Modulating effect of apolipoprotein E polymorphisms on secondary brain insult and outcome after childhood brain trauma

The aim of this study was to determine the relationship between apolipoprotein E (APO E) alleles, the amount of cerebral perfusion pressure (CPP) insult and outcome in children after brain trauma. In a prospective two-centre case-control study, the APO E genotypes of 65 critically ill children admitted after brain trauma were correlated with age-related CPP insult quantification, conscious state at the time of discharge from intensive care and global outcome at 6 months post-injury. One hundred sixty healthy age- and sex-matched children were genotyped as controls. The CPP insult level among the e4 carriers with poor outcome was significantly less than the non-e4 carriers (p = 0.03). Homozygotic e3 patients with good recovery did so despite having suffered nearly 26 times more CPP insult than those who were not e3 homzygous (p = 0.02). Different APO E alleles may potentially affect cerebral ischaemic tolerance differently in children after brain trauma.