Xenotransplantation of hDAF transgenic pig hearts

Hearts of transgenic pigs expressing a human regulator of complement activa tion, decay accelerating factor (hDAF). were transplanted either heterotopi cally into the abdomen of cynomolgus monkeys or orthotopically into baboons . None of these transgenic hearts was hyperacutely rejected. Immunosuppress ion with a combination of cyclosporine A, cyclophosphamide and steroids pro duced a maximum survival of 62 days (median 40 days) in the heterotopic mod el. Transgenic hearts transplanted into the orthotopic position allowed a m aximum survival of 9 days (median 2.5 days). A more effective and less toxi c immunosuppressive protocol for the prevention of accelerated xenograft re jection is the subject of ongoing research. The use of organs from transgen ic pigs may help to solve the problem of donor shortage in clinical allotra nsplantation.