Association Between DNA and RNA Oxidative Damage and Mortality of Patients with Traumatic Brain Injury

The hyperoxidative state in traumatic brain injury (TBI) could produce oxidative damage on the ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Oxidative damage to nucleic acids in TBI patients has been studied, and higher concentrations of 8-OHdG were found in postmortem brain samples of subjects who died following TBI than in subjects who died from sudden cardiac death. Thus, the objective of this study was to determine whether there is an association between serum DNA and RNA oxidative damage and mortality in TBI patients. We included patients with severe isolated TBI defined as a lower score than 9 points in the Glasgow Coma Scale (GCS) and lower than 9 points in non-cranial aspects in the Injury Severity Score. We determined serum concentrations of the three oxidized guanine species (OGS) (8-OHdG from DNA, 8-hydroxyguanosine from RNA, and 8-hydroxyguanine from DNA or RNA) and malondialdehyde (to estimate lipid peroxidation) on the day of TBI. Mortality at 30 days was the end-point study. We found higher serum concentrations of OGS (p