title: Folate and homocysteine in the cerebrospinal fluid of patients with Alzheimer's disease or dementia: a case control study.
abstract: BACKGROUND
  Amyloid deposition in the brain is an early event in Alzheimer's disease (AD), but a dysfunction of the blood-brain barrier or a disturbance in the metabolism of folate and homocysteine (Hcy) may affect the development of dementia. We investigated if the concentrations of folate and Hcy would be modified in cerebrospinal fluid (CSF) of clinically diagnosed AD patients.
  
  
  METHODS
  We included 70 AD patients, 33 patients with another type of dementia (nAD) and 30 age-matched control subjects. Plasma Hcy was assayed as well as Hcy, folate, Aβ1-42 and T-tau in CSF. We used ANOVAs for comparison between groups, and then pairwise comparisons by Wilcoxon tests with Bonferroni-corrected p values. Correlations were tested with the Spearman's rank test.
  
  
  RESULTS
  Levels of Aβ1-42, T-tau and folates in CSF were significantly different between groups, but not Hcy. In addition, the average folate in CSF was lower in AD patients compared with controls (18.7 ± 2.4 vs. 20.3 ± 1.7 nmol/l, Bonferroni-corrected p value < 0.02). There was no correlation between Aβ1-42 or T-tau and folate or Hcy in CSF, regardless of the group. In the AD group, there was a significant inverse correlation between Hcy and folate in CSF (ρ = -0.63, p < 0.0001), whereas in the nAD group, a significant correlation was found for Hcy between plasma and CSF (ρ = 0.59, p < 0.0005).
  
  
  CONCLUSIONS
  The concentration of folate in CSF was found to be decreased in AD patients. These findings support the hypothesis of a possible role of folate in the onset or worsening of AD.
authors.affiliation: Department of Biochemistry, Sousse, Tunisia.
authors.forename: Mohamed Ali
authors.initials: MA
authors.lastname: Smach
authors.forename: Nelly
authors.initials: N
authors.lastname: Jacob
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Golmard
authors.forename: Bassem
authors.initials: B
authors.lastname: Charfeddine
authors.forename: Turkia
authors.initials: T
authors.lastname: Lammouchi
authors.forename: Leila
authors.initials: L
authors.lastname: Ben Othman
authors.forename: Hedi
authors.initials: H
authors.lastname: Dridi
authors.forename: Soufien
authors.initials: S
authors.lastname: Bennamou
authors.forename: Khalifa
authors.initials: K
authors.lastname: Limem
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid*; D016022:Case-Control Studies; D003704:Dementia / Q000134:cerebrospinal fluid*; D005260:Female; D005492:Folic Acid / Q000134:cerebrospinal fluid*; D006710:Homocysteine / Q000097:blood / Q000134:cerebrospinal fluid*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014416:Tunisia
chemical_list: D006710:Homocysteine; D005492:Folic Acid