A pioneering treatment for Diabetes mellitus, which offers the possibility of a cure for the disease, is about to be tested on humans in the UK.
The new technique, developed in Canada by Dr James Shapiro, involves transplanting insulin-producing cells into the liver of diabetes patients. So far 13 patients treated have been able to stop injecting themselves daily with insulin.
Diabetes affects 110 million people worldwide, and its prevalence is expected to double by 2010. There are two types, Type I or insulin-dependent, and Type II which is controlled by diet and tablets.
Diabetes affects 5 per cent of people in the Republic. Of these 185,000 people - 10 per cent - have Type I and must inject themselves with insulin several times a day.
Dr Shapiro and colleagues at the University of Alberta in Edmonton have developed a method of taking insulin-producing cells, called islet cells, from a donor and injecting them into the patient's liver. In Type I diabetics the islet cells in the pancreas are for some reason destroyed by the body's immune system.
The new technique can be completed in half a day and is done under local anaesthetic. After the islet cell injections, the body's insulin production is restarted, and the patient can scale down and ultimately stop the insulin injections.
As with any form of human transplantation there is a danger that the body will destroy the donor cells, which its immune system perceives as "foreign". The fact that Type I diabetes results from the immune system destroying pancreatic cells adds to this likelihood.
Thirteen of 15 patients who had the treatment in Canada have not had to inject insulin for two years. Ideally the cell treatment should take place before any of the complications of diabetes set in.
"We have to balance the risks of the treatment procedure and anti-rejection drugs against the risks these patients face every day. These patients have a 25 times greater risk of kidney failure, heart attacks, strokes and blindness and have an average of 15 years sliced off their life span," Dr Shapiro said.
The next step will be to turn the technique into one using stem cells from the patient's own body. Stem cells are "mother" cells which are able to differentiate different types of tissue. As these cells would be taken from the patients being treated, the issue of immune rejection would not arise.
"If we can trick them to grow more islets, that's where the ultimate goal will be," Dr Shapiro said. "It might take 10 years or longer to refine these techniques."
