Autoimmune neuropathies: Diagnosis, treatment, and recent topics
Here, we have reviewed the clinical patterns, diagnostic paradigms, etiopathogenesis, and therapeutic strategies of autoimmune neuropathies such as Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and IgM paraproteinemic neuropathy. Antiganglioside antibodies are frequently present in the serum samples obtained during the acutephase of GBS and Miller Fisher syndrome (MFS), a subtype of GBS. Recently, we found that some patients with GBS and MFS have serum antibodies against antigenic epitopes formed by 2 different gangliosides (ganglioside complex). The antibodies against GD1a/GD1b and/or GD1b/GT1b complexes are associated with severe disability and a requirement for mechanical ventilation. Anti-GM1/GalNAc-GD1a antibodies are found to be associated with pure motor GBS with frequent conduction blocks. In GBS, corticosteroids given alone do not significantly hasten the recovery or affect the long-term treatment outcome. Intravenous immunoglobulin therapy (IVIg) or plasma exchange (PE) is equally effective. Combined treatment with corticosteroids and IVIg may be a promising therapy for GBS. On the basis of the EFNS/PNS guidelines, we describe the treatment of chronic autoimmune neuropathies such as CIDP, MMN, and IgM paraproteinemic neuropathy. In treating CIDP, corticosteroids, IVIg, and plasma exchange are equally effective. In MMN, IVIg is the first-choice therapy; corticosteroids and PE are ineffective or even detrimental. IgM paraproteinemic neuropathies are known to be intractable, and these patients often have anti-myelin-associated glycoprotein antibodies and may respond to immunosuppressive and immunomodulatory therapies. However, the potential therapeutic benefits should be balanced against their possible side effects and usual slow disease progression.