Johansson_2013_PLoS.One_8_e81989

BACKGROUND: Little is known of vitamin D concentration in cerebrospinal fluid (CSF) in Alzheimer s disease (AD) and its relation with CSF acetylcholinesterase (AChE) activity, a marker of cholinergic function.
METHODS: A cross-sectional study of 52 consecutive patients under primary evaluation of cognitive impairment and 17 healthy controls. The patients had AD dementia or mild cognitive impairment (MCI) diagnosed with AD dementia upon follow-up (n = 28), other dementias (n = 12), and stable MCI (SMCI, n = 12). We determined serum and CSF concentrations of calcium, parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), and CSF activities of AChE and butyrylcholinesterase (BCHE). FINDINGS: CSF 25OHD level was reduced in AD patients (P < 0.05), and CSF AChE activity was decreased both in patients with AD (P < 0.05) and other dementias (P < 0.01) compared to healthy controls. None of the measured variables differed between BCHE K-variant genotypes whereas the participants that were homozygous in terms of the apolipoprotein E (APOE) epsilon4 allele had decreased CSF AChE activity compared to subjects lacking the APOE epsilon4 allele (P = 0.01). In AD patients (n=28), CSF AChE activity correlated positively with CSF levels of total tau (T-tau) (r = 0.44, P < 0.05) and phosphorylated tau protein (P-tau) (r = 0.50, P < 0.01), but CSF activities of AChE or BCHE did not correlate with serum or CSF levels of 25OHD.
CONCLUSIONS: In this pilot study, both CSF 25OHD level and CSF AChE activity were reduced in AD patients. However, the lack of correlations between 25OHD levels and CSF activities of AChE or BCHE might suggest different mechanisms of action, which could have implications for treatment trials.