Fats in the blood may predict who will get Alzheimer's disease
Scientists have developed a blood test that can diagnose who is at risk for Alzheimer's disease with ninety percent accuracy three years before symptoms appear. The blood test measures levels of 10 lipids, or fats in the blood that are already known to be risk factors for developing Alzheimer's disease.
The development of an early risk assessment for dementia and Alzheimer's disease (AD) means clinicians could intervene early when treatment would be most effective.
Alzheimer's disease rates are expected to soar as baby boomers become the largest segment of the US population, making treatment and management of AD a focus of researchers.
There is no cure for Alzheimer's disease that affects 35.6 million people worldwide. The disease is expected to strike 115.4 million people by 2050. Thee study's corresponding author Howard J. Federoff, MD, PhD, professor of neurology and executive vice president for health sciences at Georgetown University Medical Center suggests most drugs that are prescribed for AD are given too late in the disease process, which is why they fail.
Identifying those at risk early would mean new approaches to managing Alzheimer's disease.
"The preclinical state of the disease offers a window of opportunity for timely disease-modifying intervention," Federoff said in a press release. "Biomarkers such as ours that define this asymptomatic period are critical for successful development and application of these therapeutics."
All of the drugs developed have failed for Alzheimer's disease. Federoff explains biomarkers for the disease have been developed for the first time that can be used to help identify people at risk for Alzheimer's disease that could in turn help delay the onset of symptoms.
Lipids thought to destroy brain cells
The scientists are developing a clinical trial to further validate the preliminary findings. The 10 lipids used in the testing are known to break down neural cells in the brain that can lead to memory loss.
For their study, the researchers tested 525 healthy participants aged 70 or beyond whose blood was tested at the study's start and periodically throughout the 5-year investigation.
Forty-six of the participants were diagnosed with mild cognitive impairment on enrollment. During the course of the study 28 people were diagnosed with either mild Alzheimer's disease or mild cognitive impairment (MCI).
The lipid biomarkers were identified in the third year of the study by matching 53 study participants with mild memory loss, 18 of whom developed cognitive impairment during the study (converters), to 53 people with normal memory as a control.
To further validate the findings, the researchers tested the remaining 21 with memory impairment, 10 of whom were converters and 20 controls. The scientists then tested whether the blood test could be used to identify people who would develop Alzheimer's disease.
"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.
Federoff says the blood test is a "major step forward" for commercializing a test that could screen large numbers of people for Alzheimer's disease. Clinical trials take years. The blood test won't hit the market anytime soon. There are also questions about whether or not people would want to know their risk for the AD. So far the test is 90 percent accurate, meaning some people could be falsely diagnosed.
"Plasma phospholipids identify antecedent memory impairment in older adults"
Mark Mapstone, et al.