Blood Test Can Accurately Detect Alzheimer's Disease

A blood test that can accurately detect the presence of Alzheimer's disease is being developed which would give physicians an opportunity to intervene at the earliest, most treatable stage.

As blood vessels in the brain weaken or become brittle with age, they begin to leak, which allows plasma components including brain-reactive autoantibodies into the brain. There, the autoantibodies can bind to neurons and accelerate the accumulation of β-amyloid deposits, a hallmark of Alzheimer's pathology.

Scientists at the Rowan University School of Osteopathic Medicine (Stratford, NJ, USA) have focused focuses on utilizing autoantibodies as blood-based biomarkers to accurately detect the presence of myriad diseases and pinpoint the stage to which a disease has progressed. By detecting Alzheimer's disease long before symptoms emerge, they hope those with disease-related autoantibody biomarkers will be encouraged to make beneficial lifestyle changes that may help to slow development of the disease.

All humans possess thousands of autoantibodies in their blood and these autoantibodies specifically bind to blood-borne cellular debris generated by organs and tissues all over the body. An individual's autoantibody profile is strongly influenced by age, gender and the presence of specific diseases or injuries, and diseases cause characteristic changes in autoantibody profiles that, when detected, can serve as biomarkers that reveal the presence of the disease. The blood test developed by the team has also shown promise in detecting other diseases, including Parkinson's disease, multiple sclerosis, and breast cancer.

The team developed a microarray, a slide dotted with tiny proteins that light up in reaction to certain autoantibodies, to test for very early stages of Alzheimer’s disease. To test the blood for specific autoantibodies, the investigators took a drop of blood and smeared it on a microarray, a 2.54-cm by 7.62-cm slide dotted with 23,500 tiny proteins, about a third of all proteins made in the human body. When scanned with a laser, the proteins light up in reaction to certain autoantibodies. The brighter the color, the more of that autoantibody is present.

Robert Nagele, PhD, the senior author of the study said, “There are significant benefits to early disease detection because we now know that many of the same conditions that lead to vascular disease are also significant risk factors for Alzheimer's. People found to have preclinical disease can take steps to improve their vascular health, including watching their diet, exercising and managing any weight and blood pressure issues to help stave off or slow disease progression.” The study was presented at the Osteopathic Medical Conference & Exposition, held October 17–21, 2015, in Orlando (FL, USA).

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Rowan University School of Osteopathic Medicine