Novel AD biomarker based on platelets tau: Expanding to plasma detection

Background Alzheimer’s disease (AD) is the most prevalent cause of dementia in the elderly. One of the major drawbacks of this disease is the lack of molecular biomarkers that could provide of an early detection, as the ones currently available are invasive (CSF biomarkers), not cost‐efficient (neuroimaging, PET scan) and do not provide an early detection. In this work we propose the novel biomarker Alz‐tau®, based on platelet tau, as a non‐invasive and cost‐efficient way for early detection of pathological events that may lead Alzheimer’s disease. Methods Plasma samples were obtained by centrifugation. Platelets were obtained from blood samples of AD patients and controls, lysed to obtain protein extracts and further processed for a western blot analysis. The immuno‐ detection was performed with a novel monoclonal antibody tau51, which detects two variants of tau protein: a high molecular weight variant (HMW) and a low molecular weight variant (LMW). The results obtained were subjected to a densitometric analysis with ImageJ and the algorithm HWM/LMW was obtained. Results We demonstrated that in platelets the algorithm HWM/LMW was statistically higher in AD patients when compared to controls. Similar results were obtained in plasma. Likewise, the platelet biomarker has a proven sensitivity of 71.43% and a specificity of 69.23%, while a sensibility of 80% and specificity of 66.5% was found in plasma samples. Conclusions Here, we demonstrate the efficiency and functionality of of a novel, non‐invasive, and cost‐efficient biomarker for early detection of AD, based on 4 clinical trials. The most relevant feature of this biomarker is that it is able to detect alterations before the patient presents any symptoms, thus it would be highly beneficial for prevention of AD.