New therapeutic strategies in chronic inflammatory neuropathies

Abstract

The spectrum of chronic inflammatory neuropathies comprises chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), multifocal motor neuropathy with persistent conduction block (MMN), and neuropathies associated with paraproteinemia, the more documented being polyneuropathy associated with IgM monoclonal gammopathy binding to myelin-associated-glycoprotein (IgM anti-MAG neuropathy). These neuropathies have common features, which are clinical and electrophysiological signs indicative of a demyelinating process, raised protein in CSF, the presence in some of them of serum auto-antibodies binding to recognized antigens of the peripheral nerve myelin, and signs of demyelination/remyelination in nerve biopsies. Chronic inflammatory neuropathies need to be distinguished on defined criteria, as there are striking differences in response to treatment. For example, MMN and IgM anti-MAG neuropathy do not respond to corticosteroids, while CIDP may respond either to corticosteroids, plasma exchange or high-dose intravenous immunoglobulin (IVIg)/subcutaneous immunoglobulin (SCIg). The more used Guidelines have been edited in 2006, then revised in 2010, by a joint task force of the EFNS (now EAN) and of the Peripheral Nerve Society, on management of respectively CIDP, MMN and paraproteinemic demyelinating neuropathies. This review will give an update on the treatment of these immune-mediated neuropathies, starting with an overview of the various therapeutic strategies, and trying to select the best regimen for immunomodulators to be given for first-line and long-term therapy.