Interictal interleukin-6 and tumor necrosis factor α levels are associated with seizure recurrence in adults with epilepsy

Background: Although there are models predicting epilepsy recurrence under different clinical conditions, few studies have examined blood biomarkers. Inflammation plays a crucial role in the occurrence and development of epilepsy. We analyzed inflammatory mediators in a regional hospital-based epilepsy cohort and investigated their relationship with subsequent epilepsy recurrence.

Methods: Interictal inflammatory mediators were measured in 128 patients diagnosed with epilepsy participating in a prospective study. Inflammatory mediators were compared during the follow-up period between patients who experienced epilepsy recurrence and those who did not. We also assessed the correlation between inflammatory mediators and the time interval until the next recurrence.

Results: Over a median 4-month follow-up period, 41 patients experienced seizure recurrence. Differences in interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) levels were observed between seizure recurrence and non-recurrence groups. After adjusting for covariates through multivariate Cox regression analysis, the patients in the third IL-6 tertile (>2.31 pg/mL; HR: 2.49; 95 % CI: 1.00-6.16; P = 0.049) and in the third TNF-α tertile (>0.74 pg/mL; HR: 2.80; 95 % CI: 1.13-6.92; P = 0.026) had higher risk of seizure recurrence. The time until the next recurrence was negatively correlated with IL-6 level (ρ = - 0.392, P = 0.011).

Conclusion: High levels of IL-6 and TNF-α are associated with a higher possibility of seizure recurrence. Future predictive models should also include inflammatory mediators in addition to clinical variables.