title: [A new approach to the Alzheimer's disease diagnosis with biomarkers: description of the AD-CSF-Index].
abstract: BACKGROUND
  Studies with cerebrospinal fluid (CSF) biomarkers in patients with confirmed Alzheimer's disease (AD) pathology have shown that decreased levels of Abeta(1-42) and increased levels of tau and p-tau, are a specific feature of the AD type pathology.
  
  
  OBJECTIVE
  To describe a new method for determining the AD-CSF-Index, through the values obtained with CSF biomarkers and thus optimize AD diagnosis.
  
  
  METHODS
  We recruited a total of 61 subjects in the Alzheimer's unit and other cognitive disorders of the Hospital Clinic of Barcelona, of which 42 were cognitively healthy controls and 19 were diagnosed with AD according to the new research criteria proposed by Dubois et al: episodic memory impairment and atrophy of medial temporal areas using the Scheltens scale. The AD-CSF-Index was constructed from the addition of normalized values between the minimum and maximum values of amyloid and tau proteins.
  
  
  RESULTS
  Subjects diagnosed with AD presented a significantly higher AD-CSF-Index (1.17) than healthy subjects (0.72) (p < 0.001; 95% CI of the difference = 0.32-0.57). In the ROC analysis, the AD-CSF-Index obtained the best results of all, showing the cut-off point of 0.93 a sensitivity of 92% and a specificity of 89%.
  
  
  CONCLUSIONS
  The AD-CSF-Index represents a novel approach that combines optimally the observed CSF biomarkers alterations, which allows establishing the diagnosis of AD with high sensitivity and specificity.
authors.affiliation: Unidad de Alzheimer y otros trastornos cognitivos, Hospital Clínic, Barcelona, España. jlmoli@clinic.ub.es
authors.forename: José L
authors.initials: JL
authors.lastname: Molinuevo
authors.forename: Juan D
authors.initials: JD
authors.lastname: Gispert
authors.forename: Jesús
authors.initials: J
authors.lastname: Pujol
authors.forename: Santiago
authors.initials: S
authors.lastname: Rojas
authors.forename: Albert
authors.initials: A
authors.lastname: Lladó
authors.forename: Mircea
authors.initials: M
authors.lastname: Balasa
authors.forename: Anna
authors.initials: A
authors.lastname: Antonell
authors.forename: Raquel
authors.initials: R
authors.lastname: Sánchez-Valle
authors.forename: Lorena
authors.initials: L
authors.lastname: Rami
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D006801:Humans; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D016875:tau Proteins / Q000134:cerebrospinal fluid*
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins