor with both types of blood stem cell collection procedures. Not only is the anaesthetic risk higher with bone marrow donations, but with peripheral blood stem cell collection, it is also difficult to gauge precisely how much medication is needed, which may increase the chances of side-effects.

The health and safety of our donors is our number one priority and the weight limits are in place purely for the protection of our donors.

Severe illnesses of the central nervous system or mental illness

The eligibility of a potential blood stem cell donor depends on the severity of the depression/anxiety. First of all, the question is whether or not the potential donor is limited due to their illness and how resilient they are in their everyday life. The donation process might be an additional mental burden, which has to be managed on top of everything else.

It is not only the question of whether the donor will be able to reliably come to the donation appointment, but also how they can handle the situation after the donation. Even though they may be strangers, donors and recipients share a unique connection and many donors really worry about the recipient of their donation.

There are also concerns related to many psychotropic drugs causing changes in the blood count. Neuroleptics are especially problematic, making it impossible to donate blood stem cells. If suffering from severe psychological illnesses, it is unfortunately not possible to register as a donor. Those illnesses include severe depression requiring treatment, borderline syndrome, any form of psychosis, schizo-effective disorders, and bipolar/manic affective illnesses.

It is possible to register as a donor if suffering from a “mild” depression, receiving treatment for a limited amount of time, and feeling well enough to manage everyday life. This applies to donors whose medication contains less problematic substances, such as Citalopram or Fluoxetine.

Systemic autoimmune diseases or other serious chronic diseases (e.g. diabetes, rheumatism)

If you have diabetes mellitus type 1, registering as a potential donor is unfortunately not possible due to health concerns for both you and the potential recipient.

Blood stem cells are a part of the immune system, which means that a donation from a type 1 diabetic could mean that the condition is passed on to the recipient. As the patient’s health is already compromised, it is difficult to predict how their condition might develop. Serious complications would be likely to occur.

In addition, increased blood sugar levels may already have damaged the donor’s nerves and blood vessels to varying degrees, and donating blood stem cells could compromise their health even further.

With diabetes mellitus type II, or type 2 diabetes, some cells become resistant to insulin. This prevents them from absorbing sufficient glucose from the bloodstream. Increased blood sugar levels may already have damaged nerves and blood vessels to varying degrees. Donating blood stem cells could compromise their health even further – so again, we cannot include anyone with type 2 diabetes as a potential blood stem cell donor.

Rheumatoid conditions, even when there are no symptoms, are another factor preventing people from registering. They include rheumatoid arthritis, Bekhterev’s disease, and juvenile arthritis, all of which are autoimmune diseases and therefore mean that unfortunately you cannot register as a blood stem cell donor.

A stem cell transplant involves the transfer of cells from the immune system, and if the donor’s immune system is damaged, it will have adverse effects on the recipient, compromising their health.


It is not possible for someone to register as a blood stem cell donor if they are suffering from a rheumatic disease, even if they are not currently experiencing any symptoms. Rheumatic diseases include rheumatic arthritis, Bekhterev´s disease, and Juvenile Arthritis. The reason for excluding people suffering from those conditions is that they are autoimmune diseases.

During the stem cell transplantation, cells of the immune system are transmitted into the recipient, leading to a risk of a possible negative reaction in the body of the recipient. Because the recipient is already physically burdened due to their disease, the chemotherapy in preparation for the transplantation, and the transplantation itself, a negative autoimmune reaction could potentially be fatal. This is why it is not possible to donate blood stem cells and therefore to register as a blood stem cell donor if suffering from autoimmune diseases.

Cancer (including former patients who have been given the all-clear)

Unfortunately, anyone who has previously had a malignant condition is not able to donate blood stem cells.

If you have ever had a malignant growth (or, to be more precise, one that is not specifically benign) you cannot donate blood or stem cells — no matter how long ago the illness was or how successful the therapy was.

Addictions (alcohol, drugs, medications)

Occasional marijuana/cannabis consumption is not an issue – although the emphasis here is on the word ‘occasional’.

This is in part because regular drug use raises the question of reliability. It is not that a donor who takes drugs would be any more likely to suffer any complications, but unreliability is extremely problematic. The timing and scheduling of blood stem cell donations and transplants is crucial to the survival chances of the patient.

For you to register, we need to know what drugs you take and for how long you have been taking them. If you have been consuming them for a long time, it might be better not to register, but if you are ready and able to quit, then you are welcome to join us as a potential blood stem cell donor.

Severe cardiovascular diseases

High blood pressure that is successfully regulated or a mitral valve prolapse with no further symptoms do not affect your ability to become a blood stem cell donor. The same goes for people with an unusually high or low resting pulse rate: as long as it is regular, that is all that matters.

