title: Apolipoprotein E polymorphism and gender difference in outcome after severe traumatic brain injury.
abstract: BACKGROUND
  Traumatic brain injury (TBI) is one of the most common causes of death and dismal outcome among children and young adults. The morbidity and mortality differ but more aggressive monitoring and more designated neuro intensive care units have improved the results. Studies have demonstrated a connection between apolipoprotein E (APOE) genotype and outcome after TBI, but few are prospective and none is from northern Europe. APOE has three alleles: epsilon2, epsilon3 and epsilon4.
  
  
  METHODS
  A total of 96 patients with Glasgow coma score (GCS) < or =8 were prospectively and consecutively included. APOE genotypes were all analyzed at the same laboratory from blood samples by polymerase chain reaction-restriction fragment length polymorphism.
  
  
  RESULTS
  All patients were assessed at 1 year with Glasgow outcome scale extended (GOSE), National Institute of Health Stroke Scale (NIHSS) and the Barthel daily living index. The genotype was available in all patients. Twenty-six patients expressed APOE epsilon4 while 70 patients did not. Outcome demonstrated that patients with APOE epsilon4 had worse outcome vs. those lacking this allele. When subdividing patients into gender, males with APOE epsilon4 did worse, a difference not detected among female patients.
  
  
  CONCLUSIONS
  APOE epsilon4 correlated to worse outcome in TBI patients. We also found that males with APOE epsilon4 had poor outcome while females did not. Thus, the results indicate that genetic polymorphism may influence outcome after TBI.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden. martin.ost@gmail.com
authors.forename: M
authors.initials: M
authors.lastname: Ost
authors.forename: K
authors.initials: K
authors.lastname: Nylén
authors.forename: L
authors.initials: L
authors.lastname: Csajbok
authors.forename: K
authors.initials: K
authors.lastname: Blennow
authors.forename: L
authors.initials: L
authors.lastname: Rosengren
authors.forename: B
authors.initials: B
authors.lastname: Nellgård
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001057:Apolipoproteins E / Q000032:analysis*; D001930:Brain Injuries / Q000235:genetics* / Q000401:mortality; D002648:Child; D015331:Cohort Studies; D004311:Double-Blind Method; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011379:Prognosis; D011446:Prospective Studies; D012737:Sex Factors; D015996:Survival Rate; D055815:Young Adult
chemical_list: D001057:Apolipoproteins E