United Kingdom-Pig organ transplants for humans.

UNITED KINGDOM-PIG ORGAN AND CELL TRANSPLANTS TO HUMANS.

Transplants of piglet cells could be used to treat diabetes patients following successful experiments in monkeys, scientists said yesterday.

Two new studies have shown that insulin-producing islet cells from the pancreases of newborn pigs can reverse type-1 diabetes in primates without major side effects.

The findings, from teams in Canada and the US, pave the way for human clinical trials and both groups of researchers hope to start recruiting patients within three to five years.

If successful, millions of people with both type-1 and type-2 diabetes could benefit from treatment.

The procedure has had encouraging results, but its prospects are limited by an acute shortage of human tissue for transplants, which typically require islets from two pancreases donated after death.Scientists have turned to pigs as a potential source of islet cells as the animals produce a similar form of insulin to humans.

Grafts of tissue from animals, however, pose ethical and safety concerns because they raise the prospect of introducing viruses which might prove harmful.

Pigs carry viruses known as retroviruses written into their genetic code.

While these cause the pigs no harm, there are concerns that they could trigger potentially dangerous diseases in humans.

There is currently a moratorium on xenotransplantation in Britain, though human experiments using pig islet cells have been conducted in Mexico.

Studies in the University of Minnesota and the University of Alberta examined the potential of islet cells from newborn piglets to be transplanted into diabetic monkeys.

In the Alberta study, the transplants worked so well that the four monkeys involved have been able to come off insulin injections, one for almost a year. The Minnesota team achieved similar results with five monkeys.

Ray Rajotte, Professor of Surgery at the University of Alberta, said: "It’s hoped that within the next five years we’ll be transplanting patients with pig islets once we prove it’s safe." Should the technique work in people, it would require them to take immuno-suppressant drugs to minimise the chance the pig cells would be rejected.

These have side effects, making transplants a less attractive option for patients whose diabetes is well-controlled with insulin. (© The Times, London)