Nearly a decade ago‚ Bernhard Hering‚ M.D.‚ and his team were making strides for patients suffering from a dangerous complication of type 1 diabetes known as hypoglycemia unawareness.
Hering’s group was among the first in the world to bring islet-cell transplantation to clinical trials‚ hoping to restore sensitivity to low blood sugar levels for the 12 percent of people with type 1 diabetes who no longer feel important warning signs like shakiness when their blood sugar plummets‚ which can result in a loss of consciousness or even brain damage.
The results of the first four islet-cell clinical trials at the University of Minnesota’s Diabetes Institute for Immunology and Transplantation far surpassed expectations.
In nearly 90 percent of patients who received a transplant—consisting of a mere teaspoon-sized infusion of insulin-producing islet cells from a donor pancreas—the procedure not only cured hypoglycemia unawareness‚ but it also eliminated the need for daily shots of insulin‚ at least temporarily. Fifty percent of people in the trial were still insulin-independent after five years.
“The proof of concept has been shown‚” says Hering‚ who holds the Eunice L. Dwan Diabetes Research Chair and serves as scientific director of the Diabetes Institute. “We can reverse diabetes with a cell-based therapy.”
Now Hering’s group has initiated a critical round of studies to refine the course of treatment and improve long-term outcomes.
The goal is to improve the immunosuppression that’s required to keep recipients from rejecting the donated cells. The agents they’re investigating include antibodies given at the time of the transplant that may enhance islet-cell longevity as well as new drugs that may replace the potent immunosuppressive medication typically used in transplant surgery‚ which can be damaging to the kidneys.
But there’s no doubt that successful islet transplants can be life-changing for patients.
Forty-four-year-old Stephanie Arneson grew up vigilant about monitoring her blood sugar. “You never get a day off from diabetes‚” she says.
Then‚ in 1999‚ she stopped sensing the signals of hypoglycemia and started passing out unexpectedly. For the energetic mother of two young girls‚ frequent finger pricks and strategic eating weren’t maintenance enough. When she blacked out while driving‚ knocking into a cement wall on an exit ramp‚ she knew something had to change.
Arneson signed on for one of the early clinical trials at the Diabetes Institute. Despite initial setbacks‚ which are now rare‚ the islet-cell transplant that took prompted an instant turnaround. Arneson was able to feel signs of low blood sugar again.
Now she’s gone five years without needing a single insulin shot‚ taking only daily immunosuppressive medication to keep her body from rejecting the transplanted tissue.
The hardest part today‚ she says‚ “is explaining to people‚ ‘Well‚ I used to have diabetes.’”
Hering’s group hopes that more people will have to offer that explanation in the near future. The Diabetes Institute is one of three principal sites in the United States conducting phase III trials‚ the final round of study before applying for licensure from the Food and Drug Administration‚ to determine whether human islets can be used as a standard therapy for diabetes.
“This will be a landmark achievement‚” says Hering. “It will really open the door to more opportunities for patients.”