Analysis of tissue characteristics
Once we receive your blood sample or buccal swab, tissue typing will take place. A laboratory will determine your individual tissue characteristics (HLA characteristics). Following tissue typing, we will send your tissue characteristics together with your anonymized donor number to the ZKRD, the German National Registry of Blood Stem Cell Donors in Ulm, Germany, and to the National Marrow Donor Program (NMDP) in the USA.

From this point on, your tissue characteristics will be available for patient searches from across the world. If your tissue characteristics match those of a patient, DKMS will get in touch with you.

In order to save vital time when a donor proves to be a match for a patient, we carry out high-resolution (very detailed) typing of the ten most important tissue characteristics relevant to transplantation. This means we do not have to carry out additional analyses. It also saves time as it is easy to see whether a donor is suitable for a particular patient.

Your address is vitally important
A few weeks after your registration, you will receive your personal donor card through the mail with your donor number on it. Please refer to this number whenever you contact us, e.g. when you need to inform us of a change of address.

We will also remain in contact with you over the years. This means that we can make sure you are kept up-to-date regarding the vital work being undertaken by DKMS and that we always have your current address and contact details. This will enable us to get in touch with you easily if you do prove to be a match for a patient.

Stem cells can be found in all bones, but large quantities exist in the iliac crest and can be collected using two different methods. The method used depends on the needs of the patient. The wishes of the donor are taken into account if possible. It may be that the donor is more suited to one method than the other for medical reasons.

1. Peripheral stem cell collection (apheresis)
In 80% of the cases, peripheral stem cell collection is used. With this method, a growth factor, which is similar to a hormone, is injected under the skin on each of the five days before the procedure. This material is called G-CSF and it promotes the production of stem cells, which are present primarily in bone marrow. These cells then flow into the bloodstream.

Once the pre-treatment process is concluded, stem cells can be collected from the blood using a special procedure (apheresis). This involves setting up venous lines to both arms. The blood flows from one arm through a cell separator to the other line and back into the body. This is an outpatient procedure that does not require the use of an anesthetic and usually lasts at least four hours. In 20% of cases, apheresis must be repeated on the following day in order to collect enough stem cells.

This process has been used in medicine since 1988 and for DKMS donors since 1996. While receiving the pretreatment drug, donors may experience flu-like symptoms. There have been no reports of long-term effects in any research to date. We stay in regular contact with our donors to make sure that if they do experience any effects, we quickly become aware of them.

2. Bone marrow collection
With collection from the bone marrow (not to be confused with the spinal cord), approximately one liter of bone marrow blood mixture is collected from the iliac crest while the donor is under general anesthetic. This accounts for approximately 5% of the total bone marrow in the body and will fully regenerate in about two weeks. Generally, all that is required is two small cuts and some stitches around the rear pelvic bone area. The cuts are so small that they heal quickly and only require a few stitches if any at all. Collection takes approximately 60 minutes. Including admission, bone marrow collection, and monitoring, you will remain in the hospital for two to three days.

The risk for you is low. It is limited mainly to the usual risks involved with undergoing general anesthesia. Following collection, there may be some localized pain, similar to a bruise, from the wound for a few days. Sometimes you may experience pain that lasts longer than this, but this is rare.

How are stem cell donors found? – Donor search basics
You can become a donor for a particular patient if your tissue characteristics, or HLA (human leukocyte antigens) characteristics, match those of the patient.

Currently, we know of more than 7,000 tissue characteristics, which can occur in millions of different combinations. The probability of finding a suitable donor outside the family is relatively small – it is currently one in 20,000 to one in several million. This is why the search for a suitable donor begins within the family.

Family search
The potential for a patient and a donor’s tissue characteristics to match is at its highest within the patient’s family with a probability of approximately 30%. This is because children inherit half of their tissue characteristics from their mother and half from their father.

First, the clinic treating the patient will check whether any of the patient’s siblings are suitable. If this is not successful, the search will be extended to other relatives. The probability of either parent being a suitable donor for a patient is 1%. Generally, only one branch of the family tree will have the relevant tissue characteristics.

A maximum of 30% of patients find a suitable donor within their family.

If there is no suitable donor within the family, the search for a non-relative donor begins (unrelated donor).

Search for an unrelated donor
If family tissue typing is unsuccessful, the immunogenetic institute and doctor treating the patient will request the ZKRD (German National Registry of Blood Stem Cell Donors) in Ulm to start the search for a donor. If the patient’s insurance company agrees to cover the costs of the search and provides a declaration of informed consent from the patient, the ZKRD will give the requesting institute access to the anonymized data of all suitable donors.

Regrettably, in Germany many patients are without a matching donor. This is why it is necessary for DKMS to continue expanding and registering new donors.

In order to also improve the situation for patients from other countries, DKMS strives to increase the number of tissue characteristics in its database. This is achieved, for example, though the minority program, which is aimed at encouraging people from immigrant backgrounds to register as they often have different tissue characteristics than people from German backgrounds.

Despite our efforts to make the public aware of stem cell donation, a number of myths surrounding the process still exist. Here, we give you the true facts behind some of the most common myths.

Myth 1 / Wrong:
Stem cells are taken from the spinal cord.

Fact:
The spinal cord (a part of the central nervous system) and the bone marrow (the most important organ for blood formation in humans) are often confused. The spinal cord of the donor remains untouched. If a surgical procedure is required, bone marrow or stem cells are taken from the iliac crest. Cell collection is done under general anesthetic.

Myth 2 / Wrong:
Surgery is always required for stem cell donation.

Fact:
In addition to a surgical procedure namely the removal of bone marrow from the iliac crest there is also another means of collecting stem cells. This is called peripheral stem cell collection and is actually the procedure that is most frequently used (in approximately 80% of cases). This involves collecting stem cells from the blood using a special outpatient procedure that does not involve the use of anesthesia.

Myth 3 / Wrong:
If I donate stem cells, then I can never get them back.

Fact:
The body will generate new stem cells within two weeks. The procedure is comparable to blood donation and does not result in the permanent loss of stem cells.

Myth 4 / Wrong:
The donor must have the same blood type as the patient.

Fact:
The stem cell transplant does not come down to the same blood type, but to the most exact match possible between the tissue characteristics (HLA characteristics) of the donor and of the patient. Finding a 100 percent match is very complicated and is often compared to looking for the proverbial needle in a haystack. If a donation is possible, then the stem cell recipient even assumes the blood type of the donor.