Oxysterols and Parkinson´s Disease. Evidence that Levels of 24S-Hydroxycholesterol in Cerebrospinal Fluid Correlates with the Duration of the Disease.

Oxysterols are important for cholesterol homeostasis in the brain and may be affected in neurodegenerative diseases. The levels of the brain-derived oxysterol 24S-hydroxycholesterol (24S-OH) have been reported to be markedly reduced in the circulation of patients with Parkinson\u27s disease (PD) (Lee et al., Antioxid. Redox Signal. 11 (2009) 407–420). The finding is surprising in view of the fact that other neurodegenerative diseases are associated with relatively modest effects on the circulating levels of 24S-OH. We determined the plasma and cerebrospinal fluid (CSF) levels of 24S-OH and 27-hydroxycholesterol (27-OH) in patients with PD with different disease duration using a highly accurate method based on isotope dilution-mass spectrometry. All the patients had plasma levels of the different oxysterols within the normal range. When analyzing CSF, 10% of the PD patients were found to have levels of 24S-OH above the cut-off level and interestingly there was a significant correlation between levels of 24S-OH in CSF and duration of the disease (r = 0.40, P \u3c 0.05). The CSF level of 27-OH was found to be above the cut-off level in 10% of the patients, indicating a defect blood–brain barrier function. There was no correlation between levels of 27-OH in CSF and duration of the disease. These data indicates that oxysterol levels in CSF may be of value to follow disease progression

Diagnostic Power of 24S-Hydroxycholesterol in Cerebrospinal Fluid: Candidate Marker of Brain Health

We evaluated the diagnostic potential of 24S-hydroxycholesterol (24OHC) in cerebrospinal fluid. At a memory clinic, we investigated subjects with subjective cognitive impairment (SCI, n = 33), mild cognitive impairment (MCI) patients (n = 27), MCI patients with later progression into Alzheimer dementia at follow up (n = 10), and patients with AD (n = 24). We also had a control group of healthy volunteers who did not later develop cognitive problems (n = 13). The fraction of the population with pathological levels of 24OHC was 8% in controls, 34% in SCI, 37% in MCI, 80% in MCI with progression, and 42% in AD. The corresponding fractions for T-tau, P-tau, and A beta(42) were lower in the case of SCI and MCI but higher in the case of controls and AD. In case of MCI with progression, the fraction of pathological levels of 24OHC and A beta(42) were 80% and 63% respectively. We also studied a population of old healthy subjects age 75-99 years (n = 25). The fraction of individuals in this population with pathological levels of 24OHC was 0% whereas the fraction of individuals with pathological level of at least one of the other three biomarkers was 40%. The diagnostic power of 24OHC in cerebrospinal fluid seems to be similar to or lower than that of the established biomarkers T-tau, P-tau, and A beta(42) in the diagnosis of established AD. Our data suggest that 24OHC may be more sensitive than the classical biomarkers in an early phase of the neurodegenerative process and a better marker for "brain health" in old age

First international descriptive and interventional survey for cholesterol and non-cholesterol sterol determination by gas- and liquid-chromatography-Urgent need for harmonisation of analytical methods

Serum concentrations of lathosterol, the plant sterols campesterol and sitosterol and the cholesterol metabolite 5 alpha-cholestanol are widely used as surrogate markers of cholesterol synthesis and absorption, respectively. Increasing numbers of laboratories utilize a broad spectrum of well-established and recently developed methods for the determination of cholesterol and non-cholesterol sterols (NCS). In order to evaluate the quality of these measurements and to identify possible sources of analytical errors our group initiated the first international survey for cholesterol and NCS. The cholesterol and NCS survey was structured as a two-part survey which took place in the years 2013 and 2014. The first survey part was designed as descriptive, providing information about the variation of reported results from different laboratories. A set of two lyophilized pooled sera (A and B) was sent to twenty laboratories specialized in chromatographic lipid analysis. The different sterols were quantified either by gas chromatography-flame ionization detection, gas chromatography- or liquid chromatography-mass selective detection. The participants were requested to determine cholesterol and NCS concentrations in the provided samples as part of their normal laboratory routine. The second part was designed as interventional survey. Twenty-two laboratories agreed to participate and received again two different lyophilized pooled sera (C and D). In contrast to the first international survey, each participant received standard stock solutions with defined concentrations of cholesterol and NCS. The participants were requested to use diluted calibration solutions from the provided standard stock solutions for quantification of cholesterol and NCS. In both surveys, each laboratory used its own internal standard (5 alpha-cholestane, epicoprostanol or deuterium labelled sterols). Main outcome of the survey was, that unacceptably high interlaboratory variations for cholesterol and NCS concentrations are reported, even when the individual laboratories used the same calibration material. We discuss different sources of errors and recommend all laboratories analysing cholesterol and NCS to participate in regular quality control programs.Peer reviewe