8-OHdG and Oxidative Stress in Febrile Seizures

July 3, 2026 updated by: Kayseri City Hospital

Serum 8-Hydroxy-2'-Deoxyguanosine (8-OHdG) and Oxidative DNA Damage in Children With Simple and Complex Febrile Seizures: An Exploratory Prospective Case-Control Study

This prospective case-control study investigates whether serum 8-hydroxy-2'-deoxyguanosine (8-OHdG), an established biomarker of reactive oxygen species-mediated DNA oxidation, is elevated in children with febrile seizures compared with healthy children, and whether it differs between simple and complex febrile seizure subtypes. Children presenting with a febrile seizure and age-matched healthy controls have serum 8-OHdG measured within 24 hours of seizure onset, alongside routine inflammatory markers (white-cell count, C-reactive protein) and haemoglobin. The primary aim is to determine whether acute oxidative DNA damage is detectable after febrile seizures and whether 8-OHdG levels distinguish simple from complex subtypes. The study is exploratory and hypothesis-generating; it is not designed to establish 8-OHdG as a clinically applicable diagnostic biomarker.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

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.

Study Type

Observational

Enrollment (Actual)

156

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Children aged 6 to 72 months presenting to the paediatric emergency department of Kayseri City Training and Research Hospital (Kayseri, Türkiye). Three groups: simple febrile seizure, complex febrile seizure, and age- and sex-matched healthy controls. Participants were enrolled prospectively by convenience sampling from consecutive eligible admissions.

Description

Inclusion Criteria:

  1. Age between 6 and 72 months
  2. 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

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

Exclusion Criteria:

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Group 1 Health Controls
Healthy controls (afebrile) n:57 Serum 8-OHdG measurement
Diagnostic test: Group 1 Health Controls
Single venous blood sample obtained from each participant; serum 8-hydroxy-2'-deoxyguanosine (8-OHdG) was measured by enzyme-linked immunosorbent assay (ELISA) within 24 hours of seizure onset. This was an observational measurement only; no therapeutic intervention was administered.
Group 2 SFC
Simple febrile seizure (SFC) n:50 Serum 8-OHdG measurement
Diagnostic test: Group 2 SFC
Single venous blood sample obtained from each participant; serum 8-hydroxy-2'-deoxyguanosine (8-OHdG) was measured by enzyme-linked immunosorbent assay (ELISA) within 24 hours of seizure onset. This was an observational measurement only; no therapeutic intervention was administered.
Group 3 CFC
Complex febrile seizure (CFC) n:49 Serum 8-OHdG measurement
Diagnostic test: Group 3 CFC
Single venous blood sample obtained from each participant; serum 8-hydroxy-2'-deoxyguanosine (8-OHdG) was measured by ELISA within 24 hours of seizure onset. The same measurement was performed in all three groups (healthy controls, simple febrile seizure, and complex febrile seizure). This was an observational measurement only; no therapeutic intervention was administered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Primary Outcome Measure
Time Frame: Time Frame: Within 24 hours of seizure onset (single measurement)

Title: Serum 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentration Description: Serum 8-OHdG concentration (ng/mL), quantified by ELISA, compared among children with simple febrile seizure, complex febrile seizure, and healthy controls, to determine whether acute oxidative DNA damage differs across these groups.

Time Frame: Within 24 hours of seizure onset (single measurement) Unit of Measure: ng/mL
Time Frame: Within 24 hours of seizure onset (single measurement)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Secondary Outcome Measures
Time Frame: Within 24 hours of seizure onset
  • Diagnostic discrimination of serum 8-OHdG (ROC AUC) - Area under the ROC curve for serum 8-OHdG in discriminating febrile seizure subtypes from controls. (Time Frame: Within 24 hours of seizure onset)
  • 8-OHdG in febrile status epilepticus (FSE) subgroup - Comparison of serum 8-OHdG between CFC patients with vs. without FSE. (Time Frame: Within 24 hours of seizure onset)
  • Association with inflammatory markers - Relationship between serum 8-OHdG and white-cell count, C-reactive protein, and haemoglobin. (Time Frame: Within 24 hours of seizure onset)
Within 24 hours of seizure onset

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Kayseri City Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2021

Primary Completion (Actual)

June 30, 2022

Study Completion (Actual)

December 30, 2022

Study Registration Dates

First Submitted

June 16, 2026

First Submitted That Met QC Criteria

June 16, 2026

First Posted (Actual)

June 22, 2026

Study Record Updates

Last Update Posted (Actual)

July 7, 2026

Last Update Submitted That Met QC Criteria

July 3, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Etik C.D.No:461(Kayseri CH)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data underlying the published results (serum 8-OHdG concentrations, demographic and clinical variables, and laboratory parameters) are available from the corresponding author on reasonable request. Data will be shared with qualified researchers whose proposed use has been approved and for purposes consistent with the original ethics approval; a data-use agreement may be required.

IPD Sharing Time Frame

Data will become available after publication of the main results and will remain accessible for 5 years thereafter, upon reasonable request to the corresponding author.

IPD Sharing Access Criteria

Qualified researchers may request access by contacting the corresponding author. Requests will be evaluated for scientific merit and consistency with the original ethics approval, and a data-use agreement may be required before de-identified data are shared.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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