Background: Islet, as well as pancreas transplantations, are alternative procedures providing diabetic patients with insulin independence and optimal blood glucose control. Here, we assessed the utility of islet transplantation after the failure of a pancreas graft and the utility of pancreas transplantation in patients with declining islet graft function. 

Materials and Methods: Four patients with insulin-deficient diabetes and problematic hypoglycemia were transplanted with islets allografts after the failure of prior pancreas transplants (IAP). Another four patients who had previously received islet allotransplants were transplanted with a pancreas after their islet graft function declined (PAI patients). Tacrolimus and mycophenolate were used for immunosuppression supplemented with steroids for PAI patients. 

Results: All four IAP patients became insulin independent after their first islet transplant. Two remained insulin independent 11 and 12 months later; the remaining two patients required a second ITx to extend insulin independence over 3 years and one of them a third ITx to extend freedom from insulin over 8 years. 

All 4 patients receiving PAI had uncomplicated clinical courses and maintained optimal blood glucose control without insulin more than 4 years after the pancreas transplant. None of the patients developed de novo HLA antibodies after PAI or IAP transplantation. 

Conclusions: Pancreas and islet transplantations are alternative beta cell replacement transplant procedures, allowing successful extension of  insulin independence in case one type of those therapies had initially failed.