title: Critical Comparison of Different Biomarkers for Alzheimer's Disease in a Clinical Setting.
abstract: BACKGROUND
  Biomarkers of neuronal injury and amyloid pathology play a pivotal role in the diagnosis of Alzheimer's disease (AD). The degree of AD biomarker congruence is still unclear in clinical practice.
  
  
  OBJECTIVE
  Diagnosis of AD with regard to the congruence of the clinical diagnosis and different biomarkers.
  
  
  METHODS
  In this prospective cross-sectional observational study, 54 patients with mild cognitive impairment or dementia due to AD or not due to AD were investigated. Biomarkers of neuronal injury were medial temporal lobe atrophy (MTA) on magnetic resonance imaging (MRI) and tau concentration in the cerebrospinal fluid (CSF). CSF Aβ(1-42) and amyloid-targeting positron emission tomography (PET) were considered as biomarkers of amyloid pathology.
  
  
  RESULTS
  Forty cases were diagnosed as AD and 14 cases were diagnosed as non-AD based on clinical and routine MRI assessment. AD cases had higher MTA scores, higher levels of CSF tau and lower levels of CSF Aβ(1- 42), and higher amyloid load on PET compared to the non-AD group. In the AD group, completely consistently pathological biomarkers were found in 32.5% , non-pathological in 5% . In 62.5% the findings were inconsistent. Congruence of biomarkers was 67.5% for neuronal injury and for amyloid dysfunction, respectively. In two patients, clinical diagnosis switched to non-AD due to completely consistent non-pathological biomarker findings. The criteria of the international working group were met in 75.0% .
  
  
  CONCLUSIONS
  Surprisingly, the number of completely congruent biomarkers was relatively low. Interpretation of AD biomarkers is complicated by multiple biomarker constellations. However, the level of biomarker consistency required to reliably diagnose AD remains uncertain.
authors.affiliation: Department of Psychiatry, University of Leipzig, Leipzig, Germany.|Department of Neurology, University of Leipzig, Leipzig, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Weise
authors.affiliation: Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Solveig
authors.initials: S
authors.lastname: Tiepolt
authors.affiliation: Department of Psychiatry, University of Leipzig, Leipzig, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Awissus
authors.affiliation: Department of Neuroradiology, University of Leipzig, Leipzig, Germany.
authors.forename: Karl-Titus
authors.initials: KT
authors.lastname: Hoffmann
authors.affiliation: Department of Neuroradiology, University of Leipzig, Leipzig, Germany.
authors.forename: Donald
authors.initials: D
authors.lastname: Lobsien
authors.affiliation: Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Kaiser
authors.affiliation: Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Henryk
authors.initials: H
authors.lastname: Barthel
authors.affiliation: Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Osama
authors.initials: O
authors.lastname: Sabri
authors.affiliation: Department of Psychiatry, University of Leipzig, Leipzig, Germany.
authors.forename: Hermann-Josef
authors.initials: HJ
authors.lastname: Gertz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D000682:Amyloid / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D010865:Pilot Projects; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D016875:tau Proteins / Q000134:cerebrospinal fluid*
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides; D015415:Biomarkers; C054369:MAPT protein, human; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins
keywords: Alzheimer’s disease; biomarkers; cerebrospinal fluid; dementia; magnetic resonance imaging; positron emission tomography