Cell-free plasma DNA as a predictor of outcome in severe sepsis and septic shock.
BACKGROUND
Increased concentrations of cell-free DNA have been found in plasma of septic and critically ill patients. We investigated the value of plasma DNA for the prediction of intensive care unit (ICU) and hospital mortality and its association with the degree of organ dysfunction and disease severity in patients with severe sepsis.


METHODS
We studied 255 patients with severe sepsis or septic shock. We obtained blood samples on the day of study inclusion and 72 h later and measured cell-free plasma DNA by real-time quantitative PCR assay for the beta-globin gene.


RESULTS
Cell-free plasma DNA concentrations were higher at admission in ICU nonsurvivors than in survivors (median 15 904 vs 7522 genome equivalents [GE]/mL, P < 0.001) and 72 h later (median 15 176 GE/mL vs 6758 GE/mL, P = 0.004). Plasma DNA values were also higher in hospital nonsurvivors than in survivors (P = 0.008 to 0.009). By ROC analysis, plasma DNA concentrations had moderate discriminative power for ICU mortality (AUC 0.70-0.71). In multiple regression analysis, first-day plasma DNA was an independent predictor for ICU mortality (P = 0.005) but not for hospital mortality. Maximum lactate value and Sequential Organ Failure Assessment score correlated independently with the first-day plasma DNA in linear regression analysis.


CONCLUSIONS
Cell-free plasma DNA concentrations were significantly higher in ICU and hospital nonsurvivors than in survivors and showed a moderate discriminative power regarding ICU mortality. Plasma DNA concentration was an independent predictor for ICU mortality, but not for hospital mortality, a finding that decreases its clinical value in severe sepsis and septic shock.
Saukkonen
Katri
K
Departments of Medicine and Emergency Care, Helsinki University Central Hospital, Helsinki, Finland. katri.saukkonen@helsinki.fi
Lakkisto
Päivi
P
Pettilä
Ville
V
Varpula
Marjut
M
Karlsson
Sari
S
Ruokonen
Esko
E
Pulkki
Kari
K
D000368:Aged; D004247:DNA / Q000097:blood*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005914:Globins / Q000235:genetics; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D010949:Plasma; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018805:Sepsis / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D012720:Severity of Illness Index; D012772:Shock, Septic / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology
D005914:Globins; D004247:DNA