A Blood Test for Alzheimer's

By Jane Farrell

There’s an Alzheimer’s blood test now – a procedure that can detect whether a healthy person will develop mild cognitive impairment or Alzheimer’s within three years.

The test has a 90 percent accuracy rate.

Described in the April issue of Nature Medicine, the test could lead to the development of treatment for early-stage Alzheimer’s, when therapy would be more effective at slowing or preventing onset of symptoms.

It could be ready for use in clinical studies in as few as two years and, researchers say, could be used for other diagnostic purposes as well.

“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,” says the study’s corresponding author Howard J. Federoff, MD, PhD, professor of neurology and executive vice president for health sciences at Georgetown University Medical Center.

Worldwide, about 35.6 million individuals have the disease and, according to the World Health Organization, the number will double every 20 years to 115.4 million people. There is no known treatment or cure.

Federoff explains there have been many efforts to develop drugs to slow or reverse the progression of Alzheimer’s disease, but all of them have failed. He says one reason may be the drugs were evaluated too late in the disease process.

The study included 525 healthy participants aged 70 and older who gave blood samples upon enrolling and at various points in the study. Over the course of the five-year study, 74 participants met the criteria for either mild Alzheimer’s disease (AD) or amnestic mild cognitive impairment (aMCI), in which memory loss is prominent. Of these, 46 were diagnosed upon enrollment and 28 developed aMCI or mild AD during the study.

The researchers discovered a panel of 10 lipids, which appears to reveal the breakdown of neural cell membranes in participants who develop symptoms of cognitive impairment or AD.

“The lipid panel was able to distinguish with 90 percent accuracy these two distinct groups: cognitively normal participants who would progress to MCI or AD within two to three years, and those who would remain normal in the near future,” Federoff says.

The researchers also examined if the presence of the APOE4 gene, a known risk factor for developing AD, would contribute to accurate classification, but found it was not a significant predictive factor in this study.

Federoff said that his team was working toward a clinical trial to confirm the findings.