8-OHdG and Oxidative Stress in Febrile Seizures

Febrile seizures are the most common convulsive events of early childhood. Oxidative stress contributes to seizure-induced neuronal injury, but clinical data on oxidative DNA damage across febrile seizure subtypes are limited. This single-centre, prospective case-control study was conducted at the paediatric emergency department of Kayseri City Training and Research Hospital between September and December 2021.

Participants were allocated to three groups: children with a simple febrile seizure, children with a complex febrile seizure, and age- and sex-matched healthy controls. After enrolment, a single venous blood sample was obtained from each child within 24 hours of seizure onset (or at presentation for controls). Serum was separated and stored at -80 °C until analysis.

Serum 8-hydroxy-2'-deoxyguanosine (8-OHdG) was quantified by a commercial enzyme-linked immunosorbent assay (ELISA), with all samples measured in duplicate. Routine laboratory parameters-white-cell count, haemoglobin, and C-reactive protein-and body temperature were recorded concurrently.

Serum 8-OHdG concentrations were compared among the three groups, and the ability of 8-OHdG to discriminate febrile seizure subtypes was explored. Pre-specified subgroup analyses examined complex febrile seizure patients with versus without febrile status epilepticus, and the relationship between 8-OHdG and inflammatory markers. The analysis was framed as exploratory; the study was not powered to validate 8-OHdG as a diagnostic test.

Inclusion criteria

• Age between 6 and 72 months
• Presentation with a febrile seizure (simple or complex) to the paediatric emergency department, OR healthy age- and sex-matched child (control group) 3) For seizure groups: a seizure occurring in the context of fever, meeting clinical criteria for simple or complex febrile seizure

• Serum sample obtainable within 24 hours of seizure onset (seizure groups) Written informed consent provided by a parent or legal guardian

Exclusion criteria

• Central nervous system (CNS) infection (e.g., meningitis, encephalitis)
• Known epilepsy or prior afebrile seizures
• Neurodevelopmental delay
• Chronic systemic illness
• Use of antioxidant supplements within the preceding 3 months
• Incomplete clinical or laboratory data