Blood Test May Help Detect Or Rule Out Alzheimer's Disease

A blood test which identifies biomarkers in blood serum may help clinicians accurately classify individuals withAlzheimer's disease as well as identifying people who do not have the disease, researchers have revealed in an article published inArchives of Neurology.

Detecting blood biomarkers has many advantages over other ways of classifying Alzheimer's patients, including detecting biomarkers found in the cerebrospinal fluid and neuroimaging.

Blood is much easier to collect; it can be done at any clinic, and even at home. Most patients generally agree to a blood test. Not all facilities are able to carry out a lumbar puncture to obtain cerebrospinal fluid, the authors explain. A higher number of elderly patients will refuse to have a lumbar puncture, compared to a blood test. Some patients may not be able to undergo neuroimaging if they have a pacemaker or certain health problems.

Sid E. O'Bryant, Ph.D., Texas Tech University Health Sciences Center, Lubbock, and team in the Texas Alzheimer's Research Consortium examined proteins in the serum of Alzheimer's patients and 203 individuals who did not have Alzheimer's (controls). A biomarker score was devised using statistical analyses, which included levels of the following protein biomarkers:

• fibrinogen (a clotting protein)
• interleukin-10 (associated with the immune system)
• C-reactive protein (an inflammatory marker)

The final biomarker risk score identified 80% of the Alzheimer's patients accurately, and correctly excluded 91% of those without Alzheimer's disease, the researchers wrote.

When age, sex, education and whether the person had the APOE gene (linked to Alzheimer's disease) were taken into account, the score accurately identified 94% of the people with Alzheimer's disease, and correctly classified 84% of those without Alzheimer's.

The researchers note that their findings provide support that there is an inflammatory subtype of Alzheimer's disease.