Role of early cell-free DNA levels decrease as a predictive marker of fatal outcome after severe traumatic brain injury.
BACKGROUND
Circulating cell-free DNA levels are increased after trauma injury. This increase is higher since the first hours after trauma and may be related with primary outcome. A sensitive and reliable biomarker for patients at higher risk is needed to identify these patients to initiate early intervention. In this way, circulating DNA may be a possible biological marker after severe TBI.


METHODS
We investigated DNA plasma concentrations after severe traumatic brain injury and during the next 96 h in the Intensive Care Unit (ICU) by real time PCR. 65 patients suffering severe TBI were included in the study.


RESULTS
Cell-free DNA levels were considerably higher in patients samples compared with voluntary control ones. After the following four days we observed a 51% decrease during the first 24h and a 71% fall from 48 h. TBI population was stratified for the primary outcome (survivors/non-survivor) and DNA levels decrease ratio was calculated for the first 48 h. A higher decrease in the survivors from 0 h to 24h compared with the non-survivors was found. A cut-off point of 1.95 ratio was established for the detection of the highest proportions of patients after the TBI that will not survive after the injury with a sensitivity of 70% and specificity of 66%.


CONCLUSIONS
In summary we showed that severe TBI is associated with elevated cf-DNA levels and we propose that cf-DNA decrease during the first 24h may predict patient outcome.
Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Spain. hadamacher@hotmail.com
Hada
H
Macher
Juan J
JJ
Egea-Guerrero
Jaume
J
Revuelto-Rey
Elena
E
Gordillo-Escobar
Judy
J
Enamorado-Enamorado
Antonio
A
Boza
Ana
A
Rodriguez
Patrocinio
P
Molinero
Juan M
JM
Guerrero
José Maria
JM
Dominguez-Roldán
Francisco
F
Murillo-Cabezas
Amalia
A
Rubio
D000328:Adult; D015415:Biomarkers / Q000097:blood; D001930:Brain Injuries / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D004247:DNA / Q000097:blood* / Q000235:genetics; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011379:Prognosis
D015415:Biomarkers; D004247:DNA