Neurologic autoantibodies

The concept that autoantibodies contribute to the pathogenesis of neurologic disorders is not new. The past decade, however, has seen a dramatic increase in the discovery and description of new autoantibodies and their clinical associations. Commercial autoantibody testing is now available for many neurologic disorders, including paraneoplastic syndromes and autoimmune neuromuscular disorders. Additionally, autoantibodies have been proposed to be important in the diagnosis or pathogenesis of other disorders, including some forms of autonomic failure, ataxia, movement disorder, dementia, epilepsy, and CNS demyelinating disease.

Some neurologic autoantibodies cause disease directly by interacting with targets in vivo. This has been definitively proven in few instances, most notably acetylcholine receptor (AChR) antibodies in myasthenia gravis.^1,2 Other well-defined autoantibodies are not directly pathogenic but are still important as specific diagnostic markers of a neurologic disease (e.g., antineuronal nuclear antibodies in lung cancer–related paraneoplastic disorders).³ Unfortunately, many newly reported autoantibodies will ultimately prove to be neither pathogenic nor specific for a particular neurologic disease. In addition to the presence of a specific antibody, the criteria for defining an antibody-mediated disorder are a clinical response to treatments that reduce antibody levels, replication of the disease by active immunization, and transmission of …