Predicting treatment response in chronic, acquired demyelinating neuropathies

Chronic inflammatory demyelinating polyradiculopathy is an immune-mediated neuropathy that was first described approximately 30 years ago. Since that time an increasingly wide spectrum of chronic acquired demyelinating polyneuropathies exhibiting different phenotypes, clinical course and treatment responses to immunomodulatory treatment have been described. Several new therapeutic agents have been prescribed for such conditions, some with promising results. This review summarizes what is presently known about the clinical courses, treatment responses and predictors of response of the chronic inflammatory demyelinating polyradiculopathy subgroups.

Initial and long-term management of autoimmune neuropathies

The inflammatory neuropathies (chronic inflammatory demyelinating polyradiculoneuropathy [CIDP], Guillain-Barré syndrome [GBS] and multifocal motor neuropathy [MMN]) affect only one to two individuals per 100 000 of the population, but result in major disability and impairment. Intravenous immunoglobulin (IVIg) can be used as an initial treatment for CIDP, GBS and MMN. While plasma exchange and corticosteroids can also be used initially, they are not as uniformly effective for each of these disorders as IVIg. Substituting corticosteroids, plasma exchange or immunosuppressants may be appropriate for patients not responding to initial IVIg therapy, and combination therapy may be needed in some patients. There are no data from controlled clinical trials of long-term management strategies for CIDP and MMN; however, empirical evidence suggests that a positive long-term response to IVIg can be achieved by increasing the initial dose or its frequency of administration. Corticosteroids and immunosuppressants may be appropriate in some patients with CIDP. Adverse events with IVIg are usually mild and not treatment limiting; however, patients do need to be monitored for uncommon, but serious, adverse events such as renal insufficiency, stroke and thromboembolic events. Nevertheless, the safety profile of IVIg is exceptional relative to the potential complications of other long-term treatments for CIDP and MMN, especially corticosteroids and immunosuppressants. Predictors of response have been reported for each of the neuropathies, and until controlled clinical trials provide evidence on which to base treatment strategies, effective management will require individualising therapy according to patient response.