Irish researchers make Alzheimer’s test breakthrough

Blood test developed by team at RCSI can diagnose brain disease in its early stages

A blood test that can diagnose Alzheimer's disease in its early stages, and can also predict how the disease will progress, has been developed by researchers based in Ireland.

The breakthrough, led by a team at the Royal College of Surgeons in Ireland, has shown concentration changes of a small molecule in the blood can diagnose the disease at a stage when other symptoms are mild.

Early diagnosis holds the best opportunity for potential future treatments of the disease and improving the quality of life for patients with Alzheimer's, according to lead researcher physiologist Dr Tobias Engel.

The soon-to-be-published research, carried out with a team in Madrid, is among innovations being presented at the annual RCSI Research Day in Dublin on Wednesday.


For treatments to be successful, early stages preceding full onset of Alzheimer's need to be targeted

“People are living longer today and because of this the incidence of age-related brain diseases such as Alzheimer’s will rise. Research into the condition is largely focused on the development of new therapies. However, new therapies need diagnostic methods which are affordable and minimally invasive and can be used to screen large populations,” Dr Engel explained.

He added: “Our research carried out over the past four years has identified changes in blood levels of a small molecule called microRNA which is able to diagnose Alzheimer’s disease at a very early stage and is able to distinguish Alzheimer’s from brain diseases with similar symptoms.”


Alzheimer’s is one of the most devastating brain diseases, affecting 48 million worldwide and an estimated 20,000 to 25,000 people in Ireland, with an associated cost of up to €400 million per year to the healthcare system.

No new therapy has passed clinical trials in 20 years, and much of the failure in clinical trials has been attributed to application of therapies at advanced stages of Alzheimer’s, where damage to the brain becomes irreversible.

For treatments to be successful, early stages preceding full onset of Alzheimer’s need to be targeted. At present there is no blood test available to clinicians that can be used to diagnose Alzheimer’s, though many researchers throughout the world are seeking to develop reliable options. The challenge is to be able to distinguish from symptoms that are part of the natural ageing process or other neurodegenerative diseases similar to Alzheimer’s.

The unique aspects of the RCSI test is that it enables prediction of who will develop Alzheimer’s, and the ability to identify those likely to develop related conditions, notably vascular dementia, Dr Engel said.

This study was carried out by scientists from Ireland and Spain, including the work of PhD student Aidan Kenny, based at RCSI Department of Physiology and Medical Physics. The test was developed based on evaluation of 1,000 patients in Madrid. The next step is to extend it to patients in Ireland and other locations, Dr Engel said.

Kevin O'Sullivan

Kevin O'Sullivan

Kevin O'Sullivan is Environment and Science Editor and former editor of The Irish Times