In allogeneic stem cell transplantation, a patient receives stem cells from a healthy volunteer donor. To ensure the success of an allogeneic transplantation, donor and recipient must share certain tissue characteristics. These characteristics are part of the human HLA system (human leukocyte antigen system). The HLA genes are very important to the human immune system. They help the immune system to differentiate between self and non-self tissue. This monitoring system is the basis of a functional immune system. It also prevents the introduction of foreign genes into body cells, e.g., via viruses. The system essentially operates by recognizing foreign tissue components and destroying them using targeted defensive measures.
Therefore, these HLA markers must match in donor and recipient. If recipient and donor have the same HLA markers, the transplant is considered HLA-identical.
In general, potential donors include healthy siblings and HLA-identical unrelated donors. If an HLA-identical donor could not be found in the global donor banks, a haploidentical transplant can be performed at our center. This involves using one of the patient’s parents as a donor.