Now, pigs might be able to help diabetics live a disease-free life. For, University of Minnesota researchers have found a way to cure type 1 diabetes in monkeys by transplanting into them pig cells responsible for the production of insulin. According to the researchers, the success of the study has implications for humans
Under the study, the researchers injected about 12 diabetic monkeys with pig islet cells, the cells in pancreas that produce insulin. A follow-up of six months showed that the monkeys could live without regular insulin injections. Even though some of the monkeys rejected the transplant of pig islet cells, in five of them the transplant was successful using a cocktail of drugs.
“These results suggest it is feasible to use pig islet cells as a path to a far-reaching cure for diabetes,” said Bernhard Hering, the lead author of the study. “Now that we have identified critical pathways involved in immune recognition and rejection of pig islet transplants, we can begin working on better and safer therapies with the eventual goal of bringing the treatment into people,” he added. The researchers would start human trials by 2009.
Earlier, human diabetes has been cured using islet cells from human pancreas. However, the demand far outnumbered the supply and so the researchers looked at animal cells for the transplant. Over 20 million Americans suffer from diabetes, with the worldwide figures being pegged at over 150 million.
According to Dr Brian Flanagan, one of the study's authors from New York's Juvenile Diabetes Research Foundation, the use of pig islet cells might help meet the demand. “I would say it's one of the more promising things on the horizon. This overcomes the issue of source, so potentially you have an unlimited supply of islets for transplantation. That is a major hurdle to overcome,” he said.
The next step now is to develop the combination of drugs that can ensure the cells are not rejected by the human body. “If we want to make this available for people, it cannot come with a lot of immuno-suppression. It must be a very safe treatment. This is where all of our research has to be focused,” Hering said.
Trying to raise funds for further research is Tom Cartier, who has established the Spring Point Project in Duluth to help the researchers. Cartier, whose 23-year-old son is a diabetic, has already managed to put together US$ 4 million.
“It hasn't been easy, mainly because it wasn't a story we could really tell, yet. We're hoping, once people realize this is the answer we've been looking for, they'll get behind this thing,” said Cartier, the owner of an insurance agency.
Meanwhile, diabetologists and scientists working in the field have hailed the study. Diabetes UK's Jo Brodie said that the study eliminates the problem of supply of islet cells. “A major limiting factor in the use of either whole pancreas or islet cell transplantation is the lack of available donor organs. This research offers the potential for a new source of islet cells without the need for patients to be given anti-rejection drugs which have serious side effects,” Brodie said, adding that further research is needed to address not only medical issues but also ethical ones.
According to Oxford's Paul Johnson, seeking islet cells from animals was an obvious step considering the lack of donor organs. “The shortage of donor organs means we either have to turn to human stem cells or animal cells as an alternative. This is an advance but there's still a lot of work to be done before we can apply it to humans,” he said.
A detailed report of the study has been published in
Nature Medicine.
