title: The concentration of cell-free DNA in focal epilepsy.
abstract: BACKGROUND
  Increased production of cell-free DNA (cf-DNA), a marker of inflammation, cell death and degeneration, has been observed in stroke and severe traumatic brain injury among other medical conditions. The purpose of the present study was to evaluate the significance of cf-DNA in patients with focal epilepsy.
  
  
  METHODS
  cf-DNA was measured in 167 consecutive well-evaluated patients with focal epilepsy (147 with refractory epilepsy). Epilepsy was characterized based on the patient history, electroclinical findings, neuroimaging results and etiology. 250 healthy individuals served as control subjects.
  
  
  RESULTS
  The majority of the patients (125/167; 74.8%) had increased concentrations of cf-DNA. The median concentration of cf-DNA was significantly higher in the patients (0.867 μg/ml) compared to the control group (0.759 μg/ml) (p<0.001). Symptomatic etiology was associated with increased concentrations of cf-DNA compared to probably symptomatic etiology (p=0.036).
  
  
  CONCLUSIONS
  The study confirms that the release of cf-DNA is more active in symptomatic refractory focal epilepsy, whereas this process is less pronounced in patients with unknown cause of epilepsy.
authors.affiliation: Department of Neurology and Rehabilitation, Tampere University Hospital, P.O. Box 2000, 33521 Tampere, Finland. suvi.liimatainen@fimnet.fi
authors.forename: Suvi P
authors.initials: SP
authors.lastname: Liimatainen
authors.forename: Juulia
authors.initials: J
authors.lastname: Jylhävä
authors.forename: Jani
authors.initials: J
authors.lastname: Raitanen
authors.forename: Jukka T
authors.initials: JT
authors.lastname: Peltola
authors.forename: Mikko A
authors.initials: MA
authors.lastname: Hurme
mesh_terms: D001327:Autoimmune Diseases / Q000150:complications; D015331:Cohort Studies; D004247:DNA / Q000097:blood*; D004828:Epilepsies, Partial / Q000097:blood* / Q000145:classification / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D004247:DNA
keywords: AED; CD; CNS; Cell-free DNA; Etiology; FLE; Focal Epilepsy; HS; IL; IL1-RA; Inflammation; MRI; NSE; Neurodegeneration; OLE; PLE; S-100b; S-100b protein; SD; TBI; TLE; TNF-α; UDP-glucuronosyltransferase 1; UGT1A1; XTLE; antiepileptic drug; celiac disease; cell-free DNA; central nervous system; cf-DNA; extra-temporal lobe epilepsy; frontal lobe epilepsy; hippocampal sclerosis; iNOS; inducible nitric oxide synthase; interleukin; interleukin 1 receptor antagonist; magnetic resonance imaging; neuron-specific enolase; occipital lobe epilepsy; parietal lobe epilepsy; standard deviation; temporal lobe epilepsy; traumatic brain injury; tumor necrosis factor-α