HLA-C and HLA-DQB1 compatibility in unrelated cord blood transplants

Background and Objective. Umbilical cord blood (UCB) cells have been definitively proved to be a source of hematopoietic stem cells with repopulating capacity when transplanted into pediatric hosts with neoplastic or non-neoplastic disease. Moreover, due to the immaturity of the UCB lymphoid compartment, these transplants are usually associated with a low incidence and severity of GvHD. This clinical observation and the immaturity of the UCB lymphoid compartment justify the acceptance of UCB units which differ from their recipient by 1 or 2 HLA antigens of the six HLA A, B and DRB1 antigens conventionally typed. Whether the number and type of HLA disparities affect clinical outcome of UCB transplants has not, however, been clearly demonstrated yet.