Plasma nuclear and mitochondrial DNA levels as predictors of outcome in severe sepsis patients in the emergency room

Background and aim: The sensitivity and specificity of biomarkers and scoring systems used for predicting fatality of severe sepsis patients remain unsatisfactory. This study aimed to determine the prognostic value of circulating plasma DNA levels in severe septic patients presenting at the Emergency Department (ED). Methods: Sixty-seven consecutive patients with severe sepsis and 33 controls were evaluated. Plasma DNA levels were estimated by real-time quantitative polymerase chain reaction assay using primers for the human beta-hemoglobin and ND2 gene. The patients' clinical and laboratory data on admission were analyzed. Results: The median plasma nuclear and mitochondria DNA levels for severe septic patients on admission were significantly higher than those of the controls. The mean plasma nuclear DNA level on admission correlated with lactate concentration (gamma = 0.36, p = 0.003) and plasma mitochondrial DNA on admission (gamma = 0.708, p < 0.001). Significant prognostic factors for fatality included mechanical ventilation within the first 24 hours (p = 0.013), mean sequential organ failure assessment (SOFA) score on admission (p = 0.04), serum lactate (p < 0.001), and both plasma nuclear and mitochondrial DNA on admission (p < 0.001). Plasma mitochondrial DNA was an independent predictor of fatality by stepwise logistic regression such that an increase by one ng/mL in level would increase fatality rate by 0.7%. Conclusion: Plasma DNA has potential use for predicting outcome in septic patients arriving at the emergency room. Plasma mitochondrial DNA level on admission is a more powerful predictor than lactate concentration or SOFA scores on admission.