Patients receiving blood stem cell transplants are matched with a volunteer donor through a test called HLA tissue typing. The immune system uses HLA proteins found in the surface of cells to identify which cells belong to your own body and which do not.

Transplant physicians start looking for a matching donor in the patient’s family, but will extend the search when no matching donor is available in the family. Alternatives for a matching family donor may be:

  • family members who are not a complete HLA match;
  • unrelated adult volunteers who are a complete HLA match;
  • umbilical cord blood units that are a complete HLA match; or
  • unrelated volunteers or umbilical cord blood units that are not a complete HLA match.