title: Cerebrospinal fluid amyloid-β 2-42 is decreased in Alzheimer's, but not in frontotemporal dementia.
abstract: Alzheimer's dementia (AD) and frontotemporal dementias (FTD) are common and their clinical differential diagnosis may be complicated by overlapping symptoms, which is why biomarkers may have an important role to play. Cerebrospinal fluids (CSF) Aβ2-42 and 1-42 have been shown to be similarly decreased in AD, but 1-42 did not display sufficient specificity for exclusion of other dementias from AD. The objective of the present study was to clarify the diagnostic value of Aβ2-42 peptides for the differential diagnosis of AD from FTD. For this purpose, 20 non-demented disease controls (NDC), 22 patients with AD and 17 with FTD were comparatively analysed by a novel sequential aminoterminally and carboxyterminally specific immunoprecipitation protocol with subsequent Aβ-SDS-PAGE/immunoblot, allowing the quantification of peptides 1-38(ox), 2-40 and 2-42 along with Aβ 1-37, 1-38, 1-39, 1-40, 1-40(ox) and 1-42. CSF Aβ1-42 was decreased in AD as compared to NDC, but not to FTD. In a subgroup of the patients analyzed, the decrease of Abeta2-42 in AD was evident as compared to both NDC and FTD. Aβ1-38 was decreased in FTD as compared to NDC and AD. For differentiating AD from FTD, Aβ1-42 demonstrated sufficient diagnostic accuracies only when combined with Aβ1-38. Aβ2-42 yielded diagnostic accuracies of over 85 % as a single marker. These accuracy figures could be improved by combining Aβ2-42 to Aβ1-38. Aβ2-42 seems to be a promising biomarker for differentiating AD from other degenerative dementias, such as FTD.
authors.affiliation: Department of Psychiatry, University of Goettingen, von-Siebold-Str. 5, 37075, Goettingen, Germany. m.bibl@kliniken-essen-mitte.de
authors.forename: Mirko
authors.initials: M
authors.lastname: Bibl
authors.forename: Marion
authors.initials: M
authors.lastname: Gallus
authors.forename: Volker
authors.initials: V
authors.lastname: Welge
authors.forename: Hermann
authors.initials: H
authors.lastname: Esselmann
authors.forename: Stefanie
authors.initials: S
authors.lastname: Wolf
authors.forename: Eckart
authors.initials: E
authors.lastname: Rüther
authors.forename: Jens
authors.initials: J
authors.lastname: Wiltfang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D003866:Depressive Disorder / Q000134:cerebrospinal fluid / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D057180:Frontotemporal Dementia / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C442220:amyloid beta-protein (2-42)