title: Cerebrospinal fluid tau and beta-amyloid: how well do these biomarkers reflect autopsy-confirmed dementia diagnoses?
abstract: BACKGROUND
  Tau and beta-amyloid (Abeta) are proposed diagnostic biomarkers for Alzheimer disease (AD). Previous studies report their relationship to clinical diagnoses of AD and other dementias. To understand their value as predictors of disease-specific pathology, levels determined during life must be correlated with definitive diagnoses in mixed dementia groups and cognitively normal subjects.
  
  
  OBJECTIVE
  To correlate antemortem cerebrospinal fluid (CSF) tau and Abeta levels with definitive dementia diagnosis in a diverse group of patients; to calculate statistics for CSF tau and Abeta.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Ten clinics experienced in the diagnosis of neurodegenerative dementias. Patients One hundred six patients with dementia and 4 cognitively normal subjects with a definitive diagnosis, and 69 clinically diagnosed cognitively normal subjects.
  
  
  METHODS
  Correlation of CSF tau and Abeta with final diagnosis.
  
  
  RESULTS
  Mean tau level was 612 pg/mL for the 74 patients with AD, 272 pg/mL for 10 patients with frontal dementia, 282 pg/mL for 3 patients with dementia with Lewy bodies, and 140 pg/mL for 73 cognitively normal control subjects. Tau was less than 334 pg/mL for 20 patients with AD. Abeta42 was reduced in patients with AD (61 fmol/mL) compared with patients with frontal dementia (133 fmol/mL) and control subjects (109 fmol/mL), but not compared with patients with dementia with Lewy bodies (14 fmol/mL) or prion disease (60 fmol/mL).
  
  
  CONCLUSIONS
  Elevated CSF tau levels are associated with AD pathology and can help discriminate AD from other dementing disorders. However, some patients with AD have a level less than the mean +/- 2 SDs of the cognitively normal cohort.
authors.affiliation: Departments of Neurology, Center for Neuerodegenerative Disease Research, alzheimer's Disease Center, Philadelphia, PA 19104, USA. clarkc@mail.med.upenn.edu
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Clark
authors.forename: Sharon
authors.initials: S
authors.lastname: Xie
authors.forename: Jesse
authors.initials: J
authors.lastname: Chittams
authors.forename: Douglas
authors.initials: D
authors.lastname: Ewbank
authors.forename: Elaine
authors.initials: E
authors.lastname: Peskind
authors.forename: Douglas
authors.initials: D
authors.lastname: Galasko
authors.forename: John C
authors.initials: JC
authors.lastname: Morris
authors.forename: Daniel W
authors.initials: DW
authors.lastname: McKeel
authors.forename: Martin
authors.initials: M
authors.lastname: Farlow
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Weitlauf
authors.forename: Joseph
authors.initials: J
authors.lastname: Quinn
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Kaye
authors.forename: David
authors.initials: D
authors.lastname: Knopman
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Arai
authors.forename: Rachelle S
authors.initials: RS
authors.lastname: Doody
authors.forename: Charles
authors.initials: C
authors.lastname: DeCarli
authors.forename: Susan
authors.initials: S
authors.lastname: Leight
authors.forename: Virginia M-Y
authors.initials: VM
authors.lastname: Lee
authors.forename: John Q
authors.initials: JQ
authors.lastname: Trojanowski
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D019540:Area Under Curve; D015415:Biomarkers / Q000134:cerebrospinal fluid; D016022:Case-Control Studies; D015331:Cohort Studies; D003704:Dementia / Q000134:cerebrospinal fluid* / Q000175:diagnosis*; D006801:Humans; D020961:Lewy Body Disease / Q000134:cerebrospinal fluid; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D016875:tau Proteins / Q000134:cerebrospinal fluid*
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D016875:tau Proteins