[Diagnostic significance of autoantibodies in neurological diseases]

Significance of autoantibodies in neurological diseases is roughly grouped into three, as 1) disease process is thought to be directly caused by the antibodies because the antibody can reproduce the disease process, like anti-acetylcholine receptor antibody in myasthenia gravis, anti-P/Q type voltage-gated calcium channel antibody in Lambert-Eaton myasthenic syndrome, etc., 2) antibodies are thought to be closely related to the disease because plasma exchange ameliorate the disease promptly, however without success of transfer experiments, like Guillain-Barré syndrome/Miller Fisher syndrome and anti-ganglioside antibodies and 3) antibodies are very specific and become the useful markers for the diagnosis, however without direct evidence of disease transfer, like paraneoplastic neurological syndromes and anti-Yo or Hu antibodies. Overall, the roles of antibodies are different between diseases, but the presence of antibodies support the basis of intervening immunotherapy, antibody titers predicted the activity of the diseases, or they are useful markers for exploring underlying cancers in paraneoplastic neurological syndromes.