title: Association of apolipoprotein E polymorphism with outcome after aneurysmal subarachnoid hemorrhage: a preliminary study.
abstract: OBJECTIVE
  Variation in the outcome after aneurysmal subarachnoid hemorrhage (SAH) is not fully explained by known prognostic factors. APOE genotype is the most important genetic determinant of susceptibility to Alzheimer's disease, and it is also shown to be associated with the outcome after traumatic brain injury. We studied the association of apolipoprotein E polymorphism with the outcome after aneurysmal SAH.
  
  
  METHODS
  A total of 160 consecutive patients were admitted after SAH to a neurosurgical unit. The clinical assessment after the SAH was performed with the Hunt and Hess grading scale. The severity of the bleeding as visualized on CT was assessed by Fisher's grading system. Outcome was assessed with the Glasgow Outcome SCALE: APOE genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism.
  
  
  RESULTS
  126 patients had aneurysmatic SAH, and detailed information on outcome and APOE genotype was available for 108 patients (86%). Sixteen (40%) of 40 patients with APOE epsilon4 had an unfavorable outcome compared with 13 (19%) of 68 without the APOE epsilon4 allele (OR 2.8, 95% CI 1.18 to 6.77). Association was more significant after adjustment for age, rebleeding, clinical status on admission, and CT scan findings (OR 7.1, 95% CI 1.9 to 26.3; P=0.0035).
  
  
  CONCLUSIONS
  Our findings show a significant genetic association of APOE polymorphism with outcome after spontaneous aneurysmal SAH. Genetic factors thus seem to explain a part of individual differences in the recovery of SAH.
authors.affiliation: Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland. tero.niskakangas@hus.fi
authors.forename: T
authors.initials: T
authors.lastname: Niskakangas
authors.forename: J
authors.initials: J
authors.lastname: Ohman
authors.forename: M
authors.initials: M
authors.lastname: Niemelä
authors.forename: E
authors.initials: E
authors.lastname: Ilveskoski
authors.forename: T A
authors.initials: TA
authors.lastname: Kunnas
authors.forename: P J
authors.initials: PJ
authors.lastname: Karhunen
mesh_terms: D001057:Apolipoproteins E / Q000235:genetics*; D005260:Female; D005387:Finland; D005838:Genotype; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D011379:Prognosis; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000235:genetics* / Q000628:therapy; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D001057:Apolipoproteins E