An investigation of auto-reactivity after head injury.

Murine models of CNS injury show auto-reactive T cell responses directed at myelin antigens, associated with improved neuronal survival and functional recovery. This pilot study shows, for the first time, that similar immune responses against myelin occur in human traumatic brain injury (TBI), with an expansion of lymphocytes recognising myelin basic protein observed in 40% of patients studied. "Reactive" patients did not have greater contusion volume on imaging, but were younger than the "unreactive" subgroup and tended towards a more favorable outcome. These findings are consistent with the concept of "beneficial autoimmunity".