Plasma mitochondrial DNA levels in patients with trauma and severe sepsis: Time course and the association with clinical status

Purpose: This study aimed to investigate the serial changes in plasma levels of mitochondrial DNA (mtDNA) in patients with trauma and severe sepsis and the mechanism of increase in mtDNA levels and the association between the levels and severity. Materials and Methods: We conducted a prospective observational study of patients with trauma having injuries with an Abbreviated Injury Scale score of 3 or higher (n = 37) and patients with severe sepsis (n = 23). The mtDNA concentrations in clarified plasma were measured using real-time quantitative polymerase chain reaction. Results: Concentrations of mtDNA peaked on the day of admission (day 1) in patients with trauma, whereas they increased on day 1 and remained constant until day 5 in patients with sepsis. The mtDNA levels on day 1 correlated with the maximal levels of creatinine phosphokinase in patients with trauma (R² = 0.463, P < .05) but not in patients with sepsis (R² = 0.028, P = .43). The mtDNA levels on day 1 were significantly higher in nonsurvivors compared with survivors of trauma (P < .05) but not sepsis. Conclusions: The levels of mtDNA were elevated during traumatic injury and severe sepsis, although time course and prognostic significance differed between the groups, suggesting that the mechanisms of mtDNA release into plasma differ.