A technique for transplanting pancreatic islets as a vascularized graft and prevention of rejection with cyclosporin A.

Transplants of isolated allogeneic pancreatic islets behave as if extremely immunogenic but vascularized segmental pancreatic allografts do not evoke such a rapid rejection of islet tissue. We have transplanted rat pancreatic islets as a vascularized graft by implanting isolated islets under the renal capsule of a syngeneic diabetic rat and, after successful reversal of diabetes, a composite graft of kidney and islets was transplanted into an allogeneic diabetic host. Cyclosporin A was used to suppress rejection of the allografts in doses that have previously been shown to completely suppress rejection of renal allografts and delay rejection of vascularized segmental pancreatic allografts. This strategy produced indefinite survival of the allogeneic isolated pancreatic islets.