New Research Finds another Biomarker of Dementia

Amy Taylor February 20, 2015

Researchers from University of Technology, Sydney (UTS) found a biomarker of Alzheimer’s disease that may help in the diagnosis of the disease.

The study by Dr Dominic Hare and his colleagues at the University, promises to help reveal the cause of the baffling disorder.

"The disease develops so slowly and has so many effects on the body, being able to separate what’s cause and what’s effect is a big problem," he says. "If we can identify why the disease is happening, we could intervene to alleviate the symptoms and potentially halt the disease process."

At present, a diagnosis of Alzheimer’s disease is made only after careful clinical consultation, and any diagnosis can be confirmed only by examining the brain after death.

However, Dr Hare and his co-workers are not looking in the brain for clues. They’re looking in the blood. In a recent article in the US journal ACS Neuroscience, the group outlined its work with a potential biomarker and a possible causative culprit: iron.

"The body uses metals like copper, zinc and iron to facilitate biochemical reactions it wants. In the case of disease, these are reactions that are unwanted," Dr Hare says, adding that iron plays a very important role in the ageing process, and ageing is the key risk factor for Alzheimer’s disease. One in four people over the age of 85 have dementia; 75 per cent of those have Alzheimer’s.

Professor Perminder Sachdev, co-director of the Centre for Healthy Brain Ageing at the University of NSW, says metals have previously been linked to Alzheimer’s but the findings were inconclusive.

"This study by Dr Hare and his colleagues is, therefore, of interest to researchers in the field," says Professor Sachdev, chief medical adviser to Alzheimer’s Australia.

Specifically, Dr Hare’s team is studying transferrin, a protein that helps ferry iron around the body. In the case of Alzheimer’s, if transferrin falls down on the job iron may accumulate in the brain, where it contributes to the build-up of "plaques" and "tangles". Plaques impede the transmission of signals among brain cells and tangles kill them.

The results of their investigation revealed, first, that compared to healthy volunteers, participants with Alzheimer’s had lower levels of iron in their plasma, a condition linked with anaemia of unknown cause.

Intriguingly, results from the ICP-MS and SEC-ICP-MS tests, showed healthy and Alzheimer’s participants had the same amount of transferrin in their blood but that the amount of iron carried by the transferrin was lower in Alzheimer’s samples. The implication: transferrin isn’t shuttling excess iron efficiently from the brain.

"The next step is to look at a copper-binding protein called ceruloplasmin that interacts with transferrin," says Dr Hare. "Putting all these pieces together will help find methods to maintain quality of life, possibly slowing or even halting the progress of the disease."

The paper was published in the journal ACS Neuroscience.

Source of this article: Iron may be a factor in dementia