title: Toward a reliable distinction between patients with mild cognitive impairment and Alzheimer-type dementia versus major depression.
abstract: BACKGROUND
  Cerebrospinal fluid (CSF) levels of soluble amyloid precursor protein (sAPP) and its alpha-secreted form (alpha-sAPP) were investigated as a means to distinguish between individuals with mild cognitive impairment (MCI) and Alzheimer-type dementia (DAT) and those with major depressive episode (MDE) showing secondary memory deficits.
  
  
  METHODS
  Twenty-seven patients with MCI, 32 with probable DAT, and 24 with MDE attending a memory clinic were studied. Cerebrospinal fluid levels of sAPP/amyloid precursor-like protein 2 (APLP2) and alpha-sAPP were detected by Western blotting.
  
  
  RESULTS
  Patients with MDE had the highest CSF levels of total sAPP/APLP2 as compared with MCI and DAT patients (p < .001); sAPP/APLP2 levels were higher in MCI than in DAT subjects. Whereas alpha-sAPP levels did not differ between the MCI and DAT groups, median levels of this peptide were significantly lower in MCI and DAT versus MDE patients.
  
  
  CONCLUSIONS
  Soluble amyloid precursor protein/APLP2 and alpha-sAPP concentrations in CSF can differentiate between DAT and MCI versus MDE, facilitating early ameliorative interventions and appropriate treatment regimens.
authors.affiliation: Max Planck Institute of Psychiatry, Munich, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Post
authors.forename: Nibal
authors.initials: N
authors.lastname: Ackl
authors.forename: Monika
authors.initials: M
authors.lastname: Rücker
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Schreiber
authors.forename: Elisabeth B
authors.initials: EB
authors.lastname: Binder
authors.forename: Marcus
authors.initials: M
authors.lastname: Ising
authors.forename: Annette
authors.initials: A
authors.lastname: Sonntag
authors.forename: Florian
authors.initials: F
authors.lastname: Holsboer
authors.forename: Osborne F X
authors.initials: OF
authors.lastname: Almeida
mesh_terms: D000328:Adult; D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid / Q000150:complications* / Q000175:diagnosis*; D053829:Amyloid Precursor Protein Secretases; D016564:Amyloid beta-Protein Precursor / Q000134:cerebrospinal fluid / Q000145:classification; D016282:Aspartic Acid Endopeptidases; D015153:Blotting, Western / Q000379:methods; D016009:Chi-Square Distribution; D003072:Cognition Disorders / Q000134:cerebrospinal fluid / Q000209:etiology*; D003865:Major Depressive Disorder / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D003937:Diagnosis, Differential; D010450:Endopeptidases / Q000134:cerebrospinal fluid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000134:cerebrospinal fluid
chemical_list: C084104:APLP2 protein, human; D016564:Amyloid beta-Protein Precursor; D009419:Nerve Tissue Proteins; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human