NIH Logo Prior investigations have already laid down the possible means to detect Alzheimer’s disease in the beginning stages itself, as changes take place in the brain years before symptoms appear. Scientists have now introduced a blood test to identify levels of beta-amyloid protein in the brain, which is the key to the disease. The findings can possibly lead to the development of a blood test for predicting Alzheimer’s disease risk.

Having employed the proteomics technology, expert scrutinized blood samples of 57 older and symptom-free volunteers. This method apparently analyzes hundreds of proteins from a small blood sample and enables to determine whether specific proteins are linked with amyloid burden in the brain. Investigators measured brain amyloid with the help of PET scans and Pittsburgh Compound B that binds to amyloid plaques. During the investigation, authors observed that the amount the apolipoprotein E, or ApoE protein was strongly associated with the level of beta amyloid in the brain.

High blood levels of the protein probably had dramatically greater deposits of amyloid in the medial temporal lobe. This region of the brain seems to be vital for memory function. Madhav Thambisetty, M.D., Ph.D., of the Intramural Research Program at the National Institute on Aging (NIA), part of the NIH, lead author on the study and colleagues claim that the APOE gene is the most robust genetic risk factor for late-onset Alzheimer’s. Changing blood levels of ApoE protein presumably correlate with pathological alterations in the brain over time.

The study is published in the December 20, 2010, issue of the Journal of Alzheimer’s Disease.