Cerebrospinal fluid and serum d-serine concentrations are unaltered across the whole clinical spectrum of Alzheimer's disease

• Published in: Biochimica et biophysica acta. Proteins and proteomics Vol. 1868; no. 12; p. 140537
• Main Authors: Nuzzo, Tommaso, Miroballo, Mattia, Casamassa, Alessia, Mancini, Andrea, Gaetani, Lorenzo, Nisticò, Robert, Eusebi, Paolo, Katane, Masumi, Homma, Hiroshi, Calabresi, Paolo, Errico, Francesco, Parnetti, Lucilla, Usiello, Alessandro
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2020
• Subjects: Aged; Aged, 80 and over; Alzheimer disease; Alzheimer Disease - blood; Alzheimer Disease - cerebrospinal fluid; Alzheimer Disease - diagnosis; Alzheimer's disease; Amyloid beta-Peptides - blood; Amyloid beta-Peptides - cerebrospinal fluid; amyloidosis; Aspartic Acid - blood; Aspartic Acid - cerebrospinal fluid; Biomarker; Biomarkers; blood serum; Brain - metabolism; Brain - pathology; cerebrospinal fluid; cortex; D-amino acids; Dementia; Female; Humans; Male; Mild cognitive impairment; neurons; Organ Specificity; Postpartum Period; Prognosis; serine; Serine - blood; Serine - cerebrospinal fluid; tau Proteins - blood; tau Proteins - cerebrospinal fluid; D-amino acids; Biomarker; Mild cognitive impairment; Alzheimer's disease; Dementia
• ISSN: 1570-9639; 1878-1454; 1878-1454
• DOI: 10.1016/j.bbapap.2020.140537

The diagnosis of Alzheimer's disease (AD) relies on the presence of amyloidosis and tauopathy, as reflected in cerebrospinal fluid (CSF), independently from the clinical stage. Recently, CSF d-serine has been proposed as a possible new AD biomarker, reflecting dysfunctional activation of neuronal glutamatergic N-methyl-d-aspartate receptor (NMDAR). In this study, we measured blood serum and CSF concentration of two NMDAR modulators, such as d-serine and d-aspartate, in a cohort of drug-free subjects encompassing the whole AD clinical spectrum. In addition, we also analyzed d-serine levels in a cohort of post-mortem AD and control cortex samples. We reported unaltered serum and CSF concentrations of d-serine and d-aspartate in AD patients both during the AD progression and compared to non-demented controls. Accordingly, no correlation was detected between serum or CSF d-serine content and mini-mental state examination or Clinical Dementia Rating. Similarly, cortical d-serine levels were also unaltered in post-mortem samples of AD patients. Overall, our results failed to confirm previous findings indicating the CSF d-serine as a novel biomarker for AD. •CSF d-serine has been proposed as possible new Alzheimer's Disease (AD) biomarker.•CSF and serum content of d-serine were unaltered in Alzheimer's Disease patients.•No correlation was found between CSF d-serine and MMSE or CDR scores.•Our study does not confirm CSF d-serine as a novel biomarker for AD.