Treatment of dysimmune neuropathies

Several therapies are currently used in dysimmune neuropathies including steroids, plasma exchange ( PE), high-dose intravenous immunoglobulins (IVIg), and immunosuppressive agents ( IS). Even if there is substantial evidence that these treatments may improve the course of the neuropathy, their effectiveness is far from being complete and is sometime hampered by the occurrence of associated side effects. In Guillain-Barre syndrome (GBS), IVIg and PE are similarly effective in accelerating the recovery but there is still little evidence that they can reduce mortality or long-term disability. Recent reports on the association of intravenous methylprednisolone or interferon-beta (IFN-beta) to IVIg did not result in significant further improvement. In chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) steroids, PE, and IVIG are initially similarly effective. The short-term effect of PE and IVIg and the side effects associated with the long-term use of steroids have prompted the use of several IS, interferon and,more recently, the anti-CD20 monoclonal-antibody Rituximab, but their efficacy has still to be proved in controlled studies. The recent identification of multifocal motor neuropathy (MMN) was shortly followed by the finding of an effective therapy. Almost 80% of patients respond to IVIg whose effect needs to be maintained with periodic infusions for long periods of time, and tends to decrease after several years. Also in this condition a number of immune modulating agents have been used to reduce the frequency or improve the effectiveness of IVIg, but their efficacy has not been so far confirmed in randomized trials. Similar conclusions can be drawn for neuropathies associated with monoclonal gammopathies where only PE and IVIg have proved to be effective in controlled studies, while the promising initial results obtained with Rituximab in neuropathy associated IgM monoclonal gammopathy awaits confirmation from controlled trials.