title: Rethinking on the concept of biomarkers in preclinical Alzheimer's disease.
abstract: The neuropathological processes eventually leading to Alzheimer's disease (AD) are thought to start decades before the appearance of clinical symptoms and the clinical diagnosis of AD dementia. The term "preclinical AD" has been recently introduced to identify this "silent stage" of AD, when the disease is already present, but symptoms are not yet clinically evident. Advances in AD biomarkers have dramatically improved the ability to detect AD pathological processes in vivo in cognitively intact subjects, thus demonstrating the presence of AD pathology in the preclinical phase. This review focuses on the recent advances in the field of neuroimaging and CSF AD biomarkers specifically in the preclinical phase of AD, and aims to discuss the significance that such biomarkers could have in cognitively intact subjects. Even though the use of such biomarkers in AD preclinical phase has contributed to improve our understanding of AD early pathological processes, it raised also a number of new challenges that still remain to be overcome, such as a better definition of the clinical and individual significance of currently known biomarkers in preclinical stages and the development of novel biomarkers of different early AD-related events.
authors.affiliation: Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", Nuclear Medicine Unit, University of Florence, Largo Brambilla 3, 50134, Florence, FI, Italy. valentina.berti@unifi.it.
authors.forename: Valentina
authors.initials: V
authors.lastname: Berti
authors.affiliation: Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", Nuclear Medicine Unit, University of Florence, Largo Brambilla 3, 50134, Florence, FI, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Polito
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Largo Brambilla 3, 50134, Florence, FI, Italy.
authors.forename: Gemma
authors.initials: G
authors.lastname: Lombardi
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Largo Brambilla 3, 50134, Florence, FI, Italy.
authors.forename: Camilla
authors.initials: C
authors.lastname: Ferrari
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Largo Brambilla 3, 50134, Florence, FI, Italy.
authors.forename: Sandro
authors.initials: S
authors.lastname: Sorbi
authors.affiliation: Department of Biomedical, Experimental and Clinical Sciences "Mario Serio", Nuclear Medicine Unit, University of Florence, Largo Brambilla 3, 50134, Florence, FI, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Pupi
mesh_terms: D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000000981:diagnostic imaging*; D015415:Biomarkers / Q000134:cerebrospinal fluid*; D018450:Disease Progression; D006801:Humans; D059906:Neuroimaging
chemical_list: D015415:Biomarkers
keywords: Amyloid; Biomarkers; CSF; Neuroimaging; Preclinical AD