title: Targeted lipidomics distinguishes patient subgroups in mild cognitive impairment (MCI) and late onset Alzheimer's disease (LOAD).
abstract: BACKGROUND
  Diverse research approaches support the concept that a clinical diagnosis of Late-Onset Alzheimer's Disease (LOAD) does not distinguish between subpopulations with differing neuropathologies, including dementia patients with amyloid deposition and dementia patients without amyloid deposition but with cortical thinning. Mild cognitive impairment (MCI) is generally considered the prodromal phase for LOAD, however, while a number of studies have attempted to define plasma biomarkers for the conversion of MCI to LOAD, these studies have not taken into account the heterogeneity of patient cohorts within a clinical phenotype.
  
  
  METHODS
  Studies of MCI and LOAD in several laboratories have demonstrated decrements in ethanolamine plasmalogen levels in plasma and brain and increased levels of diacylglycerols in plasma and brain. To further extend these studies and to address the issue of heterogeneity in MCI and LOAD patient groups we investigated the levels of diacylglycerols and ethanolamine plasmalogens in larger cohorts of patients utilizing, high-resolution (0.2 to 2 ppm mass error) mass spectrometry.
  
  
  RESULTS
  For the first time, our lipidomics data clearly stratify both MCI and LOAD subjects into 3 different patient cohorts within each clinical diagnosis. These include i) patients with lower circulating ethanolamine plasmalogen levels; ii) patients with augmented plasma diacylglycerol levels; and iii) patients with neither of these lipid alterations.
  
  
  CONCLUSIONS
  These represent the first serum biochemical data to stratify MCI and LOAD patients, advancing efforts to biochemically define patient heterogeneity in cognitive disorders.
  
  
  CONCLUSIONS
  Lipidomics offers a new approach for identifying biomarkers and biological targets in cognitive disorders.
authors.affiliation: Metabolomics Unit, Dept. of Physiology and Pharmacology, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, 6965 Cumberland Gap Pkwy., Harrogate, TN 37752, United States.
authors.forename: Paul L
authors.initials: PL
authors.lastname: Wood
authors.affiliation: Metabolomics Unit, Dept. of Physiology and Pharmacology, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, 6965 Cumberland Gap Pkwy., Harrogate, TN 37752, United States.
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Locke
authors.affiliation: Metabolomics Unit, Dept. of Physiology and Pharmacology, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, 6965 Cumberland Gap Pkwy., Harrogate, TN 37752, United States.
authors.forename: Patrick
authors.initials: P
authors.lastname: Herling
authors.affiliation: Medical Science Dept., Cardiopulmonary and Internal Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Angelina
authors.initials: A
authors.lastname: Passaro
authors.affiliation: Medical Science Dept., Cardiopulmonary and Internal Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Vigna
authors.affiliation: Medical Science Dept., Cardiopulmonary and Internal Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Volpato
authors.affiliation: Department of Life Sciences and Biotechnology, University of Ferrara, Via Luigi Borsari 46, 44121, Ferrara, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Valacchi
authors.affiliation: Department of Biomedical and Specialist Surgical Sciences, Section of Medical Biochemistry, Molecular Biology and Genetics, University of Ferrara, via Borsari 46, 44121 Ferrara, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Cervellati
authors.affiliation: Medical Science Dept., Cardiopulmonary and Internal Medicine, University of Ferrara, Ferrara, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Zuliani
keywords: AD; DAG; MCI; Patient stratification; Plasmalogens