Reversing type 1 diabetes with stem cell–derived islets: a step closer to the dream?

Ernest McCulloch and James Till established the properties of stem cells in the 1960s (1), fueling interest in exploiting the ability of pluripotent cells to replace dysfunctional tissue in disease states. This concept has particular appeal for type 1 diabetes, a condition in which the loss of approximately 0.8 g of pancreatic β cells results in a lifelong need for insulin injections. Added to this, type 1 diabetes can be reversed by a pancreas or islet cell transplant, which provides proof of principle for cell-based therapy (2). Whole pancreas transplants require major surgery, and 99% of the allograft has no relevance to insulin secretion. Intraportal infusion of islets isolated from the pancreas of braindead donors has been carried out with partial success for more than 20 years. Barriers to wider use of isolated islets include a marked shortage of suitable donors, physical and ischemic damage to islets during isolation and transfer, and the need for long-term immunosuppression. Even so, insulin independence can be transformative for those who achieve it.