Hope of cure for diabetes after success of mice trials

Researchers in the United States said yesterday they had achieved a breakthrough in their search for a cure for diabetes. Such a cure might be readily available by the end of the decade.

Tests on mice suggest they are able to reverse type 1 diabetes by injecting spleen cells that turn themselves into cells that produce insulin.

"It's a potential breakthrough in finding a cure for diabetes," said Marita Gomez, a spokeswoman for the Iacocca Foundation, which has been funding the research. "Within the next 12 months you should start to see the beginning of human trials." Researchers at the Massachusetts General Hospital's Immunobiology Laboratory, led by Dr Denise Faustman, worked with mice that developed a strain of diabetes similar to the type 1 form of the disease that afflicts humans.

They discovered that injecting live spleen cells from healthy, non-diabetic mice achieved a reversal of the diabetes, even in those close to death. They hope the technique could be useful for other autoimmune conditions, in which the body's immune system attacks its own tissue.

"The lowly spleen has a new unsuspected job assignment other than representing a useless bag of white blood cells," said Dr Faustman. "The spleen is a source of adult precursor cells that accelerates the insulin-secreting islet regeneration." The team had shown previously that the autoimmune destruction of the insulin-producing islet cells in the pancreas of diabetic mice could be reversed and islet cell function restored by injection of donor spleen cells.

The unanswered question from that study was whether the few remaining islet cells were being rescued or whether insulin-secreting islet cells were being regenerated. In today's edition of the journal Science, Dr Faustman's team confirm that the islet cells are being regenerated. "The injected spleen cells contain cells that rapidly differentiate into islet ... cells within the pancreas," the researchers write.

A separate report published today by the World Health Organisation (WHO) to mark World Diabetes Day says an explosion in diabetes cases over coming decades could compound the problems of health care in the developing world, already battling diseases such as AIDS. It says the number of sufferers in the developing world could more than double in 30 years to around 285 million from 115 million at present.

"Even as these countries are struggling to address the problems of HIV/AIDS, malaria and tuberculosis, they must also prepare to deal with the onslaught of diseases that come with changes in lifestyle and ageing," says Dr Catherine Le Gales-Camus, the WHO's assistant director general.

The Massachusetts researchers say a lack of funding is holding up human trials. "We must get 500 calls a month from people who want to be in clinical trials," said Dr Faustman. "[But] there is a huge amount of momentum required ... in moving from raising $1m [£600,000] a year to raising $20m a year to get human trials started." So far the tests have been financed by the Iacocca Foundation, set up by automotive legend Lee Iacocca to support diabetes research after his wife, Mary, died of complications of the disease.

The research could help explain the existence of the spleen. The organ is not considered essential and people can live without a spleen because its function can be taken over by other organs.