title: Cerebrospinal fluid Aβ40 is similarly reduced in patients with Frontotemporal Lobar Degeneration and Alzheimer's Disease.
abstract: Cerebrospinal fluid (CSF) biomarkers have been increasingly studied for dementia diagnosis, however the accuracy to distinguish between different forms of dementia is still unsatisfactory. In this study, the added value of another CSF Aβ-peptide (Aβ40), along with the core CSF markers t-Tau, p-Tau, and Aβ42, in the discrimination between two large dementia groups of Frontotemporal Lobar Degeneration (FTLD; n=107), Alzheimer's Disease (AD; n=107) and non-demented subjects (n=33) was evaluated. In FTLD, t-Tau and p-Tau were significantly increased in relation to controls, but lower than in AD, while Aβ42 was similar in FTLD and controls, but higher than in AD. Equally reduced Aβ40 levels were seen in both dementia groups, and therefore the combination of Aβ40 with core CSF biomarkers optimally discriminated FTLD and AD patients from controls. Aβ42 and t-Tau were selected as the best biomarker subset to differentiate FTLD from AD, with no added value of Aβ40 to the model. Diagnostic accuracy between FTLD and AD was still sub-optimal, with a significant percentage (23%) of FTLD patients, in particularly women, carrying an ApoE-ε4 allele, showing a CSF-AD biomarkers profile. Although CSF Aβ40 does not appear to have an additional value in the distinction between FTLD and AD, it increases the discrimination between subjects with dementia from controls. A CSF-AD biomarker profile can be seen in patients with a clinical phenotype of FTLD, reinforcing the need for autopsy confirmation.
authors.affiliation: Laboratory of Neurochemistry, Coimbra University Hospital, Portugal; Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Portugal. Electronic address: ines.baldeiras@sapo.pt.
authors.forename: Inês
authors.initials: I
authors.lastname: Baldeiras
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Portugal; Neurology Department, Coimbra University Hospital, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Santana
authors.affiliation: Laboratory of Neurochemistry, Coimbra University Hospital, Portugal; Center for Neuroscience and Cell Biology, University of Coimbra, Portugal.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Leitão
authors.affiliation: Laboratory of Neurochemistry, Coimbra University Hospital, Portugal; Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Portugal.
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Ribeiro
authors.affiliation: Laboratory of Neurochemistry, Coimbra University Hospital, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Pascoal
authors.affiliation: Neurology Department, Coimbra University Hospital, Portugal.
authors.forename: Diana
authors.initials: D
authors.lastname: Duro
authors.affiliation: Neurology Department, Coimbra University Hospital, Portugal.
authors.forename: Raquel
authors.initials: R
authors.lastname: Lemos
authors.affiliation: Neurology Department, Coimbra University Hospital, Portugal.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Santiago
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, Portugal.
authors.forename: Maria Rosário
authors.initials: MR
authors.lastname: Almeida
authors.affiliation: Laboratory of Neurochemistry, Coimbra University Hospital, Portugal; Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Portugal.
authors.forename: Catarina Resende
authors.initials: CR
authors.lastname: Oliveira
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D005260:Female; D057174:Frontotemporal Lobar Degeneration / Q000134:cerebrospinal fluid*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D012680:Sensitivity and Specificity
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40)
keywords: Ab40; Biomarkers; Cerebrospinal fluid; Diagnostic accuracy; Frontotemporal lobar degeneration, Alzheimer's Disease