Long-term follow-up of a large cohort with focal epilepsy of unknown cause: deciphering their clinical and prognostic characteristics

Circulating glial fibrillary acidic protein and ubiquitin carboxy-terminal hydrolase-L1 as markers of neuronal damage in children with epileptic seizures

BACKGROUND

Epilepsy is a common neurological disease that has a negative impact on physical, social, and cognitive function. Seizure-induced neuronal injury is one of the suggested mechanisms of epilepsy complications. We aimed to evaluate the circulating level of glial fibrillary acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1) as markers of neuronal damage in children with epilepsy and its relation to epilepsy characteristics.

STUDY DESIGN

METHODS: This case control study included 30 children with epilepsy and 30 healthy children as a control group. Seizure severity was determined based on Chalfont score. Serum level of GFAP and UCH-L1were measured, and their associations with epilepsy characteristics were investigated.

RESULTS

Circulating levels of GFAP and UCH-L1 were significantly higher in children with epilepsy than in controls (17.440 ± 6.74 and 5.700 ± 1.64 vs 7.06 ± 3.30 and 1.81 ± 0.23, respectively) especially in those with generalized and active seizures. GFAP and UCH-L1 were significantly correlated to the severity of seizures in the previous 6 months. Elevated GFAP level was a predictor for active seizures (OR 1.841, 95%CI 1.043-3.250, P = 0.035).

CONCLUSION

Circulating GFAP and UCH-L1 expression is increased in children with epilepsy especially those with active seizures.

SIGNIFICANCE

GFAP and UCH-L 1may serve as peripheral biomarkers for neuronal damage in children with epilepsy that can be used to monitor disease progression and severity for early identification of those with drug-resistant epilepsy and those who are in need for epilepsy surgery.

Adaptive immunity cells are differentially distributed in the peripheral blood of glycine receptor antibody-positive patients with focal epilepsy of unknown cause

AIM

Glycine receptor (GlyR) autoantibodies (Ab) have been recently detected in epilepsy patients. Our study aimed to investigate the peripheral blood distribution of B and T cell subgroups responsible for antibody production to find clues supporting the distinct organization of adaptive immunity in focal epilepsy of unknown cause (FEUC).

METHOD

Seven GlyR-Ab positive and 15 GlyR-Ab negative FEUC patients and 25 age-sex matched healthy individuals were included. Peripheral blood mononuclear cells were isolated and immunophenotyped by flow cytometry.

RESULTS

There were no significant differences between CD19⁺ B, CD3⁺ T, CD4⁺ helper T, CD8⁺ cytotoxic T, and CD19⁺CD24⁺⁺CD38⁺⁺ regulatory B cell ratios among the groups. GlyR-Ab negative epilepsy patients had significantly higher CD19⁺IgD⁺CD27^- naive B cells and GlyR-Ab positive patients showed reduced percentages of CD19⁺CD38⁺CD138⁺ plasma cells than healthy controls. By contrast, GlyR-Ab positive patients exhibited significantly increased CD3⁺CD4⁺CD25^highregulatory T (Treg) cells and CD3⁺CD4⁺CD25^highCD127^low/- Treg cells and relatively increased CD19⁺IgD-CD27⁺ memory B cells without attaining statistical significance.

CONCLUSION

The increase of Tregs, which are capable of suppressing B cells, maybe a compensating countermeasure to prevent the conversion of effector B cell subgroups. Thus, our findings lend support to the involvement of adaptive immunity in focal epilepsy of unknown cause.