Transplantation of the islets of langerhans: New hope for treatment of type 1 diabetes mellitus

For move than two decades, islet transplantation has been pursued as a cura tive treatment for type I diabetes mellitus (T1DM) with little success. It is likely! that the failures of the past have involved technical difficulti es in harvesting human islets, transplantation of insufficient amounts of i slet tissue, the antagonistic effects of immune suppressive drugs, includin g calcineurin inhibitors and glucocorticoids, graft rejection and recurrent autoimmune disease. More recently, success has been reported in seven out of seven consecutive transplants using approaches that overcome the technic al and therapeutic problems of the past. Although this success is noteworth y, issues remain that preclude the general application of islet transplants for treatment of the majority of patients with T1DM. These include the nee d for chronic immunosuppression and the requirement of large numbers of isl ets. Efforts are under way, using a variety of immunological, molecular and cellular strategies, to make this promising treatment available to the maj ority of patients 1 with this disease.