Increased plasma deoxyribonucleic acid (DNA) levels may be associated with disease severity after acute traumatic brain injury (TBI). This study posits that increased plasma DNA levels in acute TBI are predictive of outcome. Both serial plasma nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) levels were examined in 88 consecutive patients with acute TBI and 66 control subjects. Additional samples were obtained on day 4 and day 7. Results showed that plasma nDNA and mtDNA on admission were significantly increased in patients with TBI compared with controls. Plasma nDNA, but not plasma mtDNA, levels in patients with acute TBI significantly correlated with Glasgow Coma Scale (GCS) score and Injury Severity Score (ISS) on presentation. Plasma nDNA increased significantly from day 1 to day 7 in patients with poor outcome. Its levels on presentation were independently associated with outcome and higher levels (cutoff value >72.95 ng/mL) were associated with poorer outcomes. These findings suggest plasma nDNA levels reflect the severity of cerebral damage and can be considered a neuropathologic marker of patients with acute TBI. Further studies with bigger patient populations are warranted for better unbiased comparison.
Keywords: mitochondrial DNA; nuclear DNA; outcome; traumatic brain injury.