Long-term survival of cynomolgus monkeys following pig-to-primate kidney xenotransplantation using h-DAF transgenic donor organs

KIDNEYS from pigs transgenic for human decay accelerating factor (h-DAF) have been shown not to be hyperacutely rejected when transplanted into nonhuman primates. In the initial reports on the use of h-DAF kidneys profound anemia was the reason for termination of the experiments in most of the monkeys. This was probably due to either species incompatibility of the porcine erythropoietin in the recipient cynomolgus monkeys, the induction of neutralizing anti-pig erythropoietin antibodies, or cyclophosphamide bone marrow toxicity. We have developed a life-supporting kidney xenotransplantation model with bilateral ligature of the recipients’ native ureters but preservation of the native kidneys, thus allowing ongoing recipient erythropoietin production.