title: Diagnostic use of cerebral and extracerebral oxysterols.
abstract: BACKGROUND
  24S-Hydroxycholesterol (24OHC) and 27-hydroxycholesterol (27OHC) are two structurally similar oxysterols of different origins--the former almost exclusively formed in the brain and the latter formed to a lesser extent in the brain than in most other organs. HYPOTHESIS TO BE TESTED: Neuronal damage and/or demyelination causes increased flux of 24OHC from the brain into the cerebrospinal fluid (CSF), whereas a defect blood-brain barrier causes increased flux of 27OHC from the circulation into the CSF.
  
  
  METHODS
  Isotope dilution-mass spectrometry was used to assay the two oxysterols in CSF and plasma from more than 250 patients with different neurological and geriatric diseases.
  
  
  RESULTS
  The CSF-levels of the two oxysterols were much more affected by the different diseases than the plasma levels. Patients with active demyelinating diseases had increased levels of 24OHC in CSF with a relatively high 24OHC/27OHC ratio. Patients with meningitis in general had high levels of both steroids with a low 24OHC/27OHC ratio. Patients with Alzheimer's disease had slightly increased levels of 24OHC in CSF with less increase in 27OHC. Patients with multiple sclerosis had a tendency to have higher levels of 24OHC during active periods with a high 24OHC/ 27OHC ratio.
  
  
  CONCLUSIONS
  Measurements of the two oxysterols in CSF and plasma may add significantly to existing biochemical methods for evaluation of neurological diseases.
authors.affiliation: Department of Experimental and Clinical Biomedical Science (DSBSC), University of Insubria, Varese, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Leoni
authors.forename: Thomas
authors.initials: T
authors.lastname: Masterman
authors.forename: Fariba S
authors.initials: FS
authors.lastname: Mousavi
authors.forename: Bengt
authors.initials: B
authors.lastname: Wretlind
authors.forename: Lars-Olof
authors.initials: LO
authors.lastname: Wahlund
authors.forename: Ulf
authors.initials: U
authors.lastname: Diczfalusy
authors.forename: Jan
authors.initials: J
authors.lastname: Hillert
authors.forename: Ingemar
authors.initials: I
authors.lastname: Björkhem
mesh_terms: D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000097:blood / Q000134:cerebrospinal fluid* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D006888:Hydroxycholesterols / Q000097:blood / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged
chemical_list: D006888:Hydroxycholesterols; C044563:24-hydroxycholesterol; C076996:27-hydroxycholesterol