A 63-year-old man with Type 1 diabetes received a transplant of insulin-producing cells with the aid of a device that eliminated use of immune-blocking drugs, a potential breakthrough that may lead to safer and more effective procedures to revive weakened organs.
The cells, which survived for 10 months, showed signs of insulin production, according to a study released today by the Proceedings of the National Academy of Sciences. The new approach may lead to diabetes therapies, as well as open the possibility of other types of tissue transplants where side effects of immune suppression may outweigh the benefits.
The cells were extracted from a cadaver and implanted using a gel that masked them to protect against the immune system. Without an exact donor match, a transplant recipient’s immune system often rejects organs or tissue without drugs to quiet the response. Today’s finding offers hope for diabetics and others with similarly difficult-to-treat organ failures.
“A lot of people have been looking for methods for transplanting,” said Norman Block, a study co-author and the clinical director of endocrine polypeptide and cancer institute, at the Veterans Administration Medical Center in Miami. “You can use immunosuppression for other transplants, but in this case, that makes the treatment worse than the disease.”
The insulin in human bodies is excreted from cells in the pancreas called beta cells. These cells are difficult to harvest, and transplanting them usually requires immunosuppressing drugs to prevent the patient’s body from rejecting them.
Additionally, human beta cells are hard to come by, because they are among the first cells to begin decaying after death, Block said. However, pigs’ beta cells work very similarly to human beta cells, and this device may make them useful in treating diabetics, Block said.
Type 1 diabetes occurs when the body doesn’t produce insulin, as opposed to the more-common Type 2 diabetes, a condition associated with obesity in which the body doesn’t produce enough insulin or ignores it. Insulin converts blood sugar into energy.
The patient, a mathematician, had been given daily insulin therapy for 20 years. The device, implanted under his skin, contained the beta cells and a supply of oxygen to keep the cells alive until the blood vessels could carry fuel to them.
After the transplant, his blood showed signs that insulin was being made. When the device was removed and stimulated with glucose, it released a marker for insulin activity. Though the cells functioned over the entire 10 months, only slight improvement on the man’s blood sugar levels was observed by the scientists, and he still required insulin injections. That may be because only a small amount of beta cells were transplanted, according to the paper.
Today’s report, showing it’s possible to prevent rejection without drugs, may open more avenues for transplant in other diseases, such as those of the adrenal cortex, which releases hormones in response to stress and where the side-effects from transplant might otherwise outweigh the benefits. Stefan Bornstein, at the University Hospital Carl Gusvac Carus in Dresden and a co-author of the paper, is working on a project to adapt the technology for the adrenal cortex.
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