title: Improved discrimination of AD patients using beta-amyloid(1-42) and tau levels in CSF.
abstract: OBJECTIVE
  To evaluate CSF levels of beta-amyloid(1-42) (Abeta42) alone and in combination with CSF tau for distinguishing AD from other conditions.
  
  
  METHODS
  At 10 centers in Europe and the United States, 150 CSF samples from AD patients were analyzed and compared with 100 CSF samples from healthy volunteers or patients with disorders not associated with pathologic conditions of the brain (CON), 84 patients with other neurologic disorders (ND), and 79 patients with non-Alzheimer types of dementia (NAD). Sandwich ELISA techniques were used on site for measuring Abeta42 and tau.
  
  
  RESULTS
  Median levels of Abeta42 in CSF were significantly lower in AD (487 pg/mL) than in CON (849 pg/mL; p = 0.001), ND (643 pg/mL; p = 0.001), and NAD (603 pg/mL; p = 0.001). Discrimination of AD from CON and ND was significantly improved by the combined assessment of Abeta42 and tau. At 85% sensitivity, specificity of the combined test was 86% (95% CI: 81% to 91%) compared with 55% (95% CI: 47% to 62%) for Abeta42 alone and 65% (95% CI: 58% to 72%) for tau. The combined test at 85% sensitivity was 58% (95% CI: 47% to 69%) specific for NAD. The APOE e4 gene load was negatively correlated with Abeta42 levels not only in AD but also in NAD.
  
  
  CONCLUSIONS
  The combined measure of CSF Abeta42 and tau meets the requirements for clinical use in discriminating AD from normal aging and specific neurologic disorders.
authors.affiliation: Innogenetics NV, Ghent, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Hulstaert
authors.forename: K
authors.initials: K
authors.lastname: Blennow
authors.forename: A
authors.initials: A
authors.lastname: Ivanoiu
authors.forename: H C
authors.initials: HC
authors.lastname: Schoonderwaldt
authors.forename: M
authors.initials: M
authors.lastname: Riemenschneider
authors.forename: P P
authors.initials: PP
authors.lastname: De Deyn
authors.forename: C
authors.initials: C
authors.lastname: Bancher
authors.forename: P
authors.initials: P
authors.lastname: Cras
authors.forename: J
authors.initials: J
authors.lastname: Wiltfang
authors.forename: P D
authors.initials: PD
authors.lastname: Mehta
authors.forename: K
authors.initials: K
authors.lastname: Iqbal
authors.forename: H
authors.initials: H
authors.lastname: Pottel
authors.forename: E
authors.initials: E
authors.lastname: Vanmechelen
authors.forename: H
authors.initials: H
authors.lastname: Vanderstichele
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D006801:Humans; D008875:Middle Aged; D011786:Quality Control; D016875:tau Proteins / Q000134:cerebrospinal fluid*
chemical_list: D016229:Amyloid beta-Peptides; D016875:tau Proteins