Long-term IgG immunoadsorption improves Rasmussen's encephalitis

Rasmussen's encephalitis (RE) is a rare syndrome characterized by childhood-onset of focal or generalized seizures, progressive dysfunction of one cerebral hemisphere and cognitive decline. Seizures are usually refractory to antiepileptic drugs. Neuropathologic examination of affected brain tissue shows inflammatory changes. Antibodies to glutamate receptor 3 (GluRS) were detected in sera of patients with active RE, suggesting an autoimmune pathogenesis and the use of therapeutic plasma exchange that produced a transient improvement in some cases. Since anti-GluR3 antibodies are IgG, we evaluated the efficacy of longterm IgG immunoadsorption by protein A in a RE patient with anti-GluR3 antibodies unresponsive to conventional antiepileptic drugs. A significant neurological and neuropsychological improvement was observed, which was maintained along the first year of treatment with protein A; anti-GluR3 antibodies were markedly reduced. We propose the use of protein A in selected RE patients. Protein A immunoadsorption could be an effective alternative to hemispherectomy.