Scientists at the University of Brescia, Italy have moved one step closer to developing a diagnostic exam that can definitively diagnose a person with Alzheimer’s disease in the early stages of the ailment. A new blood test that measures amyloid precursor proteins in blood platelets may be useful for the identification of preclinical Alzheimer’s patients.

In a study published in the January 2002, edition of the Archives of Neurology, lead researcher Alessandro Padovani, M.D., Ph.D, set out to evaluate the levels of amyloid precursor protein (APP) in blood platelets as a marker for early identification of Alzheimer’s disease. APP is the substance known to accumulate in the minds of Alzheimer’s patients and produce memory loss. Researchers are finding that APP is found on, and can be measured with platelets, the small disks in the blood stream that assist in blood clotting.

The study included 86 participants that had been previously diagnosed with mild memory problems, but were not severe enough to be classified as full blown Alzheimer’s disease or dementia. Specifically, 35 patients had mild Alzheimer’s disease, 21 patients had very mild Alzheimer’s disease, and 30 subjects had mild cognitive impairment. They were then evaluated against 25 healthy patients of the same age.

Researchers measured the levels of APP in the blood stream by using a Western blot analysis, and determined that Alzheimer’s patients had unusually low levels of APP in their platelets. The results showed that new test was approximately 90% successful at identifying patients with mild Alzheimer’s or mild cognitive impairment.

“Alteration of platelet APP forms is an early event in Alzheimer’s disease, and the measurement of APP [ratios] may be useful for the identification of preclinical Alzheimer’s disease in patients with mild cognitive impairment,” the researchers stated in the study.

The test is still in the experimental stages and is not yet an option for physicians in making a diagnosis; however, the examination holds great potential as a future detector of Alzheimer’s disease, which can help doctors to identify the disease in its early stages and begin treatment when it is most effective.