German citizens made as many as 4.166 haematopoietic stem cell donations in 2008. The cells were donated in order to help patients suffering from leukaemia as well as other malignant blood or immune system diseases. “Haematopoietic stem cell donations are often the only chance of a cure for many of these sufferers,” explained Dr. Dr. Carlheinz Müller, Managing Director of the Central German Bone Marrow Donor Registry (ZKRD).
There are about 30 donor registries in Germany which transmit the information they have stored about potential donors to the central ZKRD where suitable donor and patient data are matched. The ZKRD also coordinates the national and international search process. Thanks to the willingness of Germans to donate haematopoietic stem cells, the ZKRD is by far the biggest registry in Europe, and – in terms of the number of actual donations – the most efficient world-wide.
In order to find a suitable donor for a particular patient, it is important to find a tissue (HLA) type that matches the recipient. Matching, and hence the actual search process, is performed at the ZKRD, which has not only access to the data of German donors, but also to data of donors around the world. The ZKRD, which acts on behalf of the German Federal Ministry of Health, has access to the data of about 13 million donors.
If a suitable donor is found, then another blood sample is taken and analysed for additional tissue properties that are compared with those of the potential recipient. If a suitable match is found, then the haematopoietic stem cells can be isolated from the peripheral blood of the donor by being filtered directly from the blood in a process that is similar to dialysis.
Nowadays, the donation of bone marrow, for example bone marrow removed from the iliac crest, is not necessary in the majority of cases. The treated haematopoietic stem cells are transferred to the recipient by way of infusion. Thanks to the donation, the body of the recipient is then able to establish a new haematopoietic system.