Islet transplantation 30 years after the first transplants.

First clinical islet allotransplantation in patients affected by type 1 diabetes mellitus was performed about 30 years ago. Despite the progressive improvement of the success rate, the clinical indication to the islet allotransplantation remains limited to selected patients affected by brittle type 1 diabetes mellitus. The burden of the immunosuppression therapy still represents the main critical issue but other areas might be subject to further improvements, such as the islet production, islet engraftment and long-term function.  Several strategies have been proposed to increase the success rate of pancreas digestion and islet purification or to facilitate islet engraftment by reducing islet hypoxia and the inflammatory reaction occurring in the site of transplantation. The co-transplantation of progenitors of beta cell together with the islets has expected to contribute to prolong graft function. Clinical trials are expected soon. Scientific advances, as well as economical efforts, are required to make this procedure a real therapeutical option for patients with type 1 diabetes mellitus.