title: Alpha-synuclein in gastric and colonic mucosa in Parkinson's disease: Limited role as a biomarker.
abstract: BACKGROUND
  Gastric and colonic alpha-synuclein immunoreactivity has been reported in patients with Parkinson's disease (PD). However, enteric alpha-synuclein also has been reported in healthy individuals.
  
  
  OBJECTIVE
  We aimed to investigate the utility of alpha-synuclein immunoreactivity from gastric and colonic mucosal tissues obtained by routine endoscopy to detect PD, and to correlate the pathological burden of alpha-synuclein with motor and nonmotor features of PD.
  
  
  METHODS
  We recruited 104 study subjects, consisting of 38 patients with PD, 13 patients with probable multiple system atrophy (MSA), and 53 healthy controls. Gastric and colonic mucosal tissues obtained by endoscopic gastroduodenoscopy and colonoscopy were assessed using alpha-synuclein immunohistochemistry. Detailed motor and nonmotor features of PD were correlated with enteric alpha-synuclein immunoreactivity.
  
  
  RESULTS
  No difference was seen in the enteric α-SYN immunoreactivity among patients with PD (31.6% for stomach and 10.4% for colon), patients with MSA (40.0% for stomach and 8.0% for colon), and healthy controls (33.3% for stomach and 18.5% for colon). The frequency of positive alpha-synuclein immunoreactivity was higher in gastric biopsy tissues than in colonic biopsy tissues in all of the study groups (P < 0.05). No significant correlation was found between the presence of alpha-synuclein immunoreactivity and the motor and nonmotor features of PD.
  
  
  CONCLUSIONS
  The presence of alpha-synuclein immunoreactivity in gastric and colonic mucosa was detected in a similar manner in patients with PD, patients with MSA, and controls, thus suggesting a limited role of enteric mucosal alpha-synuclein as a diagnostic biomarker for PD. Future studies are warranted to detect pathological alpha-synuclein strains.
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Sun Ju
authors.initials: SJ
authors.lastname: Chung
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.|Department of Neurology, Metro hospital, Anyang, South Korea.
authors.forename: Juyeon
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.|Health Screening and Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Hyo Jeong
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Ho-Sung
authors.initials: HS
authors.lastname: Ryu
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Kiju
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Jeong Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Kee Wook
authors.initials: KW
authors.lastname: Jung
authors.affiliation: Department of Neurology, Bobath Memorial Hospital, Seongnam, Republic of Korea.
authors.forename: Mi Jung
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Health Screening and Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Mi-Jung
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Division of Biostatistics, Center for Medical Research and Information, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Sung-Cheol
authors.initials: SC
authors.lastname: Yun
authors.affiliation: Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea.
authors.forename: Joo-Yong
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Seung-Mo
authors.initials: SM
authors.lastname: Hong
authors.affiliation: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Seung-Jae
authors.initials: SJ
authors.lastname: Myung
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000737:chemistry; D005260:Female; D005753:Gastric Mucosa / Q000737:chemistry*; D006801:Humans; D007413:Intestinal Mucosa / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis*; D010300:Parkinson Disease / Q000175:diagnosis*; D051844:alpha-Synuclein / Q000032:analysis*
chemical_list: D015415:Biomarkers; D051844:alpha-Synuclein
keywords: Parkinson's disease; alpha-synuclein; biomarker; colon; stomach