[Elimination of natural antibodies in discordant xenografts].

The effect of various techniques to eliminate natural performed antibodies (IgM/IgG) in a discordant kidney xenograft model are reported. The combination of multiple plasmapheresis, splenectomy and immunosuppressive drugs allowed to prolong kidney xenograft survival until three weeks when without treatment such a graft would be rejected within hours or minutes. To prevent the rebound of preformed antibodies, the association of multiple plasmapheresis and anti-IgM monoclonal antibodies seem to be efficient in such a model. The combination of a pig liver perfusion, a sublethal total body irradiation, a bone marrow graft and various drugs prolonged kidney xenograft survival up to 2 weeks with some signs of peripheral microchimerism. Advantages and disadvantages of each techniques are discussed.