title: Cerebrospinal Fluid Biomarkers Predict Clinical Evolution in Patients with Subjective Cognitive Decline and Mild Cognitive Impairment.
abstract: BACKGROUND
  Determination of Alzheimer's disease (AD) by cerebrospinal fluid (CSF) biomarkers - 42-amino-acid amyloid-β (Aβ42), total tau and phosphorylated tau (p-tau) - has demonstrated high validity for detecting AD neuropathological changes. However, their prognostic utility to predict the onset of dementia in predementia subjects is still questioned. We aimed to study the prospective clinical evolution of a group of subjects with subjective cognitive decline (SCD) or mild cognitive impairment (MCI) and to determine the prognostic capacity of AD CSF biomarkers.
  
  
  METHODS
  149 subjects with MCI or SCD, not meeting dementia criteria, underwent a prospective clinical, neuropsychological and CSF biomarker study. Patients were initially classified as SCD or MCI following internationally accepted criteria. CSF sampling was obtained and analysed following consensus protocols. Neuropsychological and clinical evaluations were conducted at the follow-up. Statistical analysis considering the final clinical diagnosis, regression analysis to define risk factors and survival curves for progression were made.
  
  
  RESULTS
  72.4% of subjects (83% MCI and 27% SCD) with a pathological CSF ratio (Aβ42/p-tau) met criteria for dementia during the 5-year follow-up versus 18.7% of subjects from the group with a normal ratio. The pathological CSF ratio was a powerful marker of risk for AD dementia (OR 27.1; 95% CI 10.3-71.2). Kaplan-Meier survival curves showed that only 15% of subjects with a pathological CSF ratio remained free of AD dementia at 5 years of follow-up. All subjects who reverted to normal cognition presented a normal CSF profile at baseline.
  
  
  CONCLUSIONS
  An abnormal AD CSF biomarker profile in predementia subjects is a powerful predictor of cognitive and/or functional decline in the medium term.
authors.affiliation: School of Medicine, University of Barcelona, Barcelona, Spain.
authors.forename: Alba
authors.initials: A
authors.lastname: Sierra-Rio
authors.forename: Mircea
authors.initials: M
authors.lastname: Balasa
authors.forename: Jaume
authors.initials: J
authors.lastname: Olives
authors.forename: Anna
authors.initials: A
authors.lastname: Antonell
authors.forename: Alex
authors.initials: A
authors.lastname: Iranzo
authors.forename: Magda
authors.initials: M
authors.lastname: Castellví
authors.forename: Beatriz
authors.initials: B
authors.lastname: Bosch
authors.forename: Oriol
authors.initials: O
authors.lastname: Grau-Rivera
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Fernandez-Villullas
authors.forename: Lorena
authors.initials: L
authors.lastname: Rami
authors.forename: Albert
authors.initials: A
authors.lastname: Lladó
authors.forename: Raquel
authors.initials: R
authors.lastname: Sánchez-Valle
authors.forename: José Luis
authors.initials: JL
authors.lastname: Molinuevo
mesh_terms: D000368:Aged; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D001057:Apolipoproteins E / Q000235:genetics; D015415:Biomarkers / Q000134:cerebrospinal fluid; D003072:Cognition Disorders / Q000134:cerebrospinal fluid* / Q000235:genetics; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D011379:Prognosis; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D016875:tau Proteins / Q000134:cerebrospinal fluid*
chemical_list: D016229:Amyloid beta-Peptides; D001057:Apolipoproteins E; D015415:Biomarkers; C054369:MAPT protein, human; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins