Pancreatic islet cell transplantation: an update.

Transplantation of pancreatic islets, as a therapeutic modality for type 1 diabetes mellitus (T1DM), at this stage of its development, is reserved for patients with severe glycemic variability, progressive diabetic complications, and life threatening hypoglycemia unawareness, regardless of intensive insulin management. It has not succeeded to become the method of choice for treating T1DM because of limited supply and suboptimal yields of procurement and isolation of islets, graft failure, and relatively high requirements, i.e., at least 10,000 functional Islet Equivalents per kg of patient weight, to achieve prolonged insulin independence and glucose stability. Efforts aimed at making islet transplantation a competitive alternative to exogenous insulin injections for treating T1DM have focused on improving the longevity and functionality of islet cells. In order to succeed, these efforts need to be complemented by others to optimize the rate and efficiency of encapsulation.