title: Performance of Cerebrospinal Fluid Biomarkers of Alzheimer Disease in a Memory Clinic in Norway.
abstract: BACKGROUND
  Although Alzheimer disease (AD) remains a clinical diagnosis, biomarkers are in use to support the diagnosis. Three cerebrospinal biomarkers, amyloid-β (Aβ), total tau (T-tau), and phospho tau (P-tau), reflect neuropathologic changes observed in AD patients.
  
  
  OBJECTIVE
  The aim of this study was to explore the performance of the cerebrospinal fluid biomarkers used in a memory clinic setting.
  
  
  METHODS
  We included 205 patients who had been through a standardized examination including lumbar puncture. Diagnoses were made blind to the results of the spinal fluid analyses.
  
  
  RESULTS
  By combining low Aβ and high T-tau or P-tau values, the sensitivity was 31.9% and the specificity was 92.5% when comparing patients with AD with other patients. In receiver operating characteristic analyses, the AUC for the Aβ was 0.78 (SE=0.04; 95% CI, 0.7-0.85), for T-tau 0.80 (SE=0.03; 95% CI, 0.73-0.86), and for P-tau 0.76 (SE=0.04; 95% CI, 0.69-0.83). A significant difference was found between the sexes, with higher values of Aβ among younger men (under 65 y of age) with AD [799.8 (SD=317.2) vs. 558.9 (SD=123.5) for women, P-value=0.003].
  
  
  CONCLUSIONS
  The present study found a lower performance of the biomarkers than reported previously.
authors.affiliation: *Department of Geriatric Medicine, Memory clinic, Oslo University Hospital, Oslo †Norwegian National Advisory Unit on Ageing and Health, Vestfold Hospital Trust, Tønsberg, Norway.
authors.forename: Anne-Brita
authors.initials: AB
authors.lastname: Knapskog
authors.forename: Knut
authors.initials: K
authors.lastname: Engedal
authors.forename: Anne
authors.initials: A
authors.lastname: Braekhus
mesh_terms: D000328:Adult; D000367:Age Factors; 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*; D060825:Cognitive Dysfunction / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway; D012680:Sensitivity and Specificity; D012737:Sex Factors; D016875:tau Proteins / Q000134:cerebrospinal fluid
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D016875:tau Proteins