ELIMINATION OF NATURAL ANTIBODIES IN DISC ORDANT XENOTRANSPLANTATION

The effect of various techniques to eliminate natural preformed antibo dies (IgM/IgG) in a discordant kidney xenograft model are reported. Th e combination of multiple plasmapheresis, splenectomy and immunosupres sive drugs allowed to prolong kidney xenograft survival until three we eks when without treatment such a graft would be rejected within hours or minutes. To prevent the rebound of preformed antibodies, the assoc iation of multiple plasmapheresis and anti-IgM monoclonal antibodies s eem to be efficient in such a model. The combination of a pig liver pe rfusion, a sublethal total body irradiation, a bone marrow graft and v arious drugs prolonged kidney xenograft survival up to 2 weeks with so me signs of peripheral microchimerism. Advantages and disadvantages of each techniques are discussed.