Fatal Outcome in Bacteremia is Characterized by High Plasma Cell Free DNA Concentration and Apoptotic DNA Fragmentation: A Prospective Cohort Study

Abstract

IntroductionRecent studies have shown that apoptosis plays a critical role in the pathogenesis of sepsis. High plasma cell free DNA (cf-DNA) concentrations have been shown to be associated with sepsis outcome. The origin of cf-DNA is unclear.MethodsTotal plasma cf-DNA was quantified directly in plasma and the amplifiable cf-DNA assessed using quantitative PCR in 132 patients with bacteremia caused by Staphylococcus aureus, Streptococcus pneumoniae, ß-hemolytic streptococcae or Escherichia coli. The quality of cf-DNA was analyzed with a DNA Chip assay performed on 8 survivors and 8 nonsurvivors. Values were measured on days 1–4 after positive blood culture, on day 5–17 and on recovery.ResultsThe maximum cf-DNA values on days 1–4 (n = 132) were markedly higher in nonsurvivors compared to survivors (2.03 vs 1.26 ug/ml, p<0.001) and the AUCROC in the prediction of case fatality was 0.81 (95% CI 0.69–0.94). cf-DNA at a cut-off level of 1.52 ug/ml showed 83% sensitivity and 79% specificity for fatal disease. High cf-DNA (>1.52 ug/ml) remained an independent risk factor for case fatality in a logistic regression model. Qualitative analysis of cf-DNA showed that cf-DNA displayed a predominating low-molecular-weight cf-DNA band (150–200 bp) in nonsurvivors, corresponding to the size of the apoptotic nucleosomal DNA. cf-DNA concentration showed a significant positive correlation with visually graded apoptotic band intensity (R = 0.822, p<0.001).ConclusionsPlasma cf-DNA concentration proved to be a specific independent prognostic biomarker in bacteremia. cf-DNA displayed a predominating low-molecular-weight cf-DNA band in nonsurvivors corresponding to the size of apoptotic nucleosomal DNA.

Complex formation with nucleic acids and aptamers alters the antigenic properties of platelet factor 4

“…by guest www.bloodjournal.org From including trauma, 39 cancer, 40 and infections, 41 correlating with the severity of trauma or infection. 11,41 However, due to their short plasma half-life, elevated RNA/DNA plasma levels return to baseline within a few hours after tissue damage. Yet this might be sufficient to induce an immune response, as also single and minimal applications of heparin have been shown to be sufficient for the induction of HIT.…”

Evaluation of Clinical Laboratory Methods for Plasma Cell-Free DNA Analysis in Suspected Septicaemia

“…This finding is possibly influenced by the fact that hospital patients are a more heterogeneous group with a variety of underlying co-morbidities and other risk factors. In a separate study of hospital bacteremia nonsurvivors, a distinct cut-off value of plasma cfDNA concentration of 1,520 ng/mL in the first four days following blood culture was identified as an independent risk factor for case fatality [5]. In addition, apoptotic DNA correlated with poor clinical outcomes in bacteraemic patients [5].…”

“…A previous study used a subjective, visually-assessed approach to estimate apoptotic DNA [5]. Here we calculated apoptotic cfDNA relative to the proprietary DNA standards and internal size markers.…”

“…Although the main source of cfDNA remains elusive, increased baseline levels of plasma cfDNA in severe sepsis were shown to have potential prognostic value for predicting disease outcome in several independent studies [2][3][4]. Moreover, the appearance of nucleosome-sized DNA fragments was also reported as an additional marker of prognostic value in plasma of septic patients [5].…”

Host-Based Diagnostics for Detection and Prognosis of Infectious Diseases

“…Elevated cell-free DNA has been observed in cancer patients and is hypothesised to be a result of cell apoptosis or necrosis ( Jahr et al, 2001). Furthermore, cell-free DNA has been found to correlate with septic shock (Zeerleder et al, 2003), as well as predictive of fatal outcomes in certain populations of sepsis patients (Avriel et al, 2014;Forsblom et al, 2014;Huttunen et al, 2011;Saukkonen et al, 2008). Plasma cell-free DNA has also been correlated with severity of Hantaan virus infection (Yi et al, 2014) and active Schistosoma japonicum infection (Kato-Hayashi et al, 2014), though the latter observation involves schistosome cell-free DNA rather than human cell-free DNA.…”