Triple drug treatment with cyclosporine, leflunomide and mycophenolate mofetil prevents rejection of pig islets transplanted into rats and primates

Abstract THE CONCEPT of pig-to-man islet transplantation is based on the facts that porcine insulin can serve as a substitute for human insulin, that the regulation of insulin release from β-cells in pigs resembles that in humans and that pigs, without major ethical restraints, are readily available in large numbers. It is also assumed that primarily nonvascularized xenografts, such as islets, should escape hyperacute rejection. 1 However, islets and other primarily nonvascularized xenografts are rapidly destroyed by vigorous cellular rejection and we have recently shown that the characteristics of this rejection fundamentally differ from those of allogeneic rejection. 2 If pig-to-man islet transplantation is to succeed, the means of preventing such rejection must be found.