Optimal Donor Selection: Beyond HLA

Worldwide >10 million adults and 250 000 cord blood units are available for unrelated HCT. HLA matching and, in the case of cord blood units, cell dose are critical determinants for selecting among these donors. Once a list of suitable adult donors or cord blood units is established, the transplantation physician must choose the optimal donor. We review factors that go into making that decision. We conclude that for adults the optimal donor is a male who is younger and has a larger body weight. When selecting among female adults, the optimal donor is also younger with a larger body weight and has never been pregnant. Additional factors, which can be considered and are relevant particularly for cord blood units, include family and medical histories, risk-exposure history, collection site characteristics, and geographic location.