However, with most other cardiovascular conditions, requiring treatment or monitoring, the risk of complications when donating blood stem cells is significantly higher. This means that anyone suffering from conditions such as cardiac arrhythmia, damaged vascular walls, arteriosclerosis (especially if blood thinners are needed), heart attacks, strokes, or structural damage to the heart (such as valve defects) is not able to register as a potential blood stem cell donor.

Another factor that would definitely prevent you from donating blood stem cells is frequent or prolonged breathlessness.

If you are being treated for any other conditions, please contact us to check if you can still become a blood stem cell donor.

Severe lung diseases

For someone with a chronic lung disease, including diseases in the early stages, there is a risk of further damage to their lung during a blood stem cell donation. Autoimmune diseases also carry the risk of transmitting the condition onto the recipient. Many lung diseases also increase the risk associated with general anaesthetic. Those suffering from a frequent or consistent dyspnoea are not eligible to register as a potential blood stem cell donor.

Severe kidney diseases

For people with chronic kidney diseases, including diseases in the early stages, there is a risk of further damage to their kidney during a blood stem cell donation. Autoimmune diseases also carry the risk of transmitting the condition onto the recipient.

Severe metabolic diseases

Those with severe metabolic diseases, including diseases in the early stages, might see their condition worsen or lapse during a blood stem cell donation. Especially problematic are metabolic diseases that have already caused consequential damages, e.g. damages to the vessels.

Severe tropical infectious diseases

Every pre-existing infectious disease can be transmitted onto the recipient during a blood stem cell donation. This is also the case if the donor does not have any symptoms because their immune system has been able to control the disease. However, the patient does not have a working immune system at the time of the transplantation so they are not protected from infectious diseases.

Factor V Leiden

If you have a heterozygous Factor V Leiden mutation (APC resistance), you can join our register – as long as it can be confirmed that you do not have any further clotting disorders or an increased risk of thrombosis linked to smoking, the contraceptive pill, being overweight etc. and you have not previously suffered from thrombosis.

If the mutation is homozygous, unfortunately we cannot allow you to register as a donor.

Infectious diseases such as HIV, hepatitis B or C, syphilis

If you have a serious, life-threatening infection such as HIV and if there is no way of proving that you are fully cured (e.g. hepatitis C), we cannot allow you to donate blood stem cells, primarily for the protection of the recipient.

Disorders of the blood or immune system

Disorders of the blood and immune system are problematic because blood stem cells for transplantation come from the blood-forming and immune systems. To minimize the risk to recipients, both of these systems should be working as normally as possible. When blood stem cells are transplanted, acquired disorders can potentially be transplanted with them, as the cells for transplant contain mature cells of the immune system. In addition, some blood disorders can pose an increased risk to the donor: problems with clotting factors, for example, can cause thrombosis or bleeding.

I am already registered with another donor centre. Should I register with DKMS as well?

There is no need to register twice, as the details of all potential stem cell donors from all South African donor centres are collated at the Global Registry. Your donor details are already available for global donor searches in pseudonymized form, and entering them again in our database would only incur unnecessary costs.

What if I am pregnant – or become pregnant?

You can register as a potential blood stem cell donor even if you are pregnant, as long as you meet all of the other requirements. Please let us know if you are pregnant and when your due date is.

You will be blocked from donor searches during your pregnancy, until six months after your due date. After that, we will include you in searches again unless you instruct us otherwise.

If I register with DKMS, will I automatically be tested for HIV?

When you register with DKMS, we analyse some of your tissue (HLA) characteristics, necessary to find a matching donor for a patient. We do not check for any infections other than cytomegalovirus (CMV). Only when you are found to match a particular patient do we check for specific viruses, such as HIV, hepatitis B and C. However, not every donor will be a match and even if they are, this could be several years after they register.

Can I register as a blood stem cell donor if I’m gay?

Yes. Your sexuality does not affect your blood stem cell donor eligibility.

How are blood stem cells actually donated?

How does the search for a blood stem cell donor work?

Looking for a matching stem cell donor is like looking for a needle in a haystack. When a blood cancer or blood disorder patient depends on a blood stem cell transplant to survive, they need a donor whose tissue characteristics are a 100 percent match, if possible. Search requests are sent to the National Registry, and if a potential donor is found on the DKMS database, to match the patient, we will be informed and we will then contact the donor immediately.

Another problem is that even if a matching donor is found, they simply might not be available to donate at the specific point in time.

Health check and confirmatory typing (CT)

Before any donation takes place, you will be asked to fill out a detailed health questionnaire so that we can make sure early on that you are still suitable as a donor. You will then be asked for a blood sample, which will go for confirmatory typing. Your regular GP will be able to take the blood sample. Your blood will also be checked for other infections, such as HIV or hepatitis viruses. The results of your blood tests will be used to decide whether you really are the best match for the patient.

