Matrix Metalloproteinase-2 and Epidermal Growth Factor are Decreased in Platelets of Alzheimer Patients

Alzheimer's disease (AD) is the most prevalent type of dementia. Despite considerable advances in diagnostic accuracy, diagnostic procedures that are easily accessible are still sorely needed. Blood biomarkers are therefore in the focus of research. Platelets contain a high concentration of the amyloid precursor protein (APP), which has been mentioned as a potentially useful diagnostic marker. The aim of the present study was to analyze various cell adhesion molecules (CAMs), cytokines, growth factors, and matrix metalloproteinases (MMPs) in platelets of AD and mild cognitively impaired (MCI) patients as compared to healthy controls. Our data show a significant decrease in the levels of epidermal growth factor (EGF) and of MMP-2 in platelets of AD patients and decreased levels of MMP-2 in MCI. The APP ratio was slightly but not significantly decreased in AD patients, whereas CD40L and serotonin were unchanged. Our findings demonstrate specific changes in AD platelets. Whether these biomarkers can be established as potential early diagnostic biomarkers for AD remains to be established in longitudinal studies.