Post-cardiac arrest level of free-plasma DNA and DNA-histone complexes.
BACKGROUND
Plasma DNA-histone complexes and total free-plasma DNA have the potential to quantify the ischaemia-reperfusion damages occurring after cardiac arrest. Furthermore, DNA-histone complexes may have the potential of being a target for future treatment. The aim was to examine if plasma DNA-histone complexes and the levels of total free-plasma DNA were elevated in post-cardiac arrest patients compared with healthy individuals, and to examine if these biomarkers were capable of predicting mortality.


METHODS
We included 42 comatose out-of-hospital cardiac arrest patients and collected blood samples after 22, 46 and 70 h. Samples for DNA-histone complexes were quantified by Cell Death Detection ELISAplus. The total free-plasma DNA analyses were quantified with qPCR by analysing the Beta-2 microglobulin gene. The control group comprised 40 healthy individuals.


RESULTS
We found no difference in the level of DNA-histone complexes between the 22-h sample and healthy individuals (P = 0.10). In the 46-h sample, there was an increased level of DNA-histone complexes in non-survivors compared with survivors 30 days after the cardiac arrest (P < 0.01) and the area under the ROC curve was 0.78 (95% confidence interval: 0.59;0.96). The level of total free-plasma DNA was increased in the 22-h sample compared with healthy individuals (P < 0.001) but no significant difference was found between non-survivors and survivors 30 days after the cardiac arrest (all P ≥ 0.06).


CONCLUSIONS
An increased level of DNA-histone complexes was associated with increased mortality and that the level of total free-plasma DNA was elevated post-cardiac arrest.
Department of Anaesthesiology and Intensive Care Medicine, Aarhus University Hospital, Aarhus N, Denmark.
A N
http://orcid.org/0000-0003-2812-194X
AN
Jeppesen
Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus N, Denmark.
A-M
AM
Hvas
Department of Anaesthesiology and Intensive Care Medicine, Aarhus University Hospital, Aarhus N, Denmark.
A M
AM
Grejs
Department of Anaesthesiology and Intensive Care Medicine, Aarhus University Hospital, Aarhus N, Denmark.
C H V
CH
Duez
Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus N, Denmark.
B S
BS
Sorensen
Research Centre for Emergency Medicine, Aarhus University Hospital, Aarhus C, Denmark.
H
H
Kirkegaard
D000368:Aged; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D004247:DNA / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006657:Histones / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000097:blood*; D011446:Prospective Studies; D012372:ROC Curve; D060888:Real-Time Polymerase Chain Reaction
D015415:Biomarkers; D006657:Histones; D004247:DNA