UCLA study shows feasibility of blood-based test for diagnosing Alzheimer's Disease

UCLA researchers have provided the first evidence that a simple blood test could be developed to confirm the presence of beta amyloid proteins in the brain, which is a hallmark of Alzheimer's disease.

Although approximately 5 million Americans are living with Alzheimer's, no reliable blood-based test currently exists for the neurodegenerative disorder that is the sixth-leading cause of death in the United States. Using blood-based biomarkers - a signature of proteins in the blood that indicate the presence of a disease - to diagnose Alzheimer's could be a key advance.

"Blood-based biomarkers would have the important advantage of being safe, affordable and easy to administer in large groups or in rural areas, and therefore could have an enormous impact on clinical care and clinical trials alike," said Dr. Liana G. Apostolova, director of the neuroimaging laboratory at the Mary S. Easton Center for Alzheimer's Disease Research at UCLA and head of the research team. Results of the study appeared in the journal Neurology.

Alzheimer's disease can be diagnosed definitively only by examining brain tissue after death. While people are alive, physicians must rely on proxy measures, or biomarkers, along with cognitive symptoms such as memory loss.

Two current methods for determining the beta-amyloid formation characteristic of Alzheimer's disease both have drawbacks. Cerebrospinal fluid can be obtained from patients, but that requires a spinal tap, an invasive procedure that carries the risk of nerve damage and other serious side effects. Another method, the amyloid PET scan, while effective, exposes subjects to radiation. The PET scan is also expensive and is not typically covered by insurance as a diagnostic test. Also, few medical centers have the technology.

For their study, the UCLA researchers developed a simple signature for predicting the presence of brain amyloidosis - the build-up of amyloid in the brain - including several blood proteins known to be associated with Alzheimer's disease, along with information routinely obtained in the course of a clinical work-up for patients suspected to have the disease, such as results of memory testing and structural magnetic resonance imaging.

What is Alzheimer’s disease?

Alzheimer’s disease is the most common form of dementia, a serious brain disorder that impacts daily living through memory loss and cognitive changes. Although not all memory loss indicates Alzheimer’s disease, one in ten people over 65 years of age, and over half of those over 85 have Alzheimer’s disease. Currently, 26 million people worldwide have this dementia, and over 15 million Americans will be affected by the year 2050.

Symptoms of Alzheimer’s disease usually develop slowly and gradually worsen over time, progressing from mild forgetfulness to widespread brain impairment. Chemical and structural changes in the brain slowly destroy the ability to create, remember, learn, reason, and relate to others. As critical cells die, drastic personality loss occurs and body systems fail.