[Neuroimmunological diseases associated with VGKC complex antibodies]

Antibodies to voltage-gated potassium channels(VGKC) were first identified by radioimmunoassay of radioisotope labeled alpha-dendrotoxin-VGKCs solubilized from rabbit brain. These antibodies were found only in a proportion of patients with acquired neuromyotonia (Isaacs' syndrome). VGKC antibodies were also detected in Morvan's syndrome and in a form of autoimmune limbic encephalitis. Recent studies indicated that the "VGKC" antibodies are mainly directed toward associated proteins(for example LGI-1, Caspr-2) that complex with the VGKCs themselves. The "VGKC" antibodies are now usually known as VGKC-complex antibodies. In general, LGI-1 antibodies are most common in limbic encephalitis with SIADH. Caspr-2 antibodies are present in the majority of patients with Morvan's syndrome. These patients develop combinations of CNS symptoms, autonomic dysfunction, and peripheral nerve hyperexcitability.