What’s Missing Here?

Protein in blood shows promise for Alzheimer's test

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) The first signs of alzheimer’s disease may include missing keys and missing memories. What's also missing is a blood test to help identify Alzheimer's patients early. It appears this diagnostic blood test may not be missing much longer.

Madhav Thambisetty, M.D., Ph.D., of the Intramural Research Program at the National Institute on Aging (NIA), found the amount of a specific protein called ApoE in blood samples from cognitively normal older adults strongly correlated with the level of beta amyloid in the brain. Alzheimer's patients have a high level of beta amyloid, the main component of plaques that lead to cognitive impairment and memory loss.

dailyRx Insight: A simple blood test may identfy early stages of Alzheimer’s disease.

The study's volunteers are participating in the National Institute of Aging’s Baltimore Longitudinal Study of Aging (BLSA), which is the lengthiest scientific study of human aging to date. The researchers analyzed blood samples of 57 older, symptom-free volunteers to determine whether specific proteins were associated with amyloid burden in the brain. Then, they measured brain amyloid using PET (positron emission tomography) scans with Pittsburgh Compound B, a tracer that binds to amyloid plaques.

Researchers already knew one hallmark of Alzheimer's disease is the deposition of beta amyloid protein in the brain. When this protein clumps, it form plaques that destroy neurons. The destroyed neurons lead to cognitive impairment and memory loss in the Alzheimer patients. 

Additional testing to verify these results are necessary, but if equally positive, Dr. Thambisetty thinks they would be able to develop a blood test which would provide a less invasive, less expensive way to detect the early pathological changes of Alzheimer’s disease.

Alzheimer's disease is the most common form of dementia in the United States affecting approximately 5.3 million people, and the number is growing. Alzheimer’s results in memory loss, decline in cognitive functioning, and behavioral changes. Alzheimer's disease is usually diagnosed clinically from the patient history, statements from relatives, and clinical observations. There is no cure, and treatment efforts are aimed at slowing the progression of the disease and treating its symptoms. Prescription medications such as Namenda® (NMDA receptor antagonist) and Aricept® (cholinesterase inhibitor) have been shown to slow progression by altering the amounts of certain neurotransmitters in the brain to improve neuronal communication.




Reviewed by: 
Review Date: 
March 27, 2011
Last Updated:
March 29, 2011