Cytokines as a marker of central nervous system autoantibody associated epilepsy

Autoantibodies to central nervous system (CNS) antigens are increasingly identified in patients with epilepsy. Alterations in cytokines and chemokines have also been demonstrated in epilepsy, but this has not been explored in subjects with autoantibodies. If antibody positive and antibody negative subjects show a difference in immune activation, as measured by cytokine levels, this could improve diagnostic and therapeutic approaches, and provide insights into the underlying pathophysiology. We aimed to evaluate serum and CSF cytokines and chemokines in patients with and without autoantibody positivity to identify any differences between the two groups.

We studied participants who had undergone serum and CSF testing for CNS autoantibodies, as part of their clinical evaluation. Cases were classified as antibody positive or antibody negative for comparison. Stored CSF and sera were analysed for cytokine and chemokine concentrations.

25 participants underwent testing. 8 were antibody positive, 17 were antibody negative. Significant elevations in the mean concentration of IL-13 and RANTES in CSF were found in the antibody positive cases and significant elevation of CSF VEGF was found in the antibody negative cases. Significant elevations in the mean concentrations of serum TNFβ, INFγ, bNGF, IL-8, and IL-12 were seen in the antibody negative group, and there was poor correlation between the majority of serum and CSF concentrations.

Measurement of cytokines and chemokines such as IL-13 and RANTES could be useful in diagnosis of autoimmune associated epilepsy. Such markers might also guide targeted immunotherapy to improve seizure control and provide insights into the underlying pathophysiology of epilepsy associated with CNS autoantibodies.