Autoimmune Encephalitis: GFAP, DPPX, Other New Autoimmune Syndromes

Paraneoplastic (classic) encephalitis syndromes are commonly associated with, but often present before the diagnosis of, an underlying neoplasm, most commonly small cell lung cancer (SCLC), lymphoma, thymoma or various other neoplasms. These are T-cell medicated diseases that rapidly produce neuronal dysfunction that is usually irreversible; the syndromic antibody is typically not pathogenic. In contrast, the more recently described autoimmune encephalitis syndromes are associated with pathogenic antibodies that target cell surface or synapse proteins, are less commonly associated with an underlying neoplasm, and are much more treatment-responsive than the "paraneoplastic" category. The rate of these autoimmune encephalitidies appears to be increasing over time.