title: Microglial activation in Alzheimer's disease: an (R)-[¹¹C]PK11195 positron emission tomography study.
abstract: Inflammatory mechanisms, like microglial activation, could be involved in the pathogenesis of Alzheimer's disease (AD). (R)-[(11)C]PK11195 (1-(2-chlorophenyl)-N-methyl-N-1(1-methylpropyl)-3-isoquinolinecarboxamide), a positron emission tomography (PET) ligand, can be used to quantify microglial activation in vivo. The purpose of this study was to assess whether increased (R)-[(11)C]PK11195 binding is present in AD and mild cognitive impairment (MCI), currently also known as "prodromal AD."
  
  
  METHODS
  Nineteen patients with probable AD, 10 patients with prodromal AD (MCI), and 21 healthy control subjects were analyzed. Parametric images of binding potential (BP(ND)) of (R)-[(11)C]PK11195 scans were generated using receptor parametric mapping (RPM) with supervised cluster analysis. Differences between subject groups were tested using mixed model analysis, and associations between BP(ND) and cognition were evaluated using Pearson correlation coefficients.
  
  
  RESULTS
  Voxel-wise statistical parametric mapping (SPM) analysis showed small clusters of significantly increased (R)-[(11)C]PK11195 BP(ND) in occipital lobe in AD dementia patients compared with healthy control subjects. Regions of interest (ROI)-based analyses showed no differences, with large overlap between groups. There were no differences in (R)-[(11)C]PK11195 BP(ND) between clinically stable prodromal AD patients and those who progressed to dementia, and BP(ND) did not correlate with cognitive function.
  
  
  CONCLUSIONS
  Microglial activation is a subtle phenomenon occurring in AD.
authors: Department of Neurology and Alzheimer Center, VU University Medical Center, Amsterdam, the Netherlands. ASchuitemaker@zuwehofpoort.nl
authors: Alie
authors: A
authors: Schuitemaker
authors: Marc A
authors: MA
authors: Kropholler
authors: Ronald
authors: R
authors: Boellaard
authors: Wiesje M
authors: WM
authors: van der Flier
authors: Reina W
authors: RW
authors: Kloet
authors: Thalia F
authors: TF
authors: van der Doef
authors: Dirk L
authors: DL
authors: Knol
authors: Albert D
authors: AD
authors: Windhorst
authors: Gert
authors: G
authors: Luurtsema
authors: Frederik
authors: F
authors: Barkhof
authors: Cees
authors: C
authors: Jonker
authors: Adriaan A
authors: AA
authors: Lammertsma
authors: Philip
authors: P
authors: Scheltens
authors: Bart N M
authors: BN
authors: van Berckel
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000473:pathology*; D000704:Analysis of Variance; D001931:Brain Mapping; D002250:Carbon Radioisotopes; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D007546:Isoquinolines; D008279:Magnetic Resonance Imaging; D008297:Male; D017628:Microglia / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D049268:Positron-Emission Tomography
chemical_list: D002250:Carbon Radioisotopes; D007546:Isoquinolines; C037850:PK 11195