Peripheral Stem Cell Donation

In over 90 percent of cases, stem cells are taken from the bloodstream. This procedure does not require anaesthetic or admission to hospital. During the collection, a sterile needle will be placed into a vein in each of your arms. Blood is drawn through one vein and passed through a machine that collects the stem cells, before the rest of the blood is returned back into the body through the other arm. It is similar to a blood donation and it is normally completed within 4-6 hours. Occasionally a subsequent donation may be required on the following day.

For the five consecutive days leading up to the donation, the growth factor G-CSF, which is naturally present in the body, is injected subcutaneously to the donor. This is required in order to increase the number of stem cells in the blood. The donor may experience some temporary discomfort, (for example headache, body ache, fatigue, nausea) while they are receiving G-CSF. These symptoms disappear within a day or two following the donation and donors can take non-aspirin products (such as Paracetamol or Ibuprofen) for relief from the discomfort.

Bone Marrow Donation

In about two percent of cases, bone marrow is collected from the pelvic bone under a full anaesthetic using a thin, sterile needle. As a rule, two small incisions at the back of the pelvic bone are all that is required. The riskiest part of the procedure is essentially the anaesthetic. About five percent of the bone marrow is removed, which the body fully regenerates. Some donors experience localised pain from the incision, which often feels like bruising. The donor spends three days in hospital. On the first day you check in, on the second you have the procedure, and on the third you are discharged.

Does a donor get to choose the method by which cells are collected?

Our donors are our number one priority so it goes without saying that we will do everything that we can to meet your wishes – but for some patients, one particular collection method could be the preferred option. This decision is made by the patient’s physician. So ideally, you should be happy to undergo either collection procedure.

Which procedure is actually carried out depends first and foremost on the needs of the patient. Bone marrow and peripheral blood both contain the blood stem cells that are needed, but in different quantities and in combination with other immunological cells that perform different activities.

As a donor, how am I insured?

The statutory accident insurance protects all persons who take special action in the interest of another person or in the interest of the general public. The insurance protection exists by law without the requirement of a separate insurance and covers blood donors and donors of endogenous tissues. This statutory insurance protection therefore exists by law for you as a donor too. The stem cell collection process is insured, as well as also the trips to and from the collection clinic. Please contact us directly for further information.

Can you donate blood stem cells more than once?

Some people donate blood stem cells on more than one occasion, either to the same patient or to different ones. If you have blood stem cells removed, new ones will be generated to replace them, in much the same way as your blood is replaced when you make a blood donation. So it is possible to donate more than once. However, to minimize the strain on donors as far as possible, we try to keep those that have made a donation as backups, just in case their patient has a relapse and more blood stem cells are needed. We also use our Replacement Donor Program to prevent multiple donations. This identifies donors with identical combinations of tissue characteristics so we have a backup for each one.

Will I have a sick certificate to cover my time off for the donation? How do most employers react?

If you are donating via the bone marrow collection method, you will need to take one week of leave from work or study. This will cover your three days in hospital plus a four-day recovery period. If you are donating blood stem cells via the PBSC method, the G-CSF medication you will receive will not affect your ability to work. However, you will need to take time off work for your medical examination, plus another two days for the blood stem cell collection. You will not need any more time off work after that. If after the donation you happen to become sick, your regular GP will be able to issue a sick certificate for you.

In our experience, the vast majority of employers respond positively to the news that one of their staff is being invited to donate blood stem cells. If you are not covered by your employer, DKMS has a financial assistance programme that deals with lost wage compensation.

When I donate, does it mean I will be missing stem cells?

After a blood stem cell donation, the body quickly regenerates the level of blood stem cells to what they were before the donation. The process is comparable to a blood donation and does not lead to a permanent loss of blood stem cells. The donor’s own immune system will not be weakened.

How is my patient? Can I meet them?

The patient’s condition:

If the patient’s country allows it, we can request an update on their state of health at least three months after the transplant was carried out. In our experience, there is no way of knowing how long it will take for a reply to reach us. If you want to hear about your patient, you will normally be contacted by DKMS.

Meeting the patient:

International guidelines stipulate that donors and patients may only meet each other in person two years after the donation, which is additionally dependent on the regulations in the patient’s country of residence. Some countries do not allow any contact In the meantime, if allowed by the regulations in the patient’s country; donors can contact patients anonymously, sending letters or gifts via DKMS. Due to privacy reasons, DKMS has no direct contact with patients and often has only a minimal influence on the forwarding of mail to patients. Here, we depend on the support of the hospital treating the patient. Since patients often receive further treatment from another clinic or hospital after the transplantation, delays may occur. After the end of the two-year period, donors and patients may write to each other directly or meet each other in person – again mediated by DKMS provided both parties agree. Experience over the years has shown that many donors and patients want to get to know each other. Time and time again, meetings between donors and patients are very moving moments. It is not uncommon for lasting friendships to develop.

