title: Is alpha-synuclein in the colon a biomarker for premotor Parkinson's disease? Evidence from 3 cases.
abstract: BACKGROUND
  Despite clinicopathological evidence that Parkinson's disease (PD) may begin in peripheral tissues, identification of premotor Parkinson's disease is not yet possible. Alpha-synuclein aggregation underlies Parkinson's disease pathology, and its presence in peripheral tissues may be a reliable disease biomarker.
  
  
  OBJECTIVE
  We sought evidence of alpha-synuclein pathology in colonic tissues before the development of characteristic Parkinson's disease motor symptoms.
  
  
  METHODS
  Old colon biopsy samples were available for three subjects with PD. Biopsies were obtained 2-5 years before PD onset. We performed immunohistochemistry studies for the presence of alpha-synuclein and Substance P in these samples.
  
  
  RESULTS
  All subjects showed immunostaining for alpha-synuclein (two, five and two years before first motor Parkinson's disease symptom). No similar alpha-synuclein immunostaining was seen in 23 healthy controls. Staining of samples for substance P suggested colocalization of alpha-synuclein and substance P in perikarya and neurites.
  
  
  CONCLUSIONS
  This is the first demonstration of alpha-synuclein in colon tissue prior to onset of PD. Additional study is required to determine whether colonic mucosal biopsy may be a biomarker of premotor PD.
authors.affiliation: Department of Neurological Sciences, Rush Medical College, Chicago, Illinois 60612, USA. Kathleen_M_Shannon@rush.edu
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Shannon
authors.forename: Ali
authors.initials: A
authors.lastname: Keshavarzian
authors.forename: Hemraj B
authors.initials: HB
authors.lastname: Dodiya
authors.forename: Shriram
authors.initials: S
authors.lastname: Jakate
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Kordower
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D003106:Colon / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016501:Neurites / Q000378:metabolism / Q000473:pathology; D010300:Parkinson Disease / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D013373:Substance P / Q000378:metabolism; D051844:alpha-Synuclein / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D051844:alpha-Synuclein; D013373:Substance P