title: The ratio of phosphatidylcholines to lysophosphatidylcholines in plasma differentiates healthy controls from patients with Alzheimer's disease and mild cognitive impairment.
abstract: BACKGROUND
  Metabolomic processes have been identified as being strongly linked to the development of Alzheimer's disease (AD). Thus, lipid metabolites appear to be highly useful as diagnostic substrates for the diagnosis of AD and mild cognitive impairment (MCI) in plasma.
  
  
  METHODS
  We analyzed plasma samples from controls (n = 35), MCI (n = 33), and AD patients (n = 43) using the AbsoluteIDQ p180 Kit (Biocrates Life Sciences), which included quantitative analysis of 40 acylcarnitines, 21 amino acids, 19 biogenic amines, 15 sphingolipids, 90 glycerophospholipids, and sum of hexoses.
  
  
  RESULTS
  We found that individual lipid metabolites can differentiate controls from MCI and AD with relevant significance. However, the ratio between PC aa C34:4 and lysoPC a C18:2 differentiates controls from MCI (P= .0000007) and from AD (P= .0000009) with greater significance.
  
  
  CONCLUSIONS
  The results provide evidence that the ratio of these two lipid metabolites is useful for diagnosing MCI and AD with an accuracy of 82%-85%.
authors.affiliation: Biocrates Life Sciences AG, Innsbruck, Austria.
authors.forename: Kristaps
authors.initials: K
authors.lastname: Klavins
authors.affiliation: Biocrates Life Sciences AG, Innsbruck, Austria.
authors.forename: Therese
authors.initials: T
authors.lastname: Koal
authors.affiliation: Biocrates Life Sciences AG, Innsbruck, Austria.
authors.forename: Guido
authors.initials: G
authors.lastname: Dallmann
authors.affiliation: State Psychiatric Hospital, Hall in Tirol, Austria.
authors.forename: Josef
authors.initials: J
authors.lastname: Marksteiner
authors.affiliation: Department of Psychiatry and Psychotherapy, University Clinic of General and Social Psychiatry, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Georg
authors.initials: G
authors.lastname: Kemmler
authors.affiliation: Department of Psychiatry and Psychotherapy, University Clinic of General and Social Psychiatry, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Humpel
keywords: Alzheimer’s disease; Diagnosis; Metabolomics; Mild cognitive impairment; Plasma