With all the hoopla surrounding the question of embryonic stem cell transplants, I was wondering if because of the autoimmunity in type 1 diabetes, whether stem cell transplants would actually be “the cure”. Although there would be new insulin producing cells, there would still be the underlying autoimmunity that would attack the new cells. Is this correct?

Cheer up. There could be an answer; but it is a little complicated. To begin with, investigators have at last been able to induce human embryonic stem cells to produce insulin. This by itself is important because it potentially makes available an inexhaustible source cells like beta cells for transplantation. As matters stand at the moment however, these cells would indeed be vulnerable to both normal foreign protein as well as autoimmune rejection. This vulnerability might be circumvented by conventional immunosuppression which would have to be lifelong or by encapsulation of some kind which would involve periodic renewal.

One of the latest and most intriguing approaches is to establish what is called a microchimera by first of all injecting into the blood stream tiny amounts of stem cell derived white cell precursors using a temporary and very sophisticated immunosuppression regimen. Once this had taken hold it should be possible to introduce insulin producing cells from the same embryonic baseline without the risk of rejection and to continue to do this as required.

DOB