Researchers have developed a new blood test that can predict with 90% accuracy whether a healthy person will develop Alzheimer’s or cognitive decline within 3 years. They report how they identified and validated the 10 biomarkers that form the basis of the test in a study published in Nature Medicine.

Study leader Howard J. Federoff, a professor of neurology at Georgetown University Medical Center in Washington, DC, says:

“Our novel blood test offers the potential to identify people at risk for progressive cognitive decline and can change how patients, their families and treating physicians plan for and manage the disorder.”

Rates of Alzheimer’s disease – a condition that gradually clogs up and kills brain cells and leads to memory loss and mental decline – are rising rapidly around the globe. The disease mostly affects older people, although there are rare forms that can start earlier in life.

In 2010, there were 35 million people with Alzheimer’s disease worldwide. The World Health Organization (WHO) predicts this number will double every 20 years, rising to 115 million by 2050.

Ability to detect Alzheimer’s in preclinical stages is key

There are currently no treatments that cure or halt the disease, something scientists believe could be due to our inability to detect it before it has progressed to the point where clinical symptoms emerge.

Blood test
Researchers have created a new blood test that predicts with 90% accuracy who will develop a form of cognitive impairment within 3 years.

Prof. Federoff explains that while there have been many attempts to produce drugs that slow or reverse Alzheimer’s, they have all failed, and one reason could be because the drugs are tested at too late a stage of the disease.

Therefore, he and his colleagues focused on the preclinical stage of the disease, looking for biomarkers or telltale molecules that begin circulating in the blood before the disease takes hold.

Every year for 5 years, the researchers tested memory and mental skills, and blood samples of over 500 participants over the age of 70.

They then took the data of 53 participants who developed Alzheimer’s or mild cognitive impairment (MCI) and compared it with 53 who remained cognitively healthy. They used mass spectrometry to analyze the blood samples. This method is used to pinpoint the unique chemical signature of molecules.

The facts on Dementia in Ireland: Creating Excellence in Dementia Care: A Research Review for Ireland’s National Dementia Strategy report published in January 2012, and undertaken by staff in Trinity College and in NUI Galway, reports key findings from an extensive review undertaken on dementia to inform and underpin the Irish government’s forthcoming National Dementia Strategy. Currently about 41,700 people with dementia in Ireland most of whom have some form of home care. An estimated 3,583 (8.6% of all people with dementia) have early onset and most of these are men. Approximately 4,000 new cases of dementia arise in Ireland every year. Findings show that early diagnosis and sometimes any diagnosis is the exception rather than the rule.