AUTOANTIBODIES TO GLUTAMATE-RECEPTOR GLUR3 IN RASMUSSENS ENCEPHALITIS

Rasmussen's encephalitis is a progressive childhood disease of unknown cause characterized by severe epilepsy, hemiplegia, dementia, and inf lammation of the brain. During efforts to raise antibodies to recombin ant glutamate receptors (GluRs), behaviors typical of seizures and his topathologic features mimicking Rasmussen's encephalitis were found in two rabbits immunized with GluR3 protein. A correlation was found bet ween the presence of Rasmussen's encephalitis and serum antibodies to GluR3 detected by protein immunoblot analysis and by immunoreactivity to transfected cells expressing GluR3. Repeated plasma exchanges in on e seriously ill child transiently reduced serum titers of GluR3 antibo dies, decreased seizure frequency, and improved neurologic function. T hus, GluR3 is an autoantigen in Rasmussen's encephalitis, and an autoi mmune process may underlie this disease.