If you have any other questions, our Donor-Patient Contact department will be happy to help:

What is the difference between a related donor and an unrelated donor?

Tissue characteristics are hereditary, so the chances of finding a matching donor are highest within the patient’s family. About 25 percent of patients find a family member who has the tissue characteristics they are looking for.

Children inherit half of their tissue characteristics from their mother and half from their father. This means that parents are normally only haploidentical, or ‘half-matching’ donors. The highest probability of a match is between siblings, which is why they are the first family members to be tested as potential donors.

If a patient requiring a transplant has siblings, they will be the first to be tested. With young patients, the parents are typed as well. The age and state of health of the various family members is crucial. If no matching donor can be found among the patient’s immediate relatives, the search begins for a compatible unrelated donor in databases around the world.

Can I withdraw from making a donation if I have already agreed to make one?

On being identified as a match for a patient, you may withdraw from making a donation, at short notice, for personal or other reasons. Please note that we respect your decision, regardless. However, if you withdraw your commitment shortly before the actual transplantation, the doctors would have already initiated the patient’s preparation phase for the blood stem cell transplantation and at this point in time, the patient cannot survive without the transplantation of your blood stem cells.

Curing Blood Cancer

Chemotherapy as the chance of a cure

Most types of blood cancer can first be treated with chemotherapy, the aim of which is to simply destroy the cancer cells. Other forms of treatment can be used as well, such as radiation or antibody therapies, or a blood stem cell transplant.

Blood stem cell donation as the last chance

For many patients, a blood stem cell donation is their last chance to beat blood cancer. These patients need a matching donor whose tissue characteristics (HLA characteristics) should match those of the patient 100 percent, if possible. To prepare for the transplant, the patient undergoes chemotherapy to suppress their own immune system, which helps to ensure the body does not reject the donation. After the transplant, the immune system gradually rebuilds itself.


With chemotherapy, the patient is given so-called cytostatic drugs to inhibit cell division and destroy the cancer cells. The treatment is performed in a hospital over several cycles, with drugs administered on one or more days followed by a break for the body to recover before the next cycle begins. The drugs can be given in the form of tablets, an injection, or an infusion.

Radiation therapy

Radiation therapy is used to specifically target tumours. The radiation is similar to that in X-rays but considerably higher-energy, which works by damaging the genetic makeup of the cancer cells. This stops them from dividing even further and kills them off. The process also affects healthy cells, but these can regenerate later on.

Antibody therapy

Antibodies are generated by immune cells in the body. They work by recognizing surface structures (antigens) of pathogens and attaching themselves to them. Any cells that are flagged in this way are identified by other immune cells as hostile and destroyed. More and more blood cancers can now be treated with artificially produced antibodies — especially non-Hodgkin lymphoma (NHL), but also chronic lymphocytic leukaemia (CLL). They work on the basis of a 'lock and key' principle: the available antibodies are the key and work only on cancer cells with a matching lock, or antigen. If lock and key don’t match, the therapy will not work.

Blood stem cell transplant

For many blood cancers, transplanting healthy blood stem cells is one possible form of treatment — and often the only chance of a cure. Whether or not a patient can undergo a blood stem cell transplant and what method would be used, depends on numerous factors including their particular diagnosis, age and state of health.

There are three different types of transplant: autologous, allogeneic, and syngeneic.

An autologous blood stem cell transplant uses the patient’s own stem cells, which are harvested from the blood and cleared of cancer cells. The patient is given chemotherapy, and their stem cells are returned to the body.

An allogeneic stem cell transplant uses the blood stem cells of a related or unrelated donor with the closest possible match of tissue characteristics.

A syngeneic transplant is the rarest form of stem cell transplant, as it involves using the cells of identical twins.

Matching donor

One crucial factor in the success of a blood stem cell transplant is the degree of match between the tissue characteristics (HLA) of donor and patient. Tissue characteristics are protein structures on the surfaces of all cells and occur in different combinations in every individual, much like fingerprints. The immune system recognizes from these protein structures whether or not a cell belongs to its own body. If it does, the cell is left intact. If not, it is destroyed. That is why it is essential to find a donor whose HLA characteristics match the patient’s as closely as possible. This way, the new immune system that develops from the donor’s stem cells will accept the patient’s own cells.

Because tissue characteristics are inherited, the best chance of finding a match between donor and patient is within families. Parents are normally only haploidentical, or ‘half-matching’ donors, as a child inherits half of its tissue characteristics from the mother and half from the father. The highest probability of a match is between siblings, which is why they are the first family members to be tested as potential donors.

If there are no matching donors in the patient’s family, the search continues with an attempt to find a compatible unrelated donor. Around the world, over 36 million people have now chosen to register as potential blood stem cell donors, over 10 million of which are within DKMS’s worldwide database. If no suitable donor is found there, the search is extended internationally.

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