Simple blood test may facilitate diagnosis of Alzheimer’s disease

Identifying biomarkers from blood samples shows potential as a clinical screening tool to estimate the presence of Alzheimer's disease (AD) changes and blood vessel damage in the brain, as shown in a recent study.

A team of researchers from the University of Kentucky Alzheimer's Disease Research Center in the US examined blood samples from 90 individuals who had blood taken and banked within 2 years of their death. They tested the samples for a variety of angiogenic, inflammatory, and AD-related proteins and determined their associations with postmortem neuropathology.

After analysing the blood samples using a digital immunoassay, the researchers identified certain proteins in blood that indicated protein changes and changes in the brain known to cause dementia. Specifically, the tau/amyloid beta (Aβ)42 ratio, glial fibrillary acidic protein (GFAP), vascular endothelial growth factor A (VEGF-A), and placental growth factor (PlGF) were all elevated in the samples.

In proportional odds and logistic regression models adjusted for age, the biomarkers were positively associated with AD neuropathological change. On the other hand, higher Aβ42/Aβ40 ratio was inversely associated with AD neuropathology.

Higher PlGF, VEGF-A, and interleukin 6 showed inverse relationships with chronic cerebrovascular disease, while Aβ42/Aβ40 ratio was positively associated.

The present study provide evidence that a blood test could be used to identify changes in the brain related to AD and vascular contributions to cognitive impairment and dementia pathology. This could lead to early detection of changes, that is before the onset of any symptoms, and administration of treatments to help prevent any memory loss.