Cell-free plasma DNA as a predictor of outcome in severe sepsis and septic shock
ABSTRACT 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.
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.
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.
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.
Full-textDOI: · Available from: Ville Pettilä, Jan 20, 2014
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ABSTRACT: Patients with chronic kidney disease (CKD) are at increased risk of cardiovascular disease. Circulating free nucleic acids, known as cell-free DNA (cfDNA), have been proposed as a novel biomarker of cardiovascular risk. The impact of renal impairment on cfDNA levels and whether cfDNA is associated with endothelial dysfunction and inflammation in CKD has not been systematically studied. We analysed cfDNA concentrations from patients with varying degrees of CKD. In addition, to determine whether there is a relationship between cfDNA, inflammation, and endothelial dysfunction in CKD, levels of proinflammatory cytokines and von Willebrand Factor (vWF) were measured in patients treated with the peroxisome proliferator-activated receptor gamma agonist rosiglitazone or placebo for 8 weeks. cfDNA levels were not increased with renal impairment or associated with the degree of renal dysfunction (P = 0.5). Treatment with rosiglitazone for 8 weeks, but not placebo, was more likely to lead to a reduction in cfDNA levels (P = 0.046); however, the absolute changes in cfDNA concentrations during treatment were not statistically significant (P > 0.05). cfDNA levels correlated with markers of endothelial dysfunction (hsCRP P = 0.0497) and vWF (P = 0.0005). In conclusion, cell-free DNA levels are not influenced by renal impairment but do reflect endothelial dysfunction in patients with CKD.PPAR Research 01/2014; 2014:643189. DOI:10.1155/2014/643189 · 1.64 Impact Factor
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ABSTRACT: In the present study, we aimed to develop and validate a rapid and sensitive, Alu-based real-time PCR method for the detection of circulating cell-free DNA (cfDNA). This method targeted repetitive elements of the Alu reduplicative elements in the human genome, followed by signal amplification using fluorescence quantification. Standard Alu-puc57 vectors were constructed and 5 pairs of specific primers were designed. Valuation was conducted concerning linearity, variation and recovery. We found 5 linear responses (R1-5=0.998-0.999). The average intra- and inter-assay coefficients of variance were 12.98 and 10.75%, respectively. The recovery was 82.33-114.01%, with a mean recovery index of 101.26%. This Alu-based assay was reliable, accurate and sensitive for the quantitative detection of cfDNA. Plasma from normal controls and patients with myocardial infarction (MI) were analyzed, and the baseline levels of cfDNA were higher in the MI group. The area under the receiver operating characteristic (ROC) curve for Alu1, Alu2, Alu3, Alu4, Alu5 and Alu (Alu1 + Alu2 + Alu3 + Alu4 + Alu5) was 0.887, 0.758, 0.857, 0.940, 0.968 and 0.933, respectively. The optimal cut-off value for Alu1, Alu2, Alu3, Alu4, Alu5 and Alu to predict MI was 3.71, 1.93, 0.22, 3.73, 6.13 and 6.40 log copies/ml. We demonstrate that this new method is a reliable, accurate and sensitive method for the quantitative detection of cfDNA and that it is useful for studying the regulation of cfDNA in certain pathological conditions. Alu4, Alu5 and Alu showed better sensitivity and specificity for the diagnosis of MI compared with cardiac troponin I (cTnI), creatine kinase MB (CK-MB) isoenzyme and lactate dehydrogenase (LDH). Alu5 had the best prognostic ability.International Journal of Molecular Medicine 11/2014; 35(1). DOI:10.3892/ijmm.2014.1991 · 1.88 Impact Factor
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ABSTRACT: The number of studies investigating circulating nucleic acids as potential biomarkers has increased in recent years. The detection of such biomarkers is a minimally invasive alternative for the diagnosis and prognosis of various clinical conditions. The value of circulating DNA levels as a predictive biomarker has been demonstrated in patients suffering from numerous acute pathologies that have a high risk of intensive care needs and in-hospital deaths. The mechanism by which circulating DNA levels increase in patients with these conditions remains unclear. In this review, we focused on the potential use of this biomarker for prognosis prediction in critically ill and trauma patients. The literature review was performed by searching MedLine using PubMed in the English language.Revista Brasileira de Terapia Intensiva 09/2014; 26(3):305-312. DOI:10.5935/0103-507X.20140043