title: Clinical and pathologic presentation in Parkinson's disease by apolipoprotein e4 allele status.
abstract: BACKGROUND
  Apolipoprotein (APOE) e4 allele status has been linked to clinical presentation and progression in Alzheimer's disease; however, evidence for a role of APOE e4 in Parkinson's disease (PD) remains largely inconclusive. In this analysis we explored potential significant associations between APOE e4 allele status and characteristics of clinical presentation in patients with PD.
  
  
  METHODS
  Data came from 424 subjects evaluated using the Uniform Data Set (UDS) assessment collected by the National Alzheimer's Coordinating Center. Subjects had a known year of diagnosis of PD and experienced change in motor function prior to any change in cognition. Linear and logistic regression were used to model the association between APOE e4 carrier status and clinical characteristics including measures of cognitive decline and motor and neuropsychiatric symptoms. Amyloid burden was also evaluated for a subset of patients who died and consented to autopsy.
  
  
  RESULTS
  Odds of dementia were higher in APOE e4 carriers (OR = 5.15), and, on average, APOE e4 carriers scored two points worse on tests of episodic memory and the Clinical Dementia Rating Sum of Boxes assessment. There was little evidence to support an association between e4 carrier status and severity of motor features, and, of the four neuropsychiatric symptoms evaluated, only presence of hallucinations was significantly associated with APOE e4 carrier status (OR = 5.29). Neuropathology data revealed higher frequencies of neuritic and diffuse amyloid plaques in APOE e4 carriers compared to non-carriers.
  
  
  CONCLUSIONS
  APOE e4 allele status is associated with dementia and severity of Alzheimer's disease pathologic features in PD.
authors.affiliation: National Alzheimer's Coordinating Center, University of Washington, Seattle, WA 98105, USA. Electronic address: smonsell@uw.edu.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Monsell
authors.affiliation: National Alzheimer's Coordinating Center, University of Washington, Seattle, WA 98105, USA.
authors.forename: Lilah M
authors.initials: LM
authors.lastname: Besser
authors.affiliation: National Alzheimer's Coordinating Center, University of Washington, Seattle, WA 98105, USA.
authors.forename: Katherine B
authors.initials: KB
authors.lastname: Heller
authors.affiliation: Department of Family & Preventive Medicine, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Harvey
authors.initials: H
authors.lastname: Checkoway
authors.affiliation: Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA.
authors.forename: Irene
authors.initials: I
authors.lastname: Litvan
authors.affiliation: National Alzheimer's Coordinating Center, University of Washington, Seattle, WA 98105, USA.
authors.forename: Walter A
authors.initials: WA
authors.lastname: Kukull
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000235:genetics / Q000503:physiopathology*; D053327:Apolipoprotein E4 / Q000235:genetics*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D003704:Dementia / Q000235:genetics / Q000503:physiopathology*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000235:genetics* / Q000473:pathology*; D012044:Regression Analysis; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D053327:Apolipoprotein E4
keywords: APOE; Clinical symptoms; Neuropathology; Parkinson's disease