By: Scott M. King
Dr. Bernhard Hering of the University of Minnesota is recognized the world over as the premier expert on pancreatic islet transplants. He sees islet transplantation as the best hope for the cure of type 1 diabetes, and his optimism is supported by his research.
We were recently privileged to interview Dr. Hering. Asked about his life’s work, he said, “It’s a privilege, seeing patients succeed with an islet transplant, how their life can be really transformed more than by any other treatment. It’s just a real pleasure, and I’m really very grateful to contribute to this major development in diabetes.”
An optimistic and kindly man, he was steadfastly unfazed by funding problems, saying, “You see, we should not get discouraged by minor problems. Money is not a real problem. As long as we can resolve the science, and I think we can imagine how we want to do this, then we will find the resources necessary to execute.”
Transplantation Trumps Regeneration
Regarding a cure, Dr. Hering said, “In my imagination, a cure can only happen if you either replace islets or you regenerate islets. There is no other mechanism by which I think a cure can be accomplished. I think replacement comes before regeneration. And that is not to say we can only do one or the other, but it is reasonable that replacement is much easier. We know the Edmonton Protocol works. We have short term success. Now some centers have long-term success: A few days ago one of our patients celebrated her sixth year of insulin independence after a single-donor islet transplantation.”
Besting the Edmonton Protocol
Comparing his study to the Edmonton Protocol, he noted, “We have a different islet isolation protocol, we have a different immuno-suppressive protocol, so there are a number of things that are different.
We do not really know whether those factors determined long-term success or whether we just got lucky, but the fact of the matter is that we have 50 percent of our patients, if not more, enjoying long-term success. That is more than two years, and the longest now is six years with fairly stable function. So that is why I believe replacement is very very close to succeeding long term [with use of immuno-suppression].”
This Little Piggy Islet
A major sticking point with islet transplantation is the availability of islets: each transplant requires the islets of one cadaver, and there just aren’t enough to go around. That’s why Dr. Hering is looking to specially bred pigs as a source of cross-species transplants (xeno-transplants). In recent ground-breaking research, he cultured islets from pigs and transplanted them into 12 diabetic monkeys. Armed with immuno-suppressants, the monkeys began producing their own insulin, and some of them regained blood glucose control for more than 100 days.
Dr. Hering does not believe people will be concerned about receiving pig islets. He noted, “Before Dr. Shapiro reported his Edmonton Protocol, people thought, this cannot be done, this should not be done – we definitely should not immuno-suppress a patient just to protect an islet transplant.
But after he demonstrated success on a consistent basis, then everybody accepted it. Now, if we show success with pig islets, then people will become much more receptive and say, well, why not, if it is safe, if it can be done. Clearly, we are not there yet, but I think the perception will change with increasing success.”
Cross-Fertilization Will Make it Happen
Dr. Hering sees pig islet transplantation as leading to breakthroughs that will benefit all aspects of cure research. He notes that “if we can turn pig islet transplantation into a success, if we can establish new implantation sites with immune privilege, clearly this will help stem cell transplantation as well, because once you have the stem cell, then you have to ask the same questions: where to put them and how to protect them.
And maybe then, stem cell transplantation can learn from islet xeno-transplantation like islet xeno-transplantation learned from islet human transplantation, like human islet transplantation learned from pancreas transplantation. There is no competition. There is only cross-fertilization.”