What does allogeneic mean?
Allogeneic means that the transplanted cells are coming from a donor – this may be a sibling, other relative, or someone unrelated to the patient (the cells can even come from umbilical cord blood). If the cells come from an identical twin of the patient, the transplant is called syngeneic and is essentially like an autologous transplant, because the cells are identical to the patients. The cells must be “matched” to the patient, which is done by human leukocyte antigen (HLA) testing. The HLA type is made up of 6 antigens: 3 are inherited from the mother, and 3 are inherited from the father. Doctors usually look first to a family member for a match. Siblings from the same parents have a 25% chance of matching each other, but if no siblings match, that patient’s parents or children can be tested. A donor may “match” the patient in 6 out of 6, 5 out of 6, or 4 out of 6 antigens. The higher the number of matching HLA antigens, the greater the chance that the patient’s body will accept t
