Autoantibodies to Munc18, cerebral plasma cells and B-lymphocytes in Rasmussen encephalitis.

Rasmussen encephalitis (RE) is a rare form of severe unihemispheric epilepsy established to be an autoimmune disease. Here we demonstrate the presence of autoantibodies against Munc18-1 in 20% of patients collective with biopsy-proven RE. Intriguingly, brain biopsy specimens of these patients showed a striking perivascular accentuated infiltration of B-lymphocytes and plasma cells, suggesting a subgroup of RE patients harboring Munc18-1 antibodies and concomitant B- and plasma cell infiltration.