Oxidative stress and DNA damage in critically ill patients with sepsis

The aim of our study was to assess the oxidative stress and inflammatory status in critically ill patients with sepsis as well as their relationship with the level of DNA damage. The study also evaluated the influence of all analyzed parameters on the outcome of the patients. The study included 27 critically ill patients with sepsis and 20 healthy subjects. Comet Assay was used for the measurement of the level of DNA damage, expressed as genetic damage index (GDI). Both oxidative stress parameters and the antioxidant parameters were obtained spectrophotometrically. The standard laboratory methods and the appropriate autoanalyzers were performed for determination the parameters of inflammation. A higher level of oxidative stress and more pronounced inflammation were found in the patients with sepsis compared to healthy subjects. The activity of the antioxidant enzymes was statistically declined in patients with sepsis, so that the most notable differences between two groups of participants were found for the activity of superoxide dismutase (SOD) (p = 0.004). Comet assay indicated that patients with sepsis had significantly higher GDI compared to healthy subjects (p < 0.001), which positively correlated with the concentration of superoxide anion radical (О₂^-) (r = 0.497, p = 0.010), and nitrites (NО₂^-) (r = 0.473, p = 0.015), as well with the concentration of C reactive protein (CRP) (r = 0.460, p = 0.041). Regression analysis confirmed that patients' age (p = 0.033), the level of О₂^- (p = 0.007), CRP concentration (p = 0.029) and GDI (p = 0.001) increased the risk of lethal outcome in critically ill patients with sepsis. In conclusion, critically ill patients with sepsis have a higher degree of oxidative stress and inflammation which contribute to a higher level of DNA damage. Consequently, above mentioned parameters, including patients' age, adversely affect the outcome of critically ill patients with sepsis.