Long-term survival of donor-specific pancreatic islet xenografts in fully xenogeneic chimeras.

THE development of procedures to isolate large numbers of purified human pancreatic islet cells has made it possible to initiate a new phase of clinical trials in pancreatic islet transplantation for treatment of type I diabetes. l -4 Although nonspecific immunosuppressive agents have been instrumental in controlling alloreactivity to transplanted islet cells, rejection still occurs and is a major limitation to islet transplantation.5.ft The induction of donor-specific transplantation across a species barrier. using bone marrow stem cells to produce chimerism and induce donor-specific transplantation tolerance. has been suggested as a potential approach to prevent rejection of transplanted cells. 79 The purpose of this study was to determine whether long-term acceptance and function of xenogeneic pancreatic islet grafts could be achieved in fully xenogeneic chimeras.