Prognostic value of circulating cell -free DNA in patients with shock admitted to Emergency Intensive Care Unit

doi:10.3969/j.issn.1002-1949.2015.07.013

Abstract：Objective Our investigation was to explore the clinical prognosis value of plasma cell-free DNA (cf-DNA) in shock patients admission to Emergency Intensive Care Unit (EICU). Methods A prospective observational study of 69 consecutive patients with shock of the First Affiliate Hospital of Anhui Medical University in the EICU . The cf -DNA was measured by real -time quantitative PCR assay for the β-globin gene in blood samples drawn at study admission and 24 h later, while the value of lactate at admission and 24 h post-admission were detected and the Acute Physiology and Chronic Health Evaluation Ⅱ ( APACHEⅡ) scores within 24 h among these patients were investigated .A control group containing 30 patients matched in age and gender were also included in the meantime.End point of this study was 28-d mortality rate.Clinical data including cf -DNA, blood lactate and APACHEⅡscores at 0 h, 24 h after admission in survivors and non -survivors respectively . Results The median cell-free DNA concentrations from patients serum were statistically significantly higher in patient died of shock at admission and 24 h post -admission ( median, 1.91 ×106 pg/mL;interquartile range (IQR), 7.81 ×105 to 4.60 ×107, and 3.82 ×106 pg/mL, IQR 1.66 ×106 to 9.27 ×106, respectively) than in patients survived shock (median 2.85 ×105 pg/mL, IQR 7.20 ×104 to 9.35 ×105;and 5.74 ×104 pg/mL, IQR 1.12 ×104 to 5.97 ×105, respectively, P<0.05).Both the median cf-DNA levels of 0 h and 24 h were also higher in patients than those in controls (9.09 × 103 pg/mL, IQR:4.77 ×103 to 8.97 ×104).Using receiver operating curve (ROC) analysis, the best cut-off values of cf-DNA at admission and 24 h later for predicting 28-day mortality were 8.11 ×105 pg/mL ( sensitivity 75%, specificity 71.9%) and 1.39 ×106 pg/mL ( sensitivity 80%, specificity 87.5%), based on the calculated areas under the curve (AUCs) of 0.822 (95%CI 0.707 to 0.937), 0.861 (95%CI 0.759 to 0.963), respectively.In Logistic regression analysis, both cf-DNA at 24 h after admission and lactate at 24 h later were independently associated with 28 -day mortality ( P<0.05 ) .Conclusion Circulating level of cf -DNA at 24 h after admission is significantly higher in patients died of shock in EICU than patients survived and the predictive power is higher than that of the lactate value at 24 h post-admission.