TY - JOUR

T1 - Diagnostic biomarkers for Alzheimer’s disease using non‐invasive specimens

AU - Paraskevaidi, Maria

AU - Allsop, David

AU - Karim, Salman

AU - Martin, Francis

AU - Crean, StJohn

PY - 2020/6/1

Y1 - 2020/6/1

N2 - Studies in the field of Alzheimer’s disease (AD) have shown the emergence of biomarkers in biologic fluids that hold great promise for the diagnosis of the disease. A diagnosis of AD at a presymptomatic or early stage may be the key for a successful treatment, with clinical trials currently investigating this. It is anticipated that preventative and therapeutic strategies may be stage‐dependent, which means that they have a better chance of success at a very early stage-before critical neurons are lost. Several studies have been investigating the use of cerebrospinal fluid (CSF) and blood as clinical samples for the detection of AD with a number of established core markers, such as amyloid beta (Aβ), total tau (T‐tau) and phosphorylated tau (P‐tau), being at the center of clinical research interest. The use of oral samples-including saliva and buccal mucosal cells-falls under one of the least‐investigated areas in AD diagnosis. Such samples have great potential to provide a completely non‐invasive alternative to current CSF and blood sampling procedures. The present work is a thorough review of the results and analytical approaches, including proteomics, metabolomics, spectroscopy and microbiome analyses that have been used for the study and detection of AD using salivary samples and buccal cells. With a few exceptions,most of the studies utilizing oral samples were performed in small cohorts, which in combination with the existence of contradictory results render it difficult to come to a definitive conclusion on the value of oral markers. Proteins such as Aβ, T‐tau and P‐tau, as well as small metabolites, were detected in saliva and have shown some potential as future AD diagnostics. Future large‐cohortstudies and standardization of sample preparation and (pre‐)analytical factors are necessary to determine the use of these non‐invasive samples as a diagnostic tool for AD.

AB - Studies in the field of Alzheimer’s disease (AD) have shown the emergence of biomarkers in biologic fluids that hold great promise for the diagnosis of the disease. A diagnosis of AD at a presymptomatic or early stage may be the key for a successful treatment, with clinical trials currently investigating this. It is anticipated that preventative and therapeutic strategies may be stage‐dependent, which means that they have a better chance of success at a very early stage-before critical neurons are lost. Several studies have been investigating the use of cerebrospinal fluid (CSF) and blood as clinical samples for the detection of AD with a number of established core markers, such as amyloid beta (Aβ), total tau (T‐tau) and phosphorylated tau (P‐tau), being at the center of clinical research interest. The use of oral samples-including saliva and buccal mucosal cells-falls under one of the least‐investigated areas in AD diagnosis. Such samples have great potential to provide a completely non‐invasive alternative to current CSF and blood sampling procedures. The present work is a thorough review of the results and analytical approaches, including proteomics, metabolomics, spectroscopy and microbiome analyses that have been used for the study and detection of AD using salivary samples and buccal cells. With a few exceptions,most of the studies utilizing oral samples were performed in small cohorts, which in combination with the existence of contradictory results render it difficult to come to a definitive conclusion on the value of oral markers. Proteins such as Aβ, T‐tau and P‐tau, as well as small metabolites, were detected in saliva and have shown some potential as future AD diagnostics. Future large‐cohortstudies and standardization of sample preparation and (pre‐)analytical factors are necessary to determine the use of these non‐invasive samples as a diagnostic tool for AD.

KW - Alzheimer’s disease

KW - diagnostics

KW - biomarkers

KW - early detection

KW - salivary markers

KW - buccal cells

U2 - 10.3390/jcm9061673

DO - 10.3390/jcm9061673

M3 - Journal article

VL - 9

JO - Journal of Clinical Medicine

JF - Journal of Clinical Medicine

SN - 2077-0383

IS - 6

M1 - 1673

ER -