title: Microglial activation in Parkinson's disease using [18F]-FEPPA.
abstract: Neuroinflammatory processes including activated microglia have been reported to play an important role in Parkinson's disease (PD). Increased expression of translocator protein (TSPO) has been observed after brain injury and inflammation in neurodegenerative diseases. Positron emission tomography (PET) radioligand targeting TSPO allows for the quantification of neuroinflammation in vivo.
  
  
  
  Based on the genotype of the rs6791 polymorphism in the TSPO gene, we included 25 mixed-affinity binders (MABs) (14 PD patients and 11 age-matched healthy controls (HC)) and 27 high-affinity binders (HABs) (16 PD patients and 11 age-matched HC) to assess regional differences in the second-generation radioligand [18F]-FEPPA between PD patients and HC. FEPPA total distribution volume (VT) values in cortical as well as subcortical brain regions were derived from a two-tissue compartment model with arterial plasma as an input function.
  
  
  
  Our results revealed a significant main effect of genotype on [18F]-FEPPA VTin every brain region, but no main effect of disease or disease × genotype interaction in any brain region. The overall percentage difference of the mean FEPPA VTbetween HC-MABs and HC-HABs was 32.6% (SD = 2.09) and for PD-MABs and PD-HABs was 43.1% (SD = 1.21).
  
  
  
  Future investigations are needed to determine the significance of [18F]-FEPPA as a biomarker of neuroinflammation as well as the importance of the rs6971 polymorphism and its clinical consequence in PD.
authors.affiliation: Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada.|Division of Brain, Imaging and Behaviour - Systems Neuroscience, Krembil Research Institute, UHN, University of Toronto, Ontario, Canada.
authors.forename: Christine
authors.initials: C
authors.lastname: Ghadery
authors.affiliation: Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada.|Division of Brain, Imaging and Behaviour - Systems Neuroscience, Krembil Research Institute, UHN, University of Toronto, Ontario, Canada.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Koshimori
authors.affiliation: Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada.|Division of Brain, Imaging and Behaviour - Systems Neuroscience, Krembil Research Institute, UHN, University of Toronto, Ontario, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Coakeley
authors.affiliation: Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Madeleine
authors.initials: M
authors.lastname: Harris
authors.affiliation: Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Pablo
authors.initials: P
authors.lastname: Rusjan
authors.affiliation: Neurology Division, Department of Medicine, Morton and Gloria Shulman Movement Disorder Unit & E.J. Safra Parkinson Disease Program, Toronto Western Hospital, UHN, University of Toronto, Ontario, Canada.|Division of Brain, Imaging and Behaviour - Systems Neuroscience, Krembil Research Institute, UHN, University of Toronto, Ontario, Canada.
authors.forename: Jinhee
authors.initials: J
authors.lastname: Kim
authors.affiliation: Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Houle
authors.affiliation: Neurology Division, Department of Medicine, Morton and Gloria Shulman Movement Disorder Unit & E.J. Safra Parkinson Disease Program, Toronto Western Hospital, UHN, University of Toronto, Ontario, Canada. antonio.strafella@camh.ca.|Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada. antonio.strafella@camh.ca.|Division of Brain, Imaging and Behaviour - Systems Neuroscience, Krembil Research Institute, UHN, University of Toronto, Ontario, Canada. antonio.strafella@camh.ca.|Toronto Western Hospital and Institute, CAMH-Research Imaging Centre, University of Toronto, Toronto, Ontario, M5T 2S8, Canada. antonio.strafella@camh.ca.
authors.forename: Antonio P
authors.initials: AP
authors.lastname: Strafella
mesh_terms: D000368:Aged; D000813:Anilides / Q000493:pharmacokinetics*; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D017628:Microglia / Q000187:drug effects* / Q000473:pathology; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000235:genetics / Q000473:pathology*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D049268:Positron-Emission Tomography; D011725:Pyridines / Q000493:pharmacokinetics*; D018079:Receptors, GABA / Q000235:genetics; D012720:Severity of Illness Index
chemical_list: D000813:Anilides; D005462:Fluorine Radioisotopes; C530438:N-(2-((N-(4-phenoxypyridin-3-yl)acetamido)methyl)phenoxy)ethyl fluoride; D011725:Pyridines; D018079:Receptors, GABA; C499229:TSPO protein, human
keywords: Neuroinflammation; PET; Parkinson’s disease; TSPO imaging