What does a HLA (Human Leukocyte Antigens) match mean?

The match refers to proteins called HLA antigens which reside on the surface of white blood cells and other human cells. They determine the tissue compatibility between the donor and the recipient. Although complete compatibility is optimal, studies have revealed that cord blood transplantations result in a positive outcome even if the match is not perfect. Stem cells derived from cord blood are characteristic for being less mature, immunologically more “naive”, as opposed to stem cells retrieved from bone marrow.