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

Abstract

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.

Keywords: Antibody; Autoimmunity; B cell; Focal epilepsy of unknown cause; Glycine receptor; T cell.