Cell Free DNA as a Potential Biomarker of Blast-Wave Mild Traumatic Brain Injury and Posttraumatic Stress Disorder.

Abstract BackgroundIndividuals being within non-lethal distance from explosion may present with blast induced mild traumatic brain injury, post traumatic stress disorder, or combination of the two conditions. Early diagnosis to enable interventions is important. This study tested the possible role of cell free DNA in the diagnosis of blast related head injuries in a rat model.MethodsA rat controlled model of a blast. Cell free DNA concentrations were determined in the serum by a direct fluorescence method. Cognitive and behavioral tests were used to diagnose affected rats. ResultsMean cell free DNA concentration increased significantly at 2 hours following the blast compared to baseline level and remained high throughout the follow-up period (665.43±159.15 ng/ml vs. 344.20±69.62 ng/ml, p<0.0001). The rate of affected rats among the blast exposed animals was 42.5%. A significant increase in mean cell free DNA concentration was found at 2 hours after exposure in the affected group (741.40±47.18 ng/ml) compared to both the baseline concentration (372.42±149.11 ng/ml), p<0.0001 and to the well-adapted group (517.47 ng/ml), p<0.0045. ConclusionThis rat model of blast demonstrated that the incidence of mild brain injury and or PTSD is significant and that affected animals demonstrated increased serum concentrations of cell free DNA. Cell free DNA may potentially serve as a biomarker to diagnose brain psychopathology early in individuals exposed to blast.