Soon, simple blood test to help spot Alzheimer's 3 years before onset
In a major breakthrough in the world of medical research, researchers claimed to have developed a way to identify people at high risk of cognitive decline or Alzheimer's within 3 years through a simple blood test.
The study heralds the potential for developing treatment strategies for Alzheimer's at an earlier stage, when therapy would be more effective at slowing or preventing onset of symptoms.
It is the first known published report of blood-based biomarkers for preclinical Alzheimer's.
The test identifies 10 lipids, or fats, in the blood that predict disease onset. It could be ready for use in clinical studies in as few as two years and, researchers say, other diagnostic uses are possible.
The study's corresponding author Howard J. Federoff, professor of neurology at Georgetown University Medical Center, explained that there have been many efforts to develop drugs to slow or reverse the progression of Alzheimer's disease, but all of them have failed.
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 a condition known as 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 latter group called converters).
In the study's third year, the researchers selected 53 participants who developed aMCI/AD (including 18 converters) and 53 cognitively normal matched controls for the lipid biomarker discovery phase of the study.
The lipids were not targeted before the start of the study, but rather, were an outcome of the study.
A panel of 10 lipids was discovered, which researchers say appears to reveal the breakdown of neural cell membranes in participants who develop symptoms of cognitive impairment or AD.
The panel was subsequently validated using the remaining 21 aMCI/AD participants (including 10 converters), and 20 controls. Blinded data were analyzed to determine if the subjects could be characterized into the correct diagnostic categories based solely on the 10 lipids identified in the discovery phase.
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 said.
The researchers examined if the presence of the APOE4 gene, a known risk factor for developing AD, would contribute to accurate classification of the groups, but found it was not a significant predictive factor in this study.
The study is published in journal Nature Medicine.
(Posted on 10-03-2014)