Immunoglobulin therapy in the treatment of multifocal motor neuropathy.

Multifocal motor neuropathy (MMN) is a chronic immune-mediated disorder leading to slowly progressive muscle weakness and wasting. Current treatments are aimed at modulating the immune system in order to avoid further decline and to maintain functional status. Intravenous immunoglobulin (IVIg) is widely used in the treatment of immune-mediated disorders and is the only treatment approved for MMN. While patients do remain stable with maintenance IVIg treatment, most patients will slowly deteriorate over many years. The use of subcutaneous immunoglobulin (ScIg) is also gaining acceptance in this disease. The amount of axonal loss and the number of years without immunoglobulin (Ig) treatment appear to be associated with the permanence of weakness. We summarize the key literature to date that supports Ig use in the treatment of MMN.