Lack of association between the IL1A gene (-889) polymorphism and outcome after head injury.

BACKGROUND

Interleukin (IL) 1 is a proinflammatory cytokine that has been identified as an important mediator of neurodegeneration induced by ischemia or traumatic brain injury. Accumulating evidence to date has suggested that the major cytokine contributing to neurodegeneration after head injury is IL-1beta rather than IL-1alpha; however, there is no sufficient data regarding IL-1alpha in literature, and there may be an association between IL1A gene polymorphism and outcome after head injury.

METHODS

We performed a prospective clinical study and included a recruited series of 71 patients who had head injury and were admitted to our neurosurgical unit. Severity of initial injury was assessed by the Glasgow Coma Scale. Outcome at 6 months after injury was assessed by means of the Glasgow Outcome Score. Interleukin 1alpha genotypes were determined from blood samples by standard methods.

RESULTS

Of 40 patients with IL1A2, 18 (45%) had an unfavorable outcome (dead, vegetative state, or severe disability) compared with 7 (22.5%) of 31 without IL1A2 (P = .08).

CONCLUSION

Our findings show that there is no genetic association between IL1A gene polymorphism and outcome after head injury. Further clinical studies should be designed to confirm and further evaluate these findings.