title: CSF biomarker levels in early and late onset Alzheimer's disease.
abstract: OBJECTIVE
  To compare CSF levels of beta-amyloid 1-42 (Abeta(1-42)), total tau (tau) and tau phosphorylated at threonine 181 (ptau-181) between AD patients and controls according to age.
  
  
  METHODS
  248 AD patients (48% men) and 127 controls (51% men, 22 volunteers and 105 subjective complainers) underwent lumbar puncture. Both patients and controls were divided into a young (<65 years) and old (>or=65 years) group.
  
  
  RESULTS
  All three biomarkers showed main effects of diagnosis (p<0.001). There was an interaction between diagnosis and age for all three biomarkers (p<0.05), as old controls had lower Abeta(1-42) and higher (p)tau than young controls (Abeta(1-42) 699+/-250 versus 866+/-191pg/ml, tau 408+/-245 versus 243+/-102pg/ml, ptau-181 60+/-28 versus 42+/-15pg/ml), but there was no difference according to age among AD patients (Abeta(1-42) 451+/-178 versus 425+/-146pg/ml, tau 741+/-460 versus 798+/-467pg/ml, ptau-181 91+/-42 versus 91+/-41pg/ml).
  
  
  CONCLUSIONS
  We found that the older control group had lower Abeta(1-42) and higher (p)tau compared to the younger control group. This suggests that older individuals may have AD pathology, even in the absence of objective cognitive impairment.
authors.affiliation: Alzheimer Center and Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands. femke.bouwman@vumc.nl
authors.forename: Femke H
authors.initials: FH
authors.lastname: Bouwman
authors.forename: Niki S M
authors.initials: NS
authors.lastname: Schoonenboom
authors.forename: Nicolaas A
authors.initials: NA
authors.lastname: Verwey
authors.forename: Evert J
authors.initials: EJ
authors.lastname: van Elk
authors.forename: Astrid
authors.initials: A
authors.lastname: Kok
authors.forename: Marinus A
authors.initials: MA
authors.lastname: Blankenstein
authors.forename: Philip
authors.initials: P
authors.lastname: Scheltens
authors.forename: Wiesje M
authors.initials: WM
authors.lastname: van der Flier
mesh_terms: D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000375:Aging / Q000134:cerebrospinal fluid*; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D000704:Analysis of Variance; D015415:Biomarkers / Q000134:cerebrospinal fluid; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D010766:Phosphorylation; D011569:Psychiatric Status Rating Scales; D013129:Spinal Puncture; D016875:tau Proteins / Q000134:cerebrospinal fluid* / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; C054369:MAPT protein, human; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins