Autoimmune Profiling Reveals Peroxiredoxin 6 as a Candidate Traumatic Brain Injury Biomarker

Autoimmune profiling in rats revealed the antioxidant enzyme, peroxiredoxin 6 (PRDX6), as a target for autoantibodies evoked in response to traumatic brain injury (TBI). Consistent with this proposal, immunohistochemical analysis of rat cerebral cortex demonstrated that PRDX6 is highly expressed in the perivascular space, presumably contained within astrocytic foot processes. Accordingly, an immunosorbent electrochemiluminescence assay was developed for investigating PRDX6 in human samples. PRDX6 was found to be measurable in human blood and highly expressed in human cerebral cortex and platelets. Circulating levels of PRDX6 were elevated fourfold over control values 4 to 24 h following mild-to-moderate TBI. These findings suggest that PRDX6 may serve as a biomarker for TBI and that autoimmune profiling is a viable strategy for the discovery of novel TBI biomarkers.