SOUTHAMPTON scientists have discovered that every day chest and water infections can cause dementia patients to decline quicker.

Researchers at the University of Southampton found that inflammation in the brain caused by such infections could speed up the development of Alzheimer's disease.

Their study, working with mice, has shown that when both Alzheimer's and an infection is present, the immune cells in the brain fail to act as a defence and instead ramp up the levels of inflammation, causing more severe symptoms.

It is hoped that this new understanding of how the immune cells work will help develop new treatments that can slow down the disease in people.

Professor Hugh Perry, Professor of Experimental Neuropathology, who led the study with Professor Clive Holmes, said: “We observed that inflammation in the body triggered a stark change in the behaviour of immune cells in the brains of the mice.

“Having a systemic infection or inflammatory disease - one that affects the body rather than the brain - was enough to change how these cells respond to the disease in the brain.

“Rather than defending the brain against the developing disease, brain immune cells were 'primed' by the ongoing neurode¬ generation and ramped up levels of inflammation, causing even more damage.

“The findings mirror what we are observing in people with Alzheimer's disease in the clinic. We have found evidence that peo¬ple with Alzheimer's who have systemic infections, such as chest or urine infections, are more likely to have faster decline in memory and thinking and more severe symptoms.”

The findings will be presented today at the Alzheimer's Research UK Annual Conference 2014 in Oxford, the largest dementia research conference in the UK.

Prof Perry added: “If this process is key to driving diseases like Alzheimer's, then keeping it in check could be a way to slow down the disease in people.”

Alzheimer's Research UK has hailed the discovery “promising” as the need for effective treatments has never been greater, wih half a million people suffering from the disease.

Dr Eric Karran, head of research at Alzheimer's Research UK, said: “We hope that further research will pinpoint culprit pro¬teins involved in inflammation that could be used as a target for treatment development.”