An estimated 0.5–1% of the world population is epileptic, some with completely unknown etiology and no effective treatment. Epilepsies have long been viewed as diseases of the central nervous system (CNS), but in recent years, evidence has mounted that some may actually be autoimmune-mediated. If so, the way we regard and treat these epilepsies may require a revolutionary change. A session—which was sponsored by The Avraham and Sonia Rochlin Foundation—dealing, for the first time, with the “autoimmune epilepsy” concept took place in February 2002 at the International Congress of Autoimmunity in Geneva, Switzerland. Some salient findings reported at this session are relayed here.

The first clue to the autoimmune nature of some epilepsies came from the presence of antibodies to a major excitatory neurotransmitter in the CNS. Antibodies to this particular glutamate receptor, one of the AMPA (α-3-hydroxy-5-methyl-4-isoxazolepropionic acid) subtypes (GluR3), have now been found in three severe human epilepsies: Rasmussen's encephalitis (RE), noninflammatory focal epilepsy and “catastrophic” epilepsy (C. Antozzi & R. Montezzega, Italy). Specific cleavage of GluR3 by granzyme B, a serine protease released by activated immune cells, generates the GluR3B autoantigenic peptide, but only when an internal NH 2-linked glycosylation sequence within the GluR3 recognition-sequence is not glycosylated (S. Rogers' group, USA). Interestingly, CD3+ CD8+ cytotoxic T cells that contain granzyme B can be found in close association with neurons in the brains of RE patients and could contribute to neuronal death (H. Lassman's group, Austria).