title: The glial marker YKL-40 is decreased in synucleinopathies.
abstract: BACKGROUND
  Microglia are resident immunosurveillant cells in the central nervous system, and astrocytes are important for blood flow, plasticity, and neurotransmitter regulation. The aim of this study was to investigate whether astrocyte and microglial activation, estimated through markers in cerebrospinal fluid and serum, differed between synucleinopathies, tauopathies, and controls.
  
  
  METHODS
  We analyzed the glial activation markers YKL-40 and soluble CD14 in serum and cerebrospinal fluid from 37 controls, 50 patients with Parkinson's disease (PD), and 79 P+ patients (those with progressive supranuclear palsy, corticobasal degeneration, and multiple system atrophy).
  
  
  RESULTS
  Cerebrospinal fluid levels of YKL-40 were decreased significantly in patients who had PD compared with controls (P < 0.05), patients who had multiple system atrophy (P < 0.01), and patients who had tauopathies (P < 0.0001). In addition, cerebrospinal fluid levels of YKL-40 were significantly lower in patients who had synucleinopathies than in those who had tauopathies (P < 0.0001).
  
  
  CONCLUSIONS
  The decreased cerebrospinal fluid levels of YKL-40 suggest that glial activation is reduced in the brains of patients who have Parkinson's disease and synucleinopathies compared with patients who have tauopathies and controls.
authors.affiliation: Department of Psychiatry and Neurochemistry, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.
authors.forename: Bob
authors.initials: B
authors.lastname: Olsson
authors.forename: Radu
authors.initials: R
authors.lastname: Constantinescu
authors.forename: Björn
authors.initials: B
authors.lastname: Holmberg
authors.forename: Niels
authors.initials: N
authors.lastname: Andreasen
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
mesh_terms: D054392:Adipokines / Q000097:blood* / Q000134:cerebrospinal fluid*; D000368:Aged; D000704:Analysis of Variance; D001480:Basal Ganglia Diseases / Q000097:blood* / Q000134:cerebrospinal fluid*; D000071451:Chitinase-3-Like Protein 1; D005260:Female; D006801:Humans; D037102:Lectins / Q000097:blood* / Q000134:cerebrospinal fluid*; D018950:Lipopolysaccharide Receptors / Q000097:blood / Q000134:cerebrospinal fluid; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy; D019636:Neurodegenerative Diseases / Q000097:blood* / Q000139:chemically induced*; D010300:Parkinson Disease; D013494:Supranuclear Palsy, Progressive; D024801:Tauopathies / Q000097:blood / Q000134:cerebrospinal fluid; D051844:alpha-Synuclein / Q000097:blood / Q000134:cerebrospinal fluid
chemical_list: D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D037102:Lectins; D018950:Lipopolysaccharide Receptors; D051844:alpha-Synuclein
keywords: Parkinson's disease; astrocytes; biomarker; cerebrospinal fluid; microglia; parkinsonian disorders