Bone Marrow Donation

For the allogeneic transplantation just described, people are needed who agree to donate bone marrow. In the search for a suitable bone marrow donor, one can reach the goal in three different ways.

The highest probability of finding a suitable donor is among siblings, it is about 25%.
This type of search is called Core Family Donor Search (CFDS).
Other members of the family can also be searched for a suitable donor (Extended Family Donor Search – EFDS). The probability of a successful search drops to approx. 5%.
Finally, there is the possibility of foreign donation, i.e. a donor search among unrelated people registered in a registry.
This search is known as Unrelated Marrow Donor Search (UMDS). Due to the worldwide number of more than 14 million donors, a search success with a probability of about 90% is remarkable. Even if a suitable donor can be identified in this way, the chances of success are higher for tissue-compatible related donors than for tissue-compatible unrelated donors.

Bone marrow donation file

There are more than 14 million people around the world who would be willing to undergo bone marrow donation if needed. In Germany there are about 4 million registered donors. The German Bone Marrow Donor Center (DKMS) in Tübingen is the largest registry of potential donors in the world.

The data of the people who would undergo a bone marrow donation are kept by the central Bone Marrow Donor Registry Germany (ZKRD) based in Ulm. This is where data from patients and donors come together and are compared to find a suitable donor for bone marrow donation. Requirements for inclusion in the German Bone Marrow Donor Registry: For the safety of the potential donor and also of the affected person, i.e. the recipient, there are also exclusion criteria: The existence of an exclusion criterion is sufficient to make inclusion in the file impracticable.

Between 18 and 55 (maximum 60)Year of life
Physical health
Body weight of at least 50 kg and body mass index (BMI) of maximum 40
Residence in Germany or maximum 50 km from the German border
Membership in a risk group identified by the German Medical Association and several diseases: Diseases of the central nervous system and the psyche, diseases of the respiratory tract, cardiovascular diseases, disorders of blood coagulation and other diseases of the blood and blood vessels, diseases of the endocrine glands (e.g. pancreas), autoimmune diseases, cancer and also serious infectious diseases (e.g. hepatitis B, hepatitis C or HIV)
Alcohol, drug or medicine addiction
One or more organs or tissue donated by another person
Also widespread diseases: insufficiently controlled high blood pressure, coronary heart disease, diabetes mellitus and severe chronic asthma

Without the presence of one of the exclusion criteria and the aspiration to possibly complete a bone marrow donation, there is nothing to stop the donor from being included in the German bone marrow donation file. This can be done via online registration, in the course of a registration campaign or in a permanent facility.

The necessary information about the donor can be obtained by taking a blood sample or a buccal swab. This information is then registered in the German Bone Marrow Donor Center (DKMS) and the National Marrow Donor Program (NMDP) in the USA and is kept anonymously available for a potential recipient all over the world. The determination of tissue characteristics is associated with costs that are covered by the Central Bone Marrow Donor Registry for the Federal Republic of Germany (ZKRD) through monetary donations.

Shortly after successful registration, the potential donor receives a donor card with a donor number with which he can identify himself in all matters concerning bone marrow donation. Information needed to tell whether donor and recipient are a match is information about the HLA antigens (“human leukocyte antigens”). These are similar to the blood group antigens that determine whether someone has blood group A, B, AB or 0.

However, the blood group itself does not play a role in a bone marrow donation, which means that the blood group of donor and recipient does not necessarily have to match. The HLA antigens are surface structures on human cells, which provide the organism with a means of differentiating between the body’s own and foreign tissue. In order to prevent a rejection reaction from the recipient, a high degree of similarity between the tissue characteristics is absolutely necessary.

The five essential HLA characteristics are A, B, C, DRB1, DQB1, which are all located on one chromosome of the 46 chromosomes of a human being. Thus, inheritance takes place together as a so-called haploid genotype (haplotype for short). We get one haplotype from the mother and one haplotype from the father.

Consequently, an ideal donor must have exactly the 10 HLA characteristics of the recipient. However, there are many versions of each HLA characteristic (so-called alleles), which results in an immeasurable number of possible combinations. This results in a negligible probability for a perfect match of the HLA characteristics. Due to the conditions that have to be fulfilled, a maximum of five out of every hundred bone marrow donors who donate bone marrow within a period of 10 years will donate bone marrow. Young donors who have agreed to donate bone marrow have a slightly higher probability.