Touching Lives - September 2002
Diabetes: A Key Piece In The Jigsaw
When it comes to medical breakthroughs there are endless conditions which deserve such a ‘break’.
Technology is developing at a rapid speed, and genetic research is opening up exciting pathways. But so many illnesses are still misunderstood and, quite simply, remain a hard nut to crack.
Diabetes is such a condition. There is still no clear-cut reason as to why the disease occurs, and yet the number of sufferers, especially children, is on the increase.
In a three-year study funded by the Charity, London-based researchers have found strong evidence suggesting that Type 1 diabetes may be caused by a virus. Action Medical Research Press Officer Nicole Duckworth (pictured) spoke to Dr Mark Peakman, at the Department of Immunology at Guy’s, King’s and St Thomas’ School of Medicine, to help explain the impact of this exciting breakthrough.
Most people know a friend or relative who suffers from diabetes. How widespread is the condition, and what does it do?
There are known to be as many as 1.4 million people diagnosed with diabetes, and another estimated one million who don’t know they have it.
The most serious form of diabetes, Type 1, is an autoimmune disease in which the body lacks insulin (which controls the sugar levels in our bloodstream), and the individual has to inject it daily instead. The condition usually begins in childhood, affecting as many as one in 200 people, and is worryingly on the increase.
Associated problems can be blindness, kidney failure and heart disease in later life. The most common type of diabetes is Type 2, which tends to occur later in life and can often be controlled by diet and/or tablets.
So how does somebody develop the illness? Is it inherited or caused by something else?
It still isn’t clear why the disease occurs, but it’s most likely to be a complex interaction between a person’s genes and their environment. Various studies have suggested that a group of viruses could be a trigger for Type 1, by stimulating the immune system — the body’s natural defence mechanism against disease — to attack and ‘kill off’ the cells that produce insulin. But until this Action Medical Research study the evidence had been indirect and the immune cells involved were unclear.
What is the main focus of your findings?
The team (including co-worker Dr Ruben Varela-Calvino) has discovered a marked difference between the way the bodies of healthy individuals respond to a virus known as Coxsackie B4 and those of newly diagnosed diabetics.
So tell us about this virus, and why it’s important?
Coxsackie B4 virus (CVB4), is a bug that causes typical viral symptoms and is most commonly found in children. Several years ago, a strain of this bug was recovered from the pancreas of a child dying from Type 1 diabetes. Using the genetic code of the virus and the latest DNA technology, we were able to grow key parts of the virus and see how the body responds to them. We did this by using blood samples of some 40 Type 1 diabetics: teenagers and young adults who had been diagnosed within the previous five months.
What did you find out?
The team discovered that CVB4 did stimulate the immune system very readily. They found fresh evidence that the response was different depending on whether the individual was a diabetic, or non-diabetic, in a way that suggested a recent or repeated exposure to the virus.
What kind of impact did the virus have?
A virus is like an enemy invasion that the body fights by using an ‘infantry’ of anti-viral cells called effector cells, that counteract the virus. At the same time the body also keeps in reserve ‘troops’ of memory cells that can quickly turn into effector cells the next time the virus is encountered. Our research found that there were significantly more effector cells among the diabetics than the healthy controls. Importantly, the differences were most pronounced the more recent the diabetic had been diagnosed.
In simple terms then, what does this mean?
If the virus had nothing to do with the disease we would expect to find the same distribution of effector cells in healthy individuals and those with diabetes. But there were far more of these cells in the diabetics, suggesting they’d had a close and recent encounter with the CVB4 virus.
The research must be an important step forward in narrowing down the likely causes of diabetes.
Yes, this research is another piece of the jigsaw, and it adds weight to a link between viruses and the development of diabetes. We hope the study will open up new paths of research: firstly, the mechanisms involved in the immune response; and secondly, how we can prevent it or control it.
What kind of impact could your finding have on treatment?
The implications are clear. If viruses have a proven role in the disease, there is the future possibility of developing vaccines to prevent infection and therefore Type 1 diabetes. What a welcome tonic for the world that would be. Research into diabetes is unbelievably important right now if we are to help prevent a future epidemic.
‘I’m confident that in my lifetime the breakthrough that diabetes deserves will eventually happen’
As he dashes across the stage belting out a Robbie Williams number, Paul’s energy masks any sign of a daily medical disorder.
The young singer has diabetes, and the drive behind his performance mirrors the way he refuses to allow his condition to control his life.
But Paul Topham, a 30-year-old living in West Sussex, has every reason to keep a firm rein on his condition. Almost two years ago he watched helplessly as his mother, Pauline, died from a string of complications sparked by diabetes.
During just one year the 54-year-old, who relied on kidney dialysis, was forced to undergo amputations on both of her lower legs, one operation soon after the other. And a battle with a particularly complex and relentless infection proved too much. Pauline’s weary body gave up.
Paul was diagnosed with Type 1 diabetes when he was 24. He gained extreme thirst, itchy eyes, the need to frequently urinate and he became increasingly tired. Now dependent on four daily insulin injections, Paul said: “^Losing my mum made me realise how important it was to look after myself^ and make the most out of my life.
“It also made me appreciate the desperate need for further research into what can be a horrible disease, and one which is proving a difficult nut to crack. But charities like Action Medical Research are making fantastic strides forward, and I’m confident that in my lifetime, if there is enough funding and commitment, the breakthrough that diabetes deserves will eventually happen.”