Intravenous immunoglobulin (IVIG) promotes brain repair and improves cognitive outcomes after traumatic brain injury in a FcγRIIB receptor-dependent manner.

Intravenous immunoglobulin (IVIG) is a promising immune-modulatory therapy for limiting harmful inflammation and associated secondary tissue loss in neurotrauma. Here, we show that IVIG therapy attenuates spatial learning and memory deficits following a controlled cortical impact mouse model of traumatic brain injury (TBI). These improvements in cognitive outcomes were associated with increased neuronal survival, an overall reduction in brain tissue loss, and a greater preservation of neural connectivity. Furthermore, we demonstrate that the presence of the main inhibitory FcγRIIB receptor is required for the beneficial effects of IVIG treatment in TBI, with our results simultaneously highlighting the role of this receptor in reducing secondary damage arising from brain injury.