A stem cell donor can be found in the immediate family (usually a sibling) for roughly one third of all German patients. An unrelated donor must be found for the remaining two thirds. The search center will therefore ask the ZKRD to perform a search. The ZKRD receives the patient’s medical data, generates a list of suitable donors using the OptiMatch® matching software, and forwards this list to the search center.

OptiMatch® firstly screens the data provided by around 26 donor centers in Germany. If no potential donor can be found in the national database, the ZKRD extend the search beyond Germany’s borders thanks to its links with international registries. Conversely, German donors may also be requested by international registries and can thus be matched with patients abroad. Today, the ZKRD has access to the data of more than 37 million donors worldwide. Using the match list, doctors can ask for specific and more detailed tests in certain donors, e.g. more accurate determination of their HLA characteristics. The results will aid the selection of the most suitable – ideally HLA-identical – donor.

As soon as a specific donor has been selected, the donor and patient are compared once more by sending the donor’s blood sample to the transplant center’s laboratory, where typing is repeated. This is a safety step called “confirmatory typing.” Care is also taken to ensure that the donor has no illnesses which could be a risk to himself or the patient. The ZKRD supports its partners throughout the search and selection process. It examines, documents and forwards patient-related requests and the test results to the respective facilities (search centers, donor centers, transplant centers). To ensure the prompt detection of inconsistencies and avoidance of errors, all the results are carefully checked.

Thanks to a widespread willingness to donate stem cells, suitable unrelated donors can be found for half of German patients within six weeks. The overall success rate in finding donors is more than 80%.