Baboon-to-human cardiac xenotransplantation in a neonate.

The first transplantation of a baboon heart into a newborn (Baby Fae) with hypoplastic left heart syndrome (HLHS) is reported by the team involved in the operation. Details of the pretransplant immunologic testing of the organ recipient and potential baboon donors, and the pre-and post-operative course of the patient until her death 20 days after surgery are discussed. Autopsy findings showed only traces of cell-mediated rejection. Graft failure appears to have resulted from a progressive, potentially avoidable humoral response, unmodified by immunosuppression, perhaps as a result of crossing the ABO blood barrier. The authors believe that cardiac replacement by xenotransplantation is technically feasible and a reasonable investigative option for newborns with HLHS.