Association of APOE e4 and cerebrovascular pathology in traumatic brain injury

• Published in: Journal of neurology, neurosurgery and psychiatry neurosurgery and psychiatry, 2006-03, Vol.77 (3), p.363-366
• Main Authors: Smith, C, Graham, D I, Murray, L S, Stewart, J, Nicoll, J A R
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; APOE; Apolipoprotein E4; Apolipoproteins E - genetics; APP; Archives & records; Atherosclerosis; beta-amyloid precursor protein; Biological and medical sciences; Brain Concussion - diagnosis; Brain Concussion - genetics; Brain Concussion - mortality; Brain damage; Brain Injuries - diagnosis; Brain Injuries - genetics; Brain Injuries - mortality; Brain Ischemia - diagnosis; Brain Ischemia - genetics; Brain Ischemia - mortality; Brain research; Child; Child, Preschool; contusions; DAI; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; diffuse axonal injury; Female; Fractures; Genetic Carrier Screening; Genotype; Genotype & phenotype; Head injuries; head injury; Hematology; Humans; Hypotheses; Injuries of the nervous system and the skull. Diseases due to physical agents; ischaemic damage; Male; Medical sciences; Middle Aged; Neurology; Outcome Assessment (Health Care) - statistics & numerical data; Pathology; polymorphisms; Prognosis; Retrospective Studies; Risk; Rodents; Stroke; Studies; Survival Analysis; TAI; TBI; TCI; total contusion index; Transgenic animals; Traumas. Diseases due to physical agents; traumatic axonal injury; Traumatic brain injury; United Kingdom; Veins & arteries
• ISSN: 0022-3050; 1468-330X
• DOI: 10.1136/jnnp.2005.074617

Background: Previous studies have found the e4 allele of the apolipoprotein E gene (APOE e4) is associated with an unfavourable outcome after head injury, but this has not been related to specific pathological features. Objectives: This study tested the postulate that head injured patients with APOE e4, amounting to approximately a third of the population, are selectively predisposed to one or more of the different pathological features that constitute the response to traumatic brain injury (TBI), and that this underlies the association of APOE e4 with poor clinical outcome. Methods: Included in the study were 239 fatal cases of TBI (1987–1999) for which APOE genotypes were determined from archival tissue. For each case, specific pathological features of trauma were recorded by researchers blinded to the APOE e4 status. Of the 239 cases examined, 83 (35%) were APOE e4 carriers and 156 (65%) were non-carriers. Results: Possession of APOE e4 was associated with a greater incidence of moderate or severe contusions (42% v 30% for carriers versus e4 non-carriers; p =  0.05) and there was a trend towards a greater incidence of severe ischaemic brain damage (54% v 42%; p =  0.08). Significant differences were not noted between the other pathological features examined. Conclusions: Possession of APOE e4 is associated with a greater incidence of moderate/severe contusional injury and severe ischaemic brain damage in fatal cases of TBI. This may be relevant to the relatively poor outcome from traumatic brain injury in patients with APOE e4 identified in clinical studies.