Biomarkers for the early diagnosis of Alzheimer’s disease: The challenge of XXI century

AD is the most common form of dementia among the aging population. The neuropathological alterations of AD are represented by the neurofibrillary tangles and extracellular amyloid plaques formation. These two hallmarks are routinely used as biomarkers for AD diagnosis and can allow the identification of the pathology in a late phase. The urgent need to develop probes for PET analysis that can be used in an early diagnosis of this disorder opened a new scenario in which new biomarkers involved in the first step of AD can be easily detected. Recently, an increasing number of studies indicated as new biomarkers P-gp, TLR4, MIR and free serum copper that are involved in the onset of AD. It has been extensively reported that a P-gp dysfunction in brain can be considered one of the causes of the ADaccumulation in brain parenchyma and that the up-regulation of inflammatory gene expression and inflammatory signaling due to MIR and TLR4 modulated the development and the progression of